pH is a measure of acidity or alkalinity. PH, ph, pH, and Ph may also refer to: * Philippines (ISO country code PH), a country located in Southeast Asia

Arts and media

* PistonHeads, a motoring website and forum * PH (band), formerly known as Mr. Peter Hayden, a Finnish band * Pornhub, a pornographic video sharing website * Production house

Aviation

* Prefix for the Netherlands; see List of aircraft registration prefixes * IATA airline designator for Polynesian Airlines; see List of airline codes (P) * Transavia Denmark (IATA: PH)

Companies and organizations

Parker-Hannifin Parker Hannifin Corporation, originally Parker Appliance Company, usually referred to as just Parker, is an American corporation specializing in motion and control technologies. Its corporate headquarters are in Mayfield Heights, Ohio, in Greater ...

Corporation (stock ticker PH) * Pakatan Harapan (also known as "Alliance of Hope"), a political coalition in Malaysia

Places

* Port Harcourt, (alternative name of the city) *

Preston Hollow, Dallas Preston Hollow is a neighborhood in north Dallas, Texas, USA. It is bordered on the south by the city of University Park, Texas. History Beginning in the 1850s, the first settlers began receiving land grants for Preston Hollow’s land. Amon ...

, a neighborhood *

PH postcode area The PH postcode area, also known as the Perth postcode area, is a group of 43 postcode districts for post towns: Aberfeldy, Acharacle, Arisaig, Auchterarder, Aviemore, Ballachulish, Blairgowrie, Boat of Garten, Carrbridge, Corrour, Crieff, ...

, postcode area in Scotland

Science and technology

Chemistry

Phenyl group In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ...

, either -Ph or Φ, highly-stable and aromatic hydrocarbon unit found in many organic compounds * Pleckstrin homology domain, a part of many proteins which bind phosphoinositides with high affinity

Computing

.ph .ph is the Internet country code top-level domain (ccTLD) for the Philippines. The official domain registry of the .ph domain is dotPH Domains Inc.

, the Philippines' Internet country code top-level domain * Ph protocol, an early web database search for

CCSO Nameserver A CCSO name-server or Ph protocol was an early form of database search on the Internet. In its most common form it was used to look up information such as telephone numbers and email addresses. Today this service has been largely replaced by LDAP. ...

described by RFC 2378 *

PH (complexity) In computational complexity theory, the complexity class PH is the union of all complexity classes in the polynomial hierarchy: :\mathrm = \bigcup_ \Delta_k^\mathrm PH was first defined by Larry Stockmeyer. It is a special case of hierarchy of b ...

, the union of all complexity classes in the polynomial hierarchy in computational complexity theory

Physics

Phot A phot (ph) is a photometric unit of illuminance, or luminous flux through an area. It is not an SI unit but rather is associated with the older centimetre–gram–second system of units. The name was coined by André Blondel in 1921.Parry Moo ...

, or ph, a measurement of illuminance, in photometry * Picohenry, an SI Unit of electrical inductance

Other sciences

Planet Hunters Planet Hunters is a citizen science project to find exoplanets using human eyes. It does this by having users analyze data from the NASA Kepler space telescope and the NASA Transiting Exoplanet Survey Satellite. It was launched by a team led by D ...

, a group that hunts for exoplanets * Precipitation hardening, a heat treatment technique used to increase the yield strength of malleable materials * Pulmonary hypertension, a medical condition

Other uses

pʰ In phonetics, aspiration is the strong burst of breath that accompanies either the release or, in the case of preaspiration, the closure of some obstruents. In English, aspirated consonants are allophones in complementary distribution with th ...

, a phoneme *

Ph (digraph) This is a list of Digraph (orthography), digraphs used in various Latin alphabets. Capitalisation involves only the first letter (''ch'' becomes ''Ch'') unless otherwise stated (''ij'' becomes ''IJ''). Letters with diacritics are arranged in alp ...

, a common digraph that represents the phoneme /f/ (voiceless labiodental fricative) in phonetics * PH, abbreviation for

professional hunter A professional hunter (less frequently referred to as market or commercial hunter and regionally, especially in Britain and Ireland, as professional stalker or gamekeeper) is a person who hunts and/or manages game by profession. Some professional ...

used in East and Southern Africa * (ph), a notation used in transcripts to indicate that the transcriber does not know the spelling, usually of a name, and has spelled it as it was pronounced ( phonetically) *

Poul Henningsen Poul Henningsen (9 September 1894 – 31 January 1967) was a Danish author, critic, architect, and designer. In Denmark, where he often is referred to simply as PH, he was one of the leading figures of the cultural life of Denmark between the Worl ...

(1894–1967), a Danish writer and designer referred to as PH in Denmark *

Professional hunter A professional hunter (less frequently referred to as market or commercial hunter and regionally, especially in Britain and Ireland, as professional stalker or gamekeeper) is a person who hunts and/or manages game by profession. Some professional ...

* Public house, most commonly referred to as ''pub'', an establishment licensed to serve alcoholic drinks * Purple Heart, a US military award, in post-nominal designation *

Pinch hitter In baseball, a pinch hitter is a substitute Batting (baseball), batter. Batters can be substituted at any time while the dead ball (baseball), ball is dead (not in active play); the manager (baseball), manager may use any player who has not yet ...

, in baseball * abbreviation used to denote the English regnal years of

Philip II of Spain Philip II) in Spain, while in Portugal and his Italian kingdoms he ruled as Philip I ( pt, Filipe I). (21 May 152713 September 1598), also known as Philip the Prudent ( es, Felipe el Prudente), was King of Spain from 1556, King of Portugal from ...

* P^ḥ, abbreviation (e.g. on maps) for parish, also in the meaning of civil parish * Phillips, a type of cross-head screw drive bits