Young measurements

Cap Gemini Ernest Young, Measures That Matter, A survey of 575 analysts as well as interviews with portfolio managers, Cap Gemini Ernest Young, Paris, 1996. 

M. Kieman, Panel discussion on Sustainability Social and Environmental Factors in Financial Reporting, held at Cap Gemini Ernst Young Measuring the Future Conference, Cambridge, MA, October 1-3, 2000. Available at http //www.cbi.cgey.com/events/ pubconf/2000-10-4/ session/breakout/index.html sustainability. 

C. Gaseous Mixtures.— Powell, Swinton, and Young measured the gas-liquid critical temperatures of mixtures of QFg with methylated benzenes and with methylated cyclohexanes and extracted values of the interaction parameter using the Rowlinson theory mentioned earlier in Section 2B. Hicks and Young carried out similar measurements on CgFe, CeHg, and cyclo-C6F,2 with various cycloalkanes. A representative sample of values is given in Table 7. 

There are a number of relatively simple experiments with soap films that illustrate beautifully some of the implications of the Young-Laplace equation. Two of these have already been mentioned. Neglecting gravitational effects, a film stretched across a frame as in Fig. II-1 will be planar because the pressure is the same as both sides of the film. The experiment depicted in Fig. II-2 illustrates the relation between the pressure inside a spherical soap bubble and its radius of curvature by attaching a manometer, AP could be measured directly. 

Since both sides of Eq. X-39 can be determined experimentally, from heat of immersion measurements on the one hand and contact angle data, on the other hand, a test of the thermodynamic status of Young s equation is possible. A comparison of calorimetric data for n-alkanes [18] with contact angle data [95] is shown in Fig. X-11. The agreement is certainly encouraging. 

The extensive use of the Young equation (Eq. X-18) reflects its general acceptance. Curiously, however, the equation has never been verified experimentally since surface tensions of solids are rather difficult to measure. While Fowkes and Sawyer [140] claimed verification for liquids on a fluorocarbon polymer, it is not clear that their assumptions are valid. Nucleation studies indicate that the interfacial tension between a solid and its liquid is appreciable (see Section K-3) and may not be ignored. Indirect experimental tests involve comparing the variation of the contact angle with solute concentration with separate adsorption studies [173]. 

It is important to differentiate between brittie and plastic deformations within materials. With brittie materials, the behavior is predominantiy elastic until the yield point is reached, at which breakage occurs. When fracture occurs as a result of a time-dependent strain, the material behaves in an inelastic manner. Most materials tend to be inelastic. Figure 1 shows a typical stress—strain diagram. The section A—B is the elastic region where the material obeys Hooke s law, and the slope of the line is Young s modulus. C is the yield point, where plastic deformation begins. The difference in strain between the yield point C and the ultimate yield point D gives a measure of the brittieness of the material, ie, the less difference in strain, the more brittie the material. 

Young s modulus can be deterrnined by measuring the stress—strain response (static modulus), by measuring the resonant frequency of the body... 

Continuous-Pliase Coefficients There have been a large number of measurements of kc for sohd particles and gas bubbles suspended in agitated hquids [for review, see Miller, Jnd. Fng. Chem., 56(10), 18 (1964)]. A typical correlation of these data is that of Calder-bankand Moo-Young [Chem. Fng. Sci., 16, 39 (1961)] ... 

Methods of Measurement Methods of characterizing the rate process of wetting include four approaches as illustrated in Table 20-37. The first considers the ability of a drop to spread across the powder. This approach involves the measurement of a contact angle of a drop on a powder compact. The contact angle is a measure of the affinity of the fluid for the solid as given by the Young-Dupre equation, or... 

The Young s modulus of the specimen is determined by accurately measuring its resonant frequency while driving it in a standing longi-... 

The best of all methods of measuring E is to measure the velocity of sound in the material. The velocity of longitudinal waves, v, depends on Young s modulus and the density, p ... 

Since —1 < cos < 1, Young s equation is valid only when the right hand side of Eo 3 or Eq. 3a lies between these limits, i.e. the observed contact angle is finite. In le event that the measured contact angle is 0°, i.e. full spreading occurs, one may conclude only that... 

Conder, J.R. and Young, C.L., Physicochemical Measurements by Gas Chromatography. Wiley, New York, 1979. 

The work of adhesion was determined from the a versus P measurements (see Eq. 11). The work of adhesion between two rubber spheres was found to be 71 4 mJ/m. The work of adhesion reduced to 6.8 0.4 mJ/m in the presence of 0.01 M solution of dodecyl sulfate. Using these measurements of adhesion between rubber in air and a surfactant solution, Johnson et al. [6] provided the first direct experimental verification of the Young s equation (Eq. 40). They also measured... 

As previously discussed, the JKR theory predicts that the detachment force is independent of the Young s modulus. Yet despite that, when Gady et al. [117] measured the detachment force of polystyrene particles from two elastomeric substrates having Young s moduli of 3.8 and 320 MPa, respectively, they found that the detachment force from only the more compliant substrate agreed with the predicted value. The force needed to separate the particle from the more rigid substrate was about a factor of 20 lower. Estimates of the penetration depth revealed that the particles would penetrate into the more compliant substrate more deeply than the heights of the asperities. Thus, in that case, the spherical particle approximation would be reasonable. On the other hand, the penetration depth... 

Many of the most widely used methods are based on measuring the contact angles of a series of test liquids on the solid surface, and evaluating the surface energies via Young s equation, Eq. 4 above. 

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