Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 208-221). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 182-184).

Organosilanes are widely used to bond organic materials such as polymers to inorganic materials in polymer composites. However, the mechanism of adhesion is poorly understood. One postulated mechanism is the interdiffusion of the silane and polymer, along with condensation of the silane to form an interpenetrating polymer network (IPN). The techniques of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and Raman confocal microscopy have been used to study the diffusion, hydrolysis and condensation of three organosilanes in silicon / PVC / silane laminates. These processes are thought to contribute to the formation of the IPN, and hence to be vital for adhesion. The organosilanes studied were [3-(amino)propyl]trimethoxysilane, also known as A1110, [3-(phenylamino)propyl]trimethoxysilane, known as Y9669, and [3-(mercapto)propyl]triethoxysilane, known as A1891.ATR-FTIR was shown to be an excellent technique for studying the kinetics of silane diffusion through PVC films. It was shown that at room temperature, no diffusion through unplasticised PVC films occurred. At 70 °C, however, diffusion occurred readily for Y9669 and A1891. In plasticised PVC films, diffusion was observed for all three silanes at room temperature. It was shown that the diffusion occurred more quickly with higher plasticiser concentrations, and hence lower glass transition temperatures. The kinetics of diffusion was found to fit a dual mode sorption model. Hydrolysis of the silanes was also followed by infrared spectroscopy, and the kinetics of hydrolysis and condensation were shown to be highly dependent upon silane type, the concentration of water, and the presence of an acid catalyst. The hydrolysis of the silanes was found to slow their diffusion through both plasticised and unplasticised PVC films. It was shown that the presence of water in the films caused the hydrolysis of the silanes in situ. Raman depth profiles were measured of the films before, during and after diffusion. The spatial resolution was shown to be adversely affected by refraction at the air / PVC interface. It was shown that it is possible to deconvolve the confocal response of the microscope from the depth profiles, resulting in greater spatial resolution. Hydrolysis of the silanes was followed in solution by Raman spectroscopy, and it was found that each of the three silanes showed different rates of hydrolysis and condensation. It was shown that it was also possible to follow the kinetics of diffusion by Raman microscopy, and the results agreed well with those shown by ATR-FTIR spectroscopy.

Master of Science / Department of Agronomy / William T. Schapaugh Jr / Sudden Death Syndrome (SDS) in soybean, (Glycine max ( L.) Merr.) caused by Fusarium virguliforme, is an increasing problem in commercial soybean production due to the yield loss associated with the disease. Screening for genetic resistance requires extensive visual evaluations. Canopy spectral reflectance may be an indirect tool for selection of SDS resistance as well as grain yield in large segregating populations. The objective of this study was to estimate SDS resistance and seed yield in large diverse soybean populations using canopy spectral reflectance. Spectral reflectance, disease index, maturity and yield were measured on two populations consisting of 160 nested association mapping recombinant inbred lines and checks; and 140 commercial cultivars with checks. Populations were grown in three environments in 2015 and 2016 with historic SDS disease pressure. Entry, environment, and entry by environment sources of variation were significant for disease index, yield, maturity and spectral reflectance. Changes in season average reflectance were correlated to disease index, yield and maturity. Estimation models of disease index, yield and maturity were created with season averages as well as individual day readings for both populations. Season average and individual day models accounted for 11% to 77% of the phenotypic variation in disease and 41% to 93% of yield variation when measurements were taken at the height of disease pressure. Models for disease index and yield models were able to predict significant portions of the phenotypic variation between entries at most environments. These results suggest that it may be possible to estimate resistance to SDS and grain yield in soybeans using spectral reflectance in breeding populations.

