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Nybacka, Louise. "FTIR spectroscopy of glucose." Thesis, Uppsala universitet, Fasta tillståndets elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-306952.
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Approximately 450 000 people have diabetes in Sweden today, and the number of diabetics only rises. Monitoring blood sugar several times a day is a fundamental part of managing the disease, and reducing the risks of complications. Today’s glucose monitoring devices are invasive and require small needle sticks for a measurement. Providing a painless method of monitoring the blood sugar level would relieve the lives of diabetics world-wide. The objective of this project was to investigate the absorption spectra of aqueous glucose concentrations (100 to 5000 mg/dl) in the mid infrared region with Fourier Transform spectroscopy (FTIR), and finally implementing a hand-held monochromatic spectrometer to demonstrate a non-invasive concept. The method chosen for implementing the hand-held demo is due to the commercial availability of diodes and detectors at those wavelengths. The results from the FTIR showed a trend among concentrations in all wavelengths, in between 1180 to 980 cm-1, specifically at 1035 cm-1, but also in the region 2920 to 2850 cm-1. The hand-held spectrometer did not register any transmittance of the glucose samples. For future implementations, 1035 cm-1 should be investigated more in-depth for a hand-held device.
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Oliveira, Jefferson Saraiva de. "Avaliação da qualidade de biodiesel por espectroscopias ftir e ftnir associadas à quimiometria." reponame:Repositório Institucional da UnB, 2007. http://repositorio.unb.br/handle/10482/2952.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, 2007.Submitted by Érika Rayanne Carvalho (carvalho.erika@ymail.com) on 2009-12-15T22:48:09Z No. of bitstreams: 1 2007_JeffersonSaraivadeOliveira.pdf: 2593425 bytes, checksum: 49c3949a9c46118d4e28db8a3a3a2e39 (MD5)
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Após a introdução do biodiesel na matriz energética Brasileira, se tornou necessária a avaliação da qualidade deste tipo de combustível seguindo normas estabelecidas pela Agência Nacional do Petróleo (ANP). A possibilidade do uso de diferentes fontes de óleos vegetais na produção do biodiesel gera problemas relacionados à produção e qualidade deste combustível, abrindo precedentes para fraudes fiscais. Considerando esta demanda socioeconômica, a proposta é o uso de técnicas espectroscópicas combinadas com ferramentas quimiométricas como métodos para determinar o teor de ésteres metílicos (biodiesel) nas misturas diesel/biodiesel. Neste trabalho as técnicas espectroscópicas FTIR-ATR (Infravermelho com transformada de Fourier - reflectância total atenuada) e FTNIR (Infravermelho Próximo com transformada de Fourier) combinadas com a análise de PLS (Regressão por Mínimos Quadrados Parciais) e de ANN (rede neural artificial) foram empregadas. Os ésteres metílicos usados para preparar as amostras da calibração foram obtidos pela metanólise dos óleos de soja, babaçu, dendê e de óleo de soja usado em frituras. Sua pureza foi avaliada por cromatografia gasosa (GC-FID). As amostras foram separadas em dois grupos: Grupo I, misturas binárias (diesel + um tipo de éster metílico), correspondendo a 96 misturas do biodiesel (0-100%, m/m), e Grupo II, misturas quaternárias (diesel + três tipos de ésteres metílicos), correspondendo a 60 misturas do biodiesel (0-100%, m/m). Os resultados de PLS mostraram que o modelo de FTNIR para o Grupo I é mais preciso e exato (± 0,02 e ± 0,06%, m/m). No caso do Grupo II, os modelos de PLS (FTIR-ATR e FTNIR) apresentaram as mesmas exatidões, enquanto os modelos de ANN/FTNIR apresentaram melhor desempenho do que os modelos de ANN/FTIR-ATR. A melhor exatidão foi obtida pelo modelo de ANN/FTNIR para a determinação diesel (0,14%, m/m), já o modelo de ANN/FTIR-ATR para o dendê (0,6%, m/m) apresentou um desempenho inferior. As precisões na análise do Grupo II variaram de 0,06 a 0,53% (m/m) e os coeficientes de variação foram melhores que 3%, indicando que estes modelos são apropriados para a determinação das misturas diesel-biodiesel compostas por ésteres metílicos derivados de diferentes óleos vegetais. __________________________________________________________________________________________ ABSTRACT
After the introduction of biodiesel in the Brazilian energetic matrix it became necessary the evaluation of the quality of this kind of fuel following norms as established by the ANP (Brazilian Agency for Petroleum, Gas, and Biofuels). One of the problems that is concerned to the biodiesel production and quality is the use of different sources of vegetable oils in the biodiesel production, opening the possibility for fiscal frauds. Considering this socioeconomical demand it is proposed in this work the use of spectroscopic techniques combined to chemometric tools as methods to determine the content of methylseters (biodiesel) in diesel/biodiesel blends. The methods presented in this work have made use of spectroscopic techniques such as FTIR-ATR (attenuated total reflectance-Fourier transform infrared) and FTNIR (Fourier transform nearinfrared) combined to chemometric tools like PLS (partial least square regression analysis) and ANN (artificial neural network) analysis. The methyl esters used to prepare the calibration samples were obtained by the methanolysis of soybean, babassu, dende, and soybean fried oils. Their purity was evaluated by gas-chromatography (GC-FID). The samples were separated in two sets: Group I, binary mixtures (diesel + one kind of methyl ester), corresponding to 96 biodiesel blends (0–100%, w/w), and Group II, quaternary mixtures (diesel + three types of methyl esters), corresponding to 60 biodiesel blends (0–100%, w/w). The PLS results have shown that the FTNIR model for Group I is more precise and accurate (±0.02 and ±0.06%, w/w). In the case of Group II the PLS models (FTIR-ATR and FTNIR) have shown the same accuracies, while the ANN/FTNIR models has presented better performance than the ANN/FTIR-ATR models. The best accuracy was achieved by the ANN/FTNIR model for diesel determination (0.14%, w/w) while the worthiest was that of dende ANN/FTIR-ATR model (0.6%, w/w). Precisions in Group II analysis ranged from 0.06 to 0.53% (w/w) and coefficients of variation were better than 3% indicating that these models are suitable for the determination of diesel–biodiesel blends composed of methyl esters derived from different vegetable oils.
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Few, Julian William. "FTIR studies of chemical processes." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:b7dbc587-fb9e-46de-8f04-44892fde0bf4.
