The induction motor

Citation: Matthews, Howard David and Dial, Thomas E. The induction motor. Senior thesis, Kansas State Agricultural College, 1904.Morse Department of Special CollectionsIntroduction:The induction motor is a type of alternating current motor in which the magnetic flux is furnished by either a single phase or a polyphase current. Consider the action of a compass suspended over a magnetic field, the needle thus suspended will take a position parallell to the lines of force, which flow from pole to pole. Now if the nagnet be rotated the needle will change position relative to it. If the magnet be substituted for a four pole electro-magnet as shown in Fig. 1 Plate 1 and a current of electricity be allowed to flow about either of the sets of poles, and the needle be allowed to swing freely in the center, it will set its self parallel to the lines if a current is flowing in all four poles at the same time this needle will set itself diagonally half way between the sets of poles, as illustrated by Fig. 2. Plate 1. It is now easily conceivable that, if one of these currents, in the windings of the poles is becoming weaker as the other is growing stronger, t the needle will be attracted to the former until the flux reaches its maximum value. Where an alternating current is used this process of rapidly changing from maximum to minimum tends to rotate the needle. If,now, a cylinder consisting of copper conductors be used, instead of a needle, the machine becomes an Induction Motor. The direction of rotation is determined by the phase relation of the currents, The direction of rotation may be reversed by interchanging and two wires of a three phase three wire circuit. Thus by means of polyphase currents it is very easy to produce rotating fields

Control system design using optimization techniques Final report

Optimization techniques for control of fuel valve systems for air breathing jet engines and 40-60 inlet control problem

Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit

Two level systems that can be reliably controlled and measured hold promise in both metrology and as qubits for quantum information science (QIS). When prepared in a superposition of two states and allowed to evolve freely, the state of the system precesses with a frequency proportional to the splitting between the states. In QIS,this precession forms the basis for universal control of the qubit,and in metrology the frequency of the precession provides a sensitive measurement of the splitting. However, on a timescale of the coherence time, $T_2$, the qubit loses its quantum information due to interactions with its noisy environment, causing qubit oscillations to decay and setting a limit on the fidelity of quantum control and the precision of qubit-based measurements. Understanding how the qubit couples to its environment and the dynamics of the noise in the environment are therefore key to effective QIS experiments and metrology. Here we show measurements of the level splitting and dephasing due to voltage noise of a GaAs singlet-triplet qubit during exchange oscillations. Using free evolution and Hahn echo experiments we probe the low frequency and high frequency environmental fluctuations, respectively. The measured fluctuations at high frequencies are small, allowing the qubit to be used as a charge sensor with a sensitivity of $2 \times 10^{-8} e/\sqrt{\mathrm{Hz}}$, two orders of magnitude better than the quantum limit for an RF single electron transistor (RF-SET). We find that the dephasing is due to non-Markovian voltage fluctuations in both regimes and exhibits an unexpected temperature dependence. Based on these measurements we provide recommendations for improving $T_2$ in future experiments, allowing for higher fidelity operations and improved charge sensitivity

Topics concerning state variable feedback in automatic control systems. Part 1 - Specification. Part 2 - Sensitivity. Part 3 - Intentional nonlinearities. Part 4 - Unavailable states

Specifications, sensitivity, intentional nonlinearities, and unavailable states concerned with state variable feedback in automatic control system

Search for Mars lander/rover/sample-return sites: A status review

Ten Mars sites were studied in the USA for four years. The sites are the Chasma Boreale (North Pole), Planum Australe (South Pole), Olympus Rupes, Mangala Valles, Memnonia Sulci, Candor Chasma, Kasel Valles, Nilosyrtis Mensae, Elysium Montes, and Apollinaris Patera. Seven sites are being studied by the USSR; their prime sites are located at the east mouth of Kasel Valles and near Uranius Patera. Thirteen geological maps of the first six USA sites are compiled and in review. Maps of the Mangala East and West sites at 1:1/2 million scale and a 1:2 million scale map show evidence of three episodes of small-channel formation interspersed with episodes of volcanism and tectonism that span the period from 3.5 to 0.6 b.y. ago. The tectonic and geological history of Mars, both ancient and modern, can be elucidated by sampling volcanic and fluvial geologic units at equatorial sites and layered deposits at polar sites. The evidence appears clear for multiple episodes of fluvial channeling, including some that are quite recent; this evidence contrasts with the theses of Baker and Partridge (1986) and many others that all channels are ancient. Verification of this hypothesis by Mars Observer will be an important step forward in the perception of the history of Mars

Martian terrains

Terrain studies of candidate landing sites for a future rover/sample-return mission to Mars are being conducted to evaluate the geologic and trafficability aspects of each site. An optimum site should have geologic units of widely diverse ages and chemical compositions occurring in close enough proximity and in smooth enough terrain so that a roving vehicle of limited traverse ability (+ or - 100 km) could collect representative samples. In FY 1986, geologic maps were compiled at 1:500,000 and 1:2 million scales of the Mangala Valles, Kasei Valles, Chasma Boreale (north polar), and Planum Australe (south polar) areas, and a study was begun of the topography and surface roughness characteristics of the Mangala Valles site. Geologic mapping has been greatly facilitated by specially enhanced, high-resolution Viking photographs, which clarify stratigraphic relations of units unrecognized earlier. Photoclinometric profiles of topographic features provide width and depth measurements of four classes of channels, the thickness of some volcanic units, and the throw on some faults. Estimates of the surface roughness of units are calculated using a newly developed USGS computer program and using measurements derived from Earth-based radar