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Simple cycloalkanes have a prefix "cyclo-" to distinguish them from alkanes. Cycloalkanes are named as per their acyclic counterparts with respect to the number of carbon atoms in their backbones, e.g., cyclopentane (C5H10) is a cycloalkane with 5 carbon atoms just like pentane (C5H12), but they are joined up in a five-membered ring. In a similar manner, propane and cyclopropane, butane and cyclobutane, etc. Substituted cycloalkanes are named similarly to substituted alkanes – the cycloalkane ring is stated, and the substituents are according to their position on the ring, with the numbering decided by the Cahn–Ingold–Prelog priority rules. Trivial/common names. The trivial (non-systematic) name for alkanes is 'paraffins'. Together, alkanes are known as the 'paraffin series'. Trivial names for compounds are usually historical artifacts. They were coined before the development of systematic names, and have been retained due to familiar usage in industry. Cycloalkanes are also called naphthenes. Branched-chain alkanes are called isoparaffins. "Paraffin" is a general term and often does not distinguish between pure compounds and mixtures of isomers, i.e., compounds of the same chemical formula, e.g., pentane and isopentane.
The following trivial names are retained in the IUPAC system: Some non-IUPAC trivial names are occasionally used: Physical properties. All alkanes are colorless. Alkanes with the lowest molecular weights are gases, those of intermediate molecular weight are liquids, and the heaviest are waxy solids. Boiling point. Alkanes experience intermolecular van der Waals forces. The cumulative effects of these intermolecular forces give rise to greater boiling points of alkanes. Two factors influence the strength of the van der Waals forces: Under standard conditions, from CH4 to C4H10 alkanes are gaseous; from C5H12 to C17H36 they are liquids; and after C18H38 they are solids. As the boiling point of alkanes is primarily determined by weight, it should not be a surprise that the boiling point has an almost linear relationship with the size (molecular weight) of the molecule. As a rule of thumb, the boiling point rises 20–30 °C for each carbon added to the chain; this rule applies to other homologous series. A straight-chain alkane will have a boiling point higher than a branched-chain alkane due to the greater surface area in contact, and thus greater van der Waals forces, between adjacent molecules. For example, compare isobutane (2-methylpropane) and n-butane (butane), which boil at −12 and 0 °C, and 2,2-dimethylbutane and 2,3-dimethylbutane which boil at 50 and 58 °C, respectively.
On the other hand, cycloalkanes tend to have higher boiling points than their linear counterparts due to the locked conformations of the molecules, which give a plane of intermolecular contact. Melting points. The melting points of the alkanes follow a similar trend to boiling points for the same reason as outlined above. That is, (all other things being equal) the larger the molecule the higher the melting point. However, alkanes' melting points follow a more complex pattern, due to variations in the properties of their solid crystals. One difference in crystal structure that even-numbered alkanes (from hexane onwards) tend to form denser-packed crystals compared to their odd-numbered neighbors. This causes them to have a greater enthalpy of fusion (amount of energy required to melt them), raising their melting point. A second difference in crystal structure is that even-numbered alkanes (from octane onwards) tend to form more rotationally-ordered crystals compared to their odd-numbered neighbors. This causes them to have a greater entropy of fusion (increase in disorder from the solid to the liquid state), lowering their melting point.
While these effects operate in opposing directions, the first effect tends to be slightly stronger, leading even-numbered alkanes to have slightly higher melting points than the average of their odd-numbered neighbors. This trend does not apply to methane, which has an unusually high melting point, higher than both ethane and propane. This is because it has a very low entropy of fusion, attributable to its high molecular symmetry and the rotational disorder in solid methane near its melting point (Methane I). The melting points of branched-chain alkanes can be either higher or lower than those of the corresponding straight-chain alkanes, again depending on these two factors. More symmetric alkanes tend towards higher melting points, due to enthalpic effects when they form ordered crystals, and entropic effects when they form disordered crystals (e.g. neopentane). Conductivity and solubility. Alkanes do not conduct electricity in any way, nor are they substantially polarized by an electric field. For this reason, they do not form hydrogen bonds and are insoluble in polar solvents such as water. Since the hydrogen bonds between individual water molecules are aligned away from an alkane molecule, the coexistence of an alkane and water leads to an increase in molecular order (a reduction in entropy). As there is no significant bonding between water molecules and alkane molecules, the second law of thermodynamics suggests that this reduction in entropy should be minimized by minimizing the contact between alkane and water: Alkanes are said to be hydrophobic as they are insoluble in water.
Their solubility in nonpolar solvents is relatively high, a property that is called lipophilicity. Alkanes are, for example, miscible in all proportions among themselves. The density of the alkanes usually increases with the number of carbon atoms but remains less than that of water. Hence, alkanes form the upper layer in an alkane–water mixture. Molecular geometry. The molecular structure of the alkanes directly affects their physical and chemical characteristics. It is derived from the electron configuration of carbon, which has four valence electrons. The carbon atoms in alkanes are described as sp3 hybrids; that is to say that, to a good approximation, the valence electrons are in orbitals directed towards the corners of a tetrahedron which are derived from the combination of the 2s orbital and the three 2p orbitals. Geometrically, the angle between the bonds are cos−1(−) ≈ 109.47°. This is exact for the case of methane, while larger alkanes containing a combination of C–H and C–C bonds generally have bonds that are within several degrees of this idealized value.
Bond lengths and bond angles. An alkane has only C–H and C–C single bonds. The former result from the overlap of an sp3 orbital of carbon with the 1s orbital of a hydrogen; the latter by the overlap of two sp3 orbitals on adjacent carbon atoms. The bond lengths amount to 1.09 × 10−10 m for a C–H bond and 1.54 × 10−10 m for a C–C bond. The spatial arrangement of the bonds is similar to that of the four sp3 orbitals—they are tetrahedrally arranged, with an angle of 109.47° between them. Structural formulae that represent the bonds as being at right angles to one another, while both common and useful, do not accurately depict the geometry. Conformation. The spatial arrangement of the C-C and C-H bonds are described by the torsion angles of the molecule is known as its conformation. In ethane, the simplest case for studying the conformation of alkanes, there is nearly free rotation about a carbon–carbon single bond. Two limiting conformations are important: eclipsed conformation and staggered conformation. The staggered conformation is 12.6 kJ/mol (3.0 kcal/mol) lower in energy (more stable) than the eclipsed conformation (the least stable). In highly branched alkanes, the bond angle may differ from the optimal value (109.5°) to accommodate bulky groups. Such distortions introduce a tension in the molecule, known as steric hindrance or strain. Strain substantially increases reactivity.
Spectroscopic properties. Spectroscopic signatures for alkanes are obtainable by the major characterization techniques. Infrared spectroscopy. The C-H stretching mode gives a strong absorptions between 2850 and 2960 cm−1 and weaker bands for the C-C stretching mode absorbs between 800 and 1300 cm−1. The carbon–hydrogen bending modes depend on the nature of the group: methyl groups show bands at 1450 cm−1 and 1375 cm−1, while methylene groups show bands at 1465 cm−1 and 1450 cm−1. Carbon chains with more than four carbon atoms show a weak absorption at around 725 cm−1. NMR spectroscopy. The proton resonances of alkanes are usually found at "δ"H = 0.5–1.5. The carbon-13 resonances depend on the number of hydrogen atoms attached to the carbon: "δ"C = 8–30 (primary, methyl, –CH3), 15–55 (secondary, methylene, –CH2–), 20–60 (tertiary, methyne, C–H) and quaternary. The carbon-13 resonance of quaternary carbon atoms is characteristically weak, due to the lack of nuclear Overhauser effect and the long relaxation time, and can be missed in weak samples, or samples that have not been run for a sufficiently long time.
Mass spectrometry. Since alkanes have high ionization energies, their electron impact mass spectra show weak currents for their molecular ions. The fragmentation pattern can be difficult to interpret, but in the case of branched chain alkanes, the carbon chain is preferentially cleaved at tertiary or quaternary carbons due to the relative stability of the resulting free radicals. The mass spectra for straight-chain alkanes is illustrated by that for dodecane: the fragment resulting from the loss of a single methyl group ("M" − 15) is absent, fragments are more intense than the molecular ion and are spaced by intervals of 14 mass units, corresponding to loss of CH2 groups. Chemical properties. Alkanes are only weakly reactive with most chemical compounds. They only reacts with the strongest of electrophilic reagents by virtue of their strong C–H bonds (~100 kcal/mol) and C–C bonds (~90 kcal/mol). They are also relatively unreactive toward free radicals. This inertness is the source of the term "paraffins" (with the meaning here of "lacking affinity"). In crude oil the alkane molecules have remained chemically unchanged for millions of years.
Acid-base behavior. The acid dissociation constant (p"K"a) values of all alkanes are estimated to range from 50 to 70, depending on the extrapolation method, hence they are extremely weak acids that are practically inert to bases (see: carbon acids). They are also extremely weak bases, undergoing no observable protonation in pure sulfuric acid ("H"0 ~ −12), although superacids that are at least millions of times stronger have been known to protonate them to give hypercoordinate alkanium ions (see: methanium ion). Thus, a mixture of antimony pentafluoride (SbF5) and fluorosulfonic acid (HSO3F), called magic acid, can protonate alkanes. Reactions with oxygen (combustion reaction). All alkanes react with oxygen in a combustion reaction, although they become increasingly difficult to ignite as the number of carbon atoms increases. The general equation for complete combustion is: In the absence of sufficient oxygen, carbon monoxide or even soot can be formed, as shown below: For example, methane: See the alkane heat of formation table for detailed data.
The standard enthalpy change of combustion, Δc"H"⊖, for alkanes increases by about 650 kJ/mol per CH2 group. Branched-chain alkanes have lower values of Δc"H"⊖ than straight-chain alkanes of the same number of carbon atoms, and so can be seen to be somewhat more stable. Biodegradation. Some organisms are capable of metalbolizing alkanes. The methane monooxygenases convert methane to methanol. For higher alkanes, cytochrome P450 convert alkanes to alcohols, which are then susceptible to degradation. Free radical reactions. Free radicals, molecules with unpaired electrons, play a large role in most reactions of alkanes. Free radical halogenation reactions occur with halogens, leading to the production of haloalkanes. The hydrogen atoms of the alkane are progressively replaced by halogen atoms. The reaction of alkanes and fluorine is highly exothermic and can lead to an explosion. These reactions are an important industrial route to halogenated hydrocarbons. There are three steps: Experiments have shown that all halogenation produces a mixture of all possible isomers, indicating that all hydrogen atoms are susceptible to reaction. The mixture produced, however, is not statistical: Secondary and tertiary hydrogen atoms are preferentially replaced due to the greater stability of secondary and tertiary free-radicals. An example can be seen in the monobromination of propane:
In the Reed reaction, sulfur dioxide and chlorine convert hydrocarbons to sulfonyl chlorides under the influence of light. Under some conditions, alkanes will undergo Nitration. C-H activation. Certain transition metal complexes promote non-radical reactions with alkanes, resulting in so C–H bond activation reactions. Cracking. Cracking breaks larger molecules into smaller ones. This reaction requires heat and catalysts. The thermal cracking process follows a homolytic mechanism with formation of free radicals. The catalytic cracking process involves the presence of acid catalysts (usually solid acids such as silica-alumina and zeolites), which promote a heterolytic (asymmetric) breakage of bonds yielding pairs of ions of opposite charges, usually a carbocation. Carbon-localized free radicals and cations are both highly unstable and undergo processes of chain rearrangement, C–C scission in position beta (i.e., cracking) and intra- and intermolecular hydrogen transfer or hydride transfer. In both types of processes, the corresponding reactive intermediates (radicals, ions) are permanently regenerated, and thus they proceed by a self-propagating chain mechanism. The chain of reactions is eventually terminated by radical or ion recombination.
Isomerization and reformation. Dragan and his colleague were the first to report about isomerization in alkanes. Isomerization and reformation are processes in which straight-chain alkanes are heated in the presence of a platinum catalyst. In isomerization, the alkanes become branched-chain isomers. In other words, it does not lose any carbons or hydrogens, keeping the same molecular weight. In reformation, the alkanes become cycloalkanes or aromatic hydrocarbons, giving off hydrogen as a by-product. Both of these processes raise the octane number of the substance. Butane is the most common alkane that is put under the process of isomerization, as it makes many branched alkanes with high octane numbers. Other reactions. In steam reforming, alkanes react with steam in the presence of a nickel catalyst to give hydrogen and carbon monoxide. Occurrence. Occurrence of alkanes in the Universe. Alkanes form a small portion of the atmospheres of the outer gas planets such as Jupiter (0.1% methane, 2 ppm ethane), Saturn (0.2% methane, 5 ppm ethane), Uranus (1.99% methane, 2.5 ppm ethane) and Neptune (1.5% methane, 1.5 ppm ethane). Titan (1.6% methane), a satellite of Saturn, was examined by the "Huygens" probe, which indicated that Titan's atmosphere periodically rains liquid methane onto the moon's surface. Also on Titan, the Cassini mission has imaged seasonal methane/ethane lakes near the polar regions of Titan. Methane and ethane have also been detected in the tail of the comet Hyakutake. Chemical analysis showed that the abundances of ethane and methane were roughly equal, which is thought to imply that its ices formed in interstellar space, away from the Sun, which would have evaporated these volatile molecules. Alkanes have also been detected in meteorites such as carbonaceous chondrites.