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This thesis presents the study of a selection of gas phase chemical processes using time-resolved Fourier transform infrared (FTIR) emission spectroscopy. Such processes include molecular energy transfer, chemical reaction and photodissociation. The major focus of this thesis was the investigation of collisional energy transfer from the electronically excited states of NO and OH, with particular attention paid to the fate of the electronic energy. NO A2Σ+(v = 0) is prepared by laser excitation, pumping the overlapped Q1 and P21 band heads of the NO A-X (0,0) transition at 226.257 nm. The quenching of this state by O2 and CO2 was studied. Experiments were performed to investigate what channels contribute to the quenching process, the branching ratio of these different channels and the partitioning of energy among the various products. Quenching by O2 was found to proceed mostly through non-reactive channels. High vibrational excitation of NO X 2Π was observed, with population detected in v = 22, representing 79% of the available energy. The O2 product was found to be formed in more than one electronic state: the ground state, X 3Σ-g, and a high-lying electronically excited state, such as the A 3Σ+u, A' 3Δu or c 1Σ-u states. A reactive channel producing vibrationally excited NO2 was observed, but was found to be a minor process with an upper limit of 18% for the branching ratio. In contrast the quenching of NO A 2Σ+(v = 0) by CO2 was found to proceed predominately by reaction, with a branching ratio of 76 %. While emission from NO2 was observed, it was weak, and therefore it was concluded that the main reaction products were CO, O(3P) and NO X 2Π(v = 0). The nascent strong CO2 v3 emission band from the non-reactive channel exhibited a large red-shift from its fundamental position. This indicates that the CO2 vibrational distribution is significantly hotter than statistical. Investigations were then performed studying the quenching of NO A 2Σ+(v = 1) by NO and CO2, with both systems exhibiting similar characteristics to the quenching of the ground vibrational level of NO A 2Σ+. From comparison of the emission intensity of the CO fundamental and CO2 v3 mode following quenching of the v = 0 and 1 levels of the NO A 2Σ+ state, it was concluded that the branching ratio for reactive quenching was larger in the latter case. Secondly, experiments were performed to measure the rate constants for the quenching of NO A 2Σ+(v = 0) by the noble gases. The noble gases are inefficient quenchers of electronically excited NO and therefore careful experimental design was required to minimise the influence of impurities on the results. All the rate constants were found to be of the order of 10-14 cm3 molecule-1 s-1. The value for Xe was 50 times smaller than reported previously in the literature. In light of this new measurement, a re-analysis of experiments, performed previously in the group, on the electronic quenching of NO A 2Σ+(v = 0) by Xe was performed. A very hot vibrational distribution of NO X 2Π was obtained. Next, the collisional quenching of OH A 2Σ+(v = 0) by H2 was investigated. OH radicals were generated in situ by the photolysis of HNO3 at 193 nm, which were excited to the A 2Σ+(v = 0) state on the overlapped Q1(1) and P21(1) rotational lines at 307.935 nm. Reactive quenching was found to be the major pathway, in agreement with the literature. Copious emission from vibrationally excited water was observed. Comparison of this emission with theoretical calculations revealed a hotter distribution than predicted. It was concluded that the energy channelled into the vibrational modes of H2O is in excess of 60% of the available energy. Experiments performed with D2 allowed the non-reactive channel to be studied; a cold vibrational distribution of the OH X 2Π was observed. Finally the reaction between CN radicals and cyclohexane was studied. CN was generated by the photolysis of ICN at 266 nm. Prompt emission from HCN in the C-H stretching region was observed meaning the new bond was formed in a vibrationally excited state. Analysis of the emission revealed HCN was populated up to v3 = 2. Excellent agreement with the results of a theoretical study of the system was found.
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Becker, Edo. "FTIR-Emissionsspektroskopische Untersuchungen der arktischen Atmosphäre = Investigations of the arctic atmosphere by FTIR-Emission spectroscopy /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 1998. http://www.gbv.de/dms/bs/toc/247022616.pdf.
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Inberg, R. Brandon. "Enhanced step mode FTIR position control." Thesis, Montana State University, 2005. http://etd.lib.montana.edu/etd/2005/inberg/InbergR1205.pdf.
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Finch, D. C. "FTIR spectroscopy of electron irradiated polymers." Thesis, Brunel University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381899.
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Morrell, Claire. "FTIR emission studies of chemical processes." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326026.
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Gowrie, Sarah. "FTIR emission studies of energy transfer." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531817.
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Fuentes, A. Fernandez. "FTIR determination of sulphur isotope ratios." Thesis, University of Aberdeen, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334712.
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A new method for the determination of sulphur isotopic ratios by FTIR measuring the area or absorbance of individual lines, has been developed. The project could be divided into three parts: (i) In part one the infrared spectra of four sulphur gases SCO, H2S, SF6 and SO2, were collected and studied to evaluate which one would be the most appropriate to determine sulphur isotopic ratios. The synthesis of these gases was also assessed and performed in those cases where the means to carry them out were available. This part was designed to test the viability of these compounds as a means of extracting sulphur from natural samples. (ii) In part two, the methodology for the determination of sulphur isotopic ratios using the infrared spectrum of sulphur dioxide, gas chosen for this project, was performed. Different factors affecting the precision of the method, such as resolution, number of scans, etc., were evaluated and optimized. The UV/Vis spectrum of this gas was collected and the viability of using the L(1)-bound overdetermined Gaussian elimination method for assessing sulphur isotopic ratios over data obtained from this spectrum as well as from its infrared spectrum, was also tested. Both methods, integration of individual lines in the infrared spectrum of SO2, and use of the L(1)-bound overdetermined Gaussian elimination method over data also obtained from the infrared spectrum of sulphur dioxide, proved to be applicable when determining isotopic ratios in enriched samples. (iii) In part three, levels of sulphur-34 and nitrogen-15 in the biomass of four arable Scottish soils were determined. A slight enrichment in both isotopes was detected for one of the soils, being the first time such a measurement has been carried out. Sulphur and nitrogen deficiency in this soil are given as a possible explanation although the lack of sufficient number of data do not allow us to establish with certainty its cause.
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Hanh, Bui Duc, Ulrike Günther, Marcus Hartmann, Siegfried Wartewig, and Reinhard Neubert. "Drug penetration studied by FTIR methods." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-194960.
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Hanh, Bui Duc, Ulrike Günther, Marcus Hartmann, Siegfried Wartewig, and Reinhard Neubert. "Drug penetration studied by FTIR methods." Diffusion fundamentals 3 (2005) 31, S. 1, 2005. https://ul.qucosa.de/id/qucosa%3A13271.
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Noreen, Razia. "FTIR imaging of collagens in gliomas." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14316/document.
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Le gliome est le type le plus agressif et mortel de tumeur cérébrale. Ces tumeurs se caractérisent par la présence conjointe de phénotypes solides (de bas grade, moins invasif, hautement vascularisé) et diffus (haut grade, très envahissant et diffus) des glioblastomes multiformes. Les collagènes sont des composants majeurs de la MEC des cellules tumorales des gliomes, et sont également présents dans la membrane basale des vaisseaux sanguins, mais avec une composition différente entre vasculatures saine et tumorale. L'abondance et la typologie des collagènes dans la MEC des cellules tumorales et la vasculature représentent donc un marqueur potentiel de diagnostic pour la gradation des tumeurs gliales. Nous avons développé la spectro-imagerie infrarouge à transformée de Fourier pour déterminer les modifications morphologiques et moléculaires apparaissant dans les formes solides et diffuses de gliomes, ainsi que dans les vasculatures saine et tumorale. Nous avons d'abord mis en évidence les vasculatures saine et tumorale en utilisant des nanoparticules injectées dans le système sanguin. Ensuite, nous avons appliqué des méthodes de reconstruction spectrale pour distinguer les tissus sains vs. ceux des formes solide et diffuse de tumeurs sur la base de leurs contenus en collagène de la MEC. Enfin, nous avons déterminé les changements de types du collagène au cours de la progression tumorale, validant ainsi la notion que l’analyse de ces contenus est potentiellement un marqueur diagnostic pour la gradation des gliomesThe glioma is the most aggressive and lethal type of brain tumor. Such tumor is characterized both by solid (low grade, less invasive, highly vascularized) and diffuse (high grade, very invasive and diffuse) phenotypes in high-grades. Collagens are major components of ECM in glioma tumor cells, and are also present in basement membrane of blood vessels in vasculature, but with different composition between healthy and tumor capillaries. The abundance and typology of collagens in tumor cell ECM and vasculature is thus a potential diagnostic marker for grading glioma tumors. We developed Fourier transform infrared (FTIR) spectro-imaging as a functional technique to determine the morphological and molecular changes occurring in solid and diffuse form of tumor tissues as well as in healthy and tumor vasculatures. We first highlighted healthy and tumor vasculatures using nanoparticles injected in blood system. Then, we applied curve-fitting methods to distinguish between healthy tissue vs. solid and diffuse tumor tissues on the basis of the collagen contents found in ECM. Finally, we determined collagen typology changes during tumor progression, thus validating that collagen contents analysis is potentially a diagnostic marker for glioma grading
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Piwowarski, Patrick. "FTIR-spektroskopische Untersuchungen am Phytochrom Agp2." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17788.
