Measurement apparatus description

Strictly speaking the description of such local measurements can be carried out only within the framework of quantum electrodynamics, i.e, in a theory wherein photons can be exchanged between the measuring apparatus and the current distribution being measured. 

It is clear from the apparatus description in Fig. 2.49 that carrying out tests to measure extensional rheometry is a very difficult task. One of the major problems arises because of the fact that, unlike shear tests, it is not possible to achieve steady state condition with elongational rheometry tests. This is simply because the cross-sectional area of the test... 

Figure 1 illustrates the apparatus used for these measurements. Detailed description of a -radiotracer adsorption method is given in the paragraph dealing with mucin and collagen adsorption at interfaces. 

Tabera, J., Local gas hold-up measurement in stirred fermenters. 1 Description of the measurement apparatus and screening of variables, Biotechnol. Tech. 4(5) (1990), 299-304. 

The study of living animals requires measurements apparatus and working technique appreciably different from those described above, their detailed description is beyond the scope of this paper. The measurement must be volume-selective, which is assured by an emission-reception coil... 

Usually one varies the head of mercury or applied gas pressure so as to bring the meniscus to a fixed reference point [118], Grahame and co-workers [119], Hansen and co-workers [120] (see also Ref. 121), and Hills and Payne [122] have given more or less elaborate descriptions of the capillary electrometer apparatus. Nowadays, the capillary electrometer is customarily used in conjunction with capacitance measurements (see below). Vos and Vos [111] describe the use of sessile drop profiles (Section II-7B) for interfacial tension measurements, thus avoiding an assumption as to the solution-Hg-glass contact angle. 

In this section the laboratory measurements of CC -foam mobility are presented along with the description of the experimental procedure, the apparatus, and the evaluation of the mobility. The mobility results are shown in the order of the effects of surfactant concentration, CC -foam fraction, and rock permeability. The preparation of the surfactant solution is briefly mentioned in the Effect of Surfactant Concentrations section. A zwitteronic surfactant Varion CAS (ZS) from Sherex (23) and an anionic surfactant Enordet X2001 (AEGS) from Shell were used for this experimental study. 

The sample surface temperature was also measured at some of these positions during the test. A detailed description of the test apparatus, procedure and results is given in (2). 

The experiment was therefore varied by allowing the oil to rise through the solution in very fine drops of definite size. The change in concentration was again measured by taking the drop number before and after treatment with a known number of drops. The principle of this altered method will be easily understood from a description of the apparatus used in a third series of experiments, in which mercury in the form of fine drops was used as the adsorbent (Fig. io). 

The techniques and apparatus which have been developed to measure electrolytic conductivities in nonaqueous solutions have been adapted from aqueous conductivity measurements with some modifications. Direct current measurements suffer the limitation of requiring reversible electrodes - a serious limitation in nonaqueous solvents. Although this problem can be circumvented U in some instances, virtually all precision conductance data have been taken using the alternating current method. General descriptions of this method are given in several sources. 2>3)... 

The interfacial tension was measured by the pendant drop method. Detailed description of the apparatus and the method was given previously (3 ). ... 

The depth of the dent is a measure of the output. The test applies only to components producing dents greater than 0.005 and smaller than 0.100 inch in depth. A drop-ball apparatus similar to the one employed in lead-disc test, is used here. A new block is used for each test. A complete description of the procedure is given as Test No 303 in MIL-STD-331 d ) Explosive Component Output Measurement by Steel Dent. The test is similar to the A1 dent test. It applies only to components producing dents greater than 0.005 and smaller than 0.100 inch in depth. A complete description of the procedure is given as Test No 301.1 in MIL-STD-331... 

The apparatus developed for yb measurements of BLM deserves brief comment since it can be used not only to examine the effects of various substances on BLM but is readily adaptable for studying other types of interfacial films and related adsorption phenomena at either air-water or oil-water interfaces (and bifaces). Unlike both the Wil-helmy plate and film balance methods, the present technique measures 7i directly. From the description of the apparatus and procedure that the present method relies on the ability to measure the very small pressure difference across an interface (or biface). For certain BLM s, the pressure heads measured are only fractions of a millimeter of water. Therefore, the method described here has been possible only as a result of developing pressure transducers of high sensitivity. 

Many other types of apparatus for the measurement of dynamic properties of fluid systems have been published, especially for the high frequency range (up to the mega cycle range) (30, 31). However, a description of these apparatuses is out of the scope of the present author. The above mentioned apparatus may serve as an example. Some measurements carried out with this apparatus will be used in the present review. 

As has already been pointed out in Sections 1.3 and 1.5, the slit-geometry is interesting for two reasons. First, it enables the measurement of flow birefringence in the 1—3 plane. Second, it furnishes the possibility to investigate polymer melts at high shear rates, where the cone-and-plate geometry fails. In the present section it remains to give a short description of the apparatus. 

The experimental techniques were dealt with briefly in Sect. 5, where it must be noted that, for both the quantitative and qualitative description of the drag-reduction phenomenon, precisely defined measuring equipment must be used in order to be able to establish whether degradation arises as a result of the nature of the flow of the apparatus as such (corners, edges, burrs, surface, roughness). 

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