Typescript, etc. / Digitized by Kansas State University Libraries

Thesis (M.S.)--Virginia Polytechnic Institute, 1954. / Vita. Includes bibliographical references (leaves 57-59). Also available via the Internet.

Thesis (M.S.)--University of Wisconsin--Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The 3/4-race cam and dual carburetors tested in this investigation provided moderate increases in maximum power output at speeds above 3000 rpm, The fuel consumption was reduced by the use of the racing type cam and increased with the use of two standard carburetors. However in the latter case it is possible that the economy would have been improved had the proper carburetor jets been installed. The maximum power afforded by the dual carburetors occurred at about the same speed as that for the stock engine whereas the maximum power afforded by the 3/4-race cam occurred at 250 rpm higher than that of the stock engine. Large increases in maximum power output and increase in the speed for maximum power were provided by a combination of a 3/4-race cam and dual carburetors. However the gain in speed and power was obtained at the expense of fuel consumption. The above modifications in engine equipment were beneficial for high speed operation, the only advantage at low speeds being an increase in the accelerating ability of the engine. / Master of Science

Over the past decade, the satellite industry has witnessed the birth and evolution of the CubeSat standard, not only as a technology demonstrator tool but also as a human capacity development platform in universities. The use of commercial off the shelf (COTS) hardware components makes the CubeSat a cost effective and ideal solution to gain access to space in terms of budget and integration time for experimental science payloads. Satellite operations are autonomous and are essentially based on the interaction of interconnected electronic subsystems exchanging data according to the mission requirements and objectives. The onboard computer (OBC) subsystem is developed around a microcontroller and plays an essential role in this exchange process as it performs all the computing tasks and organises the collection of onboard housekeeping and payload data before downlink during an overpass above the ground station. The thesis here presented describes the process involved in the development, design and implementation of a prototype OBC for a CubeSat. An investigation covering previously developed CubeSat OBCs is conducted with emphasis on the characteristics and features of the microcontroller to be used in the design and implementation phases. A set of hardware requirements are defined and according to the current evolution on the microcontroller market, preference is given to the 32-bit core architecture over both its 8-bit and 16-bit counterparts. Following a well defined selection process, Atmel’s AT91SAM3U4E microcontroller which implements a 32-bit Cortex-M3 core is chosen and an OBC architecture is developed around it. Further, the proposed architecture is implemented as a prototype on a printed circuit board (PCB), presenting a set of peripherals necessary for the operation of the OBC. Finally, a series of tests successfully conducted on some of the peripherals are used to evaluate the proposed architecture.