K-line may refer to:

Chemistry

K-line (spectrometry) K-line in spectrometry refers to one of two different spectral features: * The calcium K line, one of the pair of Fraunhofer lines in the violet associated with ionised calcium * The x-ray peak (K-line (x-ray)) associated with iron {{set index ...

, one of two features in spectroscopy: **

Calcium K line The Fraunhofer lines are a set of spectral absorption lines. They are dark absorption lines, seen in the optical spectrum of the Sun, and are formed when atoms in the solar atmosphere absorb light being emitted by the solar photosphere. The line ...

, a Fraunhofer spectral line from ionised calcium **

K-line (x-ray) The K-line is a spectral peak in Astronomy, astronomical spectroscopy, spectrometry used, along with the L-line (spectrometry), L-line, to observe and describe the light spectrum of stars. The K-line is associated with iron (Fe) and is described ...

, an x-ray peak in astronomical spectrometry *K line, a term used in

Internal conversion Internal conversion is an atomic decay process where an excited nucleus interacts electromagnetically with one of the orbital electrons of an atom. This causes the electron to be emitted (ejected) from the atom. Thus, in internal conversion (o ...

electron spectroscopy

Computing

* K-line (artificial intelligence) (Knowledge-line), a mental agent in artificial intelligence *

K-line (IRC) An IRCd, short for Internet Relay Chat daemon, is server software that implements the IRC protocol, enabling people to talk to each other via the Internet (exchanging textual messages in real time). It is distinct from an IRC bot that connects ou ...

, a server ban in IRC

Finance

Candlestick chart A candlestick chart (also called Japanese candlestick chart or K-line) is a style of financial chart used to describe price movements of a security, derivative, or currency. While similar in appearance to a bar chart, each candlestick represent ...

, or K-line, a style of financial chart used to describe price movements of a security, derivative, or currency

Sports

*K line, the line marking the calculation point in

ski jumping Ski jumping is a winter sport in which competitors aim to achieve the farthest jump after sliding down on their skis from a specially designed curved ramp. Along with jump length, competitor's aerial style and other factors also affect the final ...

Transportation

K (Broadway Brooklyn Local) The J Nassau Street Local and Z Nassau Street Express are two rapid transit services in the B Division of the New York City Subway. Their route emblems, or "bullets", are colored since they use the BMT Nassau Street Line in Lower Manhattan. T ...

, earlier KK, discontinued in 1976 *

K (Eighth Avenue Local) The K Eighth Avenue Local, earlier the AA, was a rapid transit service of the New York City Subway. Its route bullet was colored on station signs, car rollsigns, and the official subway map since it ran on the IND Eighth Avenue Line. The K op ...

, a defunct train service on the New York City Subway, which was known as the AA until 1985 *

K Ingleside The K Ingleside is a light rail line of the Muni Metro system in San Francisco, California. It mainly serves the West Portal and Ingleside neighborhoods. The line opened on February 3, 1918, and was the first line to use the Twin Peaks Tunnel ...

, a service of the San Francisco Municipal Railway sometimes called the K Line *

K Line (Los Angeles Metro) The K Line is a light rail line in Los Angeles County, California. It is one of six lines in the Los Angeles Metro Rail system operated by the Los Angeles County Metropolitan Transportation Authority (Metro), and is the newest named line in the ...

, a light rail line in Los Angeles County, California * K (Los Angeles Railway), defunct streetcar line in Los Angeles, California *

K Line is a Japanese transportation company. It owns a fleet that includes dry cargo ships (bulk carriers), container ships, liquefied natural gas carriers, Ro-Ro ships, tankers, and container terminals. It used to be the fourteenth largest contai ...

, a Japanese shipping company *

K-Line K-Line Electric Trains is a brand name of O gauge and S gauge model railway locomotives, rolling stock, and buildings. Formerly the brand name under which Chapel Hill, North Carolina–based MDK Inc. sold its products, K-Line was then acquired b ...

, a model railway locomotive company *

bus operator in Yorkshire, England since rebranded as Tiger Blue *

Line K (Tren Interoceánico) Line K (), also known as the Ixtepec–Ciudad Hidalgo Line, is a railroad owned by the Mexican government that connects Ixtepec, Oaxaca with Ciudad Hidalgo, Chiapas. It was leased to the Ferrocarril Chiapas-Mayab. President Andrés Manuel Lóp ...

, a planned railway service in Mexico *K-Line, part of the ISO 9141

on-board diagnostics On-board diagnostics (OBD) is a term referring to a vehicle's self-diagnostic and reporting capability. In the United States, this capability is a requirement to comply with United States vehicle emission standards, federal emissions standards ...

vehicle network interface standard {{disambiguation