Over the past several decades, push-broom imaging spectrometers have become a common Earth observation tool. Instruments of this type must be calibrated to convert the raw sensor data into units of spectral radiance. Calibration is in this case a two-step process: First, a sensor model is obtained by performing calibration measurements, which is then used to convert raw signals to spectral radiance data. Further processing steps can be performed to correct for optical image distortions. In this work, we show the complete calibration process for push-broom imaging spectrometers, including uncertainty propagation. Although the focus is specifically on calibrating a HySpex VNIR-1600 airborne-imaging spectrometer, all methods can be adapted for other instruments. We discuss the theory of push-broom imaging spectrometers by introducing a generic sensor model, which includes the main parameters and effects of such instruments. Calibrating detector-related effects, such as dark signal, the noise as a function of the signal, and temperature effects is shown. Correcting temperature effects significantly reduces measurement errors. To determine the signal non-linearity, we built a setup based on the light-addition method and improved this method to allow smaller signal level distances of the sampling points of the non-linearity curve. In addition, we investigate the non-linearity of the integration time. The signal (<=15%) and the integration time (<=0.5%) non-linearities can be corrected with negligible errors. After correcting both non-linearity effects, a smearing effect is revealed, which is investigated in detail. We use a collimator and monochromator setup for calibrating the geometric and spectral parameters, respectively. To accurately model the angular and spectral response functions, we propose using cubic splines, which leads to significant improvements compared to previously used Gaussian functions. We present a new method that allows interpolation of the cubic spline based response functions for pixels not measured. The results show that the spectral and geometric properties are non-uniform and change rapidly within a few pixels. The absolute radiometric calibration is performed with a lamp-plaque setup and an integrating sphere is used for flat-fielding. To mitigate the influence of sphere non-uniformities, we rotate the instrument along the across-track angle to measure the same spot of the sphere with each pixel. We investigate potential systematic errors and use Monte Carlo simulations to determine the uncertainties of the radiometric calibration. In addition, we measure the polarization sensitivity with a wire-grid polarizer. Finally, we propose a novel image transformation method that allows manipulation of geometric and spectral properties of each pixel individually. Image distortions can be corrected by changing a pixel's center angles, center wavelength, and response function shape. This is done by using a transformation matrix that maps each pixel of a target sensor B to the pixels of a source sensor A. This matrix is derived from two cross-correlation matrices: Sensor A and itself, and sensor B and sensor A. We provide the mathematical background and discuss the propagation of uncertainty. A case study shows that the method can significantly improve data quality.

Indiana University-Purdue University Indianapolis (IUPUI) / Ion Mobility Spectrometry (IMS) is an analytical technique for separation of charged particles in the gas phase. The history of IMS is not very old, and in this century, the IMS technique has grown rapidly in the advent of modern instruments. Among currently available ion mobility spectrometers, the DTIMS, FAIMS, TWIMS, DMA are notable. Though all the IMS systems have some uniqueness in case of particle separation and detection, however, all instruments have common shortcomings. They lack in resolution, which is independent of mobility of different charged particles and they are not able to separate bigger particles (20 120 nm) with good accuracy. The work presented here demonstrates a new concept of IMS technique at atmospheric pressure which has a resolution much higher than that of the currently available DTIMS (Drift Tube Ion Mobility Spectrometry) instruments. The unique feature of this instrument is the diffusion auto-correction. Being tunable, It can separate the wide range of particles of different diameters. The working principle of this new IMS technique is different from the typical DTIMS and to simply put, it can be considered as an inversion of commonly used technique, so termed as Inverted Drift Tube (IDT).The whole work performed here can be divided into three major phases. In the first phase, the analytical solution was derived for two new separation techniques: IPF (Intermittent push flow) and NSP (Nearly stopping potential) separations. In the next phase, simulations were done to show the accuracy of the analytical solution. An ion optics simulator software called SIMION 8.1 was used for conducting the simulation works. These simulations adopted the statistical diffusion (SDS) collision algorithm to emulate the real scenario in gas phase more precisely. In the last phase, a prototype of experimental setup was built. The experimental results were then validated by simulated results.