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In der vorliegenden Arbeit wurde der lichtinduzierte Reaktionszyklus des bakteriellen Phytochroms Agp2 aus Agrobacterium tumefaciens mit FTIR‑ und UV‑Vis‑Spektroskopie untersucht. Der Photorezeptor besteht aus einem photosensorischen Modul und einer signalgebenden Histidin-Kinase-Domäne. Das photosensorische Modul bindet das Tetrapyrrol Biliverdin als Chromophor. Der Grundzustand von Agp2 (Pfr, 750 nm) ist gegenüber dem lichtaktivierten Zustand (Pr, 700 nm) rotverschoben, weshalb Agp2 den Bathyphytochromen zugeordnet wird. Die Untersuchungen erfolgten unter Verwendung von Isotopenmarkierung, H/D-Austauschexperimenten und ortsspezifischer Mutagenese. Daraus ließen sich folgende molekulare Änderungen charakterisieren, welche im Reaktionszyklus von Agp2 erfolgen: Die lichtinduzierte Isomerisierung des Chromophors führt zu einem Übergang vom Pfr- in den Pr-Zustand, wobei zwei Intermediate, Lumi‑F und Meta‑F, durchlaufen werden. Neben der Konformationsänderung des Chromophor‑D‑Rings ist auch die C‑Ring-Propionsäureseitenkette an der Photoreaktion beteiligt. Die C-Ring-Propionsäureseitenkette ist im Pfr-Zustand protoniert und wird im Übergang von Meta-F zu Pr deprotoniert. Der Pr-Zustand weist eine pH-Abhängigkeit auf, welche auf die pH-abhängige Ladung des Histidins 278 der Chromophortasche zurückzuführen ist. Je nach Ladung des Histidins 278 wird die Keto‑ bzw. Enolform der C(19)=O‑Gruppe des D‑Rings stabilisiert. Die Keto/Enol-Tautomerie ist auf eine innerhalb des Chromophors erfolgende Protontranslokation zurückzuführen und moduliert die Relaxation in den Pfr-Zustand. Änderungen der Amid-I-Absorption im Pfr-Pr-Übergang werden der Umstrukturierung der Tongue-Region des photosensorischen Moduls von einer Alpha-helikalen zu einer Beta‑Faltblatt-Struktur zugeordnet. Diese Strukturänderung wird als möglicher Weg der proteininternen Signaltransduktion zwischen photosensorischem und signalgebendem Modul vorgeschlagen.In this thesis the light-induced reaction cycle of the bacterial phytochrome Agp2 from Agrobacterium tumefaciens was investigated using FTIR and UV‑vis spectroscopy. The photoreceptor comprises a photosensitive module and a signalling histidine kinase domain. The photosensitive module binds the biliverdin tetrapyrrol as chromophore. The Agp2 ground state (Pfr, 750 nm) is red-shifted in comparison with its light-activated state (Pr, 700 nm). Therefore, Agp2 is assigned to the group of bathy phytochromes. The investigations were conducted using isotopically labelled protein, labelled chromophore as well as hydrogen‑deuterium (H‑D) exchange and site-directed mutagenesis. Based on these the following molecular changes could be characterized that occur in the reaction cycle of Agp2: The light-induced isomerization of the chromophore leads to a transition from the Pfr to the Pr state, involving two intermediates, Lumi-F and Meta-F. Besides conformational changes of the chromophore D-ring, the C-ring propionic side chain is involved in the photoreaction as well. The C-ring propionic side chain is protonated in the Pfr state and gets deprotonated in the Meta-F to Pr transition. The Pr state exhibits pH‑dependent alterations which can be explained by pH dependent polarity changes of histidine 278 in the chromophore pocket. Depending on the charge of histidine, the D‑ring C(19)=O group is stabilized either in keto or enol form. The keto/enol tautomerism involves a proton translocation within the chromophore and modulates the relaxation to the Pfr state. The changes in the amide I region in the Pfr-Pr transition are associated with an alpha‑helix to beta‑sheet secondary structure change of the PHY domain tongue‑region. This structural change is proposed as the potential path of signal transduction between the photosensitive and the signalling module.
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Saunders, Mark. "Chemical processes studied by time-resolved FTIR." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491975.
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This thesis has applied the time-resolved FTIR emission technique to the study of a number of gas phase cheinical processes, including photodissociation, chemical reaction and energy transfer. Two particular types of species are considered: vibrationally excited NO, formed from photolysis, reaction and energy transfer pathways, and organic radical compounds formed from photolysis and involved in secondary reaction processes. Vibrationally excited NO has been observed as one of the reaction products following the photolysis of N02 over a range of wavelengths in the region 193 - 327 nm. Emission from the fundamental and first overtone bands was analysed to obtain the nascent vibrational distribution at each wavelength considered. The nascent vibrational distribution was found to be strongly inverted and wavelength dependent. Photolysis at A > 244 nm proceeds via one reaction pathway; 1 A>244nm )NO+Oep) (1) and the NO(v) distribution is of atmospheric importance in determining the global concentrations of NO measured from satellite emission studies. There is a smooth trend in the inverted distributions with increasing photon energy. Nascent populations were used to produce a new model to predict the wavelength dependence of the nascent populations of NO(v) formed following photolysis of N02 in the range 265 - 370 nm. Such work has been shown to provide useful new information for atmospheric models of global concentrations of NO. Atmospheric models of NO concentrations also require input parameters for the rates of relaxation of NO(v) in collision with quenching molecules, in particular 02. The rate constants for vibrational quenching of NO(v = 1 - 16) in collisions with a number of species have been measured. Vibrationally excited NO was produced by both the 193 nm photolysis of N02 and the reaction of OeD) with N20, initiated by the 193 nm photolysis of N20. Quenching rates were measured for collisions with O2, He, NO and CO2. The vibrational distribution of NO(v) formed following photolysis of N02 at 193 nm was confirmed to be bimodal with a secondary maximum at v = 14 allowing new rates of relaxation of highly vibrationally excited NO to be determined due to the relatively large nascent populations of these levels. At A< 244 nm at second reaction channel for N02 photolysis opens up and in order to assess the contribution of this channel to the overall distribution at such wavelengths a new nascent distribution was determined following photolysis at 226 nm. The distribution was found to be bimodal and could qualitatively be described by the sum of the Oep) and OeD) channels. Vibrationally excited NO was also formed following energy transfer from NO A z:E+(v = 0), which was achieved by 226 nm pumping of ground state NO. Nascent vibrational distributions were determined for a variety of collision partners and NO was shown to be populated up to at least v = 20. The distributions obtained varied with the collision partners: NO, CO, COz and Ar. Distributions of ground state NO(v) were also acquired under conditions such that the internal energy in the products was governed by the emission coefficients. Comparison of distributions obtained by collision and fluorescence and those predicted from the emission coefficients allowed a purely collisional NO(v) distribution to be estimated when NO and CO were the quenching molecules. Emission was also observed from high vibrational modes of CO and COz indicating a direct energy transfer from NO A z:E\v = 0). Argon was found to not significantly affect the distribution at the pressures employed but afforded a dramatic increase in intensity from NO(v) that was shown to be due to hole burning and subsequent collisional hole filling. The second part of this thesis describes the generation and reactions of organic radical species. The photolysis of vinyl bromide and vinyl chloride at 193 urn was considered and nascent vibrational populations of the HBr and HCI products have been measured and found to be indicative of a three-centre formation mechanism. Secondary reaction products of the vinyl radical (CZH3) produced from this photolysis process have also been considered and mechanisms for their formation proposed. The presence of buffer gas has been shown to generate new features which have been assigned to vibronic emission from the secondary reaction product CzH. Products of the reaction of Oz with the vinyl radical, formed from the 193 nm photolysis of vinyl bromide and vinyl chloride, have been identified. In particular the existence two primary reaction channels have been confirmed by the assignment of emission from CO2, HCO and HzCO, and the mechanism of one secondary reaction channel has been proposed by analysing the kinetics of emission from CO(v). In addition a new reaction channel has been proposed by considering emission from CzHz. A qualitative branching ratio between these three reaction channels has been proposed. The reaction of CZH3 with O2 is of significance to combustion processes and a rate constant for the process has been determined to be 9.5 x 1O,tZ cm3 molecule,l S'I by assessing the kinetics of emission from HzCO. As a comparison to the generation of simple unsaturated free radicals, such as the vinyl radical, the photolysis of acetone at 266 nm to generate the simple saturated methyl radical was investigated. Primary reaction products were identified as the CH3 and CH3CO radicals and emission was observed in the C-H stretching region that was assigned on the basis of its kinetics to the methyl radical recombination product CZH6• CO(v = 1 - 6) was also observed as a secondary product of the process and attributed to photolysis of CH3CO on account of its significantly hotter nascent vibrational distribution than that obtained in previous studies at 193nm.
