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In chemistry, quenching refers to any process which decreases the fluorescent intensity of a given substance. A variety of processes can result in quenching, such as excited state reactions, energy transfer, complex-formation and collisions. As a consequence, quenching is often heavily dependent on pressure and temperature.
In materials science, quenching is the rapid cooling of a workpiece in water, gas, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating , quenching prevents undesired low-temperature processes, such as phase transformations, from occurring.
In chemistry, work-up refers to the series of manipulations required to isolate and purify the product(s) of a chemical reaction. [1] The term is used colloquially to refer to these manipulations, which may include: deactivating any unreacted reagents by quenching a reaction.
Once removed from the oven, the workpieces are often quickly cooled off in a process known as quench hardening. Typical methods of quench hardening materials involve media such as air, water, oil, or salt. Salt is used as a medium for quenching usually in the form of brine (salt water). Brine provides faster cooling rates than water.
However, quenching certain steel too fast can result in cracking, which is why high-tensile steels such as AISI 4140 should be quenched in oil, tool steels such as ISO 1.2767 or H13 hot work tool steel should be quenched in forced air, and low alloy or medium-tensile steels such as XK1320 or AISI 1040 should be quenched in brine.
Quorum quenching is the process of preventing quorum sensing by disrupting signalling. [77] This is achieved by inactivating signalling enzymes, by introducing molecules that mimic signalling molecules and block their receptors, by degrading signalling molecules themselves, or by a modification of the quorum sensing signals due to an enzyme ...
In chemistry, a dark quencher (also known as a dark sucker) is a substance that absorbs excitation energy from a fluorophore and dissipates the energy as heat; while a typical (fluorescent) quencher re-emits much of this energy as light. [1] Dark quenchers are used in molecular biology in conjunction with fluorophores.
FPIA quantifies the change in fluorescence polarization of reaction mixtures of fluorescent-labelled tracer, sample antigen, and defined antibody.Operating under fixed temperature and viscosity allows for the fluorescence polarization to be directly proportional to the size of the fluorophore.