Neutrino physics has been going through rapid developments since the particle was first proposed by Pauli. The observation of neutrino oscillations has prompted an investigation of the issue of neutrino mass, with the "seesaw" mechanism garnering theoretical support. The HUNTER (Heavy Unseen Neutrinos from the Total Energy-momentum Reconstruction) experiment brings together AMO, nuclear physics and high energy physics researchers from Temple University, Houston University, UCLA and Princeton University to develop an apparatus capable of probing the keV-mass range of sterile neutrinos with high precision. The HUNTER detector makes use of the well-established COLTRIMS techniques for the collection of all the decay products of a neutrino-producing decay, and the reconstruction of their initial momenta and energies. Energy and momentum conservation allow then for the reconstruction of the missing neutrino mass.Electrons produced in the decay are guided towards their detector by an optimized set of electrodes paired to a magnetic field to confine their trajectories into spirals. A magnetic shield protects the electron from external stray fields that could alter their trajectories. A thorough study on the main source of background, namely the source scattering of ions, was conducted. As an additional topic, the feasibility of a directional-sensitive dark matter search experiment has been studied. Simple models of galactic dark matter distribution suggest that the motion of the Earth in space might introduce a directional anisotropy in the WIMPs momentum distribution at the Earth. The shape of a WIMP-like recoil in a target material could be be used to extract directional information for the incident WIMP, and thus confirm the anisotropy. The peculiar microphysics of liquid Argon requires thermalization of ionization electrons for a signal to form. To determine if directional information can be extracted, one needs to understand the energy spectrum of the electrons emitted in recoil event. Then, one needs a model to determine the time scale of the thermalization, and the distance to which the electrons travel. / Physics

As individual health monitors continue to become more widely adopted in helping individuals make informed decisions, new technologies need to be developed to obtain more biometric data. Spectroscopy is a well-known tool to gain biological information. Traditionally spectrometers are large and expensive making personal or wearable health monitors difficult. Here we present the development and characterization of a miniaturized short wavelength infrared spectrometer for wearable applications. We present a carbon nanotube parallel hole collimator can effectively select a narrow set of allowed angles of light to be separated by a linear variable filter and detected at a photodiode array making a spectrometer. We will go over the calibration of the spectrometer showing a resolution of 13 nm at 1300 nm. Improvements on the original collimator data will be discussed, including carbon nanotube growth without infiltration and growth on transparent substrates. We will also show measurements made on human subjects yielding a pulse.

The design and construction of a coincidence spectrometer and its application to the study of the decay of Os¹⁹³ are presented. / Thesis / Doctor of Philosophy (PhD)

<p> The phonon dispersion relation in the principal symmetry directions of a crystal of Cu-Ni-Zn was measured at 298°K by means of inelastic scattering of thermal neutrons. The specimen had an electronic concentration per atom very close to that of pure copper and it came as no surprise that no significant shift in the phonon spectrum relative to that of pure copper could be observed. </p> <p> The particular specimen used had a poor mosaic distribution; this contribution was taken into account in the calculation of the line shape and it was found that the widths of the neutron groups could be well accounted for in this way. </p> <p> The appendix is divided into six parts, four of which contain a description of projects of secondary importance that were realized. </p> / Thesis / Master of Science (MSc)