Orientador: Matthieu Tubino / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-12T12:56:08Z (GMT). No. of bitstreams: 1 Queiroz_CarlosAlbertodaRocha_M.pdf: 1138911 bytes, checksum: 67f676e059efece3b6d64b209273d054 (MD5) Previous issue date: 2008 / Resumo: Neste trabalho foram desenvolvidos dois procedimentos de análise quantitativa em fluxo, um para níquel e o outro para sulfato, usando a refletância difusa na região do visível. O primeiro sistema químico estudado faz uso da clássica reação de níquel (II) com dimetilglioxima em meio alcalino amoniacal, formando o precipitado de cor rosa forte, Ni(DMG)2. Este precipitado, como se sabe, é bastante volumoso e adere facilmente às paredes do recipiente onde se encontra. Também, coagula rapidamente formando aglomerados. Estas características já desqualificam, em princípio, este precipitado para uso em sistemas de fluxo, por anunciarem problemas de entupimento nas tubulações e problemas de aderência nas janelas da cela de medida colorimétrica, se esta for a técnica usada. No presente trabalho logrou-se contornar todos estes problemas utilizando-se um sistema de fluxo muito simples. A cela desenvolvida para medidas de refletância foi construída em PTFE branco, sendo nela inseridos o detector (LDR) e emissor de luz (LED verde). O LED foi alimentado com uma fonte com voltagem adequada e o LDR foi introduzido numa ponte de Wheatstone que forneceu as medidas analíticas. Dentro desta cela foi colocado um tudo de vidro, conectado à tubulação do sistema de fluxo, onde passava o precipitado suspenso no carregador. As medidas analíticas de refletância foram feitas na cela contendo esta suspensão. O segundo sistema químico estudado foi a reação de sulfato com íons bário, formando o precipitado branco de sulfato de bário. A aplicação desta reação de precipitação em sistemas de fluxo já foi estudada, por outros autores, em medidas turbidimétricas e nefelométricas. Nossa intenção, ao usar esta reação de precipitação, foi de verificar a coerência do sistema de fluxo desenvolvido neste trabalho com aqueles da literatura, particularmente com o procedimento turbidimétrico. A cela de refletância usada para o sistema com sulfato é semelhante àquela acima descrita para a determinação de níquel. A diferença é que no presente caso o PTFE usado para a confecção do corpo da cela é preto. Esta escolha teve por intenção diminuir a refletância da luz nas suas paredes internas. Nos dois sistemas estudados, os resultados foram muito satisfatórios inclusive quando aplicados em amostras reais. / Abstract: Two flow quantitative analytical systems were developed in this work, using the diffuse reflectance in the visible region of the spectrum: one for the analysis of nickel and the other for the analysis of sulfate. The first studied chemical system used the classical analytical reaction of nickel (II) with dimethylglyoxime in presence of ammonia, forming a pink precipitate, Ni(DMG)2. This precipitate, as currently known, is volumous and easily adheres to the walls of the recipient where it is placed. Also, it easily coagulates forming agglomerates. These characteristics are enough to disqualify this precipitate for application in flux analytical systems, as they announce problems with clogging of the tubes and problems with the adherence on the cell windows if this detecting technique was used. In this work, we succeeded avoid these problems using a very simple flux system. The developed reflectance cell was constructed in white PTFE. The light emitter (green LED) and the light detector (LDR) were placed in its body. The energy was furnished to the LED by a power supplier and the LDR was introduced in a Wheatstone bridge which gave the analytical signal. Into the PTFE cell was placed a glass tube, connected to the flow system, where flowed the carrier with the suspended precipitate. The analytical reflectance measurements were done in the cell containing this suspension. The second chemical system studied was the well known reaction of sulfate with barium ions, forming the precipitate of barium sulfate. The use of this reaction in flux systems was already studied by other authors, with turbidimetric and nephelometric measurements. Our intention, when we select this precipitation reaction, was to verify the coherence among the flux system developed in this work with those already related, particularly with the turbidimetric procedure. The reflectance cell used in the sulfate system is similar to that above described for the determination of nickel. The difference is that in this cell black PTFE was used in order to decrease the reflectance of the light in the internal walls. In the two studied systems the results were quite satisfactory, also when real samples were analyzed. / Mestrado / Quimica Analitica / Mestre em Química

This paper describes the current ground-based calibration results of Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Landsat 8 Operational Land Imager (OLI), Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS), Suomi National Polar orbiting Partnership Visible Infrared Imaging Radiometer Suite (VIIRS), and Sentinel-2A Multispectral Instrument (MSI), using an automated suite of instruments located at Railroad Valley, Nevada, USA. The period of this study is 2012 to 2016 for MODIS, VIIRS, and ETM+, 2013 to 2016 for OLI, and 2015 to 2016 for MSI. The current results show that all sensors agree with the Radiometric Calibration Test Site (RadCaTS) to within +/- 5% in the solar-reflective regime, except for one band on VIIRS that is within +/- 6%. In the case of ETM+ and OLI, the agreement is within +/- 3%, and, in the case of MODIS, the agreement is within +/- 3.5%. MSI agrees with RadCaTS to within +/- 4.5% in all applicable bands. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License.

