A Time-of-Flight camera from SICK IVP AB is used to monitor a region of interest which implies that the camera has to be configured, it has to be mounted correctly and be aware of the region of interest. Performing the configuration process currently induce the user to manage the captured 3-Dimensional data in a 2-Dimensional environment which obstructs the process and possibly causes configuration errors due to misinterpretations of the captured data. The aim of the thesis is to investigate the concept of using Augmented Reality as a tool for facilitating the configuration process of a Time-of-Flight camera and evaluate if Augmented Reality enhances the understanding for the process. In order to evaluate the concept, a prototype application is developed. The thesis report discusses the motivation and background of the work, the implementation as well as the results.

Athletes have often resorted to a variety of methods to gain an edge in sporting competitions. One such method is through doping, the use of compounds or methods to produce a theoretically enhancing biological effect. In order to combat doping, many governing sports bodies have prohibited specific compounds or methods and installed programs to test for these compounds in athletes. However, due to the large number of banned substances and the varying chemistries of those compounds, it can be challenging and time consuming to determine the presence of those compounds in an athlete’s sample. Therefore, there is a necessity to develop a quick and sensitive method that can precisely and accurately screen for banned substances. This research was an attempt to develop such a method. This was accomplished using multidimensional liquid chromatography with time of flight mass spectrometry. While none of the methods tested here were useful for screening all 79 compounds tested in a single injection, a multi-method approach was evaluated in lieu of a multi-residues single method process The analytical run time was less than 10 minutes for each method. Further studies were performed to determine the limit of detection, linearity, lifetime, robustness and the optimal solid phase extraction method.

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No / This article reports on the use of comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS) for forensic geotaphonomy application. Gravesoil samples were collected at various depths and analyzed for their volatile organic compound (VOC) profile. A data processing procedure was developed to highlight potential candidate marker molecules related to the decomposition process that could be isolated from the soil matrix. Some 20 specific compounds were specifically found in the soil sample taken below the carcass and 34 other compounds were found at all depths of the gravesoil samples. The group of the 20 compounds consisted of ketones, nitriles, sulfurs, heterocyclic compounds, and benzene derivatives like aldehydes, alcohols, ketones, ethers and nitriles. The group of the 34 compounds consisted of methyl-branched alkane isomers including methyl-, dimethyl-, trimethyl-, tetramethyl-, and heptamethyl-isomers ranging from C12 to C16. A trend in the relative presence of these alkanes over the various layers of soils was observed, with an increase in the amount of the specific alkanes when coming from the carcass to the surface. Based on the specific presence of these methyl-branched alkanes in gravesoils, we created a processing method that applies a specific script to search raw data for characteristic mass spectral features related to recognizable mass fragmentation pattern. Such screening of soil samples for cadaveric decomposition signature was successfully applied on two gravesoil sites and clearly differentiates soils at proximity of buried decaying pig carcasses from control soils.

Direct, efficient oxidation of alkanes is a long-standing goal of catalysis. Gas phase FeO+ can convert methane to methanol and benzene to phenol under thermal conditions. Two key intermediates of these reactions are the [HO-Fe-R]+ insertion intermediate and Fe+(ROH) (R=CH3 or C6H5) exit channel complex. This work describes measurements of the vibrational spectra of these intermediates and electronic structure theory calculations of the potential energy surfaces for the reactions. They help to characterize the mechanism for these reactions. Chapter 1 describes previous studies of methane-to-methanol and benzene-to-phenol conversion by gas-phase transition metal oxide cations. Spectra of gas-phase reaction intermediates are obtained using photofragment spectroscopy, in which absorption of a photon leads to bond breaking. Utuilizing this technique to measure vibrational spectra is challenging, due to the low photon energies involved. Techniques used to measure vibrational spectra of ions - argon tagging, infrared multiple photon dissociation (IRMPD), vibrationally mediated photodissociation (VMP) and infrared laser assisted photodissociation spectroscopy (IRLAPS) are also detailed in chapter 1. The photofragment spectrometer and laser systems used in these studies are described in chapter 2, as is a multi-pass mirror arrangement which I implemented. This greatly improved the quality of vibrational spectra, particularly those measured using IRMPD. Chapter 3 describes studies of the O-H and C-H stretching vibrations of two intermediates of the FeO+ + CH4 reaction. These intermediates are selectively formed by reaction of laser ablated Fe+ with specific organic precursors and are cooled in a supersonic expansion. Vibrations of the sextet and quartet states of the [HO-Fe-CH3]+ insertion intermediate and Fe+(CH3OH) exit channel complex are measured by IRMPD and Ar-tagging. Studies of the O-H stretching vibrations of the [HO-Fe-C6H5] + and Fe+(C6H5OH) intermediates of the FeO+ + C6H6 reaction are discussed in chapter 4. For Fe+(C6H5OH), the O-H stretch is observed at 3598 cm-1. Photodissociation primarily produces Fe+ + C6H5OH. IRMPD of [HO-Fe-C6H5] + mainly produces FeOH+ + C6H5 and the O-H stretch spectrum consists of a peak at ~3700 cm-1 with a shoulder at ~3670 cm-1. Chapter 5 compares three techniques - IRMPD, argon-tagging, and IRLAPS - in the quality of the measured vibrational spectra of Ag+(CH3OH) ions produced under identical conditions. The sharpest spectrum is obtained using IRLAPS. The O-H stretch is observed at 3660 cm-1. Monitoring loss of argon from Ag+(CH3OH)(Ar) gives a slightly broader peak, with no significant shift. The vibrational spectrum obtained using IRMPD is shifted to 3635 cm-1, is substantially broader, and is asymmetrical, tailing to the red.

