Viscosity terminology

Viscosity is a measure of a fluid s resistance to flow. The knowledge of viscosity is needed for proper design of required temperatures for storage, pumping, or injection of hazardous fluids. Define the viscosity terminologies, and provide technical data of typical liquid pollutants for illustration. 

With this terminology in mind, we can restate the objective of this section as the interpretation of the intrinsic viscosities of solutions of rigid molecules. If the solute molecules are known to be spherical, comparison of Eqs. (9.10) and (9.14) shows that the intrinsic viscosity for such systems is given by... 

Solvents. Common terminologies used interchangeably are solvents, diluents, reducers, and thinners (Table 2). Technically, solvents are materials that completely dissolve resins in the ink vehicle. Diluents are Hquids that may not completely dissolve the resin by itself. Solvents can also be thinners, but most often thinners are blends of solvents and diluents. Reducer is another name for thinner, referring to the solvent blends used to reduce the viscosity of a virgin ink on the press to miming viscosity. 

Sensor-based methods. Whilst many methods use sensors, the simplest being temperature measurement, this terminology is often used to cover viscosity, pH, oxygen and humidity determination, etc. These are true in-line techniques and offer rapid, inexpensive real-time analysis. Humidity determination in drying ovens is a common example. 

Note This quantity and those in Definitions 3.2.20 and 3.2.21 are neither viscosities nor pure numbers. The terms are to be looked on as traditional names. Any replacement by consistent terminology would produce unnecessary confusion in the polymer literature. 

R. A. Marcus I used the words saddle-point avoidance, incidentally, to conform with current terminology in the literature. More generally, one could have said, instead, avoidance of the usual (quasi-equilibrium) transition-state region (i.e., the most probable region if viscosity effects were absent). 

The conventional names and symbols of viscosity of solutions and also the proposed terminology as approved by the International Union of Pure and Applied Chemistry (1952) are listed in Table II. 

In a discussion of rheology, one important parameter is viscosity. First, we should be aware of the different terminologies related to viscosity. Bulk viscosity is the viscosity measured in a viscometer, which was discussed previously. In situ viscosity in porous media, which is one of the subjects in this section. 

Paraffinic base oils are characterised by good viscosity/temperature characteristics, i.e. high viscosity index, adequate low-temperature properties and good stability. In oil industry terminology, they are frequently called solvent neutrals, SN, where solvent means that the base oil has been solvent refined and neutral means... 

We must perforce devote some time and attention to the concept known as the vlscoilty Index, which has become embedded in the terminology of technological lubrication with some unfortunate connotations. Whereas the Walther equation and the ASTM viscosity-temperature charts are frankly empirical devices used to linearize the viscosity-temperature relations for convenience and utility, the viscosity index is an attempt to impart the mystique of quality by assigning an evaluative aspect to the... 

However, empirical units have left a lasting impression on terminology, and while still employed from time to time in providing names for base stocks (e.g., 100N, 250N), their actual viscosity measurements and their ranges on specification sheets are measured in systematic units and converted to empirical... 

This is measured as the time (in seconds) required for a sample to flow through the orifice of a Saybolt universal viscometer, according to the conditions specified in ASTM D88. Viscosities measured are expressed as, for example, Saybolt universal seconds (SUS), Saybolt seconds universal (SSU), or Saybolt universal viscosity (SUV), and are usually measured at both 100°F and 210°F. This is an outdated method, but as mentioned earlier, its memory lingers in the industry terminology. 

THERMAL CONDUCTIVITY. The proportionality constant A is a physical property of the substance called the thermal conductivity. It, like the newtonian viscosity ft, is one of the so-called transport properties of the material. This terminology is based on the analogy between Eqs. (3.4) and (10,2). In Eq. (3.4) the quantity xg,. is a rate of momentum flow per unit area, the quantity du/dy is the velocity gradient, and jx is the required proportionality factor. In Eq. (10.2), q/A is the rate of heat flow per unit area, dTIdn is the temperature gradient, and k is the proportionality factor. The minus sign is omitted in Eq. (3.4) because of convention in choosing the direction of the force vector. 

A gas is a physical state of matter generally characterized by low density and viscosity and the abilities to greatly expand and contract with changes in temperature and pressure, mix completely with other gases, and occupy any container uniformly. These features are particularly striking when contrasted to the other states of matter, liquid and solid. See Terminology, Liquid, p.241. Terminology, Solid, p.247. 

In order to understand the literature on latex rheology, it is necessary to be familiar with the concepts and terminology used by most investigators. The viscosity of a latex is often expressed as the relative viscosity, rh, which is the viscosity of the latex divided by the viscosity of the aqueous phase, tj. ... 

Terminology and definitions to characterize viscosity are summarized in Table 7.4. 

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