Even though low mass stars (< 8 solar masses) vastly outnumber high mass stars (< 8 solar masses), the more massive stars drive the chemical evolution of galaxies from which the next generation of stars and planets can form. Understanding mass loss of asymptotic giant branch stars contributes to our understanding of the chemical evolution of the galaxy, stellar populations, and star formation history. Stars with mass < 8 solar masses form planetary nebulae, while those with mass < 8 solar masses go supernova. In both cases, these stars enrich their environments with elements heavier than simple hydrogen and helium molecules. While some general info about how stars die and form planetary nebulae are known, specific details are missing due to a lack of high-resolution observations and analysis of the intermediate stages. For example, we know that mass loss in stars creates morphologically diverse planetary nebulae, but we do not know the uniformity of these processes, and therefore lack detailed models to better predict how spherically symmetric stars form asymmetric nebulae. We have selected a specific group of late-stage stars and observed them at different scales to reveal the uniformity of mass loss through different layers close to the star. This includes observing nearby masers that trace the molecular shell structure around these stars. This study revealed detailed structure that was analyzed for uniformity to place constraints on how the mass loss processes behave in models. These results will feed into our ability to create more detailed models to better predict the chemical evolution of the next generation of stars and planets.

Chemometrics is a discipline of chemistry which uses mathematical and statistical tools to help in the extraction of chemical information from measured data. With the assistance of chemometric methods, infrared (IR) spectroscopy has become a widely applied quantitative analysis tool. This dissertation explores two challenging applications of IR spectroscopy facilitated by chemometric methods: (1) passive Fourier transform (FT) remote sensing and (2) process monitoring by near-infrared (NIR) spectroscopy. Passive FT-IR remote sensing offers a measurement method to detect gaseous species in the outdoor environment. Two major obstacles limit the application of this method in quantitative analysis: (1) the effect of both temperature and concentration on the measured spectral intensities and (2) the difficulty and cost of collecting reference data for use in calibration. To address these problems, a quantitative analysis protocol was designed based on the use of a radiance model to develop synthetic calibration data. The synthetic data served as the input to partial least-squares (PLS) regression in order to construct models for use in estimating ethanol and methanol concentrations. The methodology was tested with both laboratory and field remote sensing data. Near-infrared spectroscopy has attracted significant interest in process monitoring because of the simplicity in sample preparation and the compatibility with aqueous solutions. For use in process monitoring, the need exists for robust calibrations. A challenge in the NIR region is that weak, broad and highly overlapped spectral bands make it difficult to extract useful chemical information from measured spectra. In this case, signal processing methods can be helpful in removing unwanted signals and thereby uncovering useful information. When applying signal processing as a spectral preprocessing tool and regression analysis for building a quantitative calibration model, optimizing the parameters that specify the details of the methods is crucial. In this research, particle swarm optimization, a population-based optimization method was applied. Digital filtering and wavelet processing methods were evaluated for their utility as spectral preprocessing tools. Both a pump-controlled flowing system and bioreactor runs involving the yeast, Pichia pastoris, were studied in this work. In investigating the bioreactor runs, insufficient reference data resulted in difficulties in employing the PLS calibration method. Instead, the augmented classical least-squares modeling technique was applied since it requires only pure-component or composite spectra of the analyte and background matrix rather than a large set of mixture samples of known analyte concentration.