From introduction: The Fluorescence Excitation Spectrum or anthracene is known to vary considerably with the age and condition or the crystal. This thesis represents an attempt to improve the understanding of these variations. To put the problem on a quantitative basis it was found necessary to know both the ultraviolet reflection and absorption spectra. Reports of the reflection spectrum appear to have been confined to the case of polarised incident light. In addition the reflectivity measurements are always reported for a freshly cleaved surface. For these reasons the reflectivity of anthracene for various conditions of the reflecting surface was measured with unpolarised light. These varying reflectivities were used to further knowledge of the chemical processes at the crystal surface, as well as being used directly in the calculation of fluorescence excitation spectra. Reflection spectra with a- and b- crystallographic axis polarisations were also obtained. Since such spectra are reported in the literature it was possible, by comparison, to conclude that the experimental methods used in this thesis yielded valid results. The polarised measurements were used to obtain optical constants for the crystal. In the interests of readability most of the complicated process of converting the reflectivities to optical constants is dealt with in three appendices to the thesis.

Corn requires the most nitrogen (N) of cereal grain crops and N supply is correlated with grain yield.  Canopy reflectance has been used to assess crop N needs and to derive optimum application rates in mid-season corn.  Canopy reflectance has not been useful for N rate determination in early season corn because of low biomass and the sensing background can interfere, or overwhelm crop canopy reflectance measures.  Widespread adoption of canopy reflectance as a basis for generating in-season corn N rates would be more likely if N rate recommendations could be made early, i.e. by the V6 growth stage.  The objectives of this research were to: i) examine the influence of soil color, soil moisture, surface crop residues, and sensor orientation on normalized difference vegetation index (NDVI) readings from corn from planting through the V6 growth stage; and ii) evaluate the effect of sensor orientation and field of view at early corn growth stages on the relationship between NDVI and corn biomass, N uptake, and chlorophyll meter readings.  Soil color, soil moisture, crop residue type, and sensor orientation influenced reflectance and these factors were much more influential when sensing plants with low biomass.  Canopy reflectance was capable of differentiating between N rates in the field and altering sensor orientation did not minimize sensing background influence or improve the ability of the sensor to distinguish plant N status.  Even when canopy reflectance detected differences in crop N status, N rate prescription based on NDVI was consistently below the profitable estimated sidedress N rate. / Master of Science

No description available.

Optical biopsy is a medical technique that uses light to perform non-invasive analysis of tissue in-situ. This technology has many applications in the medical profession, opening up exciting new possibilities for surgical guidance and diagnosis of malignancies and other conditions. Optical biopsy allows a medical professional to perform near instantaneous, real time analysis of tissue composition without the need to physically remove tissue from the body, as required in traditional biopsy. A technique frequently used for this purpose is diffuse reflectance spectroscopy (DRS): collection and analysis of the spectrum of light reflected from a material. Another technique frequently used for optical biopsy is laser induced fluorescence spectroscopy (LIFS): analysis of the fluorescence spectrum returned by a material when illuminated at a specific wavelength. This thesis discusses the design and construction of a spatially resolved DRS system intended for use in a dual modality DRS and time resolved LIFS optical biopsy instrument for clinical analysis of brain tissue. This instrument is specifically intended for use in the surgical removal of malignant gliomas: infiltrating tumours associated with a poor patient prognosis. Theoretical simulation based studies were used to optimize the design of a compact, dual modality fibre optic probe for use in the system and a novel algorithm was developed to allow recovery of the optical properties of tissue from reflectance spectra obtained with this probe. This probe was manufactured and a corresponding spectrometer based system was created for the acquisition of diffuse reflectance spectra. Components were designed to allow sterilization and thus clinical use in an operating room environment. A laboratory trial of this system demonstrated its range and ability to recover the optical properties of lipid emulsion optical phantoms. / Thesis / Doctor of Philosophy (PhD)