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Absorption is a condition in which something takes in another substance. [1] In many processes important in technology, the chemical absorption is used in place of the physical process, e.g., absorption of carbon dioxide by sodium hydroxide – such acid-base processes do not follow the Nernst partition law (see: solubility).
An ore extraction process broken into its constituent unit operations (Quincy Mine, Hancock, MI ca. 1900) In chemical engineering and related fields, a unit operation is a basic step in a process. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization ...
The phrase is commonly used in engineering for physical processes that involve diffusive and convective transport of chemical species within physical systems. Some common examples of mass transfer processes are the evaporation of water from a pond to the atmosphere , the purification of blood in the kidneys and liver , and the distillation of ...
Gas–liquid absorption (a) and liquid–solid adsorption (b) mechanism. Blue spheres are solute molecules. Sorption is a physical and chemical process by which one substance becomes attached to another. Specific cases of sorption are treated in the following articles: Absorption
Adsorption is present in many natural, physical, biological and chemical systems and is widely used in industrial applications such as heterogeneous catalysts, [9] [10] activated charcoal, capturing and using waste heat to provide cold water for air conditioning and other process requirements (adsorption chillers), synthetic resins, increasing ...
Some of the most common examples of transport analysis in engineering are seen in the fields of process, chemical, biological, [1] and mechanical engineering, but the subject is a fundamental component of the curriculum in all disciplines involved in any way with fluid mechanics, heat transfer, and mass transfer.
Two-photon absorption can be measured by several techniques. Some of them are two-photon excited fluorescence (TPEF), [10] z-scan, self-diffraction [11] or nonlinear transmission (NLT). Pulsed lasers are most often used because two-photon absorption is a third-order nonlinear optical process, [12] and therefore is most efficient at very high ...
Photoexcitation is the first step in a photochemical process where the reactant is elevated to a state of higher energy, an excited state.The first law of photochemistry, known as the Grotthuss–Draper law (for chemists Theodor Grotthuss and John W. Draper), states that light must be absorbed by a chemical substance in order for a photochemical reaction to take place.