Summary and Future Developments

In this chapter, we discussed different approaches used for the design and fabrication of power SiC MOSFETs, including a review of the various structures (UMOS, DMOS, and LDMOS) and process challenges associated with each structure. 

This chapter gives an in-depth overview of ultrasonic techniques for monitoring fluid/particle flows. Ultrasonic instruments are generally favored by industrial 

FIGURE 5-41 Viscosity calibration data in low-viscosity range-obtained with polyetherimide wedge and multiple reflection technique. 

We have presented an innovative technique to measure liquid density and viscosity of a solid/liquid flow. The technique, which gives an accurate and quantitative measurement of liquid density, is the only technique that provides liquid density and viscosity separately. The drawback of this technique is that it does not measure bulk phenomena, instead, it senses the liquid properties near the pipe wall. The presence of solid particles has little effect on the measurements. 

To characterize a solid/fluid flow, particle-size distribution, solid concentration, and effects of particles on fluid viscosity must be determined. At present, no technology is available to accomplish these tasks. Optical methods can conceivably be used to determine particle-size distribution in dilute flows. Ultrasonic techniques suffer from high attenuation in solid suspensions, particularly in the frequency range of interest ( 10 MHz for typical particle sizes 

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Proposed polymer and surfactant drag reduction mechanisms Summary and future development... 

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