Electromagnetic radiation irradiance

If the oriented nuclei are now irradiated with electromagnetic radiation of the proper frequency, energy absorption occurs and the lower-energy state "spin-flips" to the higher-energy state. When this spin-flip occurs, the magnetic nuclei are said to be in resonance with the applied radiation—hence the name nuclear magnetic resonance. 

Nuclear activation analysis (NAA) is a method for qualitatively and quantitatively detg elemental compn by means of nuclear transmutations. The method involves the irradiation or bombardment of samples with nuclear particles or high-energy electromagnetic radiation for the specific purpose of creating radioactive isotopes from the stable or naturally-occurring elements present. From the numbers, types and quantities of radioactive elements or radionuclides, it is possible to deduce information about the elemental compn of the original sample... 

The monomers used in chain polymerisations are unsaturated, sometimes referred to as vinyl monomers. In order to carry out such polymerisations a small trace of an initiator material is required. These substances readily fragment into free radicals either when heated or when irradiated with electromagnetic radiation from around or just beyond the blue end of the spectrum. The two most commonly used free radical initiators for these reactions are benzoyl peroxide and azobisisobutyronitrile (usually abbreviated to AIBN). They react as indicated in Reactions 2.1 and 2.2. 

In LEIS, which is conceptually quite similar to PES, the sample is irradiated with a monochromatic electromagnetic radiation (e.g., a laser). Thus, it is possible to excite electrons from the sample to energy levels approaching or even surpassing the ionization barrier [94], The difference between LEIS and RIS is the mechanism... 

IR absorption spectroscopy follows the principles of classical absorption spectrocopy. A sample is irradiated with electromagnetic radiation and the transmitted or reflected radiation is (spectrally) analysed. In IR spectroscopy, the wavelengths used are in the pm-range. 

The heating characteristics of a particular material (for example, a solvent) under microwave irradiation conditions are dependent on the dielectric properties of the material. The ability of a specific substance to convert electromagnetic energy into heat at a given frequency and temperature is determined by the so-called loss tangent, tan <5. The loss factor is expressed as the quotient tan (3 = "/ , where e" is the dielectric loss, indicative of the efficiency with which electromagnetic radiation is... 

If a substance is irradiated with electromagnetic radiation, the energy of the incident photons may be transferred to the atoms or molecules raising them from the ground state to an excited state. This process, known as absorption, is accompanied by attenuation of the incident radiation at a particular frequency and can occur only when the energy difference between the two levels is exactly matched by the energy of the photons. The frequency of the radiation is given by... 

Polymer that exhibits an optical effect brought about by electromagnetic radiation such that the magnitude of the effect is not proportional to the irradiance. 

Research Focus Preparation of p-terphenyl-based oxime derivatives for use as latent acids activated by irradiation with actinic electromagnetic radiation and electron... 

Transition probabilities. The interaction of quantum systems with light may be studied with the help of Schrodinger s time-dependent perturbation theory. A molecular complex may be in an initial state i), an eigenstate of the unperturbed Hamiltonian, Jfo I ) = E 10- If the system is irradiated by electromagnetic radiation of frequency v = co/2nc, transitions to other quantum states /) of the complex occur if the frequency is sufficiently close to Bohr s frequency condition,... 

Consider the following statements about electromagnetic radiation and determine whether they are true or false. If they are false, state why they are false, (a) Photons of ultraviolet radiation have less energy than photons of infrared radiation, (b) The kinetic energy of an electron ejected from a metal surface when the metal is irradiated with ultraviolet radiation is independent of the frequency of the... 

There are two categories of remote sensing, active and passive. Passive techniques utilise electromagnetic radiation emitted from or transmitted through the atmosphere, the radiation source being for example the black body emission from the earth s surface or solar and stellar irradiances. The most critical part of a passive remote sensing instrument is its detector. In contrast, active remote sensing systems have their own radiation source and a detector, for example, radar and lidar techniques. 

UV irradiation. Electromagnetic radiation with a wavelength shorter than that of visible light (200-390 nm). Causes damage to DNA (mainly pyrimidine dimers). 

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