Torque imposed

Since the apparent viscosity of a non-Newtonian fluid holds only for the shear rate (as weii as temperature) at which it is determined, the Brookfield viscometer provides a known rate of shear by means of a spindle of specified configuration that rotates at a known constant speed in the fluid. The torque imposed by fluid friction can be converted to absolute viscosity units (centipoises) by a multiplication factor. See viscosity, shear stress. The viscosities of certain petroleum waxes and wax-polymer blends in the molten state can also be determined by the Brookfield test method ASTM D 2669. 

Another doubt, which unfortunately remained unresolved, concerned the opportunity to base the demonstration of sufficient strength on the presence of a traction in the rods, due to the torque imposed on the lower nuts. Indeed, if this confidence could... 

A major limitation in controlled stress rheometers is instrument inertia. It is very similar to the transducer inertia described with eq. 8.2.1. The torque imposed on the drag cup must overcome reluctance torque, air bearing friction, and rotor inertia as well as the sample viscosity. The inertia portion dominates with low viscosity samples (Kreiger, 1990). Figure 8.2.11a illustrates the problem. Stress was commanded to increase linearly from 0 to... 

The first term accounts for the height the catalyst must back up above the bed in order to overcome the weight (more precisely, torque ) imposed by the flapper plate. 

Figure 7-5. There is no standard speed-torque curve for accelerating compressors. Attempting to make a standard motor to meet all needs (heavy line) would impose unnecessary demands on motor design [7].

The device of Figure 2-70 can also operate as a motor if a DC current is applied to the rotor windings as in the alternator and an AC current is imposed on the stator windings. As the current to the stator flows in one direction, the torque developed on the rotor causes it to turn until the rotor and stator fields are aligned (5 = 0°). If, at that instant, the stator current switches direction, then mechanical momentum will carry the rotor past the point of field alignment, and the opposite direction of the stator field will cause a torque in the same direction and continue the rotation. 

Power-Factor Correction. The induction motors used for oil-well pumping have high starting torques with relatively low power factors. Also, the average load on these motors is fairly low. Therefore, it is advisable to consider the installation of capacitors to avoid paying the penalty imposed by most power companies for low-power factor. They will be installed at the individual motors and switched with them, if voltage drop in the distribution system is to be corrected as well as power factor. Otherwise they may be installed in large banks at the distribution center, if it is more economical to do so. 

Any horizontal force imposed on the vessel by ancillary equipment, the line of thrust of which does not pass through the centre line of the vessel, will produce a torque on the vessel. Such loads can arise through wind pressure on piping and other attachments. However, the torque will normally be small and usually can be disregarded. The pipe work and the connections for any ancillary equipment will be designed so as not to impose a significant load on the vessel. 

Where flanges of different ratings are bolted together, the rating of the joint shall not exceed that of the lower rated flange. Bolting torque shall be limited so excessive loads are not imposed on the lower-rated flange. 

Let us examine the instability oi strained thin films. In Fig. 3, thin films of30 ML are coherently bonded to the hard substrates. The film phase has a misfit strain, e = 0.01, relative to the substrate phase, and the periodic length is equal to 200 a. The three interface energies are identical to each other = yiv = y = Y Both phases are elastically isotropic, but the shear modulus of the substrate is twice that of the film (p = 2p). On the left-hand side, an infinite-torque condition is imposed to the substrate-vapor and film-substrate interfaces, whereas torque terms are equal to zero on the right. In the absence of the coherency strain, these films are stable as their thickness is well over 16 ML. With a coherency strain, surface undulations induced by thermal fluctuations become growing waves. By the time of 2M, six waves are definitely seen to have established, and these numbers are in agreement with the continuum linear elasticity prediction [16]. 

Equation (7.20) is to be regarded as applying throughout all of space, including the particle interiors. Boundary conditions imposed at the sphere surfaces implicitly furnish the relations determining the F s, these being related to the forces, torques, etc., exerted on the fluid by the particles. For instance, the vector F, is related to the external force acting on each particle via the expression... 

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