Liquid nitrogen

Liquid nitrogen is nitrogen in a aqueous accompaniment at a actual low temperature. It is produced industrially by apportioned beverage of aqueous air. Aqueous nitrogen is a colourless bright aqueous with body of 0.807 g/mL at its baking point and a dielectric connected of 1.4.dead link1 Aqueous nitrogen is generally referred to by the abbreviation, LN2 or "LIN" or "LN" and has the UN cardinal 1977.

At atmospheric pressure, aqueous nitrogen boils at 77K (-196°C; -321°F) and is a cryogenic aqueous which can account accelerated freezing on acquaintance with active tissue, which may advance to frostbite. When appropriately cloistral from ambient heat, aqueous nitrogen can be stored and transported, for archetype in exhaustion flasks. Here, the actual low temperature is captivated connected at 77 K by apathetic baking of the liquid, consistent in the change of nitrogen gas. Depending on the admeasurement and design, the captivation time of exhaustion flasks ranges from a few hours to a few weeks.

Liquid nitrogen can calmly be adapted to the solid by agreement it in a exhaustion alcove pumped by a rotary exhaustion pump.2 Aqueous nitrogen freezes at 63 K (−210 °C; −346 °F). Despite its reputation, aqueous nitrogen's ability as a coolant is bound by the actuality that it boils anon on acquaintance with a warmer object, enveloping the article in careful nitrogen gas. This effect, accepted as the Leidenfrost effect, applies to any aqueous in acquaintance with an article decidedly hotter than its baking point. More accelerated cooling may be acquired by coast an article into a bribery of aqueous and solid nitrogen than into aqueous nitrogen alone.

Nitrogen was aboriginal abounding at the Jagiellonian University on 15 April 1883 by Polish physicists, Zygmunt Wróblewski and Karol Olszewski.3

LN2

Liquid nitrogen can easily be converted to the solid by placing it in a vacuum chamber pumped by a rotary vacuum pump.2 Liquid nitrogen freezes at 63 K (−210 °C; −346 °F). Despite its reputation, liquid nitrogen's efficiency as a coolant is limited by the fact that it boils immediately on contact with a warmer object, enveloping the object in insulating nitrogen gas. This effect, known as the Leidenfrost effect, applies to any liquid in contact with an object significantly hotter than its boiling point. More rapid cooling may be obtained by plunging an object into a slush of liquid and solid nitrogen than into liquid nitrogen alone.

Nitrogen was first liquefied at the Jagiellonian University on 15 April 1883 by Polish physicists, Zygmunt Wróblewski and Karol Olszewski.3

Uses

Liquid nitrogen is a bunched and readily transported antecedent of nitrogen gas after pressurization. Further, its adeptness to advance temperatures far beneath the freezing point of baptize makes it acutely advantageous in a advanced ambit of applications, primarily as an open-cycle refrigerant, including:

in cryotherapy for removing cruddy or potentially cancerous bark lesions such as warts and actinic keratosis

as a coolant for CCD cameras in astronomy

to abundance beef at low temperature for class work

in cryogenics

as a antecedent of actual dry nitrogen gas

for the captivation freezing and busline of aliment products

for the cryopreservation of blood, changeable beef (sperm and egg), and added biological samples and materials

as a adjustment of freezing baptize pipes in adjustment to assignment on them in situations area a valve is not accessible to block baptize breeze to the assignment area

in the action of promession, a way to actuate of the dead

for cooling a high-temperature superconductor to a temperature acceptable to accomplish superconductivity

for the cryonic canning in the achievement of approaching reanimation.

to bottle tissue samples from surgical excisions for approaching studies

to shrink-weld accouterment genitalia together

as a coolant for exhaustion pump accessories and in controlled-evaporation processes in chemistry.

as a coolant to access the acuteness of bittersweet homing appellant active of missiles such as the Strela 3

as a coolant to briefly compress automated apparatus during apparatus accumulation and acquiesce bigger arrest fits

as a coolant for computers4

in aliment preparation, such as for authoritative ultra-smooth ice cream.5

Safety

Since the aqueous to gas amplification arrangement of nitrogen is 1:694 at 20C, a amazing bulk of force can be generated if aqueous nitrogen is rapidly vaporized. In an adventure in 2006 at Texas A&M University, the pressure-relief accessories of a catchbasin of aqueous nitrogen were adulterated and after sealed. As a aftereffect of the consecutive burden buildup, the catchbasin bootless catastrophically and exploded. The force of the access was acceptable to actuate the catchbasin through the beam anon aloft it.6

Because of its acutely low temperature, absent-minded administration of aqueous nitrogen may aftereffect in algid burns.

As aqueous nitrogen evaporates it will abate the oxygen absorption in the air and ability act as an asphyxiant, abnormally in bedfast spaces. Nitrogen is odorless, achromatic and tasteless, and may aftermath amazement after any awareness or above-mentioned warning.7 A class abettor died in Scotland in 1999, allegedly from asphyxiation, possibly acquired by aqueous nitrogen agitated in a basement accumulator room.8

Vessels absolute aqueous nitrogen can abbreviate oxygen from air. The aqueous in such a barge becomes more accomplished in oxygen (boiling point = 90 K) as the nitrogen evaporates, and can account agitated blaze of amoebic material.citation needed