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Full-Text Articles in Engineering

Spin Transport Studies In Nanoscale Spin Valves And Magnetic Tunnel Junctions, Sridhar Patibandla Oct 2008

Spin Transport Studies In Nanoscale Spin Valves And Magnetic Tunnel Junctions, Sridhar Patibandla

Theses and Dissertations

Spintronics or electronics that utilizes the spin degree of freedom of a single charge carrier (or an ensemble of charge carriers) to store, process, sense or communicate data and information is a rapidly burgeoning field in electronics. In spintronic devices, information is encoded in the spin polarization of a single carrier (or multiple carriers) and the spin(s) of these carrier(s) are manipulated for device operation. This strategy could lead to devices with low power consumption. This dissertation investigates spin transport in one dimensional and two dimensional semiconductors, with a view to applications in spintronic devices.


Fiber Bragg Grating (Fbg) Based Chemical Sensor, Gopakumar Sethuraman Aug 2008

Fiber Bragg Grating (Fbg) Based Chemical Sensor, Gopakumar Sethuraman

Theses and Dissertations

In this work, reagentless fiber optic-based chemical sensors for water quality testing were fabricated by coating fiber Bragg gratings with the glassy polymer cellulose acetate. With this polymeric matrix capable of localizing or concentrating chemical constituents within its structure, immersion of the coated grating in various chemical solutions causes the rigid polymer to expand and mechanically strain the glass fiber. The corresponding changes in the periodicity of the grating subsequently result in altered Bragg-reflected responses. A high-resolution tunable fiber ring laser interrogator is used to obtain room temperature reflectance spectrograms from two fiber gratings at 1550 nm and 1540 nm …


Prediction Of Breathing Patterns Using Neural Networks, Pavani Davuluri Jan 2008

Prediction Of Breathing Patterns Using Neural Networks, Pavani Davuluri

Theses and Dissertations

During the radio therapy treatment, it has been difficult to synchronize the radiation beam with the tumor position. Many compensation techniques have been used before. But all these techniques have some system latency, up to a few hundred milliseconds. Hence it is necessary to predict tumor position to compensate for the control system latency. In recent years, many attempts have been made to predict the position of a moving tumor during respiration. Analyzing external breathing signals presents a methodology in predicting the tumor position. Breathing patterns vary from very regular to irregular patterns. The irregular breathing patterns make prediction difficult. …