Electromagnetic measurements

Electromagnetic Measurements on Canadian 100-Ton TNT Explosion , EGG-B-2572, Edgerton, Germeshausen Grier, Inc, Boston (1963) 13) A.N. Dremin et al, The Initiation... 

Electromagnetic measurements of high conductivity soil-fluid mixtures at low frequencies are difficult to obtain due to electrode polarization. Caution must be used when interpreting data in the literature, as electrode effects may be viewed as being material behaviour. In addition, difficulties with data interpretation arise at kHz and MHz frequencies for clay-fluid mixtures due to the possible manifestation of both double layer polarization and interfacial polarization phenomena. 

As the current correlation function in the time integral has sums over all charge velocities z, effects of cross terms between ionic and molecular motions appear which cannot be identified or separated by electromagnetic measurements. In addition to static solvation and saturation effects on permittivity often considered in biological contexts, Hubbard and Onsager have pointed out "kinetic depolarization" effects which need to be considered. In II, we discuss experimental evidence and implications of the theoretical predictions of such effects. 

Figure 4. Monitor well measurements and electromagnetic measurements at same site. Top potentiometric contours showing plume flow. Bottom conductivity contours showing plume flow. (Reproduced from Ref. 2.)...

Diffusion. Acid diffusion in pH modified foods was investigated with fluorescent dyes or color indicators (18). Colorimetric pH profiles compared well with electromagnetic measurements. Effective mass diffusivities for acetic, citric, gluconic and phosphoric acids in potatoes were on the order of lO10 nr/sec. Diffusion occurs mainly in an unsteady state in heterogeneous, multilayer, cellular systems (19). Diffusion can be seen mathematically predicted by one-dimensional solutions of the second Fick equation ... 

Ghezali S, Laurent Ph, Lea S N, Santarelli G, Bahoura M, Simon E, Weyers S, Szymaniec K, Cognet L and Clairon A 1996 About the accuracy evaluation of the LPTF caesium fountain frequency standard . Conference on Precision Electromagnetic Measurements, Braunschweig (DE),THlB-2... 

Kinoshita T 1994 Improved determination of fine structure constant based on the electron g - 2 and muonium hyperfine stracture . Conference Precision Electromagnetic Measurements Digest, WE2B-1, Boulder CO (USA), (July 1994)... 

The basic definition of an effective medium is that the ESU, when embedded in the effective medium, should not be detectable in an experiment using electromagnetic measurement. In other words, the extinction of the ESU should be the same as if it were replaced with a material characterized by Ceff. This criterion makes it fruitful to use a recently derived [12] optical theorem for absorbing media it relates the extinction of the spherical cell compared to that of the surrounding medium with the scattering amplitude in the direction of the impinging beam S(0) (forward scattering amplitude) by... 

In using defined in this way, the burden of representing any relaxation effects in conductivity as a function of tu is thrown on the derived values of c. As is clear from Maxwell s equations, there is no way of separating rand e relaxation effects experimentally by electromagnetic measurements alone, and any such separation must be made by arbitrary assignment or comparison with a theoretical model. 

Araki D, Kuroda R, Kubo S, Fujita N, Tei K, Nishimoto K, Hoshrno Y, Matsushita T, Matsumoto T, Nagamune K, Kurosaka M (2011) A prospective randmnised study of anatomical single-bundle versus double-bundle anterior cruciate ligament reconstruction quantitative evaluation using an electromagnetic measurement system. Int Orthop 35(3) 439-446... 

Here the symbol M indicates any of the electromagnetically measured mechanical moments occurring on the r. h. s. ofeq. (3.10), the uncertainties of which having been assumed to be equal for all four types of... 

With these developments the macroscopic Maxwell equations relate to fields to macroscopic charge current and moment densities with further statistical averaging over appropriate ensembles giving expectation values. Before going on to these operations two points which sometimes cause difficulty should be mentioned. The first is that only total current density s 1 dP/dt is related to fields and hence that only can be determined by purely electromagnetic measurements but not conduction current 2 if significant separately from polarization current This is evident in equation (4). It may not seem so for f = 4ir (p—V f) but combining this with = 0 for... 

For a qualitative interpretation of the electromagnetic measurement results in a crude approximation, it is probably possible to use a single-band model with the dispersion law determined by the averaged effective mass of the carriers. Then the paramagnetic part of the magnetic... 

The maximum pressure to which the gravimetric technique has been applied is about 15 MPa. The volumetric method is very seldom applied above 100 MPa [29]. Bose and co-workers [30] developed a precision dielectric method for the determination of gas-solid adsorption. This method is particularly suitable for adsorption measurements up to 200 MPa actually, adsorption data up to 650 MPa were reported [31]. The great advantage of the dielectric method is that it is self-sufficient up to the highest pressures and does not depend on the availability of compressibility factor values, as in volumetric or gravimetric measurements [29]. Other new, yet less widespread, adsorption measurement techniques include oscillometry [32,33], calorimetry [34,35], and electromagnetic measurements [36,37]. 

The authors are developing an electromagnetic measurement technology that can be applied to biomedical imaging [1-4]. 

Soil resistivity can be measured by the so-called Wenner four-pin technique or, more recently, by electromagnetic measurements. The latter allows measurements in a convenient manner and at different soil depths. Another option for soil resistivity measurements is the so-called soil box method, whereby a sample is taken during excavation. Preferably sampling will be in the immediate vicinity of a buried structure (a pipe trench, for example). 

The fibres will generally show not only some preferential alignment, but also a non-uniform distribution along the length of a beam. This has been demonstrated clearly by electromagnetic measurements of fibre content carried out by Uomoto and Kobayashi [28], as shown in Figure 7.11. 

---