<p> This thesis describes a study of the photosolvolysis of N-benzoyl-5-bromo-7-nitroindoline. The investigation was instigated because N-acyl-5-bromo-7-nitroindolines have been considered as potential photoprotecting groups for the photolithographic formation of charge-mosaic membranes. However, no kinetic data, and only scant mechanistic information, has been reported for the photofragmentation process.</p> <p> Both absorption and emission spectra of N-benzoyl-5-bromo-7-nitroindoline were obtained. Based on the electronic spectra, it would seem that the two lowest energy singlet excited states are nearly isoenergetic and their relative energies are a function of the solvent medium.</p> <p> The distribution of photoproducts obtained from irradiation of N-benzoyl-5-bromo-7-nitroindoline in various solvent systems was investigated. It was shown that the photosolvolysis reaction is a function of the solvent properties. Thus 5-bromo-7-nitroindoline and benzoic acid were the only photoproducts formed in acetonitrile. In acetonitrile-water, 5-bromo-7-nitrosoindole as well as 5-bromo-7-nitroindoline and benzoic acid were identified. A correlation between solvent polarity, ET(30), and 5-bromo-7-nitrosoindole formation was observed.</p> <p> The mechanism of the fragmentation mode was examined. The presence of a free radical intermediate is suggested from the photoproduct distribution in tetrahydrofuran (THF). Observation of an electron spin resonance (e.s.r.) spectrum during irradiation of N-benzoyl-5-bromo-7-nitroindoline in an e.s.r. spectrometer cavity, 18_0 incorporation into benzoic acid, and a linear free energy relationship with sigma dot (σ•) corroborated the intermediacy of a free radical in the fragmentation process.</p> <p> Quantum yields of N-benzoyl-5-bromo-7-nitroindoline disappearance in different solvents and quenchers were measured in order to establish the reactive excited state and the effect of the medium on the efficiency of the transformation process. A solvent dependency on both the excited state lifetime and photosolvolysis reaction efficiency was noted. The results were indicative of a change in mechanism with a variation in solvent polarity and/or hydrogen bonding ability.</p> <p> A mechanism compatible with experimental results and applicable to previously reported N-acyl-2-nitroaniline photofragmentations is proposed.</p> / Thesis / Doctor of Philosophy (PhD)

<p> Edible oils consist primarily of triacylglycerols (or TAGs), which are triesters of glycerol and fatty acids. Determination of the TAG compositions of edible oils is becoming more important, given the economic value of these oil products and the increasing incidence of adulterating high quality oils with poorer quality oils. In this study we report the development of an analytical protocol using positive ion infusion electrospray mass spectrometry (ESI/MS) in conjunction with tandem mass spectrometry which affords both identification and quantification of TAGs in edible oils samples.</p> <p> This thesis reports a simple, comprehensive and quantitative method for the analysis of TAGs in edible oils in which the optimized method involves the infusion of an oil sample in chloroform:methanol (1:1) solution (~10-15 μg/mL of oil) in the presence of 0.5 mM LiCl. A sequence of corrections were applied to the raw peak area data of the TAG molecular ions, [M+Li]+, to account for: (1) normalization of peak area data using three internal standards, (2) peak area contributions of M+2 isotopic peaks of TAGs with one more degree of unsaturation and (3) peak area contributions of LiCl adduct ions, [M+Li+LiCl]+, when applicable. The major correction involved multiplication to a given TAG peak area by the appropriate electrospray relative response factor (RRF) for that TAG. The RRFs for all TAGs containing between 48 and 63 carbons in their fatty acyl chains and between 0 and 9 degrees of unsaturation were extrapolated from experimentally determined response factors of a series of standards. The RRFs were found to decrease by 6.7% for each additional acyl chain carbon but increased by 18.6% for each double bond. Comparison of these calculated RRFs to reported RRFs for a series of TAG standards showed an excellent correlation (1.06% ± 10.20% RSD).</p> <p> The use of Li+ in TAG analysis followed from the reports by Hsu and Turk [93] and Han and Gross [18] which showed that Li+ afforded more intense MS, and particularly MS/MS, spectra than either H+ or Na+. The enhanced intensities in MS/MS spectra (determined using a triple quadrupole mass spectrometer) were critical for the identification of TAGs, including the identity of the fatty acyl group located at the sn-2 position. However, this method cannot distinguish unambiguously between isobaric TAGs. This methodology was applied to the profiling of a number of edible oils including canola, olive, sesame, grape seed, walnut and hemp seed oils. The major TAGS in these samples contained 52, 54 and 56 carbons with between 0 and 11 degrees on unsaturation in a given TAG. There were minor amounts of TAGs containing 50, 55 and 57 carbons.</p> <p> The ability of this method to determine quantitatively the number of degrees of unsaturation in an oil sample was tested by examining a series of partially hydrogenated canola oil samples kindly provided by Bunge Canada. Five oil samples derived from a single feedstock with differing numbers of degrees of unsaturation, measured as iodine values, were subjected to our analytical method. The measured iodine values were compared to iodine values calculated from the number of degrees of unsaturation obtained by our MS-based method. The slope of this correlation was 1.10 with an R^2 = 0.995. Overall, this method is much simpler and more accurate than the protocol described by Han and Gross [18]. This methodology will be applied as routine method for the analysis of TAGs in biological samples such as blood samples.</p> / Thesis / Master of Science (MSc)

