Cathodoluminescence, the emission of light when atoms excited by high-energy electrons return to their ground state, is analogous to UV-induced fluorescence, and some materials such as zinc sulfide and some fluorescent dyes, exhibit both phenomena.

Cathodoluminescence is most commonly experienced in everyday life as the light emission from the inner surface of the cathode ray tube in television sets and computer CRT monitors.

Cathodoluminescence is used in cathode ray tubes, photoluminescence in fluorescent lighting and plasma display panels, phosphorescence in safety signs and low energy lighting, fluorescence in pigments, inks, optical brighteners, safety clothing, and biological and medicinal analysis and diagnostics, chemoluminescence and bioluminescence in analysis, diagnostics and sensors, and electroluminescence in the burgeoning areas of light-emitting diodes ( LEDs / OLEDs ), displays and panel lighting.

* Cathodoluminescence, an optical and electrical phenomenon

Cathodoluminescence occurs because the impingement of a high energy electron beam onto a semiconductor will result in the promotion of electrons from the valence band into the conduction band, leaving behind a hole.

** Cathodoluminescence, a result of being struck by an electron

Cathodoluminescence and EBIC are referred to as " beam-injection " techniques, and are very powerful probes of the optoelectronic behavior of semiconductors, in particular for studying nanoscale features and defects.

Cathodoluminescence has been exploited as a probe to map the local density of states of planar dielectric photonic crystals and nanostructured photonic materials.

* B. G. Yacobi and D. B. Holt, Cathodoluminescence Microscopy of Inorganic Solids, New York, Plenum ( 1990 )

* C. M. Parish and P. E. Russell, Scanning Cathodoluminescence Microscopy, in Advances in Imaging and Electron Physics, V. 147, ed.

The concept of the strain energy as a Gibbs function difference Af and exerting a force normal to the shearing face is compatible with the information obtained from optical birefringence studies of fluids undergoing shear.

Flatness may now monopolize everything, but it is a flatness become so ambiguous and expanded as to turn into illusion itself -- at least an optical if not, properly speaking, a pictorial illusion.

) An authentic diffraction pattern is always obtained and optical properties are frequently checked.

It should be noted, however, that the paraxial resolution is quite similar for both electron optical systems.

The electron optical system ( see fig. 14-1 ) is based in principle on the focusing action of concentric spherical cathode and anode surfaces.

It is clear from this discussion that cosmologists of every persuasion look hopefully toward the day when a man-made satellite can be equipped with optical devices which will open up new vistas to science.

As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular, and optical physics.

The and convention for amino acid configuration refers not to the optical activity of the amino acid itself, but rather to the optical activity of the isomer of glyceraldehyde from which that amino acid can, in theory, be synthesized (- glyceraldehyde is dextrorotary ;-glyceraldehyde is levorotatory ).

Alexander's band, an optical phenomenon, is named after him.

Shot noise is a type of electronic noise that occurs when the finite number of particles ( such as electrons in an electronic circuit or photons in an optical device ) is small enough to give rise to statistical fluctuations in a signal.

Atomic absorption spectroscopy ( AAS ) is a spectroanalytical procedure for the quantitative determination of chemical elements employing the absorption of optical radiation ( light ) by free atoms in the gaseous state.

An optical aberration is a departure of the performance of an optical system from the predictions of paraxial optics.

Aberrations occur because the simple paraxial theory is not a completely accurate model of the effect of an optical system on light, rather than due to flaws in the optical elements.

Defocus is the lowest-order true optical aberration.

The elementary theory of optical systems leads to the theorem: Rays of light proceeding from any object point unite in an image point ; and therefore an object space is reproduced in an image space.

The Gaussian theory, however, is only true so long as the angles made by all rays with the optical axis ( the symmetrical axis of the system ) are infinitely small, i. e. with infinitesimal objects, images and lenses ; in practice these conditions are not realized, and the images projected by uncorrected systems are, in general, ill defined and often completely blurred, if the aperture or field of view exceeds certain limits.

Math., 1858 ) and Ernst Abbe showed that the properties of these reproductions, i. e. the relative position and magnitude of the images, are not special properties of optical systems, but necessary consequences of the supposition ( in Abbe ) of the reproduction of all points of a space in image points ( Maxwell assumes a less general hypothesis ), and are independent of the manner in which the reproduction is effected.

In pinhole projection, the magnification of an object is inversely proportional to its distance to the camera along the optical axis so that a camera pointing directly at a flat surface reproduces that flat surface.

* One application of autocorrelation is the measurement of optical spectra and the measurement of very-short-duration light pulses produced by lasers, both using optical autocorrelators.

It is good to know that Georgia will continue to have sufficient electrical power not only to meet the demands of normal growth but to encourage a more rapid rate of industrialization.

This is used as a reference for comparing the ohmic heating and the electrical energy obtained from the measured current through the element and the measured voltage across the element.

He is a member of the Institution of Electrical Engineers, London, a registered professional engineer in Connecticut and Ohio, and a chartered electrical engineer in Great Britain.

Chapter 8, is entitled `` On Magnetism '' and in it are included such remarks as, `` One has always been tempted to compare the magnetic forces with the electrical forces.

The form of galvanic activity is halfway between the magnetic form and the electrical form.

Since electrical stimulation of the posterior hypothalamus produces the effects of wakefulness while stimulation of the anterior hypothalamus induces sleep, it may be said that the reactivity of the whole organism is altered by a change in the autonomic reactivity of the hypothalamus.

It is assumed that the gyros are designed with electrical torquers so that a torque can be applied about their output axes.

The electrical signal from the autocollimator is amplified and supplied to the Z-gyro torquer.

It is possible to locate an angular electrical pickoff, which will indicate the angular deviation between the true heading direction and the platform.

Essentially, the stator or reference portion of the pickoff is established with respect to the true heading direction, and the platform is turned either manually or automatically until the angular electrical pickoff signal is reduced to zero.

The recent publicity attending the successful federal prosecution of a conspiracy indictment against a number of electrical manufacturers has evoked a new respect for the anti-trust laws that is justified neither by their rationale nor by the results they have obtained.

The problem becomes even more complex where an enterprise is engaged in the manufacture of a wide variety of other goods in addition to the heavy electrical equipment.

The electron is by far the least massive of these particles at, with a negative electrical charge and a size that is too small to be measured using available techniques.

An axon ( also known as a nerve fiber ) is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body.

Structural, mechanical, and electrical engineers and other specialists, are hired by the client or the architect, who must ensure that the work is co-ordinated to construct the design.

RWTH Aachen University, established as Polytechnicum in 1870, is one of the Germany's Universities of Excellence with strong emphasis on technological research, especially for electrical and mechanical engineering, computer sciences, physics, and chemistry.

The ' far-away light ' () is a reference to St Elmo's Fire, an electrical discharge supposed by ancient Greek mariners to be an epiphany of the Dioscuri, but the meaning of the line was obscured by gaps in the papyrus until reconstructed by a modern scholar — such reconstructions are typical of the extant poetry ( see Scholars, fragments and sources below ).

Thus, an analog signal is one represented by a continuous stream of data, in this case along an electrical circuit in the form of voltage, current or charge changes ( compare with digital signals below ).

An anode is an electrode through which electric current flows into a polarized electrical device.

An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.

Audio is an electrical or other representation of sound.

In either case the primer is usually percussion but electrical is also used and laser ignition is emerging.