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Guo, Jing. "Diagnosing Changes in Cells Using FTIR Microspectroscopy." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/phy_astr_diss/47.
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Fourier transform infrared (FTIR) microscopy has shown promise as an analytical tool for detecting changes in cells and tissues, such as those due to viral infection, apoptosis induction or malignancy. In many cases, diagnosis via FTIR microscopy can be undertaken on a timescale shorter than that required for other physical or histological techniques.
In this work we have used FTIR microscopy to study Vero cells that have been infected with herpes simplex virus (type I) and adenovirus. We have studied cellular samples at various time intervals following exposure to the virus. Several spectral regions were identified that allow discrimination between infected and uninfected Vero cell samples at 24 hours post exposure to both HSV1 and adenovirus. Spectral features were also identified that could be used to discriminate infected cells within 2-6 hours after exposure to both viruses. FTIR microscopy is therefore a useful tool for following the kinetics of viral infection in the 2-24 hours time range, at least at the levels of infection used in this study.
In a second type of study, FTIR microscopy was used to study apoptosis induction in acute lymphoblastic leukemia T-cells. Apoptosis was induced in T-cells in three different ways. We show that FTIR microscopy can be used to distinguish T-cells in the early stages of apoptosis from normal cells. We also provide data that may suggest that FTIR microscopy can distinguish cells that have undergone apoptosis via different pathways.
For most of the FTIR microscopic studies on cellular samples we have focused on the collection of spectral data in the 1500-800 cm-1 region. Spectra were collected for control cells and variously treated cells. The two sets of cells were then analyzed statistically using: 1) pair-wise comparison, 2) logistic regression, 3) partial least square regression, 4) principle component fed linear discriminant analysis and 5) hierarchical cluster analysis. The statistical analyses rigorously quantify to what extent treated and untreated cells can be distinguished. Since different statistical methods give differing results for the same data, it is important the right statistical method should be applied. The basis for these differences is discussed.
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Broberg, Marina. "FTIR method for analysis of synthesis gas." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-94539.
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The research institute ETC in Piteå is working with energy technical research and development. Today, much work revolves around research about renewable sources for fuel. In one project, biomass such as wood pellet is heated up while producing synthesis gas. The synthesis gas is then analyzed using three different GC techniques. ETC wanted to be able to make all their analysis on one instrument and with a faster speed. They contacted the company Rowaco in Linköping for help with developing a method on FTIR for analysis of the synthesis gas and that has been the aim for this thesis. A method has been developed for analysis of water, carbon monoxide, carbon dioxide and methane. The results from this thesis show that the concentrations of the molecules in the synthesis gas are outside the calibration curved that has been made and that the high concentrations give much interference to other molecules. The thesis also shows that many areas in the spectrum from the process are roof absorbers and there is also a contamination of water and carbon dioxide in the system. Suggested improvements are to find the source for the contamination, to develop calibration points with higher concentrations, to reduce the length of the gas cell and to dilute the gas before entering the FTIR.
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Morrison, Marc. "Chemical processes studied by time resolved FTIR." Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414235.
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Jin, Changqing. "FTIR studies of TiO₂ : pigmented polymer photodegradation." Thesis, University of Newcastle Upon Tyne, 2004. http://hdl.handle.net/10443/1056.
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A novel method (in-situ quantitative infrared spectroscopy of evolved C02) for studying photo-degradation has been developed and applied to the study of several different polymers including a series of polyethylene and poly (vinyl chloride) samples containing Ti02 pigments with different photo-activitics. Infrared (IR) analysis was used to monitor carbon dioxide emitted from samples exposed to ultraviolet irradiation (UV) in atmospheres of differing composition. The experiments were conducted in a specially constructed cell that permits simultaneous UV exposure of the sample and IR interrogation of the vapour in the cell. It has been demonstrated that the in-situ gas-phase method permits a fast and convenient way of assessing the durability of pigmented and unpigmented polymer. A single test on one material occupied about 7 hours - very much less than conventional artificial weathering exposures. Excellent correlation between the C02 method and the conventional method for measuring carbonyl groups in the polyethylene films has been demonstrated, The Ti02 pigments used included anatase and rutiles with different surface treatments. Anatase-pigmented material gave significantly higher C02 emission than unpigmented polyethylene. The rutile-pigmented polyethylenes either gave reduced C02 emission or enhanced emission, according to the surface treatment. The ranking of the pigments as protectants or pro-degradants coincided with that obtained from much more time consuming laboratory testing and field experience. Similar results were obtained for the poly (vinyl chloride). The CO2 method is a convenient way to study the factors (humidity, oxygen concentration and UV intensity or wavelength), which influence the rate of carbon dioxide evolution i. e. the rate of photo-oxidation of the polymers. Blown polyethylene(PE) film was exposed to UV irradiation while held under tensile stress in a specially designed metal frame. The chemical degradation was followed using the FTIR carbonyl index. Tests were conducted on unpigmented PE and on a series of five PEs containing TiO2 pigments with different photo-activities. The yield strengths measured in tensile tests on unexposed films were typically 10 % greater in the longitudinal( machine)direction than in the transverse direction. UV exposures were conducted with stress applied both parallel and transverse to the machine direction.For all six materials, tensile stress accelerated carbonyl group development, Some samples cracked during UV exposure in tension and did so in a shorter time if the stress was applied in the machine direction than if it was transverse to it. The carbonyl index at the onset of cracking was lower for longitudinal samples than for transverse samples. Unpigmented PE was slightly more sensitive to transverse strain and the anatasepigmented PE slightly more sensitive to longitudinal strain.
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Bailie, Jillian Elaine. "FTIR studies of sulphur-modified cobalt catalysts." Thesis, University of Dundee, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319433.
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Bird, Benjamin L. "FTIR imaging : a route toward automated histopathology." Thesis, University of Nottingham, 2007. http://eprints.nottingham.ac.uk/39088/.
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The focus of this study is the potential use of FTIR imaging as a tool for objective automated histopathology. The Thesis also reports the use of multivariate statistical techniques to analyse the FTIR imaging data. These include Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), Multivariate Curve Resolution (MCR) and Fuzzy C-Means Clustering (FCM). The development of a new PCA-FCM Clustering hybrid that can automatically detect the optimum clustering structure is also reported. Chapter 1 provides a brief introduction to the use of vibrational spectroscopy to characterise biomolecules in tissues and cells for medical diagnosis. Chapter 2 details the basic histology of a lymph node before proceeding to present imaging results gained from the analysis of both healthy and diseased lymph node tissue sections. The ability of each multivariate technique to discriminate different tissue types is discussed. In addition, the spectral features that are characteristic for each tissue type are reported. The development and application of a new PCA-FCM Clustering algorithm that can automatically determine the best clustering structure is also described in full. The results indicate that cellular abnormality provides changes to both the protein and nucleic acid vibrations. However, similar spectral profiles were identified for highly proliferating cells that were contained within reactive germinal centres of the lymph node. Chapter 3 provides a short introduction to the histology of the cervlx before presenting imaging results that were gained from the analysis of both healthy and diseased cervical tissue sections. The ability of each multivariate technique to discriminate different tissue types is discussed. In addition, the spectral features that are characteristic for each tissue type are described in detail. Novel imaging experiments upon exfoliated cervical cells are also presented. It would appear that cellular abnormality in cervical tissues and cells affects both the protein and nucleic acid features of the spectra. Glycogen and glycoprotein contributions that are prevalent in healthy tissues are also absent. Chapter 4 details sample preparation methods, the instrumentation and procedures used for data acquisition, and the subsequent data processing and multivariate techniques applied to analyse the collected spectral datasets.
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Mešková, Michala. "Aplikace FTIR a NIR pro analýzu půd." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433163.
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This diploma thesis focuses on the use of infrared spectrometry methods for the analysis of soil samples. The aim of this work was to compare and analyze the soil using the ATR (Attenuated Total Reflectance) and DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) methods and to evaluate the effectiveness of these methods for soil analysis. The results showed that the ATR method is not sufficiently effective and the DRIFT method was used for soil analysis, which proved to be more suitable for the analysis of soil samples.