Occurrence of alkanes on Earth. Traces of methane gas (about 0.0002% or 1745 ppb) occur in the Earth's atmosphere, produced primarily by methanogenic microorganisms, such as Archaea in the gut of ruminants. The most important commercial sources for alkanes are natural gas and oil. Natural gas contains primarily methane and ethane, with some propane and butane: oil is a mixture of liquid alkanes and other hydrocarbons. These hydrocarbons were formed when marine animals and plants (zooplankton and phytoplankton) died and sank to the bottom of ancient seas and were covered with sediments in an anoxic environment and converted over many millions of years at high temperatures and high pressure to their current form. Natural gas resulted thereby for example from the following reaction: These hydrocarbon deposits, collected in porous rocks trapped beneath impermeable cap rocks, comprise commercial oil fields. They have formed over millions of years and once exhausted cannot be readily replaced. The depletion of these hydrocarbons reserves is the basis for what is known as the energy crisis.
Alkanes have a low solubility in water, so the content in the oceans is negligible; however, at high pressures and low temperatures (such as at the bottom of the oceans), methane can co-crystallize with water to form a solid methane clathrate (methane hydrate). Although this cannot be commercially exploited at the present time, the amount of combustible energy of the known methane clathrate fields exceeds the energy content of all the natural gas and oil deposits put together. Methane extracted from methane clathrate is, therefore, a candidate for future fuels. Biological occurrence. Aside from petroleum and natural gas, alkanes occur significantly in nature only as methane, which is produced by some archaea by the process of methanogenesis. These organisms are found in the gut of termites and cows. The methane is produced from carbon dioxide or other organic compounds. Energy is released by the oxidation of hydrogen: It is probable that our current deposits of natural gas were formed in a similar way. Certain types of bacteria can metabolize alkanes: they prefer even-numbered carbon chains as they are easier to degrade than odd-numbered chains.
Alkanes play a negligible role in higher organisms, with rare exception. Some yeasts, e.g., "Candida tropicale", "Pichia" sp., "Rhodotorula" sp., can use alkanes as a source of carbon or energy. The fungus "Amorphotheca resinae" prefers the longer-chain alkanes in aviation fuel, and can cause serious problems for aircraft in tropical regions. In plants, the solid long-chain alkanes are found in the plant cuticle and epicuticular wax of many species, but are only rarely major constituents. They protect the plant against water loss, prevent the leaching of important minerals by the rain, and protect against bacteria, fungi, and harmful insects. The carbon chains in plant alkanes are usually odd-numbered, between 27 and 33 carbon atoms in length, and are made by the plants by decarboxylation of even-numbered fatty acids. The exact composition of the layer of wax is not only species-dependent but also changes with the season and such environmental factors as lighting conditions, temperature or humidity. The Jeffrey pine is noted for producing exceptionally high levels of "n"-heptane in its resin, for which reason its distillate was designated as the zero point for one octane rating. Floral scents have also long been known to contain volatile alkane components, and "n"-nonane is a significant component in the scent of some roses. Emission of gaseous and volatile alkanes such as ethane, pentane, and hexane by plants has also been documented at low levels, though they are not generally considered to be a major component of biogenic air pollution.
Edible vegetable oils also typically contain small fractions of biogenic alkanes with a wide spectrum of carbon numbers, mainly 8 to 35, usually peaking in the low to upper 20s, with concentrations up to dozens of milligrams per kilogram (parts per million by weight) and sometimes over a hundred for the total alkane fraction. Alkanes are found in animal products, although they are less important than unsaturated hydrocarbons. One example is the shark liver oil, which is approximately 14% pristane (2,6,10,14-tetramethylpentadecane, C19H40). They are important as pheromones, chemical messenger materials, on which insects depend for communication. In some species, e.g. the support beetle "Xylotrechus colonus", pentacosane (C25H52), 3-methylpentaicosane (C26H54) and 9-methylpentaicosane (C26H54) are transferred by body contact. With others like the tsetse fly "Glossina morsitans morsitans", the pheromone contains the four alkanes 2-methylheptadecane (C18H38), 17,21-dimethylheptatriacontane (C39H80), 15,19-dimethylheptatriacontane (C39H80) and 15,19,23-trimethylheptatriacontane (C40H82), and acts by smell over longer distances. Waggle-dancing honey bees produce and release two alkanes, tricosane and pentacosane.
Ecological relations. One example, in which both plant and animal alkanes play a role, is the ecological relationship between the sand bee ("Andrena nigroaenea") and the early spider orchid ("Ophrys sphegodes"); the latter is dependent for pollination on the former. Sand bees use pheromones in order to identify a mate; in the case of "A. nigroaenea", the females emit a mixture of tricosane (C23H48), pentacosane (C25H52) and heptacosane (C27H56) in the ratio 3:3:1, and males are attracted by specifically this odor. The orchid takes advantage of this mating arrangement to get the male bee to collect and disseminate its pollen; parts of its flower not only resemble the appearance of sand bees but also produce large quantities of the three alkanes in the same ratio as female sand bees. As a result, numerous males are lured to the blooms and attempt to copulate with their imaginary partner: although this endeavor is not crowned with success for the bee, it allows the orchid to transfer its pollen, which will be dispersed after the departure of the frustrated male to other blooms.
Production. Petroleum refining. The most important source of alkanes is natural gas and crude oil. Alkanes are separated in an oil refinery by fractional distillation. Unsaturated hydrocarbons are converted to alkanes by hydrogenation: Another route to alkanes is hydrogenolysis, which entails cleavage of C-heteroatom bonds using hydrogen. In industry, the main substrates are organonitrogen and organosulfur impurities, i.e. the heteroatoms are N and S. The specific processes are called hydrodenitrification and hydrodesulfurization: Hydrogenolysis can be applied to the conversion of virtually any functional group into hydrocarbons. Substrates include haloalkanes, alcohols, aldehydes, ketones, carboxylic acids, etc. Both hydrogenolysis and hydrogenation are practiced in refineries. The can be effected by using lithium aluminium hydride, Clemmenson reduction and other specialized routes. Coal. Coal is a more traditional precursor to alkanes. A wide range of technologies have been intensively practiced for centuries. Simply heating coal gives alkanes, leaving behind coke. Relevant technologies include the Bergius process and coal liquifaction. Partial combustion of coal and related solid organic compounds generates carbon monoxide, which can be hydrogenated using the Fischer–Tropsch process. This technology allows the synthesize liquid hydrocarbons, including alkanes. This method is used to produce substitutes for petroleum distillates.
Laboratory preparation. Rarely is there any interest in the synthesis of alkanes, since they are usually commercially available and less valued than virtually any precursor. The best-known method is hydrogenation of alkenes. Many C-X bonds can be converted to C-H bonds using lithium aluminium hydride, Clemmenson reduction, and other specialized routes. Hydrolysis of Alkyl Grignard reagents and alkyl lithium compounds gives alkanes. Applications. Fuels. The dominant use of alkanes is as fuels. Propane and butane, easily liquified gases, are commonly known as liquified petroleum gas (LPG). From pentane to octane the alkanes are highly volatile liquids. They are used as fuels in internal combustion engines, as they vaporize easily on entry into the combustion chamber without forming droplets, which would impair the uniformity of the combustion. Branched-chain alkanes are preferred as they are much less prone to premature ignition, which causes knocking, than their straight-chain homologues. This propensity to premature ignition is measured by the octane rating of the fuel, where 2,2,4-trimethylpentane ("isooctane") has an arbitrary value of 100, and heptane has a value of zero. Apart from their use as fuels, the middle alkanes are also good solvents for nonpolar substances. Alkanes from nonane to, for instance, hexadecane (an alkane with sixteen carbon atoms) are liquids of higher viscosity, less and less suitable for use in gasoline. They form instead the major part of diesel and aviation fuel. Diesel fuels are characterized by their cetane number, cetane being an old name for hexadecane. However, the higher melting points of these alkanes can cause problems at low temperatures and in polar regions, where the fuel becomes too thick to flow correctly.
Precursors to chemicals. By the process of cracking, alkanes can be converted to alkenes. Simple alkenes are precursors to polymers, such as polyethylene and polypropylene. When the cracking is taken to extremes, alkanes can be converted to carbon black, which is a significant tire component. Chlorination of methane gives chloromethanes, which are used as solvents and building blocks for complex compounds. Similarly treatment of methane with sulfur gives carbon disulfide. Still other chemicals are prepared by reaction with sulfur trioxide and nitric oxide Other. Some light hydrocarbons are used as aerosol sprays. Alkanes from hexadecane upwards form the most important components of fuel oil and lubricating oil. In the latter function, they work at the same time as anti-corrosive agents, as their hydrophobic nature means that water cannot reach the metal surface. Many solid alkanes find use as paraffin wax, for example, in candles. This should not be confused however with true wax, which consists primarily of esters. Alkanes with a chain length of approximately 35 or more carbon atoms are found in bitumen, used, for example, in road surfacing. However, the higher alkanes have little value and are usually split into lower alkanes by cracking. Hazards. Alkanes are highly flammable, but they have low toxicities. Methane "is toxicologically virtually inert." Alkanes can be asphyxiants and narcotic.
Appellate procedure in the United States United States appellate procedure involves the rules and regulations for filing appeals in state courts and federal courts. The nature of an appeal can vary greatly depending on the type of case and the rules of the court in the jurisdiction where the case was prosecuted. There are many types of standard of review for appeals, such as "de novo" and abuse of discretion. However, most appeals begin when a party files a petition for review to a higher court for the purpose of overturning the lower court's decision. An appellate court is a court that hears cases on appeal from another court. Depending on the particular legal rules that apply to each circumstance, a party to a court case who is unhappy with the result might be able to challenge that result in an appellate court on specific grounds. These grounds typically could include errors of law, fact, procedure or due process. In different jurisdictions, appellate courts are also called appeals courts, courts of appeals, superior courts, or supreme courts.
The specific procedures for appealing, including even whether there is a right of appeal from a particular type of decision, can vary greatly from state to state. The right to file an appeal can also vary from state to state; for example, the New Jersey Constitution vests judicial power in a Supreme Court, a Superior Court, and other courts of limited jurisdiction, with an appellate court being part of the Superior Court. Access to appellant status. A party who files an appeal is called an "appellant", "plaintiff in error", "petitioner" or "pursuer", and a party on the other side is called an "appellee", "defendant in error", "respondent". A "cross-appeal" is an appeal brought by the respondent. For example, suppose at trial the judge found for the plaintiff and ordered the defendant to pay $50,000. If the defendant files an appeal arguing that he should not have to pay any money, then the plaintiff might file a cross-appeal arguing that the defendant should have to pay $200,000 instead of $50,000. The appellant is the party who, having lost part or all their claim in a lower court decision, is appealing to a higher court to have their case reconsidered. This is usually done on the basis that the lower court judge erred in the application of law, but it may also be possible to appeal on the basis of court misconduct, or that a finding of fact was entirely unreasonable to make on the evidence.
The appellant in the new case can be either the plaintiff (or claimant), defendant, third-party intervenor, or respondent (appellee) from the lower case, depending on who was the losing party. The winning party from the lower court, however, is now the respondent. In unusual cases the appellant can be the victor in the court below, but still appeal. An appellee is the party to an appeal in which the lower court judgment was in its favor. The appellee is required to respond to the petition, oral arguments, and legal briefs of the appellant. In general, the appellee takes the procedural posture that the lower court's decision should be affirmed. Ability to appeal. An appeal "as of right" is one that is guaranteed by statute or some underlying constitutional or legal principle. The appellate court cannot refuse to listen to the appeal. An appeal "by leave" or "permission" requires the appellant to obtain leave to appeal; in such a situation either or both of the lower court and the court may have the discretion to grant or refuse the appellant's demand to appeal the lower court's decision. In the Supreme Court, review in most cases is available only if the Court exercises its discretion and grants a writ of certiorari.
