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As wireless communication is ever-evolving, demanding higher data speeds, the requirementsincrease for the ADC, and the requirements for the comparator, which is one of the mainbuilding blocks, increase as well. The primary purpose of the comparator is to compare twovoltage levels and provide a logic output. One significant advantage of dynamic comparatorsis that they are more power-efficient than traditional comparators. There exist many differentarchitectures for dynamic comparators. In this thesis, the most promising designs areoptimized and evaluated over various parameters, such as speed, noise, offset, and hysteresis,while minimizing power consumption. The thesis includes a traditional StrongARM-latch,a double tail, and four triple tail comparators. The StrongARM-latch was the most powerefficientdesign while all the parameters were within the requirements, which was unexpected.

Much is known about the atomic/molecular theories that govern adhesion as well as the macroscopic aspects and properties of adhesion. However, adhesion in the microparticle regime is poorly characterized. We report on experiments that use centrifugal force to remove polystyrene (PS) particles from the surface of a high-speed titanium rotor operated in vacuum. This unique rotor can apply forces far greater than other centrifugal force methods or related techniques using atomic force spectroscopy. The mode of attachment, whether particles were located on the windward side versus leeward side of the spinning rotor, time spent in vacuum prior to experiments, and surface imperfections all showed an effect on adhesion. Our observations show initial agreement with published results from atomic force spectroscopy experiments. We conclude that the liquid used to help suspend and apply the PS particles greatly influences the total adhesive forces present in the system. This in turn provides valuable clues as to the nature of the adhesive interaction.

No / M3/2 sintered high speed steel and composite materials processed by initial admixing of 5 wt.% TiC (to decrease wear) and 5 wt.% MnS (to minimise friction) powders, singly and in combination, were assessed in pin-on-disc tribometers specially constructed to simulate use in the automotive valve train. Pins were of the sintered materials and the mating tribological material discs of T1 high speed steel. For comparison with existing conventional materials, identical tests were performed with discs and pins of two types of spheroidal cast iron. Testing at 110 °C, employing a few drops of fresh Shell Helix Standard SAE: 15W-40, API: SJ/CF oil, in daily segments of 5000 m of sliding distance was carried out until the break of the boundary film and appearance of the early signs of seizure. Accordingly the conditions were initially elastohydrodynamic, then mixed lubrication, then boundary, and finally decaying boundary. In comparison with the baseline cast iron system, the friction, wear and lifetime performance of all the high speed steel systems was markedly superior. MnS further lowered the coefficient of friction and TiC increased the load carrying capacity of M3/2 steel. The lifetime, test distance until seizure, was the most discriminating parameter between the high speed steel systems, being 1.5¿3 times longer for the unmodified M3/2 than the composites and 10 times longer than that of the cast irons system.

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