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<p> This thesis provides examples ~f new solid supports for Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) in two parts. </p> <p> Firstly, mesoporous and macroporous silicas were developed as new supports for the elimination of low mass interference signals in the mass spectrum. Due to the complexity of the system, a variety of factors were studied, such as sol gel morphology, matrix crystallization, polymeric molecular weight and concentration. It was observed that the mesoporous silicas and higher matrix crystallization were advantageous for optimal signal intensity and signal-to-background ratio. </p> <p> Secondly, due to the inconsistencies in the literature apropos the role of the matrix in MALDI process, we have developed chemically modified compounds and studied these as alternative MALDI matrices. It was concluded that for optimal free matrix performance, the phenolic groups were desirable while crystallization was not required. Moreover, a highly selective covalently linked silicon-based matrix was developed, which yielded a superior signal-to-background ratio at moderate signal intensities. A chemical nature of matrix and sol gel processing methodology used were the relevant factors to be considered when optimizing a tethered matrix. It was demonstrated that requirements for free and surface-bound matrices were different; hence, suggesting the drastic difference in their operating mechanisms during MALDI process. </p> / Thesis / Master of Science (MSc)

Achieving autonomous in complex natural environments has the potential to transform society by bringing the benefits of automation from the confines of the factory floor to the outdoors. There, it could benefit areas such as environmental monitoring and clean-up, precision agriculture, delivery of goods. A fundamental requirement for achieving these goals are sensors that can provide reliable support for navigation, e.g., a drone, in natural environments. In this thesis, sonar-based navigation has been investigated as an approach to parsimonious autonomous sensing for drones. Bats living in dense vegetation have demonstrated that autonomous navigation in a complex, natural environment based on two one-dimensional ultrasonic echo streams is feasible. Here, a biomimetic sonar head has been used to collect echo data from recreations of natural foliage in the lab under controlled conditions. This data was used to address the research question whether the grazing angle at which the sonar is looking at a surface can be estimated from the echoes -- despite the random three-dimensional nature of the scatter from the foliage. To investigate this, the echoes have been subjected to statistical analysis such as spectral coherence and cross-correlation. Most importantly, the foliage data was compared against predictions made by the Endura method (energy, duration, and range method) that has been devices for two-dimension random scatterers. The results of this analysis shows that -- despite their profoundly random nature -- echoes can be used to estimate the sonar grazing angle directly, i.e., without the need to resort to reconstructions of the foliage geometry. This opens the possibility of developing simple devices for navigation control in natural environments that can control the direction of motion at a very little computational cost. / Master of Science / Autonomously flying drones is a potential technology that could bring benefits to the society and improve the quality of life for humans[22]. Therefore, a study of autonomously flying in a natural environment is necessary, and this thesis will focus on drone that could recognize objects with different grazing angle and acoustic signal by collecting data from near foliage surface. For example, when a bush wall is in front of the drone, a on board computer could inform drone whether the drone airline will collide with the bush wall or the bush wall is safely out of drone’s path[5]. If on board computer reads that there will be a collision with bush wall, then drone needs to make decision (change direction or stop immediately) to avoid crush on to bush wall. A sonar based navigation system has been investigated as an approach to achieve autonomous sensing for drones, which is inspired by bats. Bats use their natural sonar system to navigate in cave or forest, hence, it is hardly to see bats slam into any obstacles while flying. Bats navigation behaviours could be reconstructed as a sonar based autonomy. Hence, this thesis is inspired by bats to determine if there is a computational way to illustrate that sonar based sensor could be a solution to achieve reactive autonomy by using different grazing angle of the surface’s acoustic signals.