In tort, equity, or other civil matters either party to a previous case may file an appeal. In criminal matters, however, the state or prosecution generally has no appeal "as of right". And due to the double jeopardy principle, the state or prosecution may never appeal a jury or bench verdict of acquittal. But in some jurisdictions, the state or prosecution may appeal "as of right" from a trial court's dismissal of an indictment in whole or in part or from a trial court's granting of a defendant's suppression motion. Likewise, in some jurisdictions, the state or prosecution may appeal an issue of law "by leave" from the trial court or the appellate court. The ability of the prosecution to appeal a decision in favor of a defendant varies significantly internationally. All parties must present grounds to appeal, or it will not be heard. By convention in some law reports, the appellant is named first. This can mean that where it is the defendant who appeals, the name of the case in the law reports reverses (in some cases twice) as the appeals work their way up the court hierarchy. This is not always true, however. In the federal courts, the parties' names always stay in the same order as the lower court when an appeal is taken to the circuit courts of appeals, and are re-ordered only if the appeal reaches the Supreme Court.
Direct or collateral: Appealing criminal convictions. Many jurisdictions recognize two types of appeals, particularly in the criminal context. The first is the traditional "direct" appeal in which the appellant files an appeal with the next higher court of review. The second is the collateral appeal or post-conviction petition, in which the petitioner-appellant files the appeal in a court of first instance—usually the court that tried the case. The key distinguishing factor between direct and collateral appeals is that the former occurs in state courts, and the latter in federal courts. Relief in post-conviction is rare and is most often found in capital or violent felony cases. The typical scenario involves an incarcerated defendant locating DNA evidence demonstrating the defendant's actual innocence. Appellate review. "Appellate review" is the general term for the process by which courts with appellate jurisdiction take jurisdiction of matters decided by lower courts. It is distinguished from judicial review, which refers to the court's overriding constitutional or statutory right to determine if a legislative act or administrative decision is defective for jurisdictional or other reasons (which may vary by jurisdiction).
In most jurisdictions the normal and preferred way of seeking appellate review is by filing an appeal of the final judgment. Generally, an appeal of the judgment will also allow appeal of all other orders or rulings made by the trial court in the course of the case. This is because such orders cannot be appealed "as of right". However, certain critical interlocutory court orders, such as the denial of a request for an interim injunction, or an order holding a person in contempt of court, can be appealed immediately although the case may otherwise not have been fully disposed of. There are two distinct forms of appellate review, "direct" and "collateral". For example, a criminal defendant may be convicted in state court, and lose on "direct appeal" to higher state appellate courts, and if unsuccessful, mount a "collateral" action such as filing for a writ of habeas corpus in the federal courts. Generally speaking, "[d]irect appeal statutes afford defendants the opportunity to challenge the merits of a judgment and allege errors of law or fact. ... [Collateral review], on the other hand, provide[s] an independent and civil inquiry into the validity of a conviction and sentence, and as such are generally limited to challenges to constitutional, jurisdictional, or other fundamental violations that occurred at trial." "Graham v. Borgen", 483 F 3d. 475 (7th Cir. 2007) (no. 04–4103) (slip op. at 7) (citation omitted).
In Anglo-American common law courts, appellate review of lower court decisions may also be obtained by filing a petition for review by prerogative writ in certain cases. There is no corresponding right to a writ in any pure or continental civil law legal systems, though some mixed systems such as Quebec recognize these prerogative writs. Direct appeal. After exhausting the first appeal as of right, defendants usually petition the highest state court to review the decision. This appeal is known as a direct appeal. The highest state court, generally known as the Supreme Court, exercises discretion over whether it will review the case. On direct appeal, a prisoner challenges the grounds of the conviction based on an error that occurred at trial or some other stage in the adjudicative process. Preservation issues. An appellant's claim(s) must usually be preserved at trial. This means that the defendant had to object to the error when it occurred in the trial. Because constitutional claims are of great magnitude, appellate courts might be more lenient to review the claim even if it was not preserved. For example, Connecticut applies the following standard to review unpreserved claims: 1.the record is adequate to review the alleged claim of error; 2. the claim is of constitutional magnitude alleging the violation of a fundamental right; 3. the alleged constitutional violation clearly exists and clearly deprived the defendant of a fair trial; 4. if subject to harmless error analysis, the state has failed to demonstrate harmlessness of the alleged constitutional violation beyond a reasonable doubt.
State post-conviction relief: collateral appeal. All States have a post-conviction relief process. Similar to federal post-conviction relief, an appellant can petition the court to correct alleged fundamental errors that were not corrected on direct review. Typical claims might include ineffective assistance of counsel and actual innocence based on new evidence. These proceedings are normally separate from the direct appeal, however some states allow for collateral relief to be sought on direct appeal. After direct appeal, the conviction is considered final. An appeal from the post conviction court proceeds just as a direct appeal. That is, it goes to the intermediate appellate court, followed by the highest court. If the petition is granted the appellant could be released from incarceration, the sentence could be modified, or a new trial could be ordered. Notice of appeal. A "notice of appeal" is a form or document that in many cases is required to begin an appeal. The form is completed by the appellant or by the appellant's legal representative. The nature of this form can vary greatly from country to country and from court to court within a country.
The specific rules of the legal system will dictate exactly how the appeal is officially begun. For example, the appellant might have to file the notice of appeal with the appellate court, or with the court from which the appeal is taken, or both. Some courts have samples of a notice of appeal on the court's own web site. In New Jersey, for example, the Administrative Office of the Court has promulgated a form of notice of appeal for use by appellants, though using this exact form is not mandatory and the failure to use it is not a jurisdictional defect provided that all pertinent information is set forth in whatever form of notice of appeal is used. The deadline for beginning an appeal can often be very short: traditionally, it is measured in days, not months. This can vary from country to country, as well as within a country, depending on the specific rules in force. In the U.S. federal court system, criminal defendants must file a notice of appeal within 10 days of the entry of either the judgment or the order being appealed, or the right to appeal is forfeited.
Appellate procedure. Generally speaking the appellate court examines the record of evidence presented in the trial court and the law that the lower court applied and decides whether that decision was legally sound or not. The appellate court will typically be deferential to the lower court's findings of fact (such as whether a defendant committed a particular act), unless clearly erroneous, and so will focus on the court's application of the law to those facts (such as whether the act found by the court to have occurred fits a legal definition at issue). If the appellate court finds no defect, it "affirms" the judgment. If the appellate court does find a legal defect in the decision "below" (i.e., in the lower court), it may "modify" the ruling to correct the defect, or it may nullify ("reverse" or "vacate") the whole decision or any part of it. It may, in addition, send the case back ("remand" or "remit") to the lower court for further proceedings to remedy the defect. In some cases, an appellate court may review a lower court decision "de novo" (or completely), challenging even the lower court's findings of fact. This might be the proper standard of review, for example, if the lower court resolved the case by granting a pre-trial motion to dismiss or motion for summary judgment which is usually based only upon written submissions to the trial court and not on any trial testimony.
Another situation is where appeal is by way of "re-hearing". Certain jurisdictions permit certain appeals to cause the trial to be heard afresh in the appellate court. Sometimes, the appellate court finds a defect in the procedure the parties used in filing the appeal and dismisses the appeal without considering its merits, which has the same effect as affirming the judgment below. (This would happen, for example, if the appellant waited too long, under the appellate court's rules, to file the appeal.) Generally, there is no trial in an appellate court, only consideration of the record of the evidence presented to the trial court and all the pre-trial and trial court proceedings are reviewed—unless the appeal is by way of re-hearing, new evidence will usually only be considered on appeal in "very" rare instances, for example if that material evidence was unavailable to a party for some very significant reason such as prosecutorial misconduct. In some systems, an appellate court will only consider the written decision of the lower court, together with any written evidence that was before that court and is relevant to the appeal. In other systems, the appellate court will normally consider the record of the lower court. In those cases the record will first be certified by the lower court.
The appellant has the opportunity to present arguments for the granting of the appeal and the appellee (or respondent) can present arguments against it. Arguments of the parties to the appeal are presented through their appellate lawyers, if represented, or "pro se" if the party has not engaged legal representation. Those arguments are presented in written briefs and sometimes in oral argument to the court at a hearing. At such hearings each party is allowed a brief presentation at which the appellate judges ask questions based on their review of the record below and the submitted briefs. In an adversarial system, appellate courts do not have the power to review lower court decisions unless a party appeals it. Therefore, if a lower court has ruled in an improper manner, or against legal precedent, that judgment will stand if not appealed – even if it might have been overturned on appeal. The United States legal system generally recognizes two types of appeals: a trial "de novo" or an appeal on the record. A trial de novo is usually available for review of informal proceedings conducted by some minor judicial tribunals in proceedings that do not provide all the procedural attributes of a formal judicial trial. If unchallenged, these decisions have the power to settle more minor legal disputes once and for all. If a party is dissatisfied with the finding of such a tribunal, one generally has the power to request a trial "de novo" by a court of record. In such a proceeding, all issues and evidence may be developed newly, as though never heard before, and one is not restricted to the evidence heard in the lower proceeding. Sometimes, however, the decision of the lower proceeding is itself admissible as evidence, thus helping to curb frivolous appeals.
In some cases, an application for "trial de novo" effectively erases the prior trial as if it had never taken place. The Supreme Court of Virginia has stated that '"This Court has repeatedly held that the effect of an appeal to circuit court is to "annul the judgment of the inferior tribunal as completely as if there had been no previous trial."' The only exception to this is that if a defendant appeals a conviction for a crime having multiple levels of offenses, where they are convicted on a lesser offense, the appeal is of the lesser offense; the conviction represents an acquittal of the more serious offenses. "[A] trial on the same charges in the circuit court does not violate double jeopardy principles, . . . subject only to the limitation that conviction in [the] district court for an offense lesser included in the one charged constitutes an acquittal of the greater offense, permitting trial de novo in the circuit court only for the lesser-included offense."
In cases where a judge rather than a jury decided issues of fact, an appellate court will apply an "abuse of discretion" standard of review. Under this standard, the appellate court gives deference to the lower court's view of the evidence, and reverses its decision only if it were a clear abuse of discretion. This is usually defined as a decision outside the bounds of reasonableness. On the other hand, the appellate court normally gives less deference to a lower court's decision on issues of law, and may reverse if it finds that the lower court applied the wrong legal standard. In some cases, an appellant may successfully argue that the law under which the lower decision was rendered was unconstitutional or otherwise invalid, or may convince the higher court to order a new trial on the basis that evidence earlier sought was concealed or only recently discovered. In the case of new evidence, there must be a high probability that its presence or absence would have made a material difference in the trial. Another issue suitable for appeal in criminal cases is effective assistance of counsel. If a defendant has been convicted and can prove that his lawyer did not adequately handle his case and that there is a reasonable probability that the result of the trial would have been different had the lawyer given competent representation, he is entitled to a new trial.
A lawyer traditionally starts an oral argument to any appellate court with the words "May it please the court." After an appeal is heard, the "mandate" is a formal notice of a decision by a court of appeal; this notice is transmitted to the trial court and, when filed by the clerk of the trial court, constitutes the final judgment on the case, unless the appeal court has directed further proceedings in the trial court. The mandate is distinguished from the appeal court's opinion, which sets out the legal reasoning for its decision. In some jurisdictions the mandate is known as the "remittitur". Results. The result of an appeal can be: There can be multiple outcomes, so that the reviewing court can affirm some rulings, reverse others and remand the case all at the same time. Remand is not required where there is nothing left to do in the case. "Generally speaking, an appellate court's judgment provides 'the final directive of the appeals courts as to the matter appealed, setting out with specificity the court's determination that the action appealed from should be affirmed, reversed, remanded or modified'". Some reviewing courts who have discretionary review may send a case back without comment other than "review improvidently granted". In other words, after looking at the case, they chose not to say anything. The result for the case of "review improvidently granted" is effectively the same as affirmed, but without that extra higher court stamp of approval.
Answer (law) In law, an answer was originally a solemn assertion in opposition to someone or something, and thus generally any counter-statement or defense, a reply to a question or response, or objection, or a correct solution of a problem. In the common law, an answer is the first pleading by a defendant, usually filed and served upon the plaintiff within a certain strict time limit after a civil complaint or criminal information or indictment has been served upon the defendant. It may have been preceded by an "optional" "pre-answer" motion to dismiss or demurrer; if such a motion is unsuccessful, the defendant "must" file an answer to the complaint or risk an adverse default judgment. In a criminal case, there is usually an arraignment or some other kind of appearance before the defendant comes to court. The pleading in the criminal case, which is entered on the record in open court, is usually either guilty or not guilty. Generally, speaking in private, civil cases there is no plea entered of guilt or innocence. There is only a judgment that grants money damages or some other kind of equitable remedy such as restitution or a permanent injunction. Criminal cases may lead to fines or other punishment, such as imprisonment. The famous Latin "Responsa Prudentium" ("answers of the learned ones") were the accumulated views of many successive generations of Roman lawyers, a body of legal opinion which gradually became authoritative. During debates of a contentious nature, deflection, colloquially known as 'changing the topic', has been widely observed, and is often seen as a failure to answer a question.
