Measurements Experimental Results

Due to technical difficulties in measurement, experimental results for the local film thickness and pressure distributions caused by asperities are quite limited that only two experiment cases recently have been reported which are employed here as the comparison reference. 

Adsorption Methods. Five grams of hematite were first conditioned in 0.001 M NaCl at pH 4.1. After the SDS had been added to the slurry and the pH adjusted as required, the samples were conditioned on a rotating shaker for two hours. The solutions were then centrifuged, and the supernatant liquid analyzed for its SDS content. The amount of SDS adsorbed was calculated as the difference between the initial amount added and the residual amount measured. Experimental results showed that two hours was sufficient time for equilibrium to be reached. Somasundaran ( ) observed similar equilibrium adsorption times for sulfonate adsorption on aluminum oxide. 

The most commercially important mechanism of all is the kinetics of solute transfer from an aqueous to a reverse micelle phase. The kinetics of extraction of metal ions have not received the same research attention as the extraction capacity of W/O microemulsions. As the mechanism of extraction of metal ions is chemical, the effect of creating a microemulsion in an organic phase that contains the reactant can be measured experimentally. Results indicate that, as in the case of extraction equilibrium, the rate of extraction may increase substantially by the presence of the microemulsion as compared with the conventional system [20,38,44] or decrease it to... 

Experimentally, the -> electric double layer at ITIES has been studied mainly by -> surface tension [x, xi] and differential capacity [xii] measurements. Experimental results and theoretical models were reviewed [xiii]. 

These forces have been measured. A further consequence of the new theories is that inferences of surface charge, "ion-binding" to surfaces as adduced from force measurements and/or electrophoretic mobility studies or NMR which involve the crude Poisson-Boltzmann theory are wrong. If the simple analytic Poisson-Boltzmann theory is used to interpret direct force measurements, experimental results can be forced into that analytic form, but the real binding constants are quite different. 

Finally one has to determine the values of the parameters introduced in the different rate expressions. The objective is to obtain the best agreement between the calculated time variations of the medium composition and the measured experimental results. There are two ways to evaluate the parameters some can be calculated directly from the experimental results and others are evaluated by a curve-fitting procedure. 

For each contact angle reported several doublets were measured. Experimental Results and Discussion... 

Carmignato S (2012) Accuracy of industrial computed tomography measurements experimental results from an international comparison. CIRP Ann Manuf Technol 61(l) 491-494... 

Marquez, J.C., Seoane, R, Lindecrantz, K., 2013. Textrode functional straps for bioimpedance measurements-experimental results for body composition analysis. Eur. J. Clin. Nutr. 67, S22—S27. 

Sorbie et al. (1987c, 1989d) have applied the above equations to the modelling of dynamic adsorption experiments using HPAM solutions in outcrop sandstone cores. In this work, a series of consecutive floods, first at 50 ppm HPAM concentration, were performed until the core had reached its maximum adsorptive capacity at that concentration (Cq = 50 ppm). A similar series of floods was performed for Cq = 100 ppm and so on. For each flood, both the polymer effluent profile and the tracer ( Cl) profile were measured. Experimental results for the first two 50 ppm floods and the first 100 ppm flood are shown in Figures 7.13 and 7.14, where they are compared with theoretical calculations based on the non-equilibrium adsorption model discussed above. Good semi-quantitative agreement is obtained in this work... 

Figure 8.11 Ds of CCI4 solutions of (O) 6.5, (0) 8.7, ( ) 29, and (A) 76 kDa three-arm polybutadienes. Solid lines show independent fits for each M dashed lines show the simultaneous fit to all measurements. Experimental results are from von Meerwall, et a/.(22).

Conductivity Measurements Experimental Results 4 1 General Remark... 

Values of C can be measured experimentally. Results are normally correlated vs. the flow parameter, defined as... 

The orientation and relaxation behaviors of a low density polyethylene melt after undergoing a shear flow in a restricted channel were investigated by using ultrasound. A capillary rheometer was used to force the polymer melt through a slit die equipped with pressure, tenperature, and ultrasound sensors, and the variation of ultrasound velocity traversing the melt was measured. Experimental results revealed that due to different mechanisms involved, the relaxations of orientation and disorientation processes show different dependences on temperatme and shear rate. 

There are two types of measurement errors, systematic and random. The former are due to an inherent bias in the measurement procedure, resulting in a consistent deviation of the experimental measurement from its true value. An experimenter s skill and experience provide the only means of consistently detecting and avoiding systematic errors. By contrast, random or statistical errors are assumed to result from a large number of small disturbances. Such errors tend to have simple distributions subject to statistical characterization. 