Abstract Amorphous Selenium (a-Se) was first commercialized for use as a photoconductor in xerography during the middle of the twentieth century. Since then the hole transport properties of a-Se have been studied extensively, however the study of electron transport remains relatively limited. Flat panel digital X-ray detectors using a-Se as a photoconductor have been developed and are being used in mammographic screening. The charge transport properties of the photoconductor layer will in part determine the performance of the flat panel detector. X-ray absorption causes electron-hole pair generation in the bulk of the photoconductor, requiring both electrons and holes to drift across the sample and be collected. If these carriers are lost in the many localized trapping states as they cross the sample, they will not contribute to the image signal resulting in unnecessary radiation exposure to the patient. Eleven a-Se samples were deposited at the University of Saskatchewan varying in thickness from 13 μm to 501 μm. Pure a-Se was chosen to ensure uniformity across the thickness of the samples, that is, to ensure the composition of the film did not change across the thickness. Time of flight transient photoconductivity experiments (TOF) and interrupted field time of flight (IFTOF) measurements were performed to measure the electron drift mobility and lifetime respectively. The product of electron drift mobility μ and lifetime τ, hence the carrier range (μτ) at a given applied electric field. The electron range is an important parameter as this places limits on the practical thickness of the photoconducting layer in a detector. This study also includes an investigation into the effect of the definition of transit time on the calculated drift mobility and analysis of the dispersive transport properties of a-Se. It was observed that as sample thickness (L) increased, electron drift mobility (μ) decreased. In addition electron lifetime (τ) decreased dramatically in samples thinner than 50 μm. Electron range (μτ) was 2.26 × 〖10〗^(-6) cm^2/V in the 147μm sample and 5.46 × 〖10〗^(-8) cm^2/V in the 13 μm sample, a difference of almost two orders of magnitude. The comparison of the half current method and inflection point methods to calculate the transit time of the same TOF curve, shows that the calculated mobility can vary by as much as 24%. This illustrates clearly that it is important to use the same point on the TOF curve to define the transit time. Charge packet dispersion (spread) in the time domain in pure a-Se samples was proportional to L^m where L is the photoconductor thickness and m ~ 1.3, measured at both 1 V/μm and 4 V/μm.

Le couplage neuro-vasculaire est un domaine grandissant. Ce dernier étudie les effets de l’activité cérébrale sur le comportement du flux sanguin cérébral (cerebral blood flow, CBF) et sur le flux des vaisseaux sanguins. Avec l’aide de l’imagerie par résonance magnétique (IRM), il est possible d’obtenir des images comme les images pondérées par susceptibilité (susceptibility weighted imaging, SWI) pour voir les veines ou bien avec des images de temps de vol par angiographie (time-of-flight magnetic resonance angiography, TOF MRA) pour imager les artères. Ces images permettent d’avoir une représentation structurelle des vaisseaux dans le cerveau. Ce mémoire présente une méthode permettant la segmentation des vaisseaux sanguins à partir d’images structurelles afin d’en extraire les caractéristiques. En utilisant le masque de segmentation, il est possible de calculer le diamètre des vaisseaux ainsi que leur longueur. Avec l’aide de tels outils de segmentation automatique, nous avons conduit une étude permettant d’analyser le comportement des vaisseaux sanguins lors d’activités neuronales. Grâce à une stimulation visuelle, nous avons fait l’acquisition de deux images; la première dite au repos et la seconde avec stimulation. Nous avons pu comparer le diamètre dans chacune des images et ainsi obtenir la vasodilatation en millimètre, mais également en pourcentage, et cela pour chaque voxel. Nous avons également calculé la distance entre le site d’activation et un voxel pour observer l’amplitude de la vasodilatation en fonction de la distance. Tout ceci permet d’avoir une meilleure compréhension du système vasculaire du cerveau humain. / Abstract : The neurovascular coupling is a growing field; it studies the effects of cerebral activity on the behaviour of cerebral blood flow (CBF) and the blood vessels themselves. With the help of magnetic resonance imaging (MRI), it is possible to obtain images such as susceptibility weighted imaging (SWI) to see the veins or time-of-flight magnetic resonance angiography (TOF MRA) to visualize the arteries. These images allow having a structural representation of vessels in the brain. This thesis presents a method to segment blood vessels from structural images and extract their features. Using the segmentation mask, it is possible to calculate the diameter of the vessels as well as their length. With the help of such automatic segmentation tools, we conducted a study to analyze the behaviour of blood vessels during neuronal activities. Due to visual stimulation, we have acquired two images; one at rest and the other with stimulation. We compare the diameter in each of the images and obtain vasodilation in millimeters, but also as a percentage in each voxel. We also calculated the distance between the activation site and each voxel to see the magnitude of the vasodilation function of the distance. All this provides a better understanding of the vascular system of the human brain.