Appellate court An appellate court, commonly called a court of appeal(s), appeal court, court of second instance or second instance court, is any court of law that is empowered to hear a case upon appeal from a trial court or other lower tribunal. Appellate courts other than supreme courts are sometimes named as Intermediate appellate court. In much of the world, court systems are divided into at least three levels: the trial court, which initially hears cases and considers factual evidence and testimony relevant to the case; at least one intermediate appellate court; and a supreme court (or court of last resort) which primarily reviews the decisions of the intermediate courts, often on a discretionary basis. A particular court system's supreme court is its highest appellate court. Appellate courts nationwide can operate under varying rules. Under its standard of review, an appellate court determines the extent of the deference it will give to the lower court's decision, based on whether the appeal is one of fact or of law. In certain civil law jurisdictions, especially those following the French legal system, a first-level appellate court has the power to second-guess the trial court's finding of facts and retry the facts of the case at that level under the principle of "double degré de juridiction".
In common law jurisdictions, an appellate court reviewing an issue of fact ordinarily gives deference to the trial court's findings. It is the duty of trial judges or juries to find facts, view the evidence firsthand, and observe witness testimony. When reviewing lower decisions on an issue of fact, courts of appeal generally look for clear error. However, the appellate court reviews issues of law (that is, without deference to the lower court's interpretation) and may reverse or modify the lower court's decision if the appellate court believes the lower court misapplied the facts or the law. If the appellate court finds a reversible error on an issue of fact, it cannot immediately retry and decide the issue itself. It can only reverse and remand with instructions to the trial court for a new trial or new findings on that issue. An appellate court may also review the lower judge's discretionary decisions, such as whether the judge properly granted a new trial or disallowed evidence. The lower court's decision is only changed in cases of an "abuse of discretion". This standard tends to be even more deferential than the "clear error" standard.
Before hearing any case, the court must have jurisdiction to consider the appeal. The authority of appellate courts to review the decisions of lower courts varies widely from one jurisdiction to another. In some areas, the appellate court has limited powers of review. Generally, an appellate court's judgment provides the final directive of the appeals courts as to the matter appealed, setting out with specificity the court's determination that the action appealed from should be affirmed, reversed, remanded or modified. Depending on the type of case and the decision below, appellate review primarily consists of: an entirely new hearing (a non trial de novo); a hearing where the appellate court gives deference to factual findings of the lower court; or review of particular legal rulings made by the lower court (an appeal on the record). Bifurcation of civil and criminal appeals. While many appellate courts have jurisdiction over all cases decided by lower courts, some systems have appellate courts divided by the type of jurisdiction they exercise. Some jurisdictions have specialized appellate courts, such as the Texas Court of Criminal Appeals, which only hears appeals raised in criminal cases, and the U.S. Court of Appeals for the Federal Circuit, which has general jurisdiction but derives most of its caseload from patent cases, on one hand, and appeals from the Court of Federal Claims on the other. In the United States, Alabama, Tennessee, and Oklahoma also have separate courts of criminal appeals. Texas and Oklahoma have the final determination of criminal cases vested in their respective courts of criminal appeals, while Alabama and Tennessee allow decisions of its court of criminal appeals to be finally appealed to the state supreme court.
Appellate courts by country. Australia. The High Court has appellate jurisdiction over all other courts. Leave must be granted by the court, before the appeal matter is heard. The High Court is paramount to all federal courts. Further, it has an constitutionally entrenched general power of appeal from the Supreme Courts of the States and Territories. Appeals to the High Court are by special leave only, which is generally only granted in cases of public importance, matters involving the interpretation of the Commonwealth Constitution, or where the law has been inconsistently applied across the States and Territories.[19] Therefore, in the vast majority of cases, the appellate divisions of the Supreme Courts of each State and Territory and the Federal Court are the final courts of appeal. New Zealand. The Court of Appeal of New Zealand, located in Wellington, is New Zealand's principal intermediate appellate court. In practice, most appeals are resolved at this intermediate appellate level, rather than in the Supreme Court.
Philippines. The Court of Appeals of the Philippines is the principal intermediate appellate court of that country. The Court of Appeals is primarily found in Manila, with three divisions each in Cebu City and Cagayan de Oro. Other appellate courts include the Sandiganbayan for cases involving graft and corruption, and the Court of Tax Appeals for cases involving tax. Appeals from all three appellate courts are to the Supreme Court. Sri Lanka. The Court of Appeal of Sri Lanka, located in Colombo, is the second senior court in the Sri Lankan legal system. United States. In the United States, both state and federal appellate courts are usually restricted to examining whether the lower court made the correct legal determinations, rather than hearing direct evidence and determining what the facts of the case were. Furthermore, U.S. appellate courts are usually restricted to hearing appeals based on matters that were originally brought up before the trial court. Hence, such an appellate court will not consider an appellant's argument if it is based on a theory that is raised for the first time in the appeal.
In most U.S. states, and in U.S. federal courts, parties before the court are allowed one appeal as of right. This means that a party who is unsatisfied with the outcome of a trial may bring an appeal to contest that outcome. However, appeals may be costly, and the appellate court must find an error on the part of the court below that justifies upsetting the verdict. Therefore, only a small proportion of trial court decisions result in appeals. Some courts, particularly supreme courts, have the power of discretionary review, meaning that they can decide whether they will hear an appeal brought in a particular case. Nomenclature. Many U.S. jurisdictions title their appellate court a court of appeal or court of appeals. Both terms are used in the United States, but the plural form is more common in American English, while in contrast, British English uses only the singular form. The correct form is whichever is the statutorily prescribed or customary form for a particular court and particular jurisdiction; in other words, one should never write "court of appeal" when the court at issue clearly prefers to be called a "court of appeals", and vice versa.
Historically, certain jurisdictions have titled their appellate court a court of errors (or court of errors and appeals), on the premise that it was intended to correct errors made by lower courts. Examples of such courts include the New Jersey Court of Errors and Appeals (which existed from 1844 to 1947), the Connecticut Supreme Court of Errors (which has been renamed the Connecticut Supreme Court), the Kentucky Court of Errors (renamed the Kentucky Supreme Court), and the Mississippi High Court of Errors and Appeals (since renamed the Supreme Court of Mississippi). In some jurisdictions, a court able to hear appeals is known as an appellate division. The phrase "court of appeals" most often refers to intermediate appellate courts. However, the New York Court of Appeals is the highest appellate court in New York. The New York Supreme Court is a trial court of general jurisdiction. The Supreme Court of Maryland was known as the Court of Appeals, and the Appellate Court of Maryland was known as the Court of Special Appeals, until a 2022 constitutional amendment changed their names. Depending on the system, certain courts may serve as both trial courts and appellate courts, hearing appeals of decisions made by courts with more limited jurisdiction.
Arraignment Arraignment is a formal reading of a criminal charging document in the presence of the defendant, to inform them of the criminal charges against them. In response to arraignment, in some jurisdictions, the accused is expected to enter a plea; in other jurisdictions, no plea is required. Acceptable pleas vary among jurisdictions, but they generally include "guilty", "not guilty", and the peremptory pleas (pleas in bar) setting out reasons why a trial cannot proceed. Pleas of "nolo contendere" ('no contest') and the Alford plea are allowed in some circumstances. By country. Australia. In the Australian legal system, arraignment is the first stage in a criminal trial. The indictment is read to the defendant, who is asked to plead guilty or not guilty. Arraignment procedures vary somewhat among jurisdictions. In New South Wales, the arraignment takes place before the judge only. In South Australian practice, the jury hears the arraignment. In Queensland the indictment is read to the defendant by the judge's associate prior to the empanelling of the jury.
Canada. In British Columbia, arraignment takes place in one of the first few court appearances by the defendant or their lawyer. The defendant is asked whether they plead guilty or not guilty to each charge. France. In France, the general rule is that one cannot remain in police custody for more than 24 hours from the time of their arrest. However, police custody can last another 24 hours in specific circumstances, especially if the offence is punishable by at least one year's imprisonment, or if the investigation is deemed to require the extra time, and can last up to 96 hours in certain cases involving terrorism, drug trafficking, or organised crime. The police need to have the consent of the prosecutor, the "procureur". In the vast majority of cases, the prosecutor will consent. Germany. In Germany, if one has been arrested and taken into custody by the police, one must be brought before a judge as soon as possible and at the latest on the day after the arrest. New Zealand. Under New Zealand law, at the first appearance of the accused, they are read the charges and asked for a plea. The available pleas are: guilty, not guilty, and no plea. The response of "no plea" allows the defendant to get legal advice on the plea, which must be made on the second appearance.
South Africa. In South Africa, arraignment is defined as the calling upon the accused to appear, the informing of the accused of the crime charged against them, the demanding of the accused whether they plead guilty or not guilty, and the entering of their plea. United Kingdom. In England, Wales, and Northern Ireland, arraignment is the first of 11 stages in a criminal trial, and involves the clerk of the court reading out the indictment. In England and Wales, the police cannot legally detain anyone for more than 24 hours without charging them, unless an officer with the rank of superintendent (or above) authorises detention for a further 12 hours (i.e., 36 hours total), or a judge (who will be a magistrate) authorises detention by the police before charge for up to a maximum of 96 hours; for terrorism-related offences a person can be held by the police for up to 28 days before charge. If they are not released after being charged, they should be brought before a court as soon as practicable. In Scotland, the police cannot detain anyone for more than 12 hours without charging them unless an officer of the rank of superintendent (or above) authorises detention for a further 12 hours (i.e., up to 24 hours in total); for terrorism-related offences a person can be held by the police for up to 14 days before charge. If they are not released after being charged, they should be brought before a court as soon as practicable.
United States. The Sixth Amendment to the United States Constitution grants criminal defendants the right to be notified of the charges against them. Under the United States' Federal Rules of Criminal Procedure, arraignment shall consist of an open reading of the indictment (and delivery of a copy) to the defendant, and a call for them to plead. In federal courts, arraignment takes place in two stages. The first is called the "initial arraignment" and must take place within 48 hours of an individual's arrest, or within 72 hours if the individual was arrested on the weekend and not able to go before a judge until Monday. During this stage, the defendant is informed of the pending legal charges and is informed of his or her right to retain counsel. The presiding judge also decides at what amount, if any, to set bail. During the second stage, the post-indictment arraignment, the defendant is allowed to enter a plea. In New York, a person arrested without a warrant and kept in custody must be brought before a local criminal court for arraignment "without unnecessary delay". A delay of more than 24 hours is rebuttably presumed to be unnecessary.
In California, arraignments must be conducted without unnecessary delay and, in any event, within 48 hours of arrest, excluding weekends and holidays. Form of the arraignment. The wording of the arraignment varies from jurisdiction to jurisdiction. However, it generally conforms with the following principles: Video arraignment. Video arraignment is the act of conducting the arraignment process using some form of videoconferencing technology. Use of video arraignment system allows the court to conduct the requisite arraignment process without the need to transport the defendant to the courtroom by using an audio-visual link between the location where the defendant is being held and the courtroom. Use of the video arraignment process addresses the problems associated with having to transport defendants. The transportation of defendants requires time, puts additional demands on the public safety organizations to provide for the safety of the public, court personnel and for the security of the population held in detention. It also addresses the rising costs of transportation.
Guilty and not-guilty pleas. If the defendant pleads guilty, an evidentiary hearing usually follows. The court is not required to accept a guilty plea. During the hearing, the judge assesses the offense, the mitigating factors, and the defendant's character, and passes sentence. If the defendant pleads not guilty, a date is set for a preliminary hearing or a trial. In the past, a defendant who refused to plead (or "stood mute") was subject to "peine forte et dure" (Law French for "strong and hard punishment"). Today, in common law jurisdictions, the court enters a plea of not guilty for a defendant who refuses to enter a plea. The rationale for this is the defendant's right to silence. Pre-trial release. This is also often the stage at which arguments for or against pre-trial release and bail may be made, depending on the alleged crime and jurisdiction.
America the Beautiful "America the Beautiful" is a patriotic American song. Its lyrics were written by Katharine Lee Bates and its music was composed by church organist and choirmaster Samuel A. Ward at Grace Episcopal Church in Newark, New Jersey, though the two never met. Bates wrote the words as a poem, originally titled "Pikes Peak". It was first published in the Fourth of July 1895 edition of the church periodical, "The Congregationalist". At that time, the poem was titled "America". Ward had initially composed the song's melody in 1882 to accompany lyrics to "Materna", basis of the hymn, "O Mother dear, Jerusalem", though the hymn was not first published until 1892. The combination of Ward's melody and Bates's poem was first entitled "America the Beautiful" in 1910. The song is one of the most popular of the many American patriotic songs. History. In 1893, at the age of 33, Bates, an English professor at Wellesley College, had taken a train trip to Colorado Springs, Colorado, to teach at Colorado College. Several of the sights on her trip inspired her, and they found their way into her poem, including the World's Columbian Exposition in Chicago, the "White City" with its promise of the future contained within its gleaming white buildings; the wheat fields of North America's heartland Kansas, through which her train was riding on July 16; and the majestic view of the Great Plains from high atop Pikes Peak.
