Editing Supersaturation (section)

== Applications ==
The characteristics of supersaturation have practical applications in terms of [[pharmaceuticals]]. By creating a supersaturated solution of a certain drug, it can be ingested in liquid form. The drug can be made driven into a supersaturated state through any normal mechanism and then prevented from precipitating out by adding precipitation inhibitors.<ref>{{cite journal|title = Evaluation of gastrointestinal drug supersaturation and precipitation: Strategies and issues|doi=10.1016/j.ijpharm.2012.11.026|pmid = 23194883|volume=453|issue = 1|journal=International Journal of Pharmaceutics|pages=25–35|year = 2013|last1 = Bevernage|first1 = Jan|last2 = Brouwers|first2 = Joachim|last3 = Brewster|first3 = Marcus E.|last4 = Augustijns|first4 = Patrick}}</ref> Drugs in this state are referred to as "supersaturating drug delivery services," or "SDDS."<ref>{{Cite journal|title = Supersaturating drug delivery systems: the answer to solubility-limited oral bioavailability?|journal = Journal of Pharmaceutical Sciences|date = Aug 2009|issn = 1520-6017|pmid = 19373886|pages = 2549–2572|volume = 98|issue = 8|doi = 10.1002/jps.21650|first1 = Joachim|last1 = Brouwers|first2 = Marcus E.|last2 = Brewster|first3 = Patrick|last3 = Augustijns}}</ref> Oral consumption of a drug in this form is simple and allows for the measurement of very precise dosages. Primarily, it provides a means for drugs with very low solubility to be made into [[aqueous solutions]].<ref>{{Cite journal|title = Supersaturating drug delivery systems: Fast is not necessarily good enough|last= Augustijns |date= 2011 |journal= Journal of Pharmaceutical Sciences |volume= 101 |issue= 1 |pages= 7–9 |doi= 10.1002/jps.22750 |pmid= 21953470 }}</ref><ref>"Gas Dissolving Method" [https://patents.google.com/patent/CA1320934C/en CA Patent 1320934] - Fitzpatrick, Nicholas; John Kuzniarski (3 August 1993) Retrieved 2009-11-15</ref> In addition, some drugs can undergo supersaturation inside the body despite being ingested in a crystalline form.<ref>{{Cite journal|last1=Hsieh|first1=Yi-Ling|last2=Ilevbare|first2=Grace A.|last3=Van Eerdenbrugh|first3=Bernard|last4=Box|first4=Karl J.|last5=Sanchez-Felix|first5=Manuel Vincente|last6=Taylor|first6=Lynne S.|date=2012-05-12|title=pH-Induced Precipitation Behavior of Weakly Basic Compounds: Determination of Extent and Duration of Supersaturation Using Potentiometric Titration and Correlation to Solid State Properties|journal=Pharmaceutical Research|language=en|volume=29|issue=10|pages=2738–2753|doi=10.1007/s11095-012-0759-8|pmid=22580905|s2cid=15502736|issn=0724-8741}}</ref> This phenomenon is known as [[in vivo supersaturation]].

The identification of supersaturated solutions can be used as a tool for marine ecologists to study the activity of organisms and populations. Photosynthetic organisms release [[O₂|O<sub>2</sub>]] gas into the water. Thus, an area of the ocean supersaturated with O<sub>2</sub> gas can likely determined to be rich with photosynthetic activity. Though some O<sub>2</sub> will naturally be found in the ocean due to simple physical chemical properties, upwards of 70% of all oxygen gas found in supersaturated regions can be attributed to photosynthetic activity.<ref>{{Cite journal|title = Oxygen supersaturation in the ocean: biological versus physical contributions|journal = Science|date = Jan 9, 1987|issn = 0036-8075|pmid = 17778634|pages = 199–202|volume = 235|issue = 4785|doi = 10.1126/science.235.4785.199|first1 = H.|last1 = Craig|first2 = T.|last2 = Hayward|bibcode = 1987Sci...235..199C |s2cid = 40425548}}</ref>

Supersaturation in vapor phase is usually present in the expansion process through steam [[nozzle]]s that operate with [[superheated steam]] at the inlet, which transitions to saturated state at the outlet. Supersaturation thus becomes an important factor to be taken into account in the design of [[steam turbine]]s, as this results in an actual mass flow of steam through the nozzle being about 1 to 3% greater than the theoretically calculated value that would be expected if the expanding steam underwent a reversible adiabatic process through equilibrium states. In these cases supersaturation occurs due to the fact that the expansion process develops so rapidly and in such a short time, that the expanding vapor cannot reach its equilibrium state in the process, behaving as if it were [[Superheated steam|superheated]]. Hence the determination of the expansion ratio, relevant to the calculation of the mass flow through the nozzle, must be done using an [[Heat capacity ratio|adiabatic index]] of approximately 1.3, like that of the superheated steam, instead of 1.135, which is the value that should have to be used for a quasi-static adiabatic expansion in the saturated region.<ref>William Johnston Kearton (1931),''Steam Turbine Theory and Practice – A Textbook for Engineering Students'' - Pitman, New York, Chicago. Chapter V, "The flow of steam through nozzles", pages 90 to 99</ref>

The study of supersaturation is also relevant to atmospheric studies. Since the 1940s, the presence of supersaturation in the [[atmosphere]] has been known. When water is supersaturated in the [[troposphere]], the formation of ice lattices is frequently observed. In a state of saturation, the water particles will not form ice under tropospheric conditions. It is not enough for molecules of water to form an ice lattice at saturation pressures; they require a surface to condense on to or conglomerations of liquid water molecules of water to freeze. For these reasons, relative humidities over ice in the atmosphere can be found above 100%, meaning supersaturation has occurred. Supersaturation of water is actually very common in the upper troposphere, occurring between 20% and 40% of the time.<ref>{{Cite journal|title =The global impact of supersaturation in a coupled chemistry-climate model |journal = Atmospheric Chemistry and Physics |volume = 7|issue = 6|pages = 1629–1643|first1=A.|last1= Gettelman |first2= D. E.|last2=Kinnison|doi=10.5194/acp-7-1629-2007|year = 2007|bibcode = 2007ACP.....7.1629G |url = https://hal.archives-ouvertes.fr/hal-00296181/file/acp-7-1629-2007.pdf|doi-access = free}}</ref> This can be determined using satellite data from the [[Atmospheric Infrared Sounder]].<ref>{{Cite journal|title = The Global Distribution of Supersaturation in the Upper Troposphere from the Atmospheric Infrared Sounder|journal = Journal of Climate|volume = 19|issue = 23|pages = 6089|doi = 10.1175/JCLI3955.1|bibcode = 2006JCli...19.6089G|last1 = Gettelman|first1 = Andrew|last2 = Fetzer|first2 = Eric J.|last3 = Eldering|first3 = Annmarie|last4 = Irion|first4 = Fredrick W.|year = 2006|url = https://zenodo.org/record/1234595|doi-access = free}}</ref>