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Hmida, Fadoua. "Spectroscopie FTIR à haute résolution de SO2F2." Thesis, Reims, 2017. http://www.theses.fr/2017REIMS042.
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Les travaux présentés dans ce manuscrit sont consacrés à l’étude de la spectroscopie FTIR à très haute résolution de la molécule de fluorure de sulfuryle SO2F2 qui est apparu récemment comme un polluant atmosphérique important. Une très bonne modélisation de son spectre d’absorption est donc essentielle pour les mesures de concentration atmosphérique.Ce manuscrit comporte cinq parties. La première partie de ce travail de thèse concerne les propriétés de la molécule du fluorure de sulfuryle. La deuxième partie décrit le modèle théorique (formalisme tensoriel, Hamiltonien et moment dipolaire effectifs) que nous avons utilisé pour effectuer les analyses. La troisième partie expose les conditions expérimentales des différents spectres que nous avons enregistré à la ligne AILES du synchrotron SOLEIL à Saint-Aubin (Paris). La quatrième partie décrit le logiciel C2vTDS et enfin dans la cinquième partie, nous présentons les résultats des différentes analyses.Cette thèse a été effectuée au sein du Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA) de l’Université de Reims Champagne-Ardenne et au Laboratoire Dynamique Moléculaire et Matériaux Photoniques (LDMMP) à l’Ecole Nationale Supérieure d’Ingénieurs de l’Université de TunisThe work presented in this manuscript is devoted to the study of very high resolution FTIR spectroscopy of the molecule of sulfuryl fluoride, SO2F2, which recently appeared as an important atmospheric pollutant. However, a very good modeling of its absorption spectrum is essential for atmospheric concentration measurements.This manuscript has five parts. The first part deals with the properties of the molecule of sulfuryl fluoride. The second part describes the theoretical model (tensor formalism and effective Hamiltonian and dipole moment) that we used to perform the analyzes. The third part presents the experimental conditions of the different spectra that we recorded at the AILES line of the SOLEIL synchrotron at Saint-Aubin (Paris). The fourth part describes the software C2vTDS and finally in the fifth part we present the results of the different analyzes.This thesis was performed in the Molecular and Atmospheric Spectrometry Group (GSMA) of the University of Reims Champagne-Ardenne and the Laboratory of Molecular Dynamics and Photonic Materials (LDMMP - ENSIT) of the University of Tunis
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Medeiros, Alex Rodrigues Brito de. "Uso de ATR/FTIR e FTNIR associado a técnicas quimiométricas para quantificação de aditivos em gasolina automotiva." reponame:Repositório Institucional da UnB, 2009. http://repositorio.unb.br/handle/10482/4963.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, 2009.Submitted by Allan Wanick Motta (allan_wanick@hotmail.com) on 2010-06-07T18:41:02Z No. of bitstreams: 1 2009_AlexRodriguesBdeMedeiros.pdf: 1759714 bytes, checksum: 81f9f0eeb757224d0931e00fafbd3431 (MD5)
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A formação de depósitos é um problema muito comum em veículos automotivos devido à formação de goma e borra durante a queima do combustível no interior do motor. Aditivos detergentes/dispersantes foram criados para diminuir a influência desses agentes no funcionamento adequado dos veículos automotivos. Esses componentes, geralmente aminas poliméricas, são adicionados ao combustível ainda na distribuidora de combustíveis na concentração indicada e são comercializados distintamente da gasolina comum pela adição de corante. Neste trabalho, é proposta uma metodologia que se utiliza de espectroscopia vibracional (FTIR e FTNIR) associada a técnicas quimiométricas e pré-concentração dos combustíveis (resíduo de goma e resíduo de destilação) para quantificar três aditivos em gasolina C comum. Foram construídas curvas de calibração multivariada (PLS1). Os resultados foram analisados por comparação através do Teste F dos RMSEP (Root Means Square Error of Prediction), cálculo de capacidade de detecção e erro relativo de previsão (REP). Os resultados mostram que limites inferiores a 200 mg/kg de aditivos podem ser monitorados em gasolina automotiva utilizando espectroscopia vibracional. Em geral, os resultados mostram que os dados de FTIR são mais consistentes que àqueles de FTNIR. Além disso, os resultados mostram que o método de pré-concentração que se utiliza de resíduo de goma não lavada, em geral, possui melhor desempenho que o de resíduo de destilação. ___________________________________________________________________________________________ ABSTRACT
Formation of deposits is a very common problem in vehicles due to the formation of gum and sludge by burning fuel inside the engine. Additives detergent / dispersants are designed to reduce the influence of these agents in the proper functioning of automotive vehicles. These components are polymeric amine matrix added in the fuel distributor at the concentration indicated and are marketed separately from gasoline by the addition of dye. In this work, we propose a methodology applying vibrational spectroscopy (FTIR and FTNIR) combined with chemometric techniques and preconcentration of fuels (unwashed gum and atmospheric distillation) to quantify three additives in gasoline. Curves were built using multivariate calibration (PLS1). The results were analyzed by using F test, detection capability and relative prediction error (REP). The results show that concentrations below than 200 mg/kg can be monitored in gasoline. In general, the results show that the FTIR data are more consistent than those of FTNIR. Also, results show that using unwashed gum for preconcentration yields better performance than atmospheric distillation residue.
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Bobiak, John Peter. "Raman and FTIR imaging of dynamic polymer systems." online version, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1133472157.
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Moser-Boroumand, Farnaz. "Spectroscopie FTIR quantitative de réflectance et transmittance diffuses /." [S.l.] : [s.n.], 1991. http://library.epfl.ch/theses/?display=detail&nr=926.
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Hauser, Karin. "FTIR-Differenzspektroskopie zur Untersuchung von Konformationsänderungen in Proteinen." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961252634.
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Baisitse, Tshepiso Revonia. "Characterisation of InAs-based epilayers by FTIR spectroscopy." Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/474.
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This study focuses on the characterization of InAs and InAs1-xSbx epitaxial layers by infrared reflectance and transmittance spectroscopy and Hall measurements. Reflectance measurements were performed in order to obtain the dielectric parameters and to extract from these information about the electrical properties (mobility and carrier concentration) of this important III-V material system. The transmittance measurements were used to determine the bandgap of InAsSb. Infrared reflectivity and transmittance measurements were performed in the wavelength range 200 – 2000 cm-1 on InAs and InAsSb layers grown on three types of substrates. A classical two oscillator model that takes into account both the free carriers and the lattice, was used to analyse the reflectance data using the BMDP® computer curve fitting software. The dielectric parameters and the electrical properties (carrier concentration and mobility) were extracted from the simulations. Due to the low free carrier concentration in the epitaxial structures, the plasma resonance frequency (ωp) values obtained from the simulations of reflectance spectra measured above 200 cm-1, were in the order of 20-30 cm-1. These low values were confirmed by direct measurements of ωp in reflectance spectra obtained in the range 15-200 cm-1. The simulated carrier concentration and mobility values determined optically were compared to the values determined by Hall measurements at room temperature and previously reported values by other researchers. The simulated values obtained were in reasonable agreement with the Hall values. The simulated and measured carrier concentrations obtained for InAs layers were significantly higher than the intrinsic carrier concentration for InAs at room temperature, indicating notable concentrations of donors resulting from the growth process.
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Lättig, Stefan. "FTIR-Spektroskopische Untersuchungen zur Hydrathülle von methylierten Cyclodextrinen." [S.l.] : [s.n.], 2006. http://www.diss.fu-berlin.de/2006/634/index.html.
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Mikuteit, Sabine. "Trendbestimmung stratosphärischer Spurengase mit Hilfe bodengebundener FTIR-Messungen." Karlsruhe : Forschungszentrum Karlsruhe, 2008. http://d-nb.info/989563669/34.
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Kramer, Isabell. "Zeitreihen troposphärischer Spurengase abgeleitet aus bodengebundenen FTIR-Messungen." Karlsruhe Forschungszentrum Karlsruhe, 2006. http://d-nb.info/985058412/34.
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Elkhider, Noha. "Applications of ATR-FTIR imaging to Pharmaceutical tablets." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520900.