The paper discusses the application of dynamic indentation method and apparatus for the evaluation of viscoelastic properties of polymeric materials. The three-element model of viscoelastic material has been used to calculate the rigidity and the viscosity. Using a measurements of the indentation as a function of a current velocity change on impact with the material under test, the contact force and the displacement diagrams as a function of time are plotted. Experimental results of the testing of polyvinyl chloride cable coating by dynamic indentation method and data of the static tensile test are presented. 

Tables I and 2 show the experimental results obtained for axial and transversal displacements respectively, where % is the displacement and Xv. is the displacement measured using our experimental. setup.

Barnes and Hunter [290] have measured the evaporation resistance across octadecanol monolayers as a function of temperature to test the appropriateness of several models. The experimental results agreed with three theories the energy barrier theory, the density fluctuation theory, and the accessible area theory. A plot of the resistance times the square root of the temperature against the area per molecule should collapse the data for all temperatures and pressures as shown in Fig. IV-25. A similar temperature study on octadecylurea monolayers showed agreement with only the accessible area model [291]. 

Figure Al.6,8 shows the experimental results of Scherer et al of excitation of I2 using pairs of phase locked pulses. By the use of heterodyne detection, those authors were able to measure just the mterference contribution to the total excited-state fluorescence (i.e. the difference in excited-state population from the two units of population which would be prepared if there were no interference). The basic qualitative dependence on time delay and phase is the same as that predicted by the hannonic model significant interference is observed only at multiples of the excited-state vibrational frequency, and the relative phase of the two pulses detennines whether that interference is constructive or destructive.

The molecular mechanics or quantum mechanics energy at an energy minimum corresponds to a hypothetical, motionless state at OK. Experimental measurements are made on molecules at a finite temperature when the molecules undergo translational, rotational and vibration motion. To compare the theoretical and experimental results it is... 

A data set [x,y] can be represented in three ways as a tabular collection of measurements, as a graph, or as an analytical function y =f x). In the process of reducing a tabular collection of results to its analytical form, some information is lost. Although y =f x) gives us the dependence of y on a , we no longer know where the particular measurement yi at x is. That information has been lost. Often, selection of the form in which experimental results will be presented depends on how (or whether) information loss influences the conclusions we seek to reach. 

The measurement of pK for bases as weak as thiazoles can be undertaken in two ways by potentiometric titration and by absorption spectrophotometry. In the cases of thiazoles, the second method has been used (140, 148-150). A certain number of anomalies in the results obtained by potentiometry in aqueous medium using Henderson s classical equation directly have led to the development of an indirect method of treatment of the experimental results, while keeping the Henderson equation (144). 

There are a few basic numerical and experimental tools with which you must be familiar. Fundamental measurements in analytical chemistry, such as mass and volume, use base SI units, such as the kilogram (kg) and the liter (L). Other units, such as power, are defined in terms of these base units. When reporting measurements, we must be careful to include only those digits that are significant and to maintain the uncertainty implied by these significant figures when transforming measurements into results. 

A measure of the agreement between an experimental result and its expected value. 

Uncertainty expresses the range of possible values that a measurement or result might reasonably be expected to have. Note that this definition of uncertainty is not the same as that for precision. The precision of an analysis, whether reported as a range or a standard deviation, is calculated from experimental data and provides an estimation of indeterminate error affecting measurements. Uncertainty accounts for all errors, both determinate and indeterminate, that might affect our result. Although we always try to correct determinate errors, the correction itself is subject to random effects or indeterminate errors. 

A quantitative solution to an equilibrium problem may give an answer that does not agree with the value measured experimentally. This result occurs when the equilibrium constant based on concentrations is matrix-dependent. The true, thermodynamic equilibrium constant is based on the activities, a, of the reactants and products. A species activity is related to its molar concentration by an activity coefficient, where a = Yi[ ] Activity coefficients often can be calculated, making possible a more rigorous treatment of equilibria. 

In describing the various mechanical properties of polymers in the last chapter, we took the attitude that we could make measurements on any time scale we chose, however long or short, and that such measurements were made in isothermal experiments. Most of the experimental results presented in Chap. 3 are representations of this sort. In that chapter we remarked several times that these figures were actually the result of reductions of data collected at different temperatures. Now let us discuss this technique our perspective, however, will be from the opposite direction taking an isothermal plot apart. 

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