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Gauge defined

Other convenient specifications for the divergence can be conceived (see below) the gauge defined by equation (8.41) is known as the Coulomb gauge. With use of this gauge condition, equation (8.40) can be rewritten in the form ... [Pg.208]

In the same section, we also see that the source of the appropriate analytic behavior of the wave function is outside its defining equation (the Schibdinger equation), and is in general the consequence of either some very basic consideration or of the way that experiments are conducted. The analytic behavior in question can be in the frequency or in the time domain and leads in either case to a Kramers-Kronig type of reciprocal relations. We propose that behind these relations there may be an equation of restriction, but while in the former case (where the variable is the frequency) the equation of resh iction expresses causality (no effect before cause), for the latter case (when the variable is the time), the restriction is in several instances the basic requirement of lower boundedness of energies in (no-relativistic) spectra [39,40]. In a previous work, it has been shown that analyticity plays further roles in these reciprocal relations, in that it ensures that time causality is not violated in the conjugate relations and that (ordinary) gauge invariance is observed [40]. [Pg.97]

One can define a phase that is given as an integral over the log of the amplitude modulus and is therefore an observable and is gauge invariant. This phase [which is unique, at least in the cases for which Eq. (9) holds] differs from other phases, those that are, for example, a constant, the dynamic phase or a gauge-transformation induced phase, by its satisfying the analyticity requirements laid out in Section I.C.3. [Pg.128]

The term aquifer is used to denote an extensive region of saturated material. There are many types of aquifers. The primary distinction between types involves the boundaries that define the aquifer. An unconfined aquifer, also known as a phraetic or water table aquifer, is assumed to have an upper boundary of saturated soil at a pressure of zero gauge, or atmospheric pressure. A confined aquifer has a low permeabiUty upper boundary that maintains the interstitial water within the aquifer at pressures greater than atmospheric. For both types of aquifers, the lower boundary is frequendy a low permeabihty soil or rock formation. Further distinctions exist. An artesian aquifer is a confined aquifer for which the interstitial water pressure is sufficient to allow the aquifer water entering the monitoring well to rise above the local ground surface. Figure 1 identifies the primary types of aquifers. [Pg.401]

Standard Chemical Pump. In 1961, the American National Standards Institute (ANSI) iatroduced a chemical pump standard (29), known as ANSI B73.1, that defined common pump envelope dimensions, connections for the auxiUary piping and gauges, seal chamber dimensions, parts mnout limits, and baseplate dimensions. This definition was to ensure the user of the availabiUty of iaterchangeable pumps produced by different manufacturers, as well as to provide plant designers with standard equipment. A typical ANSI chemical pump, known as of the mid-1990s as ASME B73.1M-1991, is shown ia Figure 6. [Pg.292]

The P-t histories illustrated by Fig. 2.9 are not histories of a particle of material moving with the flow, because the coordinate that is fixed is x, and material is flowing past it. A more useful P-t history would use a coordinate system which is attached to the material itself, as a stress or particle velocity gauge would be. Such a coordinate system is defined in the next section. [Pg.24]

Adhesion depends on a number of factors. Good adhesion is defined by most customers as substrate failure. The major adhesive manufacturers possess equipment that allows them to make bonds with customer substrates under conditions that closely simulate actual packaging lines. These bonds are peeled either automatically or by hand to gauge adhesion. The most important factors influencing adhesion are the wet-out of the substrate, partieularly by the polymer component of the adhesive system, and the specific adhesion with the substrate. Choice of resin is critical for both. Rosin, rosin esters and terpene phenolics are eommonly added for these purposes in EVA and EnBA-based systems. Adhesion at low temperatures is also influenced by the overall toughness of the system at the test temperature. [Pg.745]

Flammability, the tendency of a material to bum, can only be subjectively defined. Many materials that we normally do not consider flammable will bum, given high enough temperatures. Neither can flammability be gauged by the heat content of materials. Fuel oil has a higher heat content than many materials considered more flammable because of their lower flashpoint. In fact, flashpoint has become the... [Pg.170]

Pressure. Pressure so defined is sometimes called absolute pressure. The differential pressure is the difference between two absolute pressures. The most common types of pressure-measuring sensors are silicon pressure sensors, mechanical strain gauges, and electromechanical transducers. [Pg.301]

Features. Seven categories of bearing design and gauge protection are defined as features. Features 8 and 9 are reserved for future use. [Pg.770]

The location of the primary dull characteristic is described in the fourth space. There are six choices cone, nose, taper, shoulder, gauge, and all areas. Figure 4-167 shows four possible fixed cutter bit profiles with the different areas labeled. It is recognized that there are profiles for which the exact boundaries between areas are debatable and for which certain areas may not even exist. Notice that in the bottom profile there is no taper area shown. However, using Figure 4-167 as a guide, it should be possible to clearly define the different areas on most profiles. [Pg.811]

Threaded connections are complicated mechanisms consisting of many elements that must interact in prescribed fashion to perform a useful function. Each of these elements of a thread may be gauged individually as described in API RP 5B1, 1st Edition, April 1983. The thread elements are defined as ... [Pg.1141]

There should be no perceptible drop in pressure as shown by the test gauge, although a small leakage rate is defined which allows for testing technique limitations. [Pg.284]

Section 38 of the Factories Act 1961 defines a steam boiler as a any closed vessel in which for any purpose steam is generated under pressure greater than atmospheric pressure . Economizers used to heat water being fed to such a vessel and superheater for heating steam are also included. Every boiler must be fitted with the recommended safety measures (e.g. safety valve, stop valve, water gauge, low-water alarms, pressure gages, etc.). [Pg.1064]

Actually transversality in all the k variables already follows from transversality in any one of the k variables because of the symmetric character of the tensor alll...Un(k1, , kn). Again due to the freedom of gauge transformations an n photon configuration is not described by a unique amplitude but rather by an equivalence class of tensors. We define the notion of equivalence for these tensors, as follows a tensor rfUl. ..Bn( i, , kn) will be said to be equivalent to zero ... [Pg.559]

The matter field operators, although denoted by the same symbol, should not be confused with those defined in the Coulomb gauge by the equations of motion (11-47). The same is true for the in, out operators. The two are related by a transformation of the form... [Pg.653]

Routh and Russel [10] proposed a dimensionless Peclet number to gauge the balance between the two dominant processes controlling the uniformity of drying of a colloidal dispersion layer evaporation of solvent from the air interface, which serves to concentrate particles at the surface, and particle diffusion which serves to equilibrate the concentration across the depth of the layer. The Peclet number, Pe is defined for a film of initial thickness H with an evaporation rate E (units of velocity) as HE/D0, where D0 = kBT/6jT ir- the Stokes-Einstein diffusion coefficient for the particles in the colloid. Here, r is the particle radius, p is the viscosity of the continuous phase, T is the absolute temperature and kB is the Boltzmann constant. When Pe 1, evaporation dominates and particles concentrate near the surface and a skin forms, Figure 2.3.5, lower left. Conversely, when Pe l, diffusion dominates and a more uniform distribution of particles is expected, Figure 2.3.5, upper left. [Pg.97]


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See also in sourсe #XX -- [ Pg.1445 ]




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