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Glassford, Stefanie Elizabeth. "Applications of ATR-FTIR spectroscopic imaging to proteins." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/24835.
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Protein aggregation and crystallisation play an important role in the development of biopharmaceuticals and for structural proteomics but both processes are still poorly understood. There is a demand for new methods to screen the extensive range of conditions that promote crystallisation and aggregation as well as provide insight into the behaviour of the proteins. Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopic imaging is a powerful analytical tool which can be applied to study proteins. This technique combines ATR-FTIR spectroscopy with an infrared array detector allowing for both spatial and chemical information to be obtained from the sample. There are a range of imaging fields of view and spatial resolution possible with ATR-FTIR spectroscopic imaging and this presents multiple opportunities for the study of proteins. The purpose of this research was to further develop the application of ATR-FTIR spectroscopic imaging within the field of protein studies. ATR-FTIR imaging has been applied to study the effects of different conditions for microbatch protein crystallisation in a high throughput manner, where many samples can be analysed at the same time on the surface of a Macro ATR crystal by building a wax grid with multiple wells for different samples. Additionally, Micro ATR-FTIR imaging was combined with hanging drop protein crystallisation for high spatial resolution imaging of the growth of protein crystals. The surface properties of Silicon ATR crystals were modified to create a gradient of hydrophobicity allowing the effect of different surface properties on protein adsorption and crystallisation to be studied in situ. The development of these approaches will advance the use of spectroscopic imaging within the field of biopharmaceuticals, where it is has the potential to help the optimisation of both biopharmaceutical drug discovery processes and structural proteomics studies.
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Gu, Pei. "Thermal Analysis of Milkweed Floss Using TG/FTIR." TopSCHOLAR®, 1992. http://digitalcommons.wku.edu/theses/1556.
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The thermal analysis of milkweed and several individual commercial samples of .similar chemical composition has been carried out. By combining a two-stage thermal process. (pyrolysis-combustion) with TG-FTIR, it has been possible to identify the major organic volatile products during pyrolysis and to correlate gas evolution with the decomposition of the individual components (cellulose, hemicellulose and lignin) of the floss. During pyrolysis, acetic acid, formic acid and methanol are formed 1n addition to CO2, and H2O. The data also show that pyrolytic decomposition of the three chemical constituents of milkweed occur without any apparent synergistic interaction. The combustion of milkweed produced CO2 and H2O, as expected, but the removal of the waxy coating from the fibers results in an increased susceptibility to combustion. The coating displays no effect on the process of pyrolysis.
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Mohammadi, Shahla. "Etude par spectroscopie optique (FTIR, UV, Fluorescence) d'ADN." Paris 13, 1998. http://www.theses.fr/1998PA132013.
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Ce travail en spectroscopie optique (ftir, uv, fluorescence) a permis de determiner les conditions de formation, la stabilite, l'appariement des bases de double helices d'adn a brins paralleles et d'analyser la reconnaissance d'une sequence d'adn en double helice a partir de sites situes dans son grand sillon, d'une part en utilisant un oligonucleotide formant une triple helice d'autre part un intercalant muni de bras peptidiques. Le chapitre 1 porte sur les structures d'adn en double helices paralleles avec deux appariements differents. Le schema d'appariement trans-watson-crick connu pour les paires de bases a-t a ete complete par celui des paires g-c. Les paires g-c formees ont deux liaisons hydrogene. Les paires trans-watson-crick g-c et a-t ne sont pas isomorphes ce qui explique que la stabilite de la double helice parallele diminue quand le nombre de jonctions entre paires a-t et g-c augmente. La seconde structure parallele, limitee aux sequences homopurine-homopyrimidine, se forme avec un appariement hoogsteen a ph acide. Elle a ete stabilisee soit par des ions mg#2#+ soit par des intercalants (benzopyridoindoles). Ce meme type d'intercalant pourra stabiliser en orientation parallele par liaisons hoogsteen des oligonucleotides synthetiques sur une cible d'adn. Le chapitre 2 est consacre a l'etude de l'orientation du troisieme brin dans des triple helices ou la sequence du troisieme brin est centrosymetrique (g#3a#4g#3 et g#3t#4g#3). La fixation covalente de pyrene aux extremites des brins formant la triple helice a permis, par detection ou non de la formation d'excimere, de determiner l'orientation relative de ces brins. De plus l'etude de la cinetique de formation de la triple helice d(c#3t#4c#3)-d(g#3a#4g#3)#2 faite en marquant les deux brins cis-watson-crick suggere un mecanisme d'echange entre les brins homologues d(g#3a#4g#3). Le chapitre 3 concerne les complexes d'un derive de la porphyrine pourvue de bras arginyles (bap), avec des adn en double helices de differentes sequences. Les donnees de denaturation thermique en uv indiquent que bap, stabilise preferentiellement la double helice d(ggcgcc)#2 (que l'on retrouve dans le site pbs de hiv-1). Les spectres ir des complexes ont montre que bap, par ses bras peptidiques, interagit dans le grand sillon avec les sites n7 et o6 des guanines.
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Ling, Chen. "CAPABILITIES, LIMITATIONS AND APPLICATIONS OF ATR-FTIR IMAGING." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1403627635.
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Chen, Zhaomin. "Human Liver Metastases: Chemometrics of Imaging FTIR Data." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437662269.
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Hung, Wing Wa. "FTIR and XPS of congruent and stoichiometric LiNbO3." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/442.
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Starr, Michael J. "AFM-FTIR A New Technique for Materials Characterization /." Cincinnati, Ohio : University of Cincinnati, 2008. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1227192819.
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Thesis (M.S.)--University of Cincinnati, 2008.Advisor: James Boerio. Title from electronic thesis title page (viewed Feb.16, 2009). Includes abstract. Keywords: AFM; FTIR spectroscopy; atomic force microscopy; interphase; adhesive analysis; interferogram. Includes bibliographical references.
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Mikuteit, Sabine. "Trendbestimmung stratosphärischer Spurengase mit Hilfe bodengebundener FTIR-Messungen." [S.l. : s.n.], 2007. http://digbib.ubka.uni-karlsruhe.de/volltexte/1000007327.
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Joseph, Edith Michelle Maryse <1977>. "Application of FTIR microscopy to cultural heritage materials." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1404/1/Joseph_Edith_tesi.pdf.
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Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3).
In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems.
In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.
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Joseph, Edith Michelle Maryse <1977>. "Application of FTIR microscopy to cultural heritage materials." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1404/.
Full textAbstract:
Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3).
In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems.
In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.
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Carolei, Luciano. "Determinação de surfactantes e água em formulações de sabonetes líquidos e shampoos por infravermelho por transformada de Fourier (FTIR) utilizando a técnica de reflectância total atenuada (ATR)." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-29102007-143925/.
