.ir is the Internet country code top-level domain (ccTLD) for Iran. It is managed by the Institute for Research in Fundamental Sciences.

TLD typeCountry code top-level domain
RegistryInstitute for Research in Fundamental Sciences
Intended useEntities connected with  Iran
Actual usePopular in Iran
Registration restrictionsGenerally open for Iranians and non-Iranians; 3rd-level registrations under subdomains have varied restrictions and are restricted to Iranian-related entities
StructureMay register at second level or at third level beneath generic-category 2nd level domains
Dispute policiesIRNIC Dispute Resolution Policy
Registry Websitenic.ir

Second-level domains

  • .ir – public
  • .ac.ir – academic (tertiary education and research establishments) and learned societies.
  • .co.ir – commercial/companies
  • .gov.ir – government (Islamic Republic of Iran)
  • .id.ir – personal, everyone has a National Number from Islamic Republic of Iran
  • .net.ir – ISPs and network companies approved by IRTCT
  • .org.ir – non-profit organisations
  • .sch.ir – schools, primary and secondary education

Persian domains

Persian internationalized domain names are available for registration under .ایران.ir for public, in the Perso-Arabic script.[1]

In 2010, ICANN approved IRNIC's proposal for the ایران. IDN ccTLD (representing the Perso-Arabic spelling of Iran), pending the final step of String Delegation.[2]

Domain hacks

The URL "ryana.ir" is a redirect to the budget airline website ryanair.com. It is used as a typing shortcut. Some internet users may mistakenly believe that .ir is the ccTLD for the Republic of Ireland, the home country of Ryanair (which is actually .ie).

The URL "renmark.ir" is a redirect to the Investor Relations firm Renmark Financial Communications Inc. The .ir in this instance would stand for Investor Relations.


  • .dnssec.ir – limited term testbed for DNSSEC support


  1. ^ "Internationalized Domain Names at IRNIC". Archived from the original on 13 January 2009. Retrieved 19 January 2009.
  2. ^ "IDN ccTLD Request From the Islamic Republic of Iran Successfully Passes String Evaluation". ICANN.org. ICANN. 2010-10-15. Retrieved 2013-10-26.

External links

ASMO 449

ASMO 449 is a 7-bit coded character set to encode the Arabic language.


ISO/IEC 646 is the name of a set of ISO standards, described as Information technology — ISO 7-bit coded character set for information interchange and developed in cooperation with ASCII at least since 1964. Since its first edition in 1967 it has specified a 7-bit character code from which several national standards are derived.

ISO/IEC 646 was also ratified by ECMA as ECMA-6. The first version of ECMA-6 had been published in 1965, based on work the ECMA's Technical Committee TC1 had carried out since December 1960.Characters in the ISO/IEC 646 Basic Character Set are invariant characters. Since that portion of ISO/IEC 646, that is the invariant character set shared by all countries, specified only those letters used in the ISO basic Latin alphabet, countries using additional letters needed to create national variants of ISO 646 to be able to use their native scripts. Since transmission and storage of 8-bit codes was not standard at the time, the national characters had to be made to fit within the constraints of 7 bits, meaning that some characters that appear in ASCII do not appear in other national variants of ISO 646.

ISO/IEC 8859-1

ISO/IEC 8859-1:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 1: Latin alphabet No. 1, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1987. ISO 8859-1 encodes what it refers to as "Latin alphabet no. 1," consisting of 191 characters from the Latin script. This character-encoding scheme is used throughout the Americas, Western Europe, Oceania, and much of Africa. It is also commonly used in most standard romanizations of East-Asian languages. It is the basis for most popular 8-bit character sets and the first block of characters in Unicode.

ISO-8859-1 is (according to the standards at least) the default encoding of documents delivered via HTTP with a MIME type beginning with "text/" (HTML5 changed this to Windows-1252). As of April 2019, 3.3% of all web sites claim to use ISO 8859-1. However, this includes an unknown number of pages actually using Windows-1252 and/or UTF-8, both of which are commonly recognized by browsers despite the character set tag.

It is the default encoding of the values of certain descriptive HTTP headers, and defines the repertoire of characters allowed in HTML 3.2 documents (HTML 4.0 uses Unicode), and is specified by many other standards. This and similar sets are often assumed to be the encoding of 8-bit text on Unix and Microsoft Windows if there is no byte order mark (BOM), this is only gradually being changed to UTF-8.

