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An ultrasonic method for detection of fluid properties in the paranasal sinuses

We propose a method for detection of the degree of infection in the paranasal sinuses utilizing a previously published method whereby the viscosity in a sealed container may be measured using an ultrasound Doppler method. As ultrasound propagates in a liquid medium, due to attenuation, the resulting pressure gradient will cause the liquid to move in the propagation direction - the wellknown effect

Reactive Sintering of Cu-Al, Ni-Al and Ni-Ti Powder Mixtures

Intermetallic compounds are a distinct group of materials having attractive properties and wide applications. In the present work, the formation of intermetallic compounds from elemental components in Cu-Al, Ni-Al and Ni-Ti systems has been studied. Metallic powders were mixed in stoichiometric ratios corresponding to CuAl2, NiAl and NiTi. Calorimetric studies were made using compacted disks as we

Topics in Authentication Theory

Authentication theory deals with problems connected with the protection of information sent over insecure channels. This thesis concerns different problems in authentication theory. In particular, we consider unconditionally secure authentication, i.e., providing authentication protection agains an enemy equipped with unlimited computing power. Several topics in authentication theory are treated: