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High intensity ultrasound produces chemical and physical effects that can be used for the production or modification of a wide range of nanostructured materials. The principle that causes the modification of nanostructures in the sonochemical process is acoustic cavitation .
For example, in chemical kinetics, it has been observed that ultrasound can greatly enhance chemical reactivity in a number of systems by as much as a million-fold; [15] effectively acting to activate heterogeneous catalysts. In addition, in reactions at liquid-solid interfaces, ultrasound breaks up the solid pieces and exposes active clean ...
The reaction mechanism is described as follows: . With amines, the reaction proceeds without problems to the corresponding amides because amines are more nucleophilic.If the esterification is slow, a side-reaction occurs, diminishing the final yield or complicating purification of the product.
In organic chemistry, the Baylis–Hillman, Morita–Baylis–Hillman, or MBH reaction is a carbon-carbon bond-forming reaction between an activated alkene and a carbon electrophile in the presence of a nucleophilic catalyst, such as a tertiary amine or phosphine.
Sonication can be used for the production of nanoparticles, such as nanoemulsions, [5] nanocrystals, liposomes and wax emulsions, as well as for wastewater purification, degassing, extraction of seaweed polysaccharides [1] and plant oil, extraction of anthocyanins and antioxidants, [6] production of biofuels, crude oil desulphurization, cell disruption, polymer and epoxy processing, adhesive ...
A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. [1] Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiopharmaceuticals, which emit radiation themselves.
From an ISO 4 abbreviation: This is a redirect from an ISO 4 publication title abbreviation to the unabbreviated publication title, or an article containing information about the publication.
Discussions about carbene chemistry with one of the company's most respectable consultants at the time, William von Eggers Doering, then a professor at Yale, led the young Ph.D. graduate from Northwestern University to follow a recent procedure combining both, carbenes and butadiene. [6]