This dissertation investigates the optical design and characterization for two distinct remote sensing applications. The first application is focused on the high precision optical phase correction for the photonic Local Oscillator (LO) designed for the Atacama Large Millimeter Array (ALMA). The phase instability in the original fiber optics design scheme is characterized and a novel, singlemode fiber-based interferometric approach to measure and actively zero out the unwanted Photonic LO phase drift is introduced. The proposed technique is implemented and characterized by using a 16 km baseline with a two element array. In the second application, the first iteration of the quasioptics design used in the ATOMMS instrument is characterized. (ATOMMS-Active Temperature, Ozone and Moisture Microwave Spectrometer-is the pathfinding implementation of an Earth and Space Atmosphere Global Remote Sensing Instrument).The diffraction problems in this design which were limiting the instrument performance were analyzed. Then different design concepts to mitigate these limitations and optimize system performance are presented.

published_or_final_version / Mathematics / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

This study investigated the effect of cooking on the neutral detergent fiber (NDF) content of cauliflower and carrots. For each replication the vegetable was divided in half to serve as its own control. One half was used raw and the other half was cooked in 60 ml of distilled water for 7 to 8 minutes. Internal temperature of the cooked samples verified a uniform cooking process. Moisture and NDF were determined in both raw and cooked samples. A texture reading, determined by shear force, was also done on the cooked samples. The resulting NDF residues from the raw and cooked samples were used to compare water-absorbing capacity and ash content. In terms of 100 g dry weight, NDF decreased in cooked cauliflower from 19.13 to 17.22 g (p< 0.05) and increased in cooked carrots from 9.47 to 10.54 g (p<0.05). The exact opposite was observed for water-absorbing capacity. It increased in cooked cauliflower and decreased in cooked carrots. Ash content showed large variations but a general increase in both vegetables after cooking. No positive relationship was found between texture and NDF in the cooked vegetables. These observations confirm the complex nature of dietary fiber. Results suggest that although cooking affected the NDF in selected vegetables, the quantity of the change was not large enough to alter dietary fiber's physiological effect in the body. / Graduation date: 1981

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / This paper gives detailed ideas and methods about the design and development of high performance MIL-STD-1773 airborne fiber optic data bus. To reject impulsive interference efficaciously, the large core and large numerical aperture fiber optics are adopted, as well as high- emitted power LEDs and a low noise optical receiver structure to get high signal-to-noise ratio at decision time. Two new modulation technique----digital frequency shift keying and partial tri-level Manchester are recommended, which are very attractive in the design of modern optical bus. Meanwhile, VLSI chips COM1553B are used to construct bus control interface unit, thus many advantages have been brought out.

M.Ing. / A study was done on optical fibre hydrophones. Integrated optic hydrophone components as well as optical fibre components were investigated. An optical fibre coupler was successfully manufactured with an etch process. The coupling ratio can be varied mechanically or by means of refraction index variation. Experimental procedures and results will be shown. Bending losses excited in an optical fibre coil were investigated as a function of different coil diameters. The results were extrapolated to determine the amount of losses arising in a hydrophone coil.

Doctor of Philosophy / Department of Grain Science and Industry / Sajid Alavi / Extrusion processing is a technology widely used to make ready-to-eat snack and breakfast cereal products. The raw materials that result in optimal texture and consumer acceptance are mainly those with high levels of starch, which greatly limits the nutritional value of these products. One alternative to enhance the nutritional value is the incorporation of fruits and vegetables. Fruits and vegetables are consistently under-consumed by the American population and incorporation into extruded products may help increase the intake of important nutrients, such as dietary fiber. In the first part of this study a lab-scale twin screw extruder was used for processing directly expanded products based on corn flour and apple pomace (0-28%), resulting in a total dietary fiber content of 1.1-22.5%. Apple pomace increased nucleation and favored axial expansion. The change in cell size and alignment explained the higher mechanical resistance caused by apple pomace. The objective of the second part was to study the effect of preconditioning regimen on the extent of matrix transformation and impact on texture, microstructure and digestibility. The material was processed on a pilot scale extruder. The results showed that increasing the opportunity for hydration increased starch gelatinization at all pomace levels. Apple pomace promoted milder extrusion conditions, resulting in less starch gelatinization and solubilization and reduced starch digestibility. Digestibility was also affected by structure, with a strong correlation between the available starch fraction and cell wall thickness/cell size ratio (r=0.90). The third part of this study was designed to gain a better understanding of the impact of the individual cell wall components (cellulose, lignin, xyloglucan and pectin) on expansion and structure formation. The results suggest that compatibility with starch is critical for good dispersion in the matrix, therefore good expansion and structure forming properties.