ISO-8859-1 is the IANA preferred name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429. The following other aliases are registered: iso-ir-100, csISOLatin1, latin1, l1, IBM819. Code page 28591 a.k.a. Windows-28591 is used for it in Windows. IBM calls it code page 819 or CP819. Oracle calls it WE8ISO8859P1.

ISO/IEC 8859-10

ISO/IEC 8859-10:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 10: Latin alphabet No. 6, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1992. It is informally referred to as Latin-6. It was designed to cover the Nordic languages, deemed of more use for them than ISO 8859-4.

ISO-8859-10 is the IANA preferred charset name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429. Microsoft has assigned code page 28600 a.k.a. Windows-28600 to ISO-8859-10 in Windows. IBM has assigned Code page 919 to ISO-8859-10.

ISO/IEC 8859-13

ISO/IEC 8859-13:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 13: Latin alphabet No. 7, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1998. It is informally referred to as Latin-7 or Baltic Rim. It was designed to cover the Baltic languages, and added characters used in the Polish language missing from the earlier encodings ISO 8859-4 and ISO 8859-10. Unlike these two, it does not cover the Nordic languages.

ISO-8859-13 is the IANA preferred charset name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429.

Microsoft has assigned code page 28603 a.k.a. Windows-28603 to ISO-8859-13. IBM has assigned Code page 921 to ISO-8859-13. ISO-IR 206 replaces the currency sign at position A4 with the Euro Sign (€).

ISO/IEC 8859-14

ISO/IEC 8859-14:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 14: Latin alphabet No. 8 (Celtic), is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1998. It is informally referred to as Latin-8 or Celtic. It was designed to cover the Celtic languages, such as Irish, Manx, Scottish Gaelic, Welsh, Cornish, and Breton.

ISO-8859-14 is the IANA preferred charset name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429. CeltScript made an extension for Windows called Extended Latin-8. Microsoft has assigned code page 28604 a.k.a. Windows-28604 to ISO-8859-14.

ISO/IEC 8859-4

ISO/IEC 8859-4:1998, Information technology — 8-bit single-byte coded graphic character sets — Part 4: Latin alphabet No. 4, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1988. It is informally referred to as Latin-4 or North European. It was designed to cover Estonian, Latvian, Lithuanian, Greenlandic, and Sami. It has been largely superseded by ISO/IEC 8859-10 and Unicode. Microsoft has assigned code page 28594 a.k.a. Windows-28594 to ISO-8859-4 in Windows. IBM has assigned code page 914 to ISO 8859-4.

ISO-8859-4 is the IANA preferred charset name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429. ISO-IR 205 replaces the Currency Sign at 0xA4 with the Euro Sign.

ISO/IEC 8859-5

ISO/IEC 8859-5:1999, Information technology — 8-bit single-byte coded graphic character sets — Part 5: Latin/Cyrillic alphabet, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1988. It is informally referred to as Latin/Cyrillic. It was designed to cover languages using a Cyrillic alphabet such as Bulgarian, Belarusian, Russian, Serbian and Macedonian but was never widely used. It would also have been usable for Ukrainian in the Soviet Union from 1933–1990, but it is missing the Ukrainian letter ge, ґ, which is required in Ukrainian orthography before and since, and during that period outside Soviet Ukraine. As a result, IBM created Code page 1124.

ISO-8859-5 is the IANA preferred charset name for this standard when supplemented with the C0 and C1 control codes from ISO/IEC 6429.

The 8-bit encodings KOI8-R and KOI8-U, CP866, and also Windows-1251 are far more commonly used. Another possible way to represent Cyrillic is Unicode. In contrast to Windows-1252 and ISO 8859-1, Windows-1251 is not closely related to ISO 8859-5. The Windows code page for ISO-8859-5 is code page 28595 a.k.a. Windows-28595.

ISO/IEC 8859-7

ISO/IEC 8859-7:2003, Information technology — 8-bit single-byte coded graphic character sets — Part 7: Latin/Greek alphabet, is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1987. It is informally referred to as Latin/Greek. It was designed to cover the modern Greek language. The original 1987 version of the standard had the same character assignments as the Greek national standard ELOT 928, published in 1986. The table in this article shows the updated 2003 version which adds three characters (0xA4: euro sign U+20AC, 0xA5: drachma sign U+20AF, 0xAA: Greek Ypogegrammeni U+037A). Microsoft has assigned code page 28597 a.k.a. Windows-28597 to ISO-8859-7 in Windows. IBM has assigned code page 813 to ISO 8859-7.