On the pinnacle of that mountain, the words of the poem started to come to her, and she wrote them down upon returning to her hotel room at the original Antlers Hotel. The poem was initially published two years later in "The Congregationalist" to commemorate the Fourth of July. It quickly caught the public's fancy. An amended version was published in 1904. The first known melody written for the song was sent in by Silas Pratt when the poem was published in "The Congregationalist". By 1900, at least 75 different melodies had been written. A hymn tune composed in 1882 by Samuel A. Ward, the organist and choir director at Grace Church, Newark, was generally considered the best music as early as 1910 and is still the popular tune today. Just as Bates had been inspired to write her poem, Ward, too, was inspired. The tune came to him while he was on a ferryboat trip from Coney Island back to his home in New York City after a leisurely summer day and he immediately wrote it down. He composed the tune for the old hymn "O Mother Dear, Jerusalem", retitling the work "Materna". Ward's music combined with Bates's poem were first published together in 1910 and titled "America the Beautiful".
Ward died in 1903, not knowing the national stature his music would attain. The song's popularity was well established by the time of Bates's death in 1929. It is included in songbooks in many religious congregations in the United States. At various times in the more than one hundred years that have elapsed since the song was written, particularly during the John F. Kennedy administration, there have been efforts to give "America the Beautiful" legal status either as a national hymn or as a national anthem equal to, or in place of, "The Star-Spangled Banner", but so far this has not succeeded. Proponents prefer "America the Beautiful" for various reasons, saying it is easier to sing, more melodic, and more adaptable to new orchestrations while still remaining as easily recognizable as "The Star-Spangled Banner". Some object to the war-oriented imagery of "The Star-Spangled Banner", as well as its implicit support of slavery and racism in the third verse. Some who prefer "The Star-Spangled Banner", however, prefer it specifically "for" its war themes. While that national dichotomy has stymied any effort at changing the tradition of the national anthem, "America the Beautiful" continues to be held in high esteem by a large number of Americans, and was even being considered before 1931 as a candidate to become the national anthem of the United States.
Notable performances. Elvis Presley performed it many times in concerts starting in 1976. Bing Crosby included the song in a medley on his album "101 Gang Songs" (1961). Frank Sinatra recorded the song with Nelson Riddle during the sessions for "The Concert Sinatra" in February 1963, for a projected 45 single release. The 45 was not commercially issued however, but the song was later added as a bonus track to the enhanced 2012 CD release of "The Concert Sinatra". In 1976, while the United States celebrated its bicentennial, a soulful version popularized by Ray Charles peaked at number 98 on the US R&B chart. His version was traditionally played on New Year's Eve in Times Square following the ball drop. Charles performed the song at Republican National Convention in August 1984 and Super Bowl XXXV in January 2001. Three different renditions of the song have entered the Hot Country Songs charts. The first was by Charlie Rich, which went to number 22 in 1976. A second, by Mickey Newbury, peaked at number 82 in 1980. An all-star version of "America the Beautiful" performed by country singers Trace Adkins, Sherrié Austin, Billy Dean, Vince Gill, Carolyn Dawn Johnson, Toby Keith, Brenda Lee, Lonestar, Lyle Lovett, Lila McCann, Lorrie Morgan, Jamie O'Neal, The Oak Ridge Boys, Collin Raye, Kenny Rogers, Keith Urban and Phil Vassar reached number 58 in July 2001. The song re-entered the chart following the September 11 attacks.
Barbra Streisand released an official music video footage during Norman Lear's Special in 1982. The song has been sung before many editions of the WWE's flagship annual show WrestleMania beginning at WrestleMania 2 in 1986, interchangeably with The Star-Spangled Banner. The song has been performed by artists such as Ray Charles, Aretha Franklin, Gladys Knight, Willie Nelson, Little Richard, Boyz II Men, Boys Choir of Harlem, John Legend, Nicole Scherzinger and Fifth Harmony. During her rise to stardom, R&B singer Mariah Carey sang the song at the 1990 NBA Finals. Whitney Houston also recorded the song, covering Ray Charles' soulful rearranged version as the B-side to her 1991 rendition of "The Star Spangled Banner." The song has been performed as part of the Indianapolis 500 pre-race ceremonies since 1991. The US singer/songwriter Martin Sexton recorded a gospel-tinged version on his LP "Black Sheep," released in 1996. Popularity of the song increased greatly in the decades following 9/11; at some sporting events it was sung in addition to the traditional singing of the national anthem. During the first taping of the "Late Show with David Letterman" following the attacks, CBS newsman Dan Rather cried briefly as he quoted the fourth verse.
The hymn has been featured in the pregame for a number of Super Bowls, the championship game for each NFL season. It is sung along with the "Star-Spangled Banner" and, more recently, the hymn "Lift Every Voice and Sing," commonly referred to as the "Black national anthem". For Super Bowl XLVIII, The Coca-Cola Company aired a multilingual version of the song, sung in several different languages. The commercial received some criticism on social media sites, such as Twitter and Facebook, and from some conservatives, such as Glenn Beck. Despite the controversies, Coca-Cola later reused the Super Bowl ad during Super Bowl LI, the opening ceremonies of the 2014 Winter Olympics and 2016 Summer Olympics and for patriotic holidays. Notable performers at the Super Bowl include Ray Charles, Alicia Keys, John Legend, Jhené Aiko, Faith Hill, Mary J. Blige with Marc Anthony, Blake Shelton with Miranda Lambert, Queen Latifah, Leslie Odom Jr., and Babyface. Post Malone performed the song for the most recent game, Super Bowl LVIII, in 2024.
The song, performed by 5 Alarm Music, is featured heavily in a dystopian action horror franchise The Purge in both trailers and films. In 2016, American five-piece girl group Fifth Harmony performed a rendition to honor the United States women's national soccer team on defeating Japan 5–2 in the Final to win the 2015 FIFA Women's World Cup last July at BC Place in Vancouver, British Columbia, Canada before an undisputed AT&T Stadium audience of 101,763 to open WrestleMania 32 in Dallas, Texas. In 2017, Jackie Evancho released "Together We Stand", a disc containing three patriotic songs including "America the Beautiful." The song charted at No. 4 on "Billboard's" Classical Digital Song sales chart. An abbreviated cover with the 1911 lyrics was performed by Greg Jong for the soundtrack of the 2020 video game "Wasteland 3" and is played during the final hostile encounters in the Denver section. In 2021, Jennifer Lopez performed the song at the inauguration of Joe Biden, as the second half of a medley with "This Land Is Your Land" by Woody Guthrie.
In 2023, Cécile McLorin Salvant performed the song at the US Open woman's final. In her rendition, Salvant notably skipped ahead to the lyrics of the second half of the second verse while singing the first verse (replacing "God shed His grace on thee..." with "God mend thine every flaw...", etc.). Jazz Critic Nate Chinen wrote the following day of the performance, "What does it mean for a singer such as Salvant to inhabit a platform like the US Open, and implore God to mend America’s every flaw? What does it mean, in the Year of Our Lord 2023, for a singer like Salvant to urge the nation to confirm thy soul in self-control, and find liberty in law? I’m not going to spell it out, but it means a lot." In 2025 Carrie Underwood sang the song "a capella" after what were described as “technical difficulties” caused the failure of her backing music, during the second inauguration of Donald Trump. Idioms. "From sea to shining sea" is an American idiom meaning "from the Atlantic Ocean to the Pacific Ocean" (or vice versa). Other songs that have used this phrase include the American patriotic song "God Bless the U.S.A." and Schoolhouse Rock's "Elbow Room". The phrase and the song are also the namesake of the Shining Sea Bikeway, a bike path in Bates's hometown of Falmouth, Massachusetts. The phrase is similar to the Latin phrase "" ("From sea to sea"), which is the official motto of Canada.
"Purple mountain majesties" refers to the shade of Pikes Peak in Colorado Springs, Colorado, which inspired Bates to write the poem. The idiom inspired the Colorado Rockies to have purple as one of its team colors. In 2003, Tori Amos appropriated the phrase "for amber waves of grain" to create a personification for her song "Amber Waves". Amos imagines Amber Waves as an exotic dancer, like the character of the same name portrayed by Julianne Moore in "Boogie Nights". Books. Lynn Sherr's 2001 book "America the Beautiful: The Stirring True Story Behind Our Nation's Favorite Song" discusses the origins of the song and the backgrounds of its authors in depth. The book points out that the poem has the same meter as that of "Auld Lang Syne"; the songs can be sung interchangeably. Additionally, Sherr discusses the evolution of the lyrics, for instance, changes to the original third verse written by Bates. Melinda M. Ponder, in her 2017 biography "Katharine Lee Bates: From Sea to Shining Sea", draws heavily on Bates's diaries and letters to trace the history of the poem and its place in American culture.
Assistive technology Assistive technology (AT) is a term for assistive, adaptive, and rehabilitative devices for people with disabilities and the elderly. Disabled people often have difficulty performing activities of daily living (ADLs) independently, or even with assistance. ADLs are self-care activities that include toileting, mobility (ambulation), eating, bathing, dressing, grooming, and personal device care. Assistive technology can ameliorate the effects of disabilities that limit the ability to perform ADLs. Assistive technology promotes greater independence by enabling people to perform tasks they were formerly unable to accomplish, or had great difficulty accomplishing, by providing enhancements to, or changing methods of interacting with, the technology needed to accomplish such tasks. For example, wheelchairs provide independent mobility for those who cannot walk, while assistive eating devices can enable people who cannot feed themselves to do so. Due to assistive technology, disabled people have an opportunity of a more positive and easygoing lifestyle, with an increase in "social participation", "security and control", and a greater chance to "reduce institutional costs without significantly increasing household expenses." In schools, assistive technology can be critical in allowing students with disabilities to access the general education curriculum. Students who experience challenges writing or keyboarding, for example, can use voice recognition software instead. Assistive technologies assist people who are recovering from strokes and people who have sustained injuries that affect their daily tasks.
A recent study from India led by Dr Edmond Fernandes et al. from Edward & Cynthia Institute of Public Health which was published in WHO SEARO Journal informed that geriatric care policies which address functional difficulties among older people will ought to be mainstreamed, resolve out-of-pocket spending for assistive technologies will need to look at government schemes for social protection. Adaptive technology. Adaptive technology and assistive technology are different. "Assistive technology" is something that is used to help disabled people, while "adaptive technology" covers items that are specifically designed for disabled people and would seldom be used by a non-disabled person. In other words, assistive technology is any object or system that helps people with disabilities, while adaptive technology is specifically designed for disabled people. Consequently, adaptive technology is a subset of assistive technology. Adaptive technology often refers specifically to electronic and information technology access.
Occupational therapy and assistive technology. Occupational Therapy (OT) utilizes everyday occupations as a therapeutic tool for enhancing or enabling participation in healthy occupations to promote health and well-being (AOTA, 2020). Occupations include activities of daily living (ADLs), instrumental activities of daily living (IADLs), health management, rest and sleep, education, work, play, leisure, and social participation (AOTA, 2020).  “As occupational therapy professionals, we are uniquely trained to advocate for client-centered care that reduces barriers to participation in meaningful occupations and promotes overall well-being" (Clark, Iqbal & Myers, 2022) OT practitioners (OTP) utilize assistive technologies (AT) to modify environments and promote access and fit to facilitate independence. For example, voice activated smart home technology allows an individual to control devices such as light switches, thermostat, oven, blinds, and music from their location.  OTP evaluate client's strengths and abilities and connects with desired tasks.  OTP help empower the client to match specific goals to AT tools. The theoretical approaches or frameworks OTPs frequently use to guide a client's AT choices may include: 1) The HAAT model by Cook, Polgar & Encarnaçāo (2015) 2) The interdependence - Human Activity Assistive Technology Model (I-HAAT) by Lee, et al. (2020); 3) The SETT Framework by Zabala (2005); or 4) The Unified Theory of Acceptance and Use of Technology (UTAUT 2) by Venkatesh, Thong & Xu (2012). Also, OTPs may seek advanced training through the Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) organization to receive their Assistive Technology Professional (ATP) Certification and/or Seating and Mobility Specialist (SMS) Certification. Additional trainings and certifications may specialize in a focus area such as the Certified Assistive Technology Instructional Specialist for Individuals with Visual Impairments (CATIS™) (ACVREP, 2024).
