Three Generations of FPGA DAQ Development for the ATLAS Pixel Detector

Thesis (Master's)--University of Washington, 2016-06

Genetic uniformity of international isolates of Leifsonia xyli subsp xyli, causal agent of ratoon stunting disease of sugarcane

An international collection of the sugarcane ratoon stunting disease pathogen, Leifsonia xyli subsp. xyli, was analysed to assess genetic diversity. DNA fingerprinting using BOX primers was performed on 105 isolates, comprising 65 Australian isolates and an additional 40 isolates from Indonesia (n = 8), Japan (n = 1), USA (n = 3), Brazil (n = 2), Mali (n = 2), Zimbabwe (n = 13), South Africa (n = 9) and Reunion (n = 2). Sixty-two of these isolates were also screened using ERIC primers. No variation was found among any of the isolates. The intergenic spacer (IGS) region of the ribosomal RNA genes from 54 isolates was screened for sequence variation using single-stranded conformational polymorphism (SSCP), but none was observed. Direct sequencing of the IGS from a subset of nine isolates, representing all of the countries sampled in this study, confirmed the results of the SSCP analysis. Likewise, no sequence variation was found in the 16S ribosomal RNA genes of the same subset. Four Colombian isolates from sugarcane, morphologically similar to L. xyli subsp. xyli, were putatively shown to be an undescribed Agrococcus species of unknown pathogenicity. The lack of genetic variation among L. xyli subsp. xyli isolates, independent of time of sampling, cultivar of isolation, or country of origin, suggests the worldwide spread of a single pathogenic clone, and further suggests that sugarcane cultivars resistant to ratoon stunting disease in one area should retain this property in other regions.

Density evolution for multistage CDMA multiuser detector

An analytical framework to analyze the stage-by-stage detection dynamics of the multistage CDMA multiuser detector is presented. The density evolution idea is applied to analyze the multistage detector. Message distribution is treated basically by a Gaussian approximation, but interstage correlation of messages is systematically taken into account, which turns out to provide significant improvement.

Temperature non-uniformity in distributed temperature sensors

A study is presented of the effects of temperature non-uniformity in a distributed temperature sensor based on the temperature dependence of Brillouin gain in an optical fibre. The form of the Brillouin gain profile for a given temperature distribution is measured and successfully modelled.

A compact, portable and low cost generic interrogation strain sensor system using an embedded VCSEL, detector and fibre Bragg grating

We present a compact, portable and low cost generic interrogation strain sensor system using a fibre Bragg grating configured in transmission mode with a vertical-cavity surface-emitting laser (VCSEL) light source and a GaAs photodetector embedded in a polymer skin. The photocurrent value is read and stored by a microcontroller. In addition, the photocurrent data is sent via Bluetooth to a computer or tablet device that can present the live data in a real time graph. With a matched grating and VCSEL, the system is able to automatically scan and lock the VCSEL to the most sensitive edge of the grating. Commercially available VCSEL and photodetector chips are thinned down to 20 µm and integrated in an ultra-thin flexible optical foil using several thin film deposition steps. A dedicated micro mirror plug is fabricated to couple the driving optoelectronics to the fibre sensors. The resulting optoelectronic package can be embedded in a thin, planar sensing sheet and the host material for this sheet is a flexible and stretchable polymer. The result is a fully embedded fibre sensing system - a photonic skin. Further investigations are currently being carried out to determine the stability and robustness of the embedded optoelectronic components. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

The design of gas chromatography ionisation detectors:a study of the electron capture detector and the home ionisation detector

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

Temperature non-uniformity in distributed temperature sensors

A study is presented of the effects of temperature non-uniformity in a distributed temperature sensor based on the temperature dependence of Brillouin gain in an optical fibre. The form of the Brillouin gain profile for a given temperature distribution is measured and successfully modelled.

A compact, portable and low cost generic interrogation strain sensor system using an embedded VCSEL, detector and fibre Bragg grating

We present a compact, portable and low cost generic interrogation strain sensor system using a fibre Bragg grating configured in transmission mode with a vertical-cavity surface-emitting laser (VCSEL) light source and a GaAs photodetector embedded in a polymer skin. The photocurrent value is read and stored by a microcontroller. In addition, the photocurrent data is sent via Bluetooth to a computer or tablet device that can present the live data in a real time graph. With a matched grating and VCSEL, the system is able to automatically scan and lock the VCSEL to the most sensitive edge of the grating. Commercially available VCSEL and photodetector chips are thinned down to 20 µm and integrated in an ultra-thin flexible optical foil using several thin film deposition steps. A dedicated micro mirror plug is fabricated to couple the driving optoelectronics to the fibre sensors. The resulting optoelectronic package can be embedded in a thin, planar sensing sheet and the host material for this sheet is a flexible and stretchable polymer. The result is a fully embedded fibre sensing system - a photonic skin. Further investigations are currently being carried out to determine the stability and robustness of the embedded optoelectronic components. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).