Radiation criteria

Polymer Form Property Initial value Criterion Radiation resistance without oxidation (surface oxidation) Dose (MGy) Irradiation conditions Refs. Remarks... 

The occurrence of the mesophase in the fiber is confirmed by x-ray diffraction examination. The occurrence of three equatorial reflections 010, 110, and 100, the absence of layer and meridional reflections, and the manifestation of the intensity maximum of diffusively scattered radiation at 20 = 19 in the fiber diffraction pattern are the criterion for the presence of the mesophase. The... 

Navier-Stokes equations, 24 Negative criterion of Bendixon, 333 Negaton-positon field in an external field, 580 interacting with electromagnetic field, Hamiltonian for, 645 interaction with radiation field, 642 Negaton-positon system, 540 Negaton scattering by an external field, 613... 

Emission of light due to an allowed electronic transition between excited and ground states having the same spin multiplicity, usually singlet. Lifetimes for such transitions are typically around 10 s. Originally it was believed that the onset of fluorescence was instantaneous (within 10 to lO-" s) with the onset of radiation but the discovery of delayed fluorescence (16), which arises from thermal excitation from the lowest triplet state to the first excited singlet state and has a lifetime comparable to that for phosphorescence, makes this an invalid criterion. Specialized terms such as photoluminescence, cathodoluminescence, anodoluminescence, radioluminescence, and Xray fluorescence sometimes are used to indicate the type of exciting radiation. 

The height of a flare is fixed on the basis of the heat generated and the resulting potential damage to equipment and humans. The usual design criterion is that the heat intensity at the base of the stack is not to exceed 1500 Btu/hr/ft2. The effects of thermal radiation are shown in the following table ... 

The vacancy left in the low-energy K-shell will be filled by an electron from a higher level with the resultant emission of radiations of extra nuclear origin, X-rays, which are distinguished from the accompanying nuclear y radiation. It should be noted that the n p criterion is the same for both positron and electron capture processes and it is not unusual to find both occurring with different atoms of the same nuclide. 

Let us examine the 1300 °C criterion as a condition of flame extinction in diffusive burning to see how these critical conditions depend on oxygen and external radiation. After all, these two parameters - oxygen and radiation - are the two significant variables that make most solids bum. We will look to some data for anchoring this application. 

Using the criteria listed in the introduction, we now provide a brief summary of the performance of these materials. With reference to criterion number 5, physical properties, we restrict out discussion here to the effects of radiation damage on the crystalline structure. For materials destined for geological disposal, the long-term performance in natural systems over long periods of time (e.g., 103 to 106 years) is of critical concern. Therefore, we believe that it is necessary to consider one more criterion (6) natural samples exist and allow for an assessment of the... 

Scanlan has suggested another criterion (282). An effective network junction point is a crosslink in which at least three of the four strands radiating from it lead independently to the network. A crosslink with only two strands anchored to the network simply continues an active strand a crosslink with only one anchored strand is part of a dangling end and can make no elastic contribution at equilibrium. An elastically effective strand is therefore one which joins two effective network junction points. Accordingly, the total number of active strands is simply one half the number of gel-anchored strands radiating from effective junction points ... 

Specificity is an ever-present criterion because there are indeed few analytical techniques that detect single species without careful tuning, Frequently, filtering techniques must be used as a means of narrowing the range of detection. See Infrared Radiation and Ultraviolet Spectrometers. 

A common result of all the experiments is that most molecules quench the alkali resonance radiation very effectively with total cross sections ranging from 10 A2 to over 200 A2. However, if the molecule BC is replaced by a rare-gas atom, the quenching cross sections become very small at thermal energies. They are probably below 10 2 A2 for quenching by helium, neon, argon, krypton, and xenon.55 The latter result is easily understood in terms of Massey s adiabatic criterion.67 If Ar is a characteristic interaction range, v the impact velocity, and AE the energy difference between initial and final electronic states E(3p) and E(3s), respectively, then we must have a Massey parameter... 

The only apprehension of prospective industrial radiation processors with the nonmeasurability criterion comes from the analogies with the history of pesticide residues in foods U). Pesticides are cleared on the basis of either zero tolerance or finite tolerance, and use is rated as safe for a zero-tolerance pesticide when the residue on foods cannot be measured. However, improvements in measurement techniques with time have changed the definition of zero tolerance, sometimes abruptly. Radiation processors are apprehensive of similar experiences with radioactivity induced in food. 

A qualitative criterion to assess the extent of radiation damping may be derived[55] from the Larmor formula that estimates the energy radiated in terms of an electronic acceleration of magnitude a, for a period of time T,... 

If ETaij > E0, the energy of the electron, the effects of radiation damping will be appreciable. In the present instance the electron starts from rest and is acted upon by an applied force for an interval T. E0 therefore is the kinetic energy after acceleration, E0 m aT)2. The criterion then becomes... 

Attributing the outmost importance to the safety factor was justified as regards nuclear and radiation hazardous objects all objects of the decommissioning and environmental rehabilitation pertained to that category. The safety criterion was also highlighted as the main factor for justification of priorities in the EBRD Terms of Reference for the SMP development. 

For smaD diameter tubes which are fouled more rapidly, the increase in pressure drop is the decoking criterion, whereas, for larger>skin temperature of the tube in the radiation zone whidi indicates the degree of fouling. 

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