Mobility impairments. Wheelchairs. Wheelchairs are devices that can be manually propelled or electrically propelled, and that include a seating system and are designed to be a substitute for the normal mobility that most people have. Wheelchairs and other mobility devices allow people to perform mobility-related activities of daily living which include feeding, toileting, dressing, grooming, and bathing. The devices come in a number of variations where they can be propelled either by hand or by motors where the occupant uses electrical controls to manage motors and seating control actuators through a joystick, sip-and-puff control, head switches or other input devices. Often there are handles behind the seat for someone else to do the pushing or input devices for caregivers. Wheelchairs are used by people for whom walking is difficult or impossible due to illness, injury, or disability. People with both sitting and walking disability often need to use a wheelchair or walker. Newer advancements in wheelchair design enable wheelchairs to climb stairs, go off-road or propel using segway technology or additional add-ons like handbikes or power assists.
Transfer devices. Patient transfer devices generally allow patients with impaired mobility to be moved by caregivers between beds, wheelchairs, commodes, toilets, chairs, stretchers, shower benches, automobiles, swimming pools, and other patient support systems (i.e., radiology, surgical, or examining tables). The most common devices are transfer benches, stretcher or convertible chairs (for lateral, supine transfer), sit-to-stand lifts (for moving patients from one seated position to another i.e., from wheelchairs to commodes), air bearing inflatable mattresses (for supine transfer i.e., transfer from a gurney to an operating room table), gait belts (or transfer belt) and a slider board (or transfer board), usually used for transfer from a bed to a wheelchair or from a bed to an operating table. Highly dependent patients who cannot assist their caregiver in moving them often require a patient lift (a floor or ceiling-suspended sling lift) which though invented in 1955 and in common use since the early 1960s is still considered the state-of-the-art transfer device by OSHA and the American Nursing Association.
Walkers. A walker or walking frame or Rollator is a tool for disabled people who need additional support to maintain balance or stability while walking. It consists of a frame that is about waist high, approximately twelve inches deep and slightly wider than the user. Walkers are also available in other sizes, such as for children, or for heavy people. Modern walkers are height-adjustable. The front two legs of the walker may or may not have wheels attached depending on the strength and abilities of the person using it. It is also common to see caster wheels or glides on the back legs of a walker with wheels on the front. Treadmills. Bodyweight-supported treadmill training (BWSTT) is used to enhance walking ability of people with neurological injury. These machines are therapist-assisted devices that are used in the clinical setting, but is limited by the personnel and labor requirements placed on physical therapists. The BWSTT device, and many others like it, assist physical therapists by providing task-specific practice of walking in people following neurological injury.
Prosthesis. A prosthesis, prosthetic, or prosthetic limb is a device that replaces a missing body part. It is part of the field of biomechatronics, the science of using mechanical devices with human muscular, musculoskeletal, and nervous systems to assist or enhance motor control lost by trauma, disease, or defect. Prostheses are typically used to replace parts lost by injury (traumatic) or missing from birth (congenital) or to supplement defective body parts. Inside the body, artificial heart valves are in common use with artificial hearts and lungs seeing less common use but under active technology development. Other medical devices and aids that can be considered prosthetics include hearing aids, artificial eyes, palatal obturator, gastric bands, and dentures. Prostheses are specifically not orthoses, although given certain circumstances a prosthesis might end up performing some or all of the same functionary benefits as an orthosis. Prostheses are technically the complete finished item. For instance, a C-Leg knee alone is not a prosthesis, but only a prosthetic component. The complete prosthesis would consist of the attachment system  to the residual limb – usually a "socket", and all the attachment hardware components all the way down to and including the terminal device. Despite the technical difference, the terms are often used interchangeably.
The terms "prosthetic" and "orthotic" are adjectives used to describe devices such as a prosthetic knee. The terms "prosthetics" and "orthotics" are used to describe the respective allied health fields. An Occupational Therapist's role in prosthetics include therapy, training and evaluations. Prosthetic training includes orientation to prosthetics components and terminology, donning and doffing, wearing schedule, and how to care for residual limb and the prosthesis. Exoskeletons. A powered exoskeleton is a wearable mobile machine that is powered by a system of electric motors, pneumatics, levers, hydraulics, or a combination of technologies that allow for limb movement with increased strength and endurance. Its design aims to provide back support, sense the user's motion, and send a signal to motors which manage the gears. The exoskeleton supports the shoulder, waist and thigh, and assists movement for lifting and holding heavy items, while lowering back stress. Adaptive seating and positioning. People with balance and motor function challenges often need specialized equipment to sit or stand safely and securely. This equipment is frequently specialized for specific settings such as in a classroom or nursing home.  Positioning is often important in seating arrangements to ensure that user's body pressure is distributed equally without inhibiting movement in a desired way.
Positioning devices have been developed to aid in allowing people to stand and bear weight on their legs without risk of a fall.  These standers are generally grouped into two categories based on the position of the occupant.  Prone standers distribute the body weight to the front of the individual and usually have a tray in front of them.  This makes them good for users who are actively trying to carry out some task.  Supine standers distribute the body weight to the back and are good for cases where the user has more limited mobility or is recovering from injury. For children. Children with severe disabilities can develop learned helplessness, which makes them lose interest in their environment. Robotic arms are used to provide an alternative method to engage in joint play activities. These robotic arms allow children to manipulate real objects in the context of play activities.
Visual impairments. Many people with serious visual impairments live independently, using a wide range of tools and techniques. Examples of assistive technology for visually impairment include screen readers, screen magnifiers, Braille embossers, desktop video magnifiers, and voice recorders. Screen readers. Screen readers are used to help the visually impaired to easily access electronic information. These software programs run on a computer to convey the displayed information through voice (text-to-speech) or braille (refreshable braille displays) in combination with magnification for low vision users in some cases. There are a variety of platforms and applications available for a variety of costs with differing feature sets. Some example of screen readers are Apple VoiceOver, CheckMeister browser, Google TalkBack and Microsoft Narrator. Screen readers may rely on the assistance of text-to-speech tools. To use the text-to-speech tools, the documents must be in an electronic form, which is uploaded as the digital format. However, people usually will use the hard copy documents scanned into the computer, which cannot be recognized by the text-to-speech software. To solve this issue, people often use Optical Character Recognition technology accompanied with text-to-speech software.
Braille and braille technology. Braille is a system of raised dots formed into units called braille cells. A full braille cell is made up of six dots, with two parallel rows of three dots, but other combinations and quantities of dots represent other letters, numbers, punctuation marks, or words. People can then use their fingers to read the code of raised dots. Assistive technology using braille is called braille technology. Braille translator. A braille translator is a computer program that can translate inkprint into braille or braille into inkprint. A braille translator can be an app on a computer or be built into a website, a smartphone, or a braille device. Braille embosser. A braille embosser is, simply put, a printer for braille. Instead of a standard printer adding ink onto a page, the braille embosser imprints the raised dots of braille onto a page. Some braille embossers combine both braille and ink so the documents can be read with either sight or touch. Refreshable braille display. A refreshable braille display or braille terminal is an electro-mechanical device for displaying braille characters, usually by means of round-tipped pins raised through holes in a flat surface. Computer users who cannot use a computer monitor use it to read a braille output version of the displayed text.
Desktop video magnifier. Desktop video magnifiers are electronic devices that use a camera and a display screen to perform digital magnification of printed materials. They enlarge printed pages for those with low vision. A camera connects to a monitor that displays real-time images, and the user can control settings such as magnification, focus, contrast, underlining, highlighting, and other screen preferences. They come in a variety of sizes and styles; some are small and portable with handheld cameras, while others are much larger and mounted on a fixed stand. Screen magnification software. A screen magnifier is software that interfaces with a computer's graphical output to present enlarged screen content. It allows users to enlarge the texts and graphics on their computer screens for easier viewing. Similar to desktop video magnifiers, this technology assists people with low vision. After the user loads the software into their computer's memory, it serves as a kind of "computer magnifying glass". Wherever the computer cursor moves, it enlarges the area around it. This allows greater computer accessibility for a wide range of visual abilities.
Large-print and tactile keyboards. A large-print keyboard has large letters printed on the keys. On the keyboard shown, the round buttons at the top control software which can magnify the screen (zoom in), change the background color of the screen, or make the mouse cursor on the screen larger. The "bump dots" on the keys, installed in this case by the organization using the keyboards, help the user find the right keys in a tactile way. Navigation assistance. Assistive technology for navigation has expanded on the IEEE Xplore database since 2000, with over 7,500 engineering articles written on assistive technologies and visual impairment in the past 25 years, and over 1,300 articles on solving the problem of navigation for people who are blind or visually impaired. As well, over 600 articles on augmented reality and visual impairment have appeared in the engineering literature since 2000. Most of these articles were published within the past five years, and the number of articles in this area is increasing every year. GPS, accelerometers, gyroscopes, and cameras can pinpoint the exact location of the user and provide information on what is in the immediate vicinity, and assistance in getting to a destination.
Wearable technology. Wearable technology are smart electronic devices that can be worn on the body as an implant or an accessory. New technologies are exploring how the visually impaired can receive visual information through wearable devices. Some wearable devices for visual impairment include: OrCam device, eSight and Brainport. Personal emergency response systems. Personal emergency response systems (PERS), or Telecare (UK term), are a particular sort of assistive technology that use electronic sensors connected to an alarm system to help caregivers manage risk and help vulnerable people stay independent at home longer. An example would be the systems being put in place for senior people such as fall detectors, thermometers (for hypothermia risk), flooding and unlit gas sensors (for people with mild dementia). Notably, these alerts can be customized to the particular person's risks. When the alert is triggered, a message is sent to a caregiver or contact center who can respond appropriately. Accessibility software.
In human–computer interaction, computer accessibility (also known as accessible computing) refers to the accessibility of a computer system to all people, regardless of disability or severity of impairment, examples include web accessibility guidelines. Another approach is for the user to present a token to the computer terminal, such as a smart card, that has configuration information to adjust the computer speed, text size, etc. to their particular needs. This is useful where users want to access public computer based terminals in Libraries, ATM, Information kiosks etc. The concept is encompassed by the CEN EN 1332-4 Identification Card Systems – Man-Machine Interface. This development of this standard has been supported in Europe by SNAPI and has been successfully incorporated into the Lasseo specifications, but with limited success due to the lack of interest from public computer terminal suppliers. Hearing impairments. People in the deaf and hard of hearing community have a more difficult time receiving auditory information as compared to hearing individuals. These individuals often rely on visual and tactile mediums for receiving and communicating information. The use of assistive technology and devices provides this community with various solutions to auditory communication needs by providing higher sound (for those who are hard of hearing), tactile feedback, visual cues and improved technology access. Individuals who are deaf or hard of hearing use a variety of assistive technologies that provide them with different access to information in numerous environments. Most devices either provide amplified sound or alternate ways to access information through vision and/or vibration. These technologies can be grouped into three general categories: Hearing Technology, alerting devices, and communication support.
Hearing aids. A hearing aid or deaf aid is an electro-acoustic device which is designed to amplify sound for the wearer, usually with the aim of making speech more intelligible, and to correct impaired hearing as measured by audiometry. This type of assistive technology helps people with hearing loss participate more fully in their hearing communities by allowing them to hear more clearly. They amplify any and all sound waves through use of a microphone, amplifier, and speaker. There is a wide variety of hearing aids available, including digital, in-the-ear, in-the-canal, behind-the-ear, and on-the-body aids. Assistive listening devices. Assistive listening devices include FM, infrared, and loop assistive listening devices. This type of technology allows people with hearing difficulties to focus on a speaker or subject by getting rid of extra background noises and distractions, making places like auditoriums, classrooms, and meetings much easier to participate in. The assistive listening device usually uses a microphone to capture an audio source near to its origin and broadcast it wirelessly over an FM (Frequency Modulation) transmission, IR (Infra Red) transmission, IL (Induction Loop) transmission, or other transmission methods. The person who is listening may use an FM/IR/IL Receiver to tune into the signal and listen at his/her preferred volume.
Amplified telephone equipment. This type of assistive technology allows users to amplify the volume and clarity of their phone calls so that they can easily partake in this medium of communication. There are also options to adjust the frequency and tone of a call to suit their individual hearing needs. Additionally, there is a wide variety of amplified telephones to choose from, with different degrees of amplification. For example, a phone with 26 to 40 decibel is generally sufficient for mild hearing loss, while a phone with 71 to 90 decibel is better for more severe hearing loss. Augmentative and alternative communication. Augmentative and alternative communication (AAC) is an umbrella term that encompasses methods of communication for those with impairments or restrictions on the production or comprehension of spoken or written language. AAC systems are extremely diverse and depend on the capabilities of the user. They may be as basic as pictures on a board that are used to request food, drink, or other care; or they can be advanced speech generating devices, based on speech synthesis, that are capable of storing hundreds of phrases and words.