Neste trabalho consideramos o problema de enumerar G-fibrados sobre variedades de dimensão baixa (menor ou igual a 3), em particular fibrados vetoriais sobre as ?spherical space forms? tridimensionais. É dada uma resposta completa para estas questões e na seção 5.1 são colocadas tabelas que explicitam os possíveis fibrados vetoriais sobre as ?spherical space forms?. Este tipo de problema é recorrente em topologia algébrica e por motivos dados pela teoria de homotopia, é preciso calcular certos invariantes algébricos com sistemas de coeficientes locais, o que torna o problema mais interessante. Mostramos ainda que sobre condições consideravelmente abrangentes no grupo estrutural G, os G-fibrados sobre variedades de dimensão menor ou igual a três podem ser enumerados de maneira efetiva / In this work we consider the problem of enumerating G-bundles over low dimensional manifolds (dimension · 3) and in particular vector bundles over the three dimensional ?spherical space forms?. We give a complete answer to these questions and in section 5.1 we give tables for the possible vector bundles over the ?spherical space forms?. We deal with the problem of enumerating vector bundles over a class of manifolds. This is a long standing classical problem in algebraic topology, and because of homotopy theoretical reasons, it implies calculations of algebraic invariants with local system of coefficients, and thus becomes a cumbersome target away from the trivial occurrences. Although, we show that, under reasonably wide assumptions on the structure group G, G-bundles over low (lower or equal to three) dimensional manifolds can be counted effectively

Neste trabalho consideramos o problema de enumerar G-fibrados sobre variedades de dimensão baixa (menor ou igual a 3), em particular fibrados vetoriais sobre as ?spherical space forms? tridimensionais. É dada uma resposta completa para estas questões e na seção 5.1 são colocadas tabelas que explicitam os possíveis fibrados vetoriais sobre as ?spherical space forms?. Este tipo de problema é recorrente em topologia algébrica e por motivos dados pela teoria de homotopia, é preciso calcular certos invariantes algébricos com sistemas de coeficientes locais, o que torna o problema mais interessante. Mostramos ainda que sobre condições consideravelmente abrangentes no grupo estrutural G, os G-fibrados sobre variedades de dimensão menor ou igual a três podem ser enumerados de maneira efetiva / In this work we consider the problem of enumerating G-bundles over low dimensional manifolds (dimension · 3) and in particular vector bundles over the three dimensional ?spherical space forms?. We give a complete answer to these questions and in section 5.1 we give tables for the possible vector bundles over the ?spherical space forms?. We deal with the problem of enumerating vector bundles over a class of manifolds. This is a long standing classical problem in algebraic topology, and because of homotopy theoretical reasons, it implies calculations of algebraic invariants with local system of coefficients, and thus becomes a cumbersome target away from the trivial occurrences. Although, we show that, under reasonably wide assumptions on the structure group G, G-bundles over low (lower or equal to three) dimensional manifolds can be counted effectively

Anti-resonant hollow core fibre is a new kind of optical fibre waveguide in which light is trapped in a hollow core surrounded by the capillary formed microstructured cladding. This fibre exhibits high damage threshold, low dispersion and ultra-low nonlinearity with relatively low loss of a few tens of dB/km. Its intrinsic feature of multimode delivery limits the applications with high requirements of single mode transmission. In my thesis, I demonstrate how the design of hollow core fibre can be improved with single mode guidance. S2 imaging measurement was used to analyse the mode content of the solid core fibres. In my research, I established S2 measurement to measure the mode contents in hollow core fibres for the first time. Two hollow core fibres with 8 capillaries and 7 capillaries in their claddings were fabricated in same fashion and showed differences in low attenuations. By comparing the mode contents in both of the fibres via S2 imaging measurement, 7-capillary HCF was demonstrated to give better performance on single mode guidance. Among the applications of the HCF, the property of delivering high power in HCF makes the gas filled HCF laser possible. In my research, a continuous-wave mid-infrared acetylene filled hollow core laser was built with a slope efficiency of 33% and an output power of over 1 watt at the wavelength region of 3.1~3.2 μm. The pump source is an Erbium-doped fibre amplified tunable laser diode which works at C-band wavelength. The fibre without the gain medium has two transmission bands with low attenuation of 0.037 dB/m and 0.063 dB/m at pumping and lasing wavelengths respectively. This laser system works in either cavity-based configuration or single pass ASE configuration. The latter configuration shows a better performance in high output power and high slope efficiency. The optimized laser system was studied experimentally with the proper fibre length and gas pressure. This laser system could be extended to be filled with other molecules to longer wavelengths and has potential for high power output.