Wedge, adjusting

Shoe Delay. Defines the shoe, or wedge, delay, in tenths of microseconds, of the prohe being used. This control is used to adjust the zero point of time interval measurement to correspond to the instant that the ultrasound pulse enters the test piece. 

As illustrated in Fig. 5.2, the classic Jeffery-Hamel flow concerns two-dimensional radial flow in a wedge-shaped region between flat inclined walls. The flow may be directed radially outward (as illustrated) or radially inward. The flow is assumed to originate in a line source or terminate in a line sink. Velocity at the solid walls obeys a no-slip condition. In practice, there must be an entry region where the flow adjusts from the line source to the channel-confined flow with no-slip walls. The Jeffery-Hamel analysis applies to the channel after this initial adjustment is accomplished. 

Look at Figures Ell-1 (Caffeine) and El 1-2, p. 538 (CHCIj). Notice that the 8.2 and 13.2 pm bands of CHClj will interfere with the 8.1 and 13.4 pm bands of the caffeine spectrum. If possible, the absorption due to CHCl, should be blanked out. A wedge cell, having a variable thickness, is excellent for this purpose. Set the chart at the short wavelength end of the scale (2.5 to 3.0 pm) and adjust the %T to about 80-85%. 

Since cement contractors cannot finish foundations to exact levels, it is customary to provide a rough finished machine foundation 1 to 2 in. below the required level. The equipment is temporarily wedged and then positioned by adjusting nuts. The frame is then grouted in place by use of a mortar fill which adheres to the rough concrete surface (Fig. 8-6c). 

When a catheter tip wedges into the internal lining of the vein wall, it is considered positional. With the fluid path restricted by the vein wall, increases in line resistance may indicate a positional catheter. With patient movement, for example wrist flexation, the catheter may move in and out of the positional state. Since a positional catheter is thought to be more prone toward extravasation than other catheters, early detection of a positional catheter and appropriate adjustment of catheter position may be helpful in reducing the frequency of extravasation. 

However, as the calculations show, the contribution to the value of introduced by the additional terms involving a and / is less than -2°. Furthermore, the values of must be increased by °-1° with respect to those calculated from Eq. (4.2) in any case, because of limited accuracy in the adjustment of the wedge in the sample compartment of the spectrometer. Therefore, to calculate the angle Eq. (4.1) is recommended, and in the small-angle approximation (sin a Pa a, cos a 1), it may be rewritten as... 

Strip is now thicker on that edge (Fig. 14). Subsequently, the strip has a tendency to drift. By adjusting the parallelism between the top and bottom rolls to match the wedge in the material, tracking can be improved. 

Traditional vertical controls of the top versus bottom work roll flights are through a system of worm wheel screw jacks, either directly connected or through wedges. These screw jacks may be driven by either electric or hydraulic motors. In either case, the setting is mechanical, precise, repeatable, and relatively free of backlash. The same is true of the drives for vertical backup roll adjustment, whether by wedge or otherwise. 

---