<p> Lead isotope ratios have been determined by a VG.354 thermal ionization mass spectrometer on Sudbury Igneous Complex sulphide ores. The isotopic ratios are contrasted with the lead isotope profile of selected country rocks in the vicinity of the complex. South Range data form a linear array whose slope indicates an age of approximately 1.85 Ga, the published age of the igneous complex. They also indicate North Range data a magmatic origin for lead in the ore. North Range data describe a parallel isochron, with lower 206Pb/204Pb and 207Pb/204Pb ratios. The South and North Range data are similar to the lead-isotope composition of country rocks close to them, and indicate rather different crustal-source rocks for sulphide ores in these regions of the complex. This fact suggests that the Sudbury Igneous Complex was generated by a meteorite impact which occurred at the edge of the Huronian succession overlying the Southeast edge of the Superior Province. </p> / Thesis / Master of Science (MSc)

Microorganisms with an ability to thrive in harsh environments are referred as “extremophiles”. With advances in biotechnology, interest has grown in the extremophile research because of their unique macromolecules’ characteristics due to their growth environments. Over last decade, researchers have isolated many extremophiles from environments like volcano, salt lakes, hydrothermal vents, deep oceans, Antarctica glaciers etc. Macromolecules of these extremophiles are responsible for their survival in extreme environments. In this research work we have isolated lipid molecules from three different microorganisms. 1) GWE1 strain, a thermophilic bacterium, isolated from dark crusty material from sterilization ovens. 2) 7L strain, a thermophilic bacterium, isolated from Chilean Copahue Volcano. 3) I1P strain, a facultative anaerobe of the family Enterobacteriaceae, recently isolated from Antarctica. Complex lipid arrangement and/or type in the cell membrane are known to affect thermostability of microorganisms and efforts were made to understand the chemical nature of the polar lipids of membrane. In this work, we extracted total lipids from cell membrane, separated them by TLC into various fractions and characterize the lipid structures of fractions with analytical tools such as 1H, 13C, 31P and 2D NMR spectroscopy, ATR-FTIR spectroscopy and MSn spectrometry. In GWE1 strain, we were able to identify glycerophosphoethanolamine, glycerophosphate, glycerophosphoglycerol and cardiolipin lipid classes and an unknown glycerophospholipid class with novel MS/MS spectra pattern. We have also noticed the presence of saturated iso-branched fatty acids with NMR spectra in individual lipid classes. In case of I1P strain, we have identified glycerophosphoglycerol, glycerophosphoethanolamine, glycerophosphate, and acyl glycerophosphoglycerol lipid classes with unsaturated fatty acids in their structure, which could be one of the many reasons for survivability at lower temperatures. In case of 7L strain, we were able to identify glycerophosphoglycerol, cardiolipin, glycerophosphoethanolamine and glycerophosphate lipid classes with saturated iso branched fatty acids. FAME analysis revealed iso-15:0 (52.29 %) and iso-17:0 (18.64 %) as major fatty acyl chains. We did not observe major difference in polar head group composition of lipid classes between thermophiles (GWE1 and 7L) compare to psychrophiles (I1P). Major difference among these three strains was in fatty acid composition of lipid molecule. Both thermophiles showed presence of lipids with long chain saturated fatty acids while I1P showed presence of lipid molecule with unsaturated fatty acid chain. Lipids made of unsaturated fatty acids have lower melting points and they introduce kink in the cell membrane structure. At lower temperatures, these effects allow membrane to maintain fluidity and its functionality, which in turn allows the microorganism to grow at lower temperature. Lipids made with saturated iso branched fatty acid chain have higher melting points and they pack together densely in cell membrane. At high temperature because of higher melting point and dense packing, membrane fluidity is not affected and this effect allows microorganism to grow at the higher temperature. We believe that change in fatty acid composition is one of the many reasons for these microorganisms to survive the extreme condition. Thermostability of the other macromolecules (DNA, enzyme) of these extremophiles is not studied in this dissertation. / Chemistry