Viscosity measurement electrical detection

The emulsifying capacity is represented by the volume of oil (cm3) that is emulsified in a model system by 1 g of protein when oil is added continuously to a stirred aliquot of solution or dispersion of the tested protein. It is determined by measuring the quantity of oil at the point of phase inversion. The latter can be detected by a change in color, viscosity, or electrical resistance of the emulsion, or the power taken by the stirrer engine. The emulsifying capacity decreases with an increasing concentration of protein in the aqueous volume. It is affected by the parameters of emulsification, depending on the equipment, as well as by the properties of the oil. 

Mechanistic Ideas. The ordinary-extraordinary transition has also been observed in solutions of dinucleosomal DNA fragments (350 bp) by Schmitz and Lu (12.). Fast and slow relaxation times have been observed as functions of polymer concentration in solutions of single-stranded poly(adenylic acid) (13 14), but these experiments were conducted at relatively high salt and are interpreted as a transition between dilute and semidilute regimes. The ordinary-extraordinary transition has also been observed in low-salt solutions of poly(L-lysine) (15). and poly(styrene sulfonate) (16,17). In poly(L-lysine), which is the best-studied case, the transition is detected only by QLS, which measures the mutual diffusion coefficient. The tracer diffusion coefficient (12), electrical conductivity (12.) / electrophoretic mobility (18.20.21) and intrinsic viscosity (22) do not show the same profound change. It appears that the transition is a manifestation of collective particle dynamics mediated by long-range forces but the mechanistic details of the phenomenon are quite obscure. 

Improved instrumentation can improve control by measuring more directiy the variables governing the internal behavior of the mill. By installing an electrical conductivity probe in the wall of the mill, Moys and Montini [CIM Bulletin, 80(907), 52-6 (1987)] were able to detect the position of the ball mass during dynamic operation. This together with on-line measurement of slurry viscosity (see rheological properties, p. 20-32d) made it possible to control the mill at the desired operating point. 

The applications of the SFM include force measurement between surfaces in liquid and vapor, adhesion between similar or dissimilar materials, contact deformation, wetting and capillary condensation, viscosity in thin films, forces between surfactant and polymer-coated surfaces, and surface chemistry. Fluid-electrolyte interactions between conductive surfaces can also be measured [Smith, et. al., 1988]. A typical microforce of 10 nN can be detected over separation distances to a resolution of 0.1 nm with optical interoferometry between reflective surfaces. With electrostatic forces, relatively large separation are measured 1-100 nm, whereas, short range forces such as van der Waals forces take place over distances of less than 3.0 nm. Ultrasmooth and electrically conductive surfaces can be formed by the deposition of a metal film (40 nm thickness) such as Pt on a smooth substrate of mica [Smith, et. al., 1988]. The separation distance between the two surfaces is controlled by a... 

The detection of gas analytes using acoustic wave (AW) sensors can be based on changes in one or more of the physical characteristics of a thin film or layer in contact with the device surface (Ballantine et al. 1997). Some of the intrinsic film properties that can be utilized for gas detection include mass/ area, elastic stiffness (modulus), viscoelasticity, viscosity, electrical conductivity, and permittivity. Variations in any of these parameters alter the mechanical and/or electrical boundary conditions producing a measurable shift in the propagating acoustic wave phase velocity, v . Equation (13.1) illustrates the change in acoustic phase velocity, Av, as a result of external perturbations, assuming that the perturbations are small and linearly combined (Ippolito et al. 2009) ... 

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