Cognitive impairments. Assistive Technology for Cognition (ATC) is the use of technology (usually high tech) to augment and assist cognitive processes such as attention, memory, self-regulation, navigation, emotion recognition and management, planning, and sequencing activity. Systematic reviews of the field have found that the number of ATC are growing rapidly, but have focused on memory and planning, that there is emerging evidence for efficacy, that a lot of scope exists to develop new ATC. Examples of ATC include: NeuroPage which prompts users about meetings, Wakamaru, which provides companionship and reminds users to take medicine and calls for help if something is wrong, and telephone Reassurance systems. Memory aids. Memory aids are any type of assistive technology that helps a user learn and remember certain information. Many memory aids are used for cognitive impairments such as reading, writing, or organizational difficulties. For example, a Smartpen records handwritten notes by creating both a digital copy and an audio recording of the text. Users simply tap certain parts of their notes, the pen saves it, and reads it back to them. From there, the user can also download their notes onto a computer for increased accessibility. Digital voice recorders are also used to record "in the moment" information for fast and easy recall at a later time.
A 2017 Cochrane Review highlighted the current lack of high-quality evidence to determine whether assistive technology effectively supports people with dementia to manage memory issues. Thus, it is not presently sure whether or not assistive technology is beneficial for memory problems. Educational software. Educational software is software that assists people with reading, learning, comprehension, and organizational difficulties. Any accommodation software such as text readers, notetakers, text enlargers, organization tools, word predictions, and talking word processors falls under the category of educational software. Eating impairments. Adaptive eating devices include items commonly used by the general population like spoons and forks and plates. However they become assistive technology when they are modified to accommodate the needs of people who have difficulty using standard cutlery due to a disabling condition. Common modifications include increasing the size of the utensil handle to make it easier to grasp. Plates and bowls may have a guard on the edge that stops food being pushed off of the dish when it is being scooped. More sophisticated equipment for eating includes manual and powered feeding devices. These devices support those who have little or no hand and arm function and enable them to eat independently.
In sports. Assistive technology in sports is an area of technology design that is growing. Assistive technology is the array of new devices created to enable sports enthusiasts who have disabilities to play. Assistive technology may be used in adaptive sports, where an existing sport is modified to enable players with a disability to participate; or, assistive technology may be used to invent completely new sports with athletes with disabilities exclusively in mind. An increasing number of people with disabilities are participating in sports, leading to the development of new assistive technology. Assistive technology devices can be simple, or "low-technology", or they may use highly advanced technology. "Low-tech" devices can include velcro gloves and adaptive bands and tubes. "High-tech" devices can include all-terrain wheelchairs and adaptive bicycles. Accordingly, assistive technology can be found in sports ranging from local community recreation to the elite Paralympic Games. More complex assistive technology devices have been developed over time, and as a result, sports for people with disabilities "have changed from being a clinical therapeutic tool to an increasingly competition-oriented activity".
In education. In the United States there are two major pieces of legislation that govern the use of assistive technology within the school system. The first is Section 504 of the Rehabilitation Act of 1973 and the second being the Individuals with Disabilities Education Act (IDEA) which was first enacted in 1975 under the name The Education for All Handicapped Children Act. In 2004, during the reauthorization period for IDEA, the National Instructional Material Access Center (NIMAC) was created which provided a repository of accessible text including publisher's textbooks to students with a qualifying disability. Files provided are in XML format and used as a starting platform for braille readers, screen readers, and other digital text software. IDEA defines assistive technology as follows: "any item, piece of equipment, or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve functional capabilities of a child with a disability. (B) Exception.--The term does not include a medical device that is surgically implanted, or the replacement of such device."
Assistive technology listed is a student's IEP is not only recommended, it is required (Koch, 2017). These devices help students both with and without disabilities access the curriculum in a way they were previously unable to (Koch, 2017). Occupational therapists play an important role in educating students, parents and teachers about the assistive technology they may interact with. Assistive technology in this area is broken down into low, mid, and high tech categories. Low tech encompasses equipment that is often low cost and does not include batteries or requires charging. Examples include adapted paper and pencil grips for writing or masks and color overlays for reading. Mid tech supports used in the school setting include the use of handheld spelling dictionaries and portable word processors used to keyboard writing. High tech supports involve the use of tablet devices and computers with accompanying software. Software supports for writing include the use of auditory feedback while keyboarding, word prediction for spelling, and speech to text. Supports for reading include the use of text to speech (TTS) software and font modification via access to digital text. Limited supports are available for math instruction and mostly consist of grid based software to allow younger students to keyboard equations and auditory feedback of more complex equations using MathML and Daisy.
Computer accessibility. One of the largest problems that affect disabled people is discomfort with prostheses. An experiment performed in Massachusetts used 20 people with various sensors attached to their arms. The subjects tried different arm exercises, and the sensors recorded their movements. All of the data helped engineers develop new engineering concepts for prosthetics. Assistive technology may attempt to improve the ergonomics of the devices themselves such as Dvorak and other alternative keyboard layouts, which offer more ergonomic layouts of the keys. Assistive technology devices have been created to enable disabled people to use modern touch screen mobile computers such as the iPad, iPhone and iPod Touch. The Pererro is a plug and play adapter for iOS devices which uses the built in Apple VoiceOver feature in combination with a basic switch. This brings touch screen technology to those who were previously unable to use it. Apple, with the release of iOS 7 had introduced the ability to navigate apps using switch control. Switch access could be activated either through an external bluetooth connected switch, single touch of the screen, or use of right and left head turns using the device's camera. Additional accessibility features include the use of Assistive Touch which allows a user to access multi-touch gestures through pre-programmed onscreen buttons.
For users with physical disabilities a large variety of switches are available and customizable to the user's needs varying in size, shape, or amount of pressure required for activation. Switch access may be placed near any area of the body which has consistent and reliable mobility and less subject to fatigue. Common sites include the hands, head, and feet. Eye gaze and head mouse systems can also be used as an alternative mouse navigation. A user may use single or multiple switch sites and the process often involves a scanning through items on a screen and activating the switch once the desired object is highlighted. Home automation. The form of home automation called assistive domotics focuses on making it possible for elderly and disabled people to live independently. Home automation is becoming a viable option for the elderly and disabled who would prefer to stay in their own homes rather than move to a healthcare facility. This field uses much of the same technology and equipment as home automation for security, entertainment, and energy conservation but tailors it towards elderly and disabled users. For example, automated prompts and reminders use motion sensors and pre-recorded audio messages; an automated prompt in the kitchen may remind the resident to turn off the oven, and one by the front door may remind the resident to lock the door.
Assistive technology and innovation. Innovation is happening in assistive technology either through improvements to existing devices or the creation of new products. In the WIPO published 2021 report on Technology Trends, assistive products are grouped into either conventional or emerging technologies. Conventional assisting technology tracks innovation within well-established assistive products, whereas emerging assistive technology refers to more advanced products. These identified advanced assistive products are distinguished from the conventional ones by the use of one or more enabling technologies (for instance, artificial intelligence, Internet of things, advanced sensors, new material, Additive Manufacturing, advanced robotics, augmented and virtual reality) or by the inclusion of implantable products/components. Such emerging assistive products are either more sophisticated or more functional versions of conventional assistive products, or completely novel assistive devices. For instance, in conventional self-care assistive technology, technologies involved typically include adaptive clothing, adaptive eating devices, incontinence products, assistive products for manicure, pedicure, hair and facial care, dental care, or assistive products for sexual activities. In comparison, emerging self-care assistive technologies include health and emotion monitoring, smart diapers, smart medication dispensing and management or feeding assistant robot. Although the distinction between conventional and emerging technologies is not always clear-cut, emerging assistive technology tends to be "smarter", using AI and being more connected and interactive, and including body-integrated solutions or components.
To a great extent this « conventional » versus « emerging » classification is based on the WHO's Priority Assistive Products List and the ISO 9999 standard for assistive products for persons with disabilities, the APL delineating the absolute minimum that countries should be offering to their citizens and ISO 9999 defining those products which are already well established in the market. This "well-established status" is reflected in the patent filings between 2013 and 2017. Patent registrations for assistive technologies identified as conventional are nearly eight times larger than the ones for emerging assistive technologies. However, patent filings related to more recent emerging assistive technologies are growing almost three times as fast as those pertaining to conventional ones. Patent filings in both conventional and emerging assistive technology are highly concentrated on mobility, hearing and vision. Investment in emerging assistive technology also focuses on environment. In the conventional sector, mobility represent 54% of all patents fillings, and is an indication of increased interest in advanced mobility assistive product categories, such as advanced prosthetics, walking aids, wheelchairs, and exoskeletons.
In the past, the top patent offices for filing, and therefore perceived target markets, in assistive technology have been the U.S. and Japan. Patenting activity has, however, been declining in these two jurisdictions. At the same time, there has been a surge in patent filings in China and an increase in filings in the Republic of Korea. This pattern is observed for both conventional and emerging assistive technology, with China's annual filings surpassing those of the U.S. in 2008 for conventional and 2014 for emerging assistive technology. Patent filings related to conventional assistive technology have also declined in Europe, especially in Germany, France, the Netherlands and Norway. Patenting activity indicates the amount of interest and the investment made in respect to an invention's applicability and its commercialization potential. There is typically a lag between filing a patent application and commercialization, with a product being classified in various stages of readiness levels, research concept, proof of concept, minimum viable product and finally commercial product. According to the 2021 WIPO report, the emerging technologies closest to a fully commercial product were for example:
The technology readiness level and the related patenting activity can also be explained through the following factors which contribute to a product's entry to market, such as the expected impact on a person's participation in different aspects of life, the ease of adoption (need for training, fitting, additional equipment for interoperability, and so on), the societal acceptance and potential ethical concerns, and the need for regulatory approval. This is mainly the case for assistive technology that qualifies as medical technology. Among these aspects, acceptability and ethical considerations are particularly relevant to those technologies that are extremely invasive (such as cortical or auditory brainstem implants), or replace the human caregiver and human interaction, or collect and use data on cloud-based services or interconnected devices (e.g., companion robots, smart nursing and health-monitoring technologies), raising privacy issues and requiring connectivity, or raise safety concerns, such as autonomous wheelchairs.
Beyond the patent landscape, industrial designs have an added importance for the field of assistive technology. Assistive technology is often not adopted, or else abandoned entirely, because of issues to do with design (lack of appeal) or comfort (poor ergonomics). Design often plays a role after the patenting activity, as a product needs to be re-designed for mass production. Impacts. Overall, assistive technology aims to allow disabled people to "participate more fully in all aspects of life (home, school, and community)" and increases their opportunities for "education, social interactions, and potential for meaningful employment". It creates greater independence and control for disabled individuals. For example, in one study of 1,342 infants, toddlers and preschoolers, all with some kind of developmental, physical, sensory, or cognitive disability, the use of assistive technology created improvements in child development. These included improvements in "cognitive, social, communication, literacy, motor, adaptive, and increases in engagement in learning activities". Additionally, it has been found to lighten caregiver load. Both family and professional caregivers benefit from assistive technology. Through its use, the time that a family member or friend would need to care for a patient significantly decreases. However, studies show that care time for a professional caregiver increases when assistive technology is used. Nonetheless, their work load is significantly easier as the assistive technology frees them of having to perform certain tasks. There are several platforms that use machine learning to identify the appropriate assistive device to suggest to patients, making assistive devices more accessible.
History. In 1988 the National institute on disability and rehabilitation research, NIDRR, awarded Gaulladet University a grant for the project "Robotic finger spelling hand for communication and access to text by deaf-blind persons". Researchers at the university developed and tested a robotic hand. Although it was never commercialized the concept is relevant for current and future research. Since this grant, many others have been written. NIDRR funded research appears to be moving from the fabrication of robotic arms that can be used by disabled persons to perform daily activities, to developing robotics that assist with therapy in the hopes of achieving long-term performance gains. If there is success in development of robotics, these mass-marketed products could assist tomorrow's longer-living elderly individuals enough to postpone nursing home stays. "Jim Osborn, executive director of the Quality of Life Technology Center, told a 2007 gathering of long-term care providers that if such advances could delay all nursing home admissions by a month, societal savings could be $1 billion monthly". Shortage of both paid personal assistants and available family members makes artificial assistance a necessity. rATA Tool by World Health Organization. The rapid assistive technology assessment (rATA) is a tool developed by World Health Organization in order to undertake household surveys which can measure various parameters needed to access assistive technology and to make informed policies for governments around the world.
