A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top, usually with a rounded U-shaped bottom.
A large test tube specifically for boiling liquids is called a boiling tube.
Test tubes are available in a multitude of lengths and widths, typically from 10 to 20 mm wide and 50 to 200 mm long. The top often features a flared lip to aid pouring out the contents; some sources consider that the presence of a lip is what distinguishes a test tube from a culture tube. A test tube has either a flat bottom, a round bottom, or a conical bottom. Some test tubes are made to accept a ground glass stopper or a screw cap. They are often provided with a small ground glass or white glaze area near the top for labelling with a pencil.
Test tubes are widely used by chemists to hold, mix, or heat small quantities of solid or liquid chemicals, especially for qualitative experiments and assays. Their round bottom and straight sides minimize mass loss when pouring, make them easier to clean, and allow convenient monitoring of the contents. The long, narrow neck slows down the spreading of vapours and gases to the environment.
The name test is reserved by the Internet Engineering Task Force (IETF) in RFC 2606 (June 1999) as a domain name that is not intended to be installed as a top-level domain (TLD) in the global Domain Name System (DNS) of the Internet for production use.
In 1999, the Internet Engineering Task Force reserved the DNS labels example, invalid, localhost, and test so that they may not be installed into the root zone of the Domain Name System.
The reason for reservation of these top-level domain names is to reduce the likelihood of conflict and confusion. This allows the use of these names for either documentation purposes or in local testing scenarios.
As of 2015, IANA distinguishes the following groups of top-level domains:
Test, TEST or Tester may refer to:
Test is a free jazz cooperative.
Tube, or Tubes, may refer to:
Tube (チューブ chūbu) is a Japanese pop rock band formed in 1985. The members of the group are Nobuteru Maeda (前田亘輝), Michiya Haruhata (春畑道哉) Hideyuki Kakuno (角野秀行) and Ryoji Matsumoto (松本玲二). Tube members Maeda and Haruhata have composed for other artists under the Pipeline Project alias. Since the group released most of its songs in April to July, the catchphrase originated "Summer comes with Tube".
Tube (Hangul: 튜브; RR: Tubeu) is a 2003 South Korean action thriller film directed by Beak Woon-hak (or Baek Woon-hak). The film features police officer Jay (Kim Suk-hoon) who is a subway police officer who spends his days reminiscing over his lost lover. The pickpocket Kay (Bae Doona) becomes infatuated with Jay and tips him off about the government assassin Bishop (Park Sang-min) hijacking a subway car. Both Jay and Kay find themselves in the target car when the Bishop makes his move.
Detective Jang Do-joon (Kim Suk-hoon) who does not know the meaning of giving up, is hot on the trail of Kang Gi-taek, a deadly terrorist. Kang Gi-taek (Park Sang-min) was an elite secret agent for the government's intelligence agency before getting tossed out for assassinating a key figure.
On the day of the new mayor's official visit to the subway, Kang Gi-taek hijacks the train and begins a full-scale act of terror. Pickpocket girl Song Yin-gyung (Bae Doona), who senses what is going on, quickly contacts Detective Jang Do-joon. The greatest act of terrorism in history, with the lives of 13 million citizens held hostage—the showdown begins between an out-of-control terrorist and a determined detective who is on the verge of life and death.