Pascal-second unit

The SI unit of viscosity is pascal-second (Pa s) or newton-second per meter squared (N s m ). Values tabulated are mN s (= centipoise, cP). The temperature in degrees Celsius at which the viscosity of a... 

The dynamic viscosity, or coefficient of viscosity, 77 of a Newtonian fluid is defined as the force per unit area necessary to maintain a unit velocity gradient at right angles to the direction of flow between two parallel planes a unit distance apart. The SI unit is pascal-second or newton-second per meter squared [N s m ]. The c.g.s. unit of viscosity is the poise [P] 1 cP = 1 mN s m . The dynamic viscosity decreases with the temperature approximately according to the equation log rj = A + BIT. Values of A and B for a large number of liquids are given by Barrer, Trans. Faraday Soc. 39 48 (1943). 

Viscosity is equal to the slope of the flow curve, Tf = dr/dj. The quantity r/y is the viscosity Tj for a Newtonian Hquid and the apparent viscosity Tj for a non-Newtonian Hquid. The kinematic viscosity is the viscosity coefficient divided by the density, ly = tj/p. The fluidity is the reciprocal of the viscosity, (j) = 1/rj. The common units for viscosity, dyne seconds per square centimeter ((dyn-s)/cm ) or grams per centimeter second ((g/(cm-s)), called poise, which is usually expressed as centipoise (cP), have been replaced by the SI units of pascal seconds, ie, Pa-s and mPa-s, where 1 mPa-s = 1 cP. In the same manner the shear stress units of dynes per square centimeter, dyn/cmhave been replaced by Pascals, where 10 dyn/cm = 1 Pa, and newtons per square meter, where 1 N/m = 1 Pa. Shear rate is AH/AX, or length /time/length, so that values are given as per second (s ) in both systems. The SI units for kinematic viscosity are square centimeters per second, cm /s, ie, Stokes (St), and square millimeters per second, mm /s, ie, centistokes (cSt). Information is available for the official Society of Rheology nomenclature and units for a wide range of rheological parameters (11). 

Thermal conductivity to convert watts per meter-kelvin to British thermal unit-feet per hour-square foot-degree Fahrenheit, multiply by 0.57779 and to convert British thermal unit-feet per hour-square foot-degree Fahrenheit to watts per meter-kelvin, multiply by 1.7307. Viscosity to convert pascal-seconds to centipoises, multiply by 1000. 

F — 32)/1.8 to convert British thermal units per hoiir-sqiiare foot-degrees Fahrenheit to joules per square meter-second-kelvins, multiply by 5.6783 to convert centipoises to pascal-seconds, multiply hy 10 . ... 

The pascal, a unit of pressure, is equivalent to 1 newton per square meter. If the newton, a unit of force, is equal to a kilogrcim-meter per second squared, what is the pascal expressed entirely in basic units ... 

The Permeability or permeation coefficient (P) is the amount of substance passing through a polymer film of unit thickness, per unit area, per second and at a unit pressure difference. Here we shall use the meter as unit of length and the Pa (i.e. Pascal) as unit of pressure, so that the dimension of P becomes m3(STP). m/(m2 s Pa) = m2/(Pa s). 

In short, the optimum flow rate is the maximum flow rate possible in the column to reach the desired maximum operating pressure. The SI units for solving these equations are AP (pascal or N/m-), p (Pas or Ns/m-). o (m/s). dp (m) and L (m). Thus, typical units for pressure are converted from psi to pascal, typical units for viscosity are converted from centipoise to pascal second, linear velocity from cm/min to m/s, particle size from micrometer to meter and column length from centimeter to meter. 

The unit of absolute viscosity is the pascal second (Pa.s), but centipoise (cP) is generally used as the alternative unit, where 1 Pa.s = 10 cP. Absolute viscosity is usually measured with rotary viscometers where a rotor spins in a container of the fluid to be measured and the resistance to rotation, torque, is measured. Absolute viscosity is an important measurement for the lubricating properties of oils used... 

The viscosity is typically measured by a viscometer. The SI unit of viscosity is the pascal second (Pa s). However, the widely used unit is poise (P) or centipoise (cP) (1 cP = 1 mPa s). The routine laboratory testing of viscosity is typically done using Brookfield viscometers and reported in cP. For non-Newtonian fluids such as those discussed above, the viscosity is dependent on the spindle size and type (number) and speed of rotation (rotation per minute or r/min) of the viscometer. 

Viscosity Parameter describing the flow properties of a liquid depending on the internal friction of the molecule. It is defined by the force in Newton (N) required to displace one interface parallel to the opposite interface with a speed of 1 m s 1 in a liquid layer with a surface area of 1 cm2 and a height of 1 cm. Unit (Pa s), Pascal second. In bonding technology, the dimension mPa s = 10-3 Pa s, milli-Pascal second is often applied for calculation. Water, for example, has a viscosity of 1 mPa s. 

Note The old unit for viscosity was the Poise = 1 dyne-sec/cm. The new SI unit is the Pascal-second. To convert, 1 Poise r 0.1 = 1 Pascal-second (Pa s)... 

In SI units, when the force is one newton, the area A one square meter and the velocity gradient one meter per second per meter, then the unit of viscosity is one newton-second per square meter, or alternately one pascal-second. The c.g.s. unit of viscosity, the poise, is one dyne-second per square centimeter. One pascal-second is therefore equal to 10 poise. 

In SI units is measured in newtons per square meter and p in kilograms per meter-second or pascal-second. In the cgs system viscosity is expressed in grams per centimeter-second, and this unit is called the poise (P). Viscosity data are generally reported in centipoises (cP = 0.01 P = 1 mPa-s), since most fluids have viscosities much less than 1 P. 

Again, the numerical factor is not quite correct, since the flow of gas produces a nonequilibrium situation. For elastic spheres, the factor should be The unit of the viscosity coefficient is 1 newton second per square metre (N sm ) = 1 pascal second (Pa s) = 1 kg m s (The cgs unit is 1 poise = 1 g cm s = 10 kg m s )... 

The viscosity at rest, i.e., zero shear rate, is clinically referred to as zero shear viscosity (unit Pas = Pascal seconds = 1000 cp = 1000 centipoise). This value can not be accurately determined by a rheometer, but is rather extrapolated mathematically, using various computation methods. Viscosity at rest is occasionally employed as the single measure for the assessment and classification of behavioral properties of viscoelastic substances. However, viscosity at rest merely reflects one aspect of the varied biophysical characteristics of viscoelastic substances which merit differentiation. 

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