LIQUEFACTION: CONCEPT, GAS, SOIL AND SEISMIC, SEMINAL - CHEMISTRY - 2024

The Liquefaction is a process of state change from a solid to liquid or gas to liquid (condensation). There are a series of processes in which the term liquefaction is used to describe disjointed situations, but which have in common the generation of entities that behave like liquids.

The phrase soil liquefaction is used to name the transformation that a soil undergoes, under the action of a seismic shock, which transforms it into a structure with liquid characteristics.

Liquefaction from a culinary point of view is appreciated every time a blender is used. Source: Amy Stephenson via Flickr (https://www.flickr.com/photos//4829135138)

Tissue liquefaction or liquefactive necrosis is a condition in which cell or tissue death occurs due to a bacterial or fungal infection, or ischemia, which produces cell destruction by the action of the enzymes of the infecting agents, as well as those of leukocytes

The destructive action that acts on cells causes the transformation of their solid form into a viscous liquid mass. In medicine, semen liquefaction is also discussed.

Likewise, there is talk of the liquefaction of coal to produce fuels or of the liquefaction of gases to facilitate their use in numerous applications; such as that of liquid oxygen, used in medicine in assisted respiration.

Liquefaction concept

What is understood by liquefaction depends on the phenomenon that is being observed. However, they all converge on one point: obtaining a liquid material, be it viscous or not.

The blender, for example, generates a mixture from solid ingredients that tends to resemble a paste or liquid. The ingredients (of whatever recipe) are said to have been blended.

It may not take severe revolutions to liquefy other substances, solids or gases, but rather the use of high pressure or lowering the temperature; or perhaps, the participation of enzymes or microorganisms.

In chemistry, liquefaction is the compression of a gas until it is condensed; in other words, it condenses by applying high pressures assisted by a drop in temperature. However, the same term is used in other areas where a solid or viscous body gains fluidity, regardless of the nature of the process.

Gas liquefaction

Methods

It is the process of transformation of a gas to the liquid phase. Gas liquefaction methods can be summarized in three:

-Compression of the gas at temperatures below its critical temperature

-Making the gas work against an external force. This produces a loss of energy and the change from the gaseous state to the liquid state

-Making the gas work against its own internal forces, which results in loss of energy and liquefaction

Many gases go into a liquid state by cooling to normal atmospheric pressure. Gases such as nitrogen, oxygen and methane require the use of very low temperatures to liquefy and store them. Other gases require high pressures for their liquefaction.

Ammonia and carbon dioxide

Ammonia gas has a critical temperature of 133ºC. To turn it into a liquid, a pressure of 112.5 atmospheres must be supplied to it. Meanwhile, carbon dioxide has a critical temperature of 30.98 ºC and a critical pressure of 73 atm to produce its liquefaction.

Air

Air liquefaction is a way to obtain nitrogen, oxygen, argon, and other gases, by subjecting liquid air to fractional distillation in a cryogenic air separation unit. Even some noble gases, such as krypton (Kr), were discovered by a similar method.

The conversion of gases to their liquid form favors their storage and use. In this way, the administration of oxygen to patients who require it and the use of nitrogen in cryogenic surgery, in the preservation of biological samples and in the maintenance of viable sperm are facilitated.

Soil liquefaction and seismic

Due to liquefaction this culvert rose above the ground. Source: No machine-readable author provided. Tubbi assumed (based on copyright claims).

Liquefaction is a decrease in the resistance or rigidity of a soil due to the action of a seismic phenomenon. This phenomenon occurs in soils saturated with water, in which there are pores filled with water between the soil particles. Water exerts relatively low pressure on soil particles.

But in the presence of a seismic shock, the pressure exerted by the water on the soil particles increases, which can cause them to separate and decrease their cohesion. This produces the transformation of the characteristics of the soil that acquires the form of a muddy liquid.

The seismic impact is the main cause of the liquefaction of soils, with fine particles being the most susceptible; such as sandy, silty and gravel soils. As a consequence, they behave like a viscous liquid.

The ground then easily deforms and loses its ability to support building foundations, and buildings on these floors tilt and may collapse.

Seminal liquefaction

Liquefaction occurs when clots formed by proteins break down and semen becomes less viscous. This process occurs within 20 minutes after ejaculation, changing semen from a thick, viscous gel to a liquid.

The determination of the semen liquefaction time is part of the spermogram: a set of tests carried out to analyze the fertility of the man. A liquefaction time within 60 minutes after ejaculation is considered within normal limits.

The semen coagulates almost immediately after ejaculation, to liquefy 5 to 40 minutes after it, by the action of a prostate-specific antigen. In some cases the liquefaction of the semen is not completed at the time of ejaculation.

Liquefaction in medicine

Tissue liquefaction is one of the causes of necrosis. This being understood as the degeneration of a tissue due to the death of its cells. The following are forms of necrosis: coagulative, fatty, gangrenous, caseous, and liquefactive or tissue liquefaction.

Tissue liquefaction

Liquefactive necrosis

Liquefactive necrosis is present in bacterial or fungal infections. The affected cells are completely digested by the hydrolytic enzymes and are transformed into a viscous liquid mass, with the presence of a yellowish pus due to the dead leukocytes and the remains of the necrotic tissue.

After removal of cell debris by white blood cells, a liquid space is formed. Liquefaction is a consequence of bacterial enzymes and lysosome hydrolase enzymes.

Brain liquefactive necrosis also occurs, but it is not the result of a bacterial infection. Rather, it is caused by an ischemic or hypoxic episode that causes tissue damage, with the release of lysosomal enzymes capable of destroying necrotic cells, thus producing liquefaction.

The affected area is soft with a liquefied center. Subsequently, a cystic space is formed that contains necrotic cell debris and macrophages with phagocytosed material.

Lungs

In the lungs, tissue liquefaction associated with the presence of abscesses is observed. In tuberculosis patients, white, cheese-like areas affected by liquefaction can be observed.

Digestive enzymes

In liquefactive necrosis, enzymatic digestion of necrotic tissue can be observed, as well as enzymatic digestion of surrounding tissues and protein denaturation. All this is a consequence of the presence of digestive enzymes in infective agents.

These enzymes can trigger an inflammatory process that facilitates cellular digestion, caused by the action of infective organisms and enzymes released by necrotic cells and leukocytes.

References

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3. Byjus. (sf). Liquefaction of gases. Recovered from: byjus.com
4. Wikipedia. (2019). Liquefaction of gases. Recovered from: en.wikipedia.org
5. Toro Montoya AI (2009). Spermogram.. Recovered from: medigraphic.com