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Demonstrou-se pela primeira vez que é possível determinar surfactantes e água em formulações de Sabonetes Líquidos (SL) e Shampoos (SH), direta e simultaneamente pela técnica de infravermelho por transformada de Fourier (FTIR) acoplada à uma cela de reflectância total atenuada (ATR). Tradicionalmente, a principal aplicação do infravermelho médio (2,50 - 15,0 µm) é a identificação de compostos orgânicos. O desenvolvimento de novos acessórios, principalmente de ATR, os avanços na área de microinformática e de métodos quimiométricos, vem viabilizando as análises quantitativas rápidas com excelentes resultados mesmo em meio aquoso. A determinação simultânea de surfactantes em formulações por FTIR-ATR é investigada em detalhes nesta tese. Dentre os surfactantes utilizados, o Lauril Éter Sulfato de Sódio (LESS) e a Cocoamidopropil Betaína (CAPB) são comuns em ambas as formulações, sendo a Coco Dietanolamida (CDEA) empregada em shampoo e o Alquilpoliglicosídeo (APG) em sabonete líquido. Espectros de absorbância de amostras padrão e de verificação foram adquiridos na região do infravermelho médio (800-1600 e 1900-3000 cm-I). Para a regressão de mínimos quadrados clássicos (CLSR), selecionou-se 200 números de onda, enquanto que para a regressão de mínimos quadrados inversos (ILSR), apenas 10. Nas regressões de componentes principais (PCR) e de mínimos quadrados parciais (PLSRI e PLSR2), utilizaram-se de 300 à 1100 números de onda. Dois conjuntos de amostras padrão foram preparados, o primeiro, contendo 27 misturas padrão, foi estudado somente pelos métodos CLSR e ILSR, enquanto que o segundo conjunto, contendo 48 amostras padrão, foi avaliado por todos os métodos mencionados acima. A seleção das regiões de quantificação favoreceu números de onda dos componentes minoritários CAPB, APG e CDEA e resultados satisfatórios foram encontrados para 18 amostras de shampoo e sabonete líquido. Interferentes como NaCl e perfume foram incluídos no segundo conjunto e os métodos PCR e PLSR proporcionaram melhores resultados. Os erros relativos (RSEP%) para água (correspondendo a 84-88% do produto) e LESS (6-10%) não excederam 1%; para CAPB (<3%) e CDEA (<2%), o RSEP% situou-se entre de 2-4% e para APG (<3%), não excedeu 5%. Avaliações do processo de normalização, repetibilidade, vulnerabilidade a interferentes (perfumes), redução no número de padrões de calibração foram conduzidos, encontrando-se resultados satisfatórios para todos os casos, com erro relativo inferior à 5,0%. Um dispositivo simples para injeção direta da amostras no acessório de ATR foi construído, permitindo aumentar a freqüência analítica de 20 para 60 análises por hora.It is demonstrated for the first time that the principal constituents of a shampoo as well as of a liquid soap -three surfactants and water- can be determined directly, simultaneously and quickly in undiluted samples by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy in the middle infrared region, despite the broad absorption bands ofthe solvent. The main application of the middle infrared (2,50 - 15,0 µm) was the identification of organic compounds. The development of new accessories, such as ATR, and the advance of computers and chemometrics, extended the technique to quantitative analysis, with excellent results. The simultaneous determination of surfactants in shampoos and liquid soap formulations by FTIRA TR is investigated in detail in this thesis. Two of the surfactants, sodium lauryl ether sulfate (LESS) and cocoamidopropyl betaine (CAPB) are common to both formulations; alkylpolyglucoside (APG) is the third surfactant of the liquid soap and cocodiethanolamide (CDEA), the corresponding ingredient of the shampoo. Absorbance data of the undiluted verification samples and calibration standards was collected in the middle infrared region of the spectrum (800-1600 and 1900-3000 cm-1). Five methods of multivariate quantification were compared: Classical Least Squares Regression (CLSR), where absorbance data measured at 200 wavenumbers was processed, Inverse Least Squares Regression (ILSR), were data at 10 selected wavenumbers was analyzed, Principal Components Regression (PCR), and Partial Least Squares Regression, which has two different approaches, PLSR1 and PLSR2. Two sets of standard samples were prepared for the method calibration. The first one, consisting of 27 standard mixtures, was evaluated by the CLSR and ILSR methods; a second set, with 48 standards, was evaluated by all the methods mentioned above. Potential interfering, such as NaCI and perfume, were inc\\uded in this second set. By favoring wavenumbers where absorption bands of the minor components (CAPB in both formulations, APG in the liquid soap and CDEA in the shampoo) are more intense, good results were obtained for 18 simulated samples of shampoo and 18 samples of liquid soap. For the second set, PCR and PLSR methods were most favorable; relative errors (RSEP%) for water (major component, 84-88%) and LESS (6-10%) did not exceed 1%; for CAPB (<3%) and CDEA(<2%), RSEP% of 2-4% were observed, and for APG(<3%), 5% was not exceeded. Tests for repeatability, normalization performance evaluation, effect of interferents presented favorable results. A simple device for direct sample injection was designed and evaluated. It permitted an increase ofthe analytical frequency from 20 to 60 samples per hour.
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Wong, Kin Chiu. "Study of mechanically aligned polystyrene thin films by FTIR /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202006%20WONG.
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Mucalo, Michael Roger. "FTIR studies of surface adsorption on noble metal hydrosols." Thesis, University of Auckland, 1991. http://hdl.handle.net/2292/1996.
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Carbon monoxide adsorption, surface speciation and particle size distributions have been studied in platinum, palladium, and rhodium hydrosol systems using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. In transmission electron micrographs of unprotected platinum and palladium hydrosols, particle necklacing believed to arise from sintering during preparation, is apparent. The average particle sizes of all hydrosols studied were in the range of 2 to 12 nm. X-ray photoelectron spectra of the metal hydrosols revealed evidence for (Pt-O)ads, Pt(II) and Pt(IV) oxides on platinum hydrosol particles whereas Pd(II) and Pd(IV) oxides were detected on the surfaces of palladium hydrosol particles. These surface oxides are found to be important in influencing hydrosol surface processes such as CO adsorption as a function of pH, inhibition of CO adsorption by alcohols and surface corrosion products resulting from the addition of iodide and cyanide. Fourier transform infrared spectra of CO-treated metal hydrosols revealed bands due to CO linearly adsorbed on the metal particles at ca. 2070 cm-1 (Pt), 2067 cm-1 (Pd) and 2045 cm-1 (Rh) whereas bands due to bridge-adsorbed (B2) CO were detected at ca.1950 cm-1 (Pd) and 1890 cm-1 (Rh). The use of CO as a spectroscopic probe molecule enabled the study of changes in the surface properties of the metal hydrosols which were induced by changes in the dispersion medium. For example, v(CO)ads was observed to decrease in infrared spectra of CO-treated platinum and rhodium hydrosols as pH was increased by KOH or other dissolved salts yielding alkaline solutions. This suggested a reduction in CO coverage resulting from hydroxyl adsorption and consequent increased oxide growth on the particles. In contrast, CO adsorption on platinum and rhodium hydrosols was enhanced in acidic media possibly as a result of the neutralisation of surface hydroxyls. The spectroscopic behaviour of adsorbed CO on platinum and rhodium hydrosols was only comparable to that of CO adsorbed at an electrode surface in acidic media when protecting agent was present which prevented aggregation of the hydrosol in such media. Inhibition of CO adsorption on platinum hydrosols was induced by the addition of aliphatic alcohols, poly(vinyl alcohol) and poisoning anions such as CN- and SH-. Correlations of v(CO)ads with CO coverage suggested that island formation of adsorbed CO was occurring for CO adsorption on unprotected palladium hydrosols and protected platinum and rhodium hydrosols as a function of pH. In allied investigations, an infrared spectroelectrochemical study of corrosion of a nickel electrode in aqueous cyanide media has revealed that [Ni(CN)4]2- is detected at potentials more cathodic than 200 mV vs. SCE. Cyanide was oxidised to cyanate (OCN-) and then successively to carbon dioxide at potentials more anodic than 200 mV vs. SCE. The appearance of features at 2094 cm-1 (HCN) and 2256 cm-1 (HNCO) were attributed to pH changes associated with the oxidation of cyanide to cyanate. The appearance of a band at ca. 2218 cm-1 in infrared spectra of the thin layer at very high potentials (> 1000 mV vs. SCE) was believed to arise from an unstable nickel(II) isocyanate complex.
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Grahn, Mattias. "Development of a novel zeolite coated ATR-FTIR sensor." Licentiate thesis, Luleå, 2004. http://epubl.luth.se/1402-1757/2004/67.
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Ventura, Gayete Josep Francesc. "Desarrollo de métodos analíticos medioambientalmente sostenibles por espectrometría FTIR." Doctoral thesis, Universitat de València, 2007. http://hdl.handle.net/10803/10253.
