Absolute viscosity, definition

Absolute porosity, definition, 220 Absolute viscosity, definition, 386 Acid number (total acid number, TAN), definition, 403 Adhesion, definition, 26-27 Adsorbed polymer layers, interaction with droplets, 62 Adsorption definition, 386... 

In addition, the U.S. Pharmacopoeia includes the explanation of kinematic viscosity [units in stoke (s) and centistoke (cs)], defined as the absolute viscosity divided by the density of the liquid at a definite temperature, p ... 

Phase diagrams from freezing point depressions show true compound formations for simpler amides—e.g., water-N-methylacetamide forms a compound at a mole ratio of 2 to 1, water-N,N-dimethylacetamide at 3 to 2 and 3 to 1, and water-N-methylpyrrolidone at 2 to 1. The heats of mixing and heat capacities at 25°C. of a number of water-amide systems were determined. All mixing curves were exothermic and possess maxima at definite mole ratios, while the heat capacities for the most part show distinct curvature changes at the characteristic mole ratios. Both experimental results point to the stability of the particular complexes even at room temperature. This is further supported by absolute viscosity studies over the whole concentration range where large maxima occur at these same mole ratios for disubsti-tuted amides and N-substituted pyrrolidones. 

In the capillary method, the time required for a liquid to flow through a capillary tube is determined. The melt under investigation flows with a constant rate through a tube with a small, definite cross-sectional area, such as a cylindrical capillary. The viscosity can be measured in an absolute way from the pressure drop. This method can yield the most reliable absolute data, the viscosity being given by a modified Hagen-Poiseuille equation ... 

Ransohoff and Radke found that for C <10 lamella generation occurred only by the leave-behind mechanism. The lamellae moderately increased the resistance to flow, raising it by about a factor of five (40). (Here p is the viscosity of the nonwetting phase, U is the total superficial velocity, R is the bead radius, K is the absolute permeability, k is the relative permeability, L is length, and Y is the interSacial tension.) The use of this definition of the capillary number, instead of the usual C = jU/y, with J the viscosity of the wetting phase, was justified in the heoretical analysis ( ). 

According to current practice, we generally use average parameters to calculate the capillary number for the whole system, regardless of a two-phase or three-phase system. When the definition Nc = up/a is used to calculate the capillary number, the velocity (u) and viscosity (p) are those of the injection fluid. When the definition Nc = k(Ap/L)/o is used, the absolute permeability (k) and the total pressure drop (Ap) along the distance L are used. In either case, we use Omo for a type ll(-) system, Omw for a type ll(-i-) system, and an average IFT for a type III system—for example, the arithmetic average of 0 0 and Omw. as Delshad et al. (1987) did. 

Incidence The incidence of contrast-induced nephrotoxicity also varies with the definition used. In a prospective study of 275 patients undergoing percutaneous coronary interventions (PCI) used ioxilan, a non-ionic, low-osmolar, low-viscosity monomer, the rate of nephrotoxicity was 3.3% when defined as an absolute increase in serum creatinine of at least 44 pmol/l (0.5 mg/dl) and 10% when it was defined as an increase in serum creatinine of at least 25% above baseline [18 ]. 

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