ISO-8859-7 is the IANA preferred charset name for this standard (formally the 1987 version, but in practice there is no problem using it for the current version, as the changes are pure additions to previously unassigned codes) when supplemented with the C0 and C1 control codes from ISO/IEC 6429.

Unicode is preferred for Greek in modern applications, especially as UTF-8 encoding on the Internet. Unicode provides many more glyphs for complete coverage, see Greek alphabet in Unicode and Ancient Greek Musical Notation for tables.

ISO 2033

ISO 2033 is character set developed by ISO to used for OCR.

ISO 5426

ISO 5426 is character set developed by ISO. It was first published in 1983.

Indian Railways

Indian Railways (IR) is India's national railway system operated by the Ministry of Railways. It manages the fourth largest railway network in the world by size, with 67,368-kilometre (41,861 mi) route.. Routes are electrified with 25 kV AC electric traction while thirty three percent of them are double or multi-tracked.Indian Railway (IR) runs more than 20,000 passenger trains daily, on both long-distance and suburban routes, from 7,349 stations across India. The trains have a five-digit numbering system. Mail or express trains, the most common types, run at an average speed of 50.6 kilometres per hour (31.4 mph). In the freight segment, IR runs more than 9,200 trains daily. The average speed of freight trains is around 24 kilometres per hour (15 mph).As of March 2017, IR's rolling stock consisted of 277,987 freight wagons, 70,937 passenger coaches and 11,452 locomotives. IR owns locomotive and coach-production facilities at several locations in India. The world's eighth-largest employer, it had 1.308 million employees as of March 2017.In the year ending March 2018, IR carried 8.26 billion passengers and transported 1.16 billion tonnes of freight. In the fiscal year 2017–18, IR is projected to have revenue of ₹1.874 trillion (US$26 billion), consisting of ₹1.175 trillion (US$16 billion) in freight revenue and ₹501.25 billion (US$7.0 billion) in passenger revenue, with an operating ratio of 96.0 percent.

Information retrieval

Information retrieval (IR) is the activity of obtaining information system resources relevant to an information need from a collection. Searches can be based on full-text or other content-based indexing. Information retrieval is the science of searching for information in a document, searching for documents themselves, and also searching for metadata that describe data, and for databases of texts, images or sounds.

Automated information retrieval systems are used to reduce what has been called information overload. An IR system is a software that provide access to books, journals and other documents, stores them and manages the document. Web search engines are the most visible IR applications.


Infrared radiation (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye, although IR at wavelengths up to 1050 nanometers (nm)s from specially pulsed lasers can be seen by humans under certain conditions. IR wavelengths extend from the nominal red edge of the visible spectrum at 700 nanometers (frequency 430 THz), to 1 millimeter (300 GHz). Most of the thermal radiation emitted by objects near room temperature is infrared. As with all EMR, IR carries radiant energy and behaves both like a wave and like its quantum particle, the photon.

Infrared radiation was discovered in 1800 by astronomer Sir William Herschel, who discovered a type of invisible radiation in the spectrum lower in energy than red light, by means of its effect on a thermometer. Slightly more than half of the total energy from the Sun was eventually found to arrive on Earth in the form of infrared. The balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate.

Infrared radiation is emitted or absorbed by molecules when they change their rotational-vibrational movements. It excites vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states for molecules of the proper symmetry. Infrared spectroscopy examines absorption and transmission of photons in the infrared range.Infrared radiation is used in industrial, scientific, military,

law enforcement, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space such as molecular clouds, detect objects such as planets, and to view highly red-shifted objects from the early days of the universe. Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatus.

Extensive uses for military and civilian applications include target acquisition, surveillance, night vision, homing, and tracking. Humans at normal body temperature radiate chiefly at wavelengths around 10 μm (micrometers). Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, detection of grow-ops, remote temperature sensing, short-range wireless communication, spectroscopy, and weather forecasting.

Infrared spectroscopy

Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) involves the interaction of infrared radiation with matter. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic techniques, it can be used to identify and study chemicals. Samples may be solid, liquid, or gas. The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) to produce an infrared spectrum. An IR spectrum can be visualized in a graph of infrared light absorbance (or transmittance) on the vertical axis vs. frequency or wavelength on the horizontal axis. Typical units of frequency used in IR spectra are reciprocal centimeters (sometimes called wave numbers), with the symbol cm−1. Units of IR wavelength are commonly given in micrometers (formerly called "microns"), symbol μm, which are related to wave numbers in a reciprocal way. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer. Two-dimensional IR is also possible as discussed below.