Abacus An abacus ( abaci or abacuses), also called a counting frame, is a hand-operated calculating tool which was used from ancient times in the ancient Near East, Europe, China, and Russia, until the adoption of the Hindu–Arabic numeral system. An abacus consists of a two-dimensional array of slidable beads (or similar objects). In their earliest designs, the beads could be loose on a flat surface or sliding in grooves. Later the beads were made to slide on rods and built into a frame, allowing faster manipulation. Each rod typically represents one digit of a multi-digit number laid out using a positional numeral system such as base ten (though some cultures used different numerical bases). Roman and East Asian abacuses use a system resembling bi-quinary coded decimal, with a top deck (containing one or two beads) representing fives and a bottom deck (containing four or five beads) representing ones. Natural numbers are normally used, but some allow simple fractional components (e.g. , , and in Roman abacus), and a decimal point can be imagined for fixed-point arithmetic.
Any particular abacus design supports multiple methods to perform calculations, including addition, subtraction, multiplication, division, and square and cube roots. The beads are first arranged to represent a number, then are manipulated to perform a mathematical operation with another number, and their final position can be read as the result (or can be used as the starting number for subsequent operations). In the ancient world, abacuses were a practical calculating tool. It was widely used in Europe as late as the 17th century, but fell out of use with the rise of decimal notation and algorismic methods. Although calculators and computers are commonly used today instead of abacuses, abacuses remain in everyday use in some countries. The abacus has an advantage of not requiring a writing implement and paper (needed for algorism) or an electric power source. Merchants, traders, and clerks in some parts of Eastern Europe, Russia, China, and Africa use abacuses. The abacus remains in common use as a scoring system in non-electronic table games. Others may use an abacus due to visual impairment that prevents the use of a calculator. The abacus is still used to teach the fundamentals of mathematics to children in many countries such as Japan and China.
Etymology. The word "abacus" dates to at least 1387 AD when a Middle English work borrowed the word from Latin that described a sandboard abacus. The Latin word is derived from ancient Greek () which means something without a base, and colloquially, any piece of rectangular material. Alternatively, without reference to ancient texts on etymology, it has been suggested that it means "a square tablet strewn with dust", or "drawing-board covered with dust (for the use of mathematics)" (the exact shape of the Latin perhaps reflects the genitive form of the Greek word, ("")). While the table strewn with dust definition is popular, some argue evidence is insufficient for that conclusion. Greek probably borrowed from a Northwest Semitic language like Phoenician, evidenced by a cognate with the Hebrew word "ʾābāq" (), or "dust" (in the post-Biblical sense "sand used as a writing surface"). Both "abacuses" and "abaci" are used as plurals. The user of an abacus is called an "abacist". History. Mesopotamia. The Sumerian abacus appeared between 2700 and 2300 BC. It held a table of successive columns which delimited the successive orders of magnitude of their sexagesimal (base 60) number system.
Some scholars point to a character in Babylonian cuneiform that may have been derived from a representation of the abacus. It is the belief of Old Babylonian scholars, such as Ettore Carruccio, that Old Babylonians "seem to have used the abacus for the operations of addition and subtraction; however, this primitive device proved difficult to use for more complex calculations". Egypt. Greek historian Herodotus mentioned the abacus in Ancient Egypt. He wrote that the Egyptians manipulated the pebbles from right to left, opposite in direction to the Greek left-to-right method. Archaeologists have found ancient disks of various sizes that are thought to have been used as counters. However, wall depictions of this instrument are yet to be discovered. Persia. At around 600 BC, Persians first began to use the abacus, during the Achaemenid Empire. Under the Parthian, Sassanian, and Iranian empires, scholars concentrated on exchanging knowledge and inventions with the countries around them – India, China, and the Roman Empire – which is how the abacus may have been exported to other countries.
Greece. The earliest archaeological evidence for the use of the Greek abacus dates to the 5th century BC. Demosthenes (384–322 BC) complained that the need to use pebbles for calculations was too difficult. A play by Alexis from the 4th century BC mentions an abacus and pebbles for accounting, and both Diogenes and Polybius use the abacus as a metaphor for human behavior, stating "that men that sometimes stood for more and sometimes for less" like the pebbles on an abacus. The Greek abacus was a table of wood or marble, pre-set with small counters in wood or metal for mathematical calculations. This Greek abacus was used in Achaemenid Persia, the Etruscan civilization, Ancient Rome, and the Western Christian world until the French Revolution. The Salamis Tablet, found on the Greek island Salamis in 1846 AD, dates to 300 BC, making it the oldest counting board discovered so far. It is a slab of white marble in length, wide, and thick, on which are 5 groups of markings. In the tablet's center is a set of 5 parallel lines equally divided by a vertical line, capped with a semicircle at the intersection of the bottom-most horizontal line and the single vertical line. Below these lines is a wide space with a horizontal crack dividing it. Below this crack is another group of eleven parallel lines, again divided into two sections by a line perpendicular to them, but with the semicircle at the top of the intersection; the third, sixth and ninth of these lines are marked with a cross where they intersect with the vertical line. Also from this time frame, the Darius Vase was unearthed in 1851. It was covered with pictures, including a "treasurer" holding a wax tablet in one hand while manipulating counters on a table with the other.
Rome. The normal method of calculation in ancient Rome, as in Greece, was by moving counters on a smooth table. Originally pebbles () were used. Marked lines indicated units, fives, tens, etc. as in the Roman numeral system. Writing in the 1st century BC, Horace refers to the wax abacus, a board covered with a thin layer of black wax on which columns and figures were inscribed using a stylus. One example of archaeological evidence of the Roman abacus, shown nearby in reconstruction, dates to the 1st century AD. It has eight long grooves containing up to five beads in each and eight shorter grooves having either one or no beads in each. The groove marked I indicates units, X tens, and so on up to millions. The beads in the shorter grooves denote fives (five units, five tens, etc.) resembling a bi-quinary coded decimal system related to the Roman numerals. The short grooves on the right may have been used for marking Roman "ounces" (i.e. fractions). Medieval Europe. The Roman system of 'counter casting' was used widely in medieval Europe, and persisted in limited use into the nineteenth century. Wealthy abacists used decorative minted counters, called jetons.
Due to Pope Sylvester II's reintroduction of the abacus with modifications, it became widely used in Europe again during the 11th century It used beads on wires, unlike the traditional Roman counting boards, which meant the abacus could be used much faster and was more easily moved. China. The earliest known written documentation of the Chinese abacus dates to the 2nd century BC. The Chinese abacus, also known as the "suanpan" (算盤/算盘, lit. "calculating tray"), comes in various lengths and widths, depending on the operator. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads each in the bottom one, to represent numbers in a bi-quinary coded decimal-like system. The beads are usually rounded and made of hardwood. The beads are counted by moving them up or down towards the beam; beads moved toward the beam are counted, while those moved away from it are not. One of the top beads is 5, while one of the bottom beads is 1. Each rod has a number under it, showing the place value. The "suanpan" can be reset to the starting position instantly by a quick movement along the horizontal axis to spin all the beads away from the horizontal beam at the center.
The prototype of the Chinese abacus appeared during the Han dynasty, and the beads are oval. The Song dynasty and earlier used the 1:4 type or four-beads abacus similar to the modern abacus including the shape of the beads commonly known as Japanese-style abacus. In the early Ming dynasty, the abacus began to appear in a 1:5 ratio. The upper deck had one bead and the bottom had five beads. In the late Ming dynasty, the abacus styles appeared in a 2:5 ratio. The upper deck had two beads, and the bottom had five. Various calculation techniques were devised for "Suanpan" enabling efficient calculations. Some schools teach students how to use it. In the long scroll "Along the River During the Qingming Festival" painted by Zhang Zeduan during the Song dynasty (960–1297), a "suanpan" is clearly visible beside an account book and doctor's prescriptions on the counter of an apothecary's (Feibao). The similarity of the Roman abacus to the Chinese one suggests that one could have inspired the other, given evidence of a trade relationship between the Roman Empire and China. However, no direct connection has been demonstrated, and the similarity of the abacuses may be coincidental, both ultimately arising from counting with five fingers per hand. Where the Roman model (like most modern Korean and Japanese) has 4 plus 1 bead per decimal place, the standard "suanpan" has 5 plus 2. Incidentally, this ancient Chinese calculation system 市用制 ("Shì yòng zhì") allows use with a hexadecimal numeral system (or any base up to 18) which is used for traditional Chinese measures of weight [("jīn" (斤) and "liǎng" (兩)]. (Instead of running on wires as in the Chinese, Korean, and Japanese models, the Roman model used grooves, presumably making arithmetic calculations much slower).
Another possible source of the "suanpan" is Chinese counting rods, which operated with a decimal system but lacked the concept of zero as a placeholder. The zero was probably introduced to the Chinese in the Tang dynasty (618–907) when travel in the Indian Ocean and the Middle East would have provided direct contact with India, allowing them to acquire the concept of zero and the decimal point from Indian merchants and mathematicians. India. The "Abhidharmakośabhāṣya" of Vasubandhu (316–396), a Sanskrit work on Buddhist philosophy, says that the second-century CE philosopher Vasumitra said that "placing a wick (Sanskrit "vartikā") on the number one ("ekāṅka") means it is a one while placing the wick on the number hundred means it is called a hundred, and on the number one thousand means it is a thousand". It is unclear exactly what this arrangement may have been. Around the 5th century, Indian clerks were already finding new ways of recording the contents of the abacus. Hindu texts used the term "śūnya" (zero) to indicate the empty column on the abacus.
Japan. In Japan, the abacus is called "soroban" (, lit. "counting tray"). It was imported from China in the 14th century. It was probably in use by the working class a century or more before the ruling class adopted it, as the class structure obstructed such changes. The 1:4 abacus, which removes the seldom-used second and fifth bead, became popular in the 1940s. Today's Japanese abacus is a 1:4 type, four-bead abacus, introduced from China in the Muromachi era. It adopts the form of the upper deck one bead and the bottom four beads. The top bead on the upper deck was equal to five and the bottom one is similar to the Chinese or Korean abacus, and the decimal number can be expressed, so the abacus is designed as a 1:4 device. The beads are always in the shape of a diamond. The quotient division is generally used instead of the division method; at the same time, in order to make the multiplication and division digits consistently use the division multiplication. Later, Japan had a 3:5 abacus called 天三算盤, which is now in the Ize Rongji collection of Shansi Village in Yamagata City. Japan also used a 2:5 type abacus.
The four-bead abacus spread, and became common around the world. Improvements to the Japanese abacus arose in various places. In China, an abacus with an aluminium frame and plastic beads has been used. The file is next to the four beads, and pressing the "clearing" button puts the upper bead in the upper position, and the lower bead in the lower position. The abacus is still manufactured in Japan, despite the proliferation, practicality, and affordability of pocket electronic calculators. The use of the soroban is still taught in Japanese primary schools as part of mathematics, primarily as an aid to faster mental calculation. Using visual imagery, one can complete a calculation as quickly as with a physical instrument. Korea. The Chinese abacus migrated from China to Korea around 1400 AD. Koreans call it "jupan" (주판), "supan" (수판) or "jusan" (주산). The four-beads abacus (1:4) was introduced during the Goryeo Dynasty. The 5:1 abacus was introduced to Korea from China during the Ming Dynasty. Native America. Some sources mention the use of an abacus called a "nepohualtzintzin" in ancient Aztec culture. This Mesoamerican abacus used a 5-digit base-20 system. The word Nepōhualtzintzin comes from Nahuatl, formed by the roots; "Ne" – personal -; "pōhual" or "pōhualli" – the account -; and "tzintzin" – small similar elements. Its complete meaning was taken as: counting with small similar elements. Its use was taught in the Calmecac to the "temalpouhqueh" , who were students dedicated to taking the accounts of skies, from childhood.
The Nepōhualtzintzin was divided into two main parts separated by a bar or intermediate cord. In the left part were four beads. Beads in the first row have unitary values (1, 2, 3, and 4), and on the right side, three beads had values of 5, 10, and 15, respectively. In order to know the value of the respective beads of the upper rows, it is enough to multiply by 20 (by each row), the value of the corresponding count in the first row. The device featured 13 rows with 7 beads, 91 in total. This was a basic number for this culture. It had a close relation to natural phenomena, the underworld, and the cycles of the heavens. One Nepōhualtzintzin (91) represented the number of days that a season of the year lasts, two Nepōhualtzitzin (182) is the number of days of the corn's cycle, from its sowing to its harvest, three Nepōhualtzintzin (273) is the number of days of a baby's gestation, and four Nepōhualtzintzin (364) completed a cycle and approximated one year. When translated into modern computer arithmetic, the Nepōhualtzintzin amounted to the rank from 10 to 18 in floating point, which precisely calculated large and small amounts, although round off was not allowed.