Engineering Commons^™

Theory And Design Of Cyclotron-Wave Traveling-Wave Amplifiers, Arthur H. Gottfried

Dissertations

A theory and design procedure for traveling-wave tubes using cyclotron-wave interactions is developed. An analysis is presented of the energy exchange mechanism and the axial beam velocity spread induced by the r.f. interactions. The analysis of the energy spread in a realistic model of the beam with nonzero size and nonzero space-charge density shows that higher maximum efficiencies at higher power is attainable (with collector depression) in cyclotron-wave amplifiers than in synchronous-wave amplifiers.

A one-watt, and a ten-watt cyclotron-wave amplifier at 3 GHz, utilizing bifilar helix circuits, scaled from a 2 kW, 5 GHz design, were constructed. A computer was …

Noise Performance Of The Klapper-Kratt Low Delay Fm Detector, Allan Brown Tarbell

Dissertations

In this dissertation the dual differentiator version of the Klapper-Kratt FM detector family is investigated with additive Gaussian noise. Prior analysis of this new detector family has been limited to the noiseless case.

The investigation was conducted both analytically and experimentally. First, the dual differentiator version of the Klapper-Kratt detector was mathematically analyzed, assuming an unmodulated carrier plus additive Gaussian noise. This analysis was verified by assembling the detector and measuring its performance in the laboratory.

It was discovered that the Klapper-Kratt detector without limiter performs identically to the conventional limiter discriminator in the linear improvement region. When compared to …

Signal Processing Techniques For Analysis Of Heart Sounds And Electrocardiograms, Alan D. Bernstein

Dissertations

Audible heart sounds represent less than 5% of the vibrational energy associated with the cardiac cycle. In this study, experiments have been conducted to explore the feasibility of examining cardiac vibration by means of a single display encompassing the entire bandwidth of the oscillations and relating components at different frequencies. Zero-phase-shift digital filtering is shown to be required in producing such displays, which extend from a recognizable phonocardiogram at one frequency extreme to a recognizable apexcardiogram at the other. Certain features in mid-systole and early diastole, observed by means of this technique, appear not to have been previously described.

Frequency …

Synthesis Of Multiarea Grid Power Systems, Bharat C. Patel

Dissertations

This dissertation presents improved development in the formation of a generalized transmission loss (B)-matrix for a multiarea grid power system. In the procedure, the individual tie powers of each area are replaced by the net interchange, sneak and circulating powers. The latter two variables are directly eliminated in the power reference frame using actual impedances, unlike current methods that require the elimination of sneak and circulating currents, the formation of complex tie current model and the complex tie power model. Consequently, manipulation of large complex current, power and impedance matrices is avoided reducing both computer time and memory requirement. Further, …

A New Mathematical Model For Nephron Macromolecular Selectivity, John Anthony Domiter

Theses

A mathematical model describing the displayed selectivity of the kidney nephron to macromolecules of varying particle size is presented. Diffusion and electrical forces are considered to be the sole mechanisms of transfer. The mass transfer principles responsible for selectivity are considered to occur within the capillary structure, and not within the membrane wall. A charge is assumed to be characteristic of the macromolecule and the membrane wall. Models describing both charged and uncharged solutes are developed.

A non-linear least squares technique, developed by Marquardt, is used to curve fit the derived functions to data relating fractional clearances of dextran and …