The overarching objective of the investigations discussed herein is the development of a model experimental system for surface-enhanced infrared absorption (SEIRA) spectroscopy, with potential applicability in higher order infrared spectroscopic techniques, specifically, surface-enhanced two-dimensional infrared (SE-2D IR) spectroscopy. Theoretical predictions that accurately predict the stability of functionalized nanoparticles enable guided design of their properties but are often limited by the accuracy of the parameters used as model inputs. Hence, first, such parameterization limitations for the extended DLVO (xDLVO) theory are overcome using a size-dependent Hamaker constant for gold, interfacial surface potentials, and tilt angles of self-assembled monolayers (SAMs), which collectively improves the predictive power of xDLVO theory for modeling nanoparticle stability. Measurements of electrical properties of functionalized gold nanoparticles validate the predictions of xDLVO theory using these new parameterizations illustrating the potential for this approach to improve the design and control of the properties of functionalized gold nanoparticles in various applications. Next, a series of experiments were conducted to elucidate the behavior of various infrared active molecules in the presence of spherical gold nanoparticles of average diameter ∼20 nm. Here, the spectroscopic anomalies, specifically the shifted vibrational frequency and the dispersive lineshape observed in the infrared spectra for SCN- in the presence of gold nanoparticles provide direct evidence of SIERA. Nevertheless, it was evidenced that nanomaterial with plasmonic properties that extends into the infrared wavelengths are imperative in observing efficient infrared enhancements. Hence, nanomaterial indicating plasmonic properties extending into the infrared wavelengths were synthesized via a straightforward, seedless, one-pot synthesis. The gold nanostars prepared here indicated plasmonic behavior clearly extending into the near infrared, with simple plasmonic tunability via changing the buffer concentration used during synthesis. The systematic understanding achieved here in terms of theoretical prediction of nanoparticle stability, origin of infrared spectral anomalies in the presence of nanomaterials, and the preparation of infrared plasmonic material, collectively provides a resilient framework for the further investigation of surface-enhanced infrared spectroscopic techniques including SEIRA and SE-2D IR spectroscopies.

Des couches de a-SiO2 déposées sur un substrat de Si ont été irradiées avec des ions lourds. L'endommagement en surface est étudié à l'aide de la Microscopie à Force Atomique (AFM). Pour des pertes d'énergie électronique supérieure à 16.0 keV/nm, des bosses apparaissent en surface. La hauteur de ces bosses diminue quand l'épaisseur de la couche d'oxyde augmente. Les études de Spectroscopie Infrarouge montrent que le seuil d'endommagement pour le a-SiO2 est autour de 2.0 keV/nm. Alors, il est probable que la formation de ces bosses en surface ait son origine dans le substrat de Si. Le modèle de la pointe thermique conforte l'hypothèse que la création des bosses est liée à la réponse du Si. Ce modèle indique un seuil d'endommagement de 1.8 keV/nm (a-SiO2) et 8.0 keV/nm (Si). L'attaque chimique après irradiation offre une possibilité technique de réaliser des trous nanométriques avec des dimensions et formes contrôlables. Il est aussi possible de déterminer le rayon de la pointe AFM.