The infrared portion of the electromagnetic spectrum is usually divided into three regions; the near-, mid- and far- infrared, named for their relation to the visible spectrum. The higher-energy near-IR, approximately 14000–4000 cm−1 (0.7–2.5 μm wavelength) can excite overtone or harmonic vibrations. The mid-infrared, approximately 4000–400 cm−1 (2.5–25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The far-infrared, approximately 400–10 cm−1 (25–1000 μm), lying adjacent to the microwave region, has low energy and may be used for rotational spectroscopy. The names and classifications of these subregions are conventions, and are only loosely based on the relative molecular or electromagnetic properties.


Iridium is a chemical element with symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is the second-densest metal (after osmium) with a density of 22.56 g/cm3 as defined by experimental X-ray crystallography. At room temperature and standard atmospheric pressure, iridium has a density of 22.65 g/cm3, 0.04 g/cm3 higher than osmium measured the same way. It is the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable.

Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named iridium for the Greek goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the rarest elements in Earth's crust, with annual production and consumption of only three tonnes. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant.

The most important iridium compounds in use are the salts and acids it forms with chlorine, though iridium also forms a number of organometallic compounds used in industrial catalysis, and in research. Iridium metal is employed when high corrosion resistance at high temperatures is needed, as in high-performance spark plugs, crucibles for recrystallization of semiconductors at high temperatures, and electrodes for the production of chlorine in the chloralkali process. Iridium radioisotopes are used in some radioisotope thermoelectric generators.

Iridium is found in meteorites in much higher abundance than in the Earth's crust. For this reason, the unusually high abundance of iridium in the clay layer at the Cretaceous–Paleogene boundary gave rise to the Alvarez hypothesis that the impact of a massive extraterrestrial object caused the extinction of dinosaurs and many other species 66 million years ago. Similarly, an iridium anomaly in core samples from the Pacific Ocean suggested the Eltanin impact of about 2.5 million years ago.

It is thought that the total amount of iridium in the planet Earth is much higher than that observed in crustal rocks, but as with other platinum-group metals, the high density and tendency of iridium to bond with iron caused most iridium to descend below the crust when the planet was young and still molten.

Manx language

Manx (native name Gaelg or Gailck, pronounced [ɡilɡ] or [ɡilk] or [ɡeːlɡ]), also known as Manx Gaelic, and also historically spelled Manks, is a is a member of the Goidelic (Gaelic) language branch of the Celtic languages of the Indo-European language family, that was spoken as a first language by the Manx people on the Isle of Man until the death of the last native speaker, Ned Maddrell, in 1974. Despite this, the language has never fallen completely out of use, with a minority having some knowledge of it; in addition, Manx still has a role as an important part of the island's culture and heritage. Manx has been the subject of language revival efforts with estimates, in 2015, of around 1,800 people with varying levels of second language conversational ability. Since the late 20th century, Manx has become more visible on the island, with increased signage, radio broadcasts and a bilingual primary school. The revival of Manx has been made easier because the language was well-recorded; for example, the Bible had been translated into Manx, and audio recordings had been made of native speakers.

Ohm's law

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:

where I is the current through the conductor in units of amperes, V is the voltage measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current. Ohm's law is an empirical relation which accurately describes the conductivity of the vast majority of electrically conductive materials over many orders of magnitude of current. However some materials do not obey Ohm's law, these are called non-ohmic.

The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. Ohm explained his experimental results by a slightly more complex equation than the modern form above (see History).

In physics, the term Ohm's law is also used to refer to various generalizations of the law; for example the vector form of the law used in electromagnetics and material science:

where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ (sigma) is a material-dependent parameter called the conductivity. This reformulation of Ohm's law is due to Gustav Kirchhoff.


Roku players, branded simply as Roku ( ROH-koo), are a series of online media players manufactured by Roku, Inc. Roku partners provide over-the-top content in the form of channels. The name comes from the Japanese word 六 (roku) meaning "six" and was named so because it was the sixth company that Anthony Wood (founder and CEO since 2002) started. A Roku streaming device receives data (the video stream) via a wired or Wi-Fi connection from an Internet router. The data is output via an audio cable, video cable, or an HDMI connector directly on some of the device models.

Programming and content for the devices are available from a wide variety of global providers.

Thermographic camera

A thermographic camera (also called an infrared camera or thermal imaging camera or infrared thermography) is a device that forms a heat zone image using infrared radiation, similar to a common camera that forms an image using visible light. Instead of the 400–700 nanometre range of the visible light camera, infrared cameras operate in wavelengths as long as 14,000 nm (14 µm). Their use is called thermography.

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