Rotations per minute

Example 6 Slurry Sampling by Rotary Traverse of Gravity Flow Increment volume, quantity of slurry extracted hy one cutter rotation, is S from hulk slurry flow B expressed in voliime-per-imit time. R is cutter rotation per minute. D is cutter angle opening, with D/360 extraction ratio for continuous cutter rotation. 

A process commonly used to apply PVP to an electrode surface is to allow a solution of the polymer in a solvent such as methanol to evaporate on the surface. The redox active species can be applied by exposing the modified electrode to a solution of the appropriate complex. Alternatively the PVP-redox complex may be formed prior to coating the electrode. A more sophisticated variation of the above technique is spin casting. A small quantity of polymer solution is dropped on to an electrode, e.g. platinum, which is then rotated at thousands of rotations per minute. 

The settling velocity of bioparticles in centrifuges is given by Equation (1). In this equation, the angular velocity co is in rads-1. Equation (24) converts angular velocity expressed in rotations per minute (rpm) to rad s"1. 

The reactor for radiation chemical synthesis with an agitator (about 200 rotations per minute) is located in the operation chamber. Inside the reactor there is a cavity for introducing sources of y-radiation. The role of the radiation source is played by 60Co in airproof stainless steel ampules the activity of 60Co radiation is about 3000 eq Ra. The consumption degree of the energy of radiation when the sources are placed in the cavity, or the radiation coefficient of efficiency, varies from 17 to 19%. The equipment is encased in a special box made of stainless steel and plexiglass the box has intensive ventilation. 

Pure dimethylphosphite can also be extracted by rotory membranous vertical apparatus with the heat exchange surface of 0.8 m2 and the rotor speed of 307 rotation per minute. In this case the optimal parameters are the following the temperature is 105-110 °C, the residual pressure is 40 GPa. The purity of dimethylphosphite can reach 98%. 

Figure 2. Shows the influence of degradation under processing for SBS copolymer 414C. (a) The molecular weight distribution (MWD) before processing, (b) The MWD after 41 min treatment in a Brabender Plasto-graph, Walzenkneter 30 temperature 180°C and rate of rotation 110 rotations per minute (with 1 % lonox added).

Expressing rotations per second n in rotations per minute N, and substituting for n, we have ... 

Pad Velocity Units of rotations per minute (rpm) or (cm/sec). If the wafer is rotated off the axis of the pad (as shown in Figure 2.6a), which is common, the pad velocity is also the average relative velocity of the pad with respect to the wafer. Mechanical abrasion rate is also proportional to velocity. Velocity also affects slurry transport across the wafer and the... 

The schematic principle of a simple arrangement, i.e., the cup and bob viscometer, is shown in Fig. 15. The driveshaft rotates with a given number of rotations per minute. If there were no friction between the two concentric cylinders, the spring would transfer the rotation completely. However, the material to be investigated, which fills the gap between the two concentric cylinders, is viscous and causes resistance against the rotation. As a result, the spring cannot follow the rotation of the drive shaft and gets twisted. Thus, a torque is produced, which is proportional to the shear stress applied. 

The Luwesta (Centriwesta) extractor is a development from Coutor [Eisenlohr, Ind. Chem., 27, p. 271 (1951)]. This centrifuge revolves about a vertical axis and contains three actual stages. It operates at 3800 rotations per minute and handles approximately 5 mVh (1300 gal/h) total liquid flow at 12-kW power requirement. Provision is made in the machine for the accumulation of solids separated from the liquids, for periodic removal. It is used, more extensively in Europe than in tlie United States, for the extraction of acetic acid, pharmaceuticals, and similar products. 

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. 

N is the rotations per minute, radius of outer eylinder, radius of iimer eylinder,... 

Table 8.6. Influence of different rotor/stator systems on the steady-state droplet size distribution (32) , stirrer speed in rotations per minute dispersion time u, volume flow rate...

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