Le règlement européen n°842/2006 ayant pour objectif la réduction des gaz à effet de serre vise à une politique de contrôle de l'étanchéité des équipements contenant plus de 3 kg de fluide. En France, l'arrêté du 7 mai 2007 spécifie que les contrôles doivent être effectués par un détecteur de fuite manuel d'une sensibilité de 5 g/an ou un contrôleur d'ambiance avec une sensibilité de 10 µmol/mol. Ces sensibilités doivent être mesurées suivant la norme EN 14624. Cette norme préconise l'utilisation de fuites calibrées de R-134a dont le débit varie de 1 à 50 g/an. Il est indispensable de disposer de fuites étalons permettant de vérifier les mesures effectuées. Comme une chaîne de mesure des débits de fuites hélium est déjà mise en place, une analyse des méthodes de mesures utilisées a mis en évidence la nécessité de développer une nouvelle méthode pour la mesure des débits de fuites de fluides frigorigènes. Pour répondre au besoin, le Centre d'Energétique et Procédés a développé une méthode de mesure basée sur l'absorption infrarouge. Elle consiste à mesurer la variation dans le temps de la concentration du gaz émis par une fuite, accumulée dans un volume fermé dit volume d'accumulation. Basée sur cette méthode, une référence nationale destinée à définir des débits de fuites de fluides frigorigènes se situant entre 1 g/an et 50 g/an a été conçu par le LNE et le CEP, avec le soutien de l'ADEME. Les phases de la conception sont présentées. En particulier, comme la méthode repose essentiellement sur la mesure d'une variation de concentration dans un volume à mesurer, le choix de la méthode de mesure de la variation de concentration et le choix de la méthode de mesure du volume d'accumulation ont été définies comme les étapes clés de la conception et sont argumentés. Une fois l'étude de conception achevée, la référence nationale a été réalisée et qualifiée. Le débit de fuite est calculé à partir de grandeurs différentes, à savoir la concentration, la pression, la température et le volume d'accumulation. La chaîne de mesure de ces grandeurs a donc été analysée afin d'estimer les modes opératoires et les incertitudes associées à l'estimation de chacune des grandeurs. Le budget d'incertitude du débit d'une fuite calibrée a finalement été établi. Une fois la traçabilité des débits de fuites frigorigènes assurée, le seuil de sensibilité des détecteurs frigorigènes peut être mesuré suivant les normes prévues telles que la norme européenne EN 14624 ou d'autres normes comme la norme SAE ou le projet de norme ASHRAE. Des études théoriques, phénoménologiques et expérimentales ont permis d'identifier les paramètres d'influence de la mesure du seuil de sensibilité et de conclure sur les précautions à prendre lors des essais. Enfin, une extension de l'étude a mis en évidence quelques précautions à prendre lors de détection sur site avec des détecteurs qualifiés.

Dans les semiconducteurs amorphes, les propriétés macroscopiques sont déterminées par les états localisés. La spectroscopie IR photomodulée nous a permis de faire une étude originale des états localisés dans ce matériau. Nous avons étudié l'absorption IR photomodulée de a-Si1-xCx:H. L'analyse des résultats nous a permis de déterminer la largeur de la queue de bande de valence et celle de la queue de bande de conduction séparément. a-Si1-xCx:H dopé au bore peut être rendu microporeux par anodisation dans un électrolyte à base de HF. Sa luminescence est décalée vers le bleu par rapport à celle du massif pour une même concentration en carbone. La caractérisation par spectroscopie IR a révélé un taux de carbone plus élevé dans les couches poreuses que dans le matériau massif correspondant. Cet enrichissement en carbone, dû à la dissolution sélective du silicium lors de l'anodisation a été confirmé quantitativement par SIMS. La variation de la photoluminescence de a-Si1-xCx:H a été mesurée entre 77 et 400K. En utilisant nos résultats de mesures d'absorption IR photomodulée, nous avons pu comprendre la dépendance de la PL avec la température grâce à un modèle.

<p>The target tracking system of an IR (InfraRed) guided missile is constantly subjected to disturbances due to the linear and angular motion of the missile. To diminish these LOS (Line Of Sight) disturbances the seeker of the missile can be built from a free gyroscope mounted in a very low friction suspension. The ability of the spinning gyroscope to maintain its direction relative to an inertial frame is used to stabilize the seeker LOS while tracking a target. The tracking velocity of the seeker, i.e. its angular velocity, is controlled by a feedback control unit where the signal from the IR detector is used as input. The electrical driven actuator consists of a set of coils and a magnet on the gyroscope. </p><p>The purpose of this thesis is to develop a real-time model of the seeker gyroscope in an existing IR MANPAD (MAN Portable Air Defense) missile. The aim is a model that is able to simulate the real system with consideration to the tracking velocity. The model should also be integrated into a hybrid simulator environment. </p><p>With relatively good knowledge of the system and its subsystems an initial physical modelling approach was used where elementary equations and accepted relations were assembled to describe the mechanism of the subsystems. This formed the framework of the model and gave a good foundation for further modelling. By using experimentation and more detailed system knowledge the initial approach could be developed and modified. Necessary approximations were made and unknown parameters were determined through system identification methods. The model was implemented in MATLAB Simulink. To make it suitable for real-time operation Real-Time Workshop was used. </p><p>The model design was evaluated in simulations where the tracking performance could be tested for different positions of the gyroscope. The results where satisfying and showed that the model was able to reproduce the output of the system well considering the speed of the model and the approximations made. One important reason that good results can be achieved with a relatively simple model is that the seeker is limited to small rotations. The model can be tuned to operate in a smaller range and the complexity can be kept low. A weakness of the model is that the output error increases for wide angles.</p>