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Esta Tesis Doctoral se ha orientado hacia la sostenibilidad medioambiental en el análisis cuantitativo por espectrometría vibracional. Cuatro han sido los ejes centrales que se han considerado: i) la búsqueda de disolventes alternativos a los habituales -clorados- o, en su defecto, la reducción de su consumo, ii) la automatización en el análisis, apostando por el empleo de la multiconmutación, iii) el empleo de técnicas de extracción combinadas con la espectrometría vibracional; y iv) el tratamiento integral de las muestras en montajes en flujo. Así, se han desarrollado una serie de aplicaciones para su utilización como técnica rutinaria en el control de calidad.Los resultados obtenidos en los 7 trabajos incluidos en la Memoria de Tesis muestran la potencialidad de la espectrometría vibracional por Transformada de Fourier en el ámbito del análisis de muestras de naturaleza diferente. Se han aplicado diversas estrategias para lograr el desarrollo de métodos analíticos medioambientalmente sostenibles. La técnica de reflectancia total atenuada en el infrarrojo medio (ATR-FTIR) permite el análisis directo de muestras acuosas, que absorben fuertemente. El empleo de accesorios ATR con celda de cristal de diamante ha resultado ser extraordinariamente útil debido a su dureza y resistencia. La posibilidad de obtener el espectro de prácticamente cualquier sustancia líquida o sólida la convierte en una técnica especialmente interesante, reduciendo al máximo la manipulación de la muestra y eliminando el consumo de disolventes nocivos.Por otra parte, se ha aplicado la multiconmutación acoplada con las técnicas del infrarrojo para resolver diversos problemas analíticos. Son aspectos prácticos de la multiconmutación: la versatilidad de la estrategia de análisis, la reducción de la manipulación de la muestra, la facilidad de diseño, la posibilidad de automatización sencilla y la miniaturización de los sistemas. Respecto a la versatilidad, hemos mostrado tres estrategias que plantean la multiconmutación de manera diferente: en una de ellas tiene como principal función reducir la manipulación de muestras y patrones midiendo en modo de flujo parado; en las otras dos se aprovecha su capacidad para realizar diluciones de muestra y adición de un estándar en línea, ejemplos de la variedad de enfoques que permite la multiconmutación al plantear un diseño experimental adecuado al problema analítico. Respecto a la manipulación de la muestra, los sistemas con multiconmutación permiten una intervención mínima del analista aumentando la comodidad y mejorando la eficiencia del laboratorio de análisis, independientemente del incremento en la frecuencia de análisis. Además, la experiencia en el desarrollo de las aplicaciones ha demostrado que mediante conocimientos mínimos de programación y electrónica se pueden diseñar los sistemas necesarios para realizar casi cualquier proceso típico de un método de análisis. Esta ventaja, quizá escasamente explotada hasta ahora, sugiere una enorme cantidad de aplicaciones casi inmediatas de gran utilidad en el análisis de campo y de rutina.También se han aplicado técnicas de tratamiento previo de la muestra, como la extracción presurizada con disolvente, que reduce el consumo de disolventes nocivos y mejora la frecuencia de análisis, y la extracción en fase sólida, que permite superar la limitación de la baja sensibilidad de la espectrometría FTIR, mediante preconcentración y elución en línea de los analitos, aplicada a muestras de tipo medioambiental.Finalmente se ha realizado el tratamiento integral en línea de la muestra con extracción selectiva del analito reduciendo la manipulación de la muestra y el consumo de disolvente, consiguiendo un método analítico aplicable al control de calidad, sostenible y fácilmente automatizable.En definitiva, se ha demostrado la gran capacidad de las técnicas FTIR y FTNIR para resolver problemas analíticos comunes y el papel decisivo que debe tener actualmente en los laboratorios analíticos.In this Thesis we faced the development of new analytical methods in terms of sustainability using vibrational techniques. This is fulfilled through four different approaches: the search of green solvents or the minimization of the chlorinated solvents consumption; the automatization of the methods, mainly through the application of multicommutation; the use of extraction techniques previously to the measurement with the vibrational spectrometry techniques; and the full sample treatment in flow systems. Seven different papers are presented here, showing the versatility of the Transform Infrared spectrometry in the quantitative analysis field, even applied to very different types of samples. Attenuated Total Reflectance (ATR) technique in the mid-infrared region allows the direct measurement of aqueous samples. The use of diamond ATR accessories has advantages due its great hardness and chemical passivity and reduces the solvent consumption and sample manipulation, making the cleaning step easier.On the other hand, the application of multiconmmutation coupled with vibrational techniques allows to carry out on-line dilution and standard addition with a minimum manipulation of sample and standards. The main factors inherent to multicommutation are the versatility of the analytical strategy, the reduction of sample manipulation, the easiness of the design of the required manifolds, the capability of easy automatization and the miniaturization of the systems. Multicommutation has been applied in a stopped-flow method and in two different continuous flow methods. Only a minimum training in electronics and informatics is needed for developing analytical methods with multicommutation. Presurized solvent extraction and solid phase extraction have been applied in some methods as previous sample treatment techniques, allowing us to reduce the solvent consumption and analysis time in the first case and overcoming the trouble of the low sensitivity of infrared spectrometry through analyte preconcentration in the second case.Finally, a method with on-line extraction as a full sample treatment is described, minimizing sample manipulation and improving the analytical throughput. So, it is showed the potential of Infrared Transform spectrometry in the field of quantitative analysis, specially applied to quality control and routine analysis.
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Memon, Khalida Perveen. "Solid fat index determination by Fourier transform (FTIR) spectroscopy." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24028.
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This work describes an investigation of the development of a Fourier Transform Infrared (FTIR) spectroscopic method for the determination of Solid Fat Index (SFI) of fats as a possible replacement of the traditional dilatometric procedure. The initial approach considered was the use of an existing FTIR analytical package which was designed to measure iodine value (IV), saponification number (SN), and cis and trans content. It was hypothesized that these measures could be related to SFI using multiple linear regression (MLR), thereby allowing the existing analytical package to simultaneously make SFI measures. It was found that there was a strong relationship between SN/cis/trans measurements and SFI, especially in sequentially hydrogenated oils. The MLR relationships, however, did not reproduce the dilatometric SFI values with sufficient accuracy in the general case, and this approach had to be abandoned. Subsequently, a partial least squares (PLS) calibration approach was investigated, relating the dilatometric SFI data directly to the spectral characteristics of the melted fats. It was found that suitable PLS calibrations could be developed for soybean and Canola oils. Based on these results, an FTIR system was programmed to determine SFI and the performance of the system validated using pre-analyzed "unknowns". It was shown that the SFI of either soybean or Canola oils could be determined to within $ pm$ 1.0 SFI. As configured, the FTIR system is capable of determining the SFI of a neat and clear, melted fat sample at 80$ sp circ$C in less than two minutes, providing four SFI values, representing the solids content at 50, 70, 80 and 92$ sp circ$F. In contrast to the standard dilatometric method, which takes over two hours to carry out, the FTIR approach provides a rapid means of determining SFI, the technique being suitable for routine quality control applications in the fats and oils industry.
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Nunn, Nicholas Simon. "FTIR and rheological studies of surfactant adsorption onto silica." Thesis, Durham University, 1993. http://etheses.dur.ac.uk/6104/.
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The adsorption of four surfactants at the silica-toluene interface have been investigated by Fourier-transform infrared - attenuated total reflection (FTIR-ATR) spectroscopy. Specifically, hexadecylamine, 1,12-diaminododecane, didecylamine and sorbitan monopalmitate were studied. The silica surface for the spectroscopic experiments was provided by the native oxide layer on a silicon ATR prism. In order to study the CH(_2) stretching vibrations, the solvent was fully deuterated. Careful calibration of the ATR experiment enabled the contribution to the ATR spectrum made by adsorbed species to be calculated. The surface excess concentration of the amines were calculated over a range of bulk solution conentrations, enabling adsorption isotherms to be constructed. The use of polarized radiation allowed the orientation of the molecules within the adsorbed layer to be studied. The adsorbed layer of hexadecylamine showed some ordering of the aliphatic chains. There is some spectral evidence that the chains in the adsorbed layer of 1,12- diaminododecane adopt a 'looped' configuration. The effect of adsorbed layers of the molecules listed above upon the rheological behaviour of Aerosil 200 dispersions in toluene was investigated. Differences in the rheological behaviour of these dispersions have been correlated to differences in adsorbed layer structure as determined by FTIR-ATR. Due to differences in the Aerosil and ATR surface these correlations must be treated cautiously.
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Ashworth, Andrew Paul. "FTIR study of the thermolysis of some MOCVD precursors." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315078.
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Watkins, Adam. "Protein interactions with model chromatography surfaces using FTIR ATR." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272744.
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