<p>Technologies for position sensing and identification are important to have in ubiquitous computing environments. These technologies can be used to track users, devices, and artefacts in the physical milieu, for example, locating the position of a cellular phone in av physical environment. The aim of this thesis was to survey and classify available technologies for location sensing and identification. </p><p>We have made a literature study on both commercial and research-oriented systems and technologies for use in indoor and outdoor environments. We compared the characteristics of the underlying sensing technologies with respect to physical size, sensing method, cost, and accuracy. We conclude the thesis with a set of recommendations to developers and discuss the requirements on future sensing technologies and their use in mobile devices and environments.</p>

<p>Syfte: Syftet med den här uppsatsen är att beskriva IR-funktionens viktigaste målgrupper och kommunikationskanaler, samt undersöka om utformningen på budskapet som kommuniceras ut varierar beroende på vilken målgrupp de riktar sig mot. Vi vill även undersöka relationernas betydelse i detta sammanhang och vad som kan skada denna relation. </p><p>Metod: Vi har valt att använda oss av både den kvalitativa och kvantitativa metoden då de kompletterar varandra, ifråga om bredd och djup. Vidare så ökar validiteten på undersökning när olika tillvägagångssätt kommer fram till samma resultat. </p><p>Slutsatser: De viktigaste målgrupperna anses vara privata och institutionella investerare, analytiker och media. De viktigaste kommunikationskanalerna är de formella kanalerna, följd av enskilda möten och Internet. När det gäller budskapets innehåll, har vi kommit fram till att samma information kommuniceras ut till alla aktörer, det är enbart utformningen som skiljer sig åt. </p><p>Vidare är det viktigt för företag att etablera nära och långvariga relationer för att skapa och upprätthålla investerarnas förtroende. Att kommunicera ut felaktig information eller frånvaro av kommunikation är ett effektivt sätt att rasera detta förtroende. </p>

<p> This thesis contains an introduction to the surface chemistry of minerals in aqueous environment, and a summary of five manuscripts concerning adsorption reactions at the surfaces of nano-sized gibbsite (α-Al(OH)3), amorphous silica and kaolinite.</p><p> Nano-sized gibbsite was synthesized and thoroughly characterized using X-ray diffraction, high-resolution transmission electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy. The adsorption of protons and the development of charge at the surfaces were studied using high precision potentiometry and zeta potential measurements. The results showed that singly coordinated surface sites at the particle edges protonate/deprotonate, while ion pairs with the medium ions are formed at doubly coordinated surface sites at the basal planes. This ion pair formation is a slow reaction, requiring long equilibrium times.</p><p> The adsorption of o-phthalate, maleate, fumarate, malonate and oxalate onto gibbsite surfaces was studied using Fourier transform infrared spectroscopy, zeta potential measurements, adsorption measurements and theoretical frequency calculations. All ligands were found to form outer-sphere complexes at the basal planes. Significant amounts of inner-sphere complexes at the particle edges were found for malonate and oxalate only. The observed adsorption was described using surface complexation models.</p><p> The proton reactions at the surface of amorphous silica were described using a two-site model. XPS indicated that Na+ is accumulated in the vicinity of the surface. Proton reactions at kaolinite surfaces were explained using a nonelectrostatic model, assuming that only the aluminol and silanol sites at the particle edges are reactive. Extensive modeling provided support for this assumption. </p>