" A series of symmetric and asymmetric 2-arylidene and 2,5-diarylidene cyclopentanone dyes have been synthesized. Their electronic absorption and fluorescence spectra have been measured in a wide variety of nonpolar and polar, aprotic and protic solvents. Absorption and fluorescence spectral maxima have been correlated with the ET(30) empirical solvent polarity scale. Lippert-Mataga analysis (in aprotic solvents) demonstrates the increase in the electronic dipole moment from the ground singlet to excited singlet states, consistent with the internal charge transfer (ICT) nature of the S0 --> S1 excitation. TD-DFT spectral calculations support the ICT natures of these compounds. Photophysical properties of these compounds involved measuring both fluorescence quantum yields and lifetimes in various solvents. Investigation of the deactivation kinetics involved determining the first-order radiative and nonradiative rates of decay upon knowledge of the quantum yield and lifetime data. Fluorescence quantum yields and lifetimes of the compounds studied varied depending on the nature of the solvent environments. Excited state protonation in acetic acid was observed for several 2,5-diarylidene cyclopentanones and deltapKa’s have been determined via the Forster Cycle. Thorough work on the photochemistry of (2E,5E)-2,5-bis(p-dimethylaminobenzylidene)-cyclopentanone (bis-dmab) was carried out, consisting of testing bis-dmab as a singlet oxygen photosensitizer, and examination of both the chemical reactivity of bis-dmab with singlet state oxygen (self-sensitized photooxidation) and (E,E) --> (E,Z) photoisomerization. "

O presente estudo avaliou a composição química da dentina radicular de dentes submetidos à radioterapia por meio de Espectroscopia Raman Confocal (ERC). Vinte pré-molares inferiores humanos homólogos foram selecionados e distribuídos em dois grupos (n=10) de acordo com a irradiação: não irradiados e irradiados, submetidos à radioterapia fraccionada com raios-X de 6 MV. Os dentes foram seccionados e submetidos à análise da composição química da dentina radicular submetida à radioterapia por meio de ERC, em relação aos picos de fosfato, carbonato e amidas I, II e III. Foi utilizada objetiva de 40x (Olympus), com luz de comprimento de onda de 785 nm, compreendendo a faixa espectral de 400 - 1800 cm-1, na região de baixa frequência, com resolução espacial de 2 &micro;m. Para a geração do espectro, a potência do laser utilizada foi de 21 mW e o tempo de exposição de 5 segundos. A intensidade dos picos fosfato - PO43- (590 cm-1) e carbonato - CO32- (1070 cm-1) no ERC são proporcionais à quantidade de conteúdo inorgânico, enquanto que a amida I (1670 cm-1), II (1453 cm-1) e III (1267 cm-1) são proporcionais ao conteúdo orgânico (colágeno). Os dados obtidos foram submetidos à análise estatística (Teste T, P<0,05) para amostras independentes, avaliando-se a influência da radioterapia nos valores de fosfato, carbonato e amidas I, II e III em diferentes regiões radiculares. Em região de dentina radicular intracanal, o grupo irradiado (1,23&plusmn;0,06) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,40&plusmn;0,18) (P<0,05). Em relação ao carbonato, foi observado que os dentes irradiados (1,56&plusmn;0,06) apresentaram menores valores quando comparados ao grupo não irradiado (1,42&plusmn;0,10) (P<0,05). Para os picos de amida, não foi observada diferença estatística entre os grupos em amida I (P=0,295) e amida II (P=0,792). No entanto, o tratamento radioterápico reduziu significativamente os valores de amida III do grupo irradiado (1,05&plusmn;0,19) em comparação ao grupo não irradiado (1,28&plusmn;0,24). Quando avaliada a região da dentina radicular média, o grupo irradiado (1,30&plusmn;0,12) apresentou menores valores de fosfato quando comparado ao grupo não irradiado (1,48&plusmn;0,22) (P<0,05); e em relação aos valores de carbonato (P=0,859), amida I (P=0,785), amida II (P=0,771) e amida III (P=0,338) não foi observada diferença estatística entre eles. Na análise em cemento, não houve diferenças estatísticas entre os grupos irradiado e não irradiado para os valores de fosfato (P=0,448), carbonato (P=0,575) e amida I (P=0,225), amida II (P=0,437) e amida III (P=0,187). Dessa forma, pode-se concluir que a radioterapia promoveu alterações nos picos de amida III, indicando modificação estrutural do colágeno. / The present study was to evaluate the root dentin chemical composition of teeth submitted to radiotherapy by Confocal Raman Spectroscopy (CRS). Twenty inferior human homologues premolars were selected and divided in two groups (n = 10) according to the irradiation protocol: non Irradiated and irradiated, submitted to fractional X-ray radiotherapy of 6 MV. The teeth were sectioned and submitted to the analysis of the chemical composition of radicular dentin submitted to radiotherapy by CRS, evaluating the phosphate, carbonate and amides I, II and III peaks. A 40x objective (Olympus) was used, generating a light with a 785 nm wavelength, comprising the spectral range of 400-1800 cm-1 in the low frequency region with spatial resolution of 2 &micro;m. For the spectrum generating the laser power used was 21 mW and the exposure time was 5 seconds. The intensity of the phosphate - PO43- (590 cm-1) and carbonate - CO32- (1070 cm-1) peaks in the CRS are proportional to the amount of inorganic content while the amide I (1670 cm-1), II (1453 cm-1) and III (1267 cm-1) are proportional to organic content (collagen). The data were submitted to statistical analysis (Test T, P<0.05) for independent samples, evaluating the influence of radiotherapy on the phosphate, carbonate and amide I, II and III values in different root regions. In the intracanal dentin root region, the irradiated group (1.23 ± 0.06) had lower phosphate values when compared to the non-irradiated group (1.40 ± 0.18) (P<0.05). In relation to the carbonate, it was observed that the irradiated teeth (1.56 + 0.06) had lower values than the non-irradiated group (1.42 + 0.10) (P<0.05). The amide peaks has no statistical difference observed between the groups in relation to the amide I (P=0,295) and amide II (P=0,792). However, the radiotherapeutic treatment significantly reduced the amide III values of the irradiated group (1.05 + 0.19) compared to the non-irradiated group (1.28 + 0.24). When the middle radicular dentin region was evaluated, the irradiated group (1.30 ± 0.12) had lower phosphate values when compared to the non-irradiated group (1.48 ± 0.22) (P<0.05); and in relation to the carbonate (P=0.859), amide I (P=0.785), amide II (P=0,771) and amide III (P=0,338) peaks no statistical difference was showed between irradiated and non-irradiated teeth. In the cement analysis, there was no statistical difference between the irradiated and non-irradiated groups for the phosphate (p = 0.448), carbonate (P=0.575), amide I P=0.225), amide II (P=0,437) and amide III (P=0,187) values. In conclusion, the radiotherapy was able to promote alterations in the amide III, changing the collagen structure.

A hemoglobina (Hb) do anelídeo Glossoscolex paulistus é uma Hb extracelular gigante. Esta é constituída por quatro cadeias polipeptídicas a, b, c e d contendo o heme. As cadeias a, b e c formam um trímero mantido por ligações dissulfeto e a cadeia d é um monômero. Neste trabalho, as técnicas espectroscópicas de absorção ótica no UV-Vís, fluorescência e dicroísmo circular foram utilizadas para monitorar as mudanças produzidas na estrutura do monômero d na forma oxi da hemoglobina extracelular gigante de Glossoscolex paulistus (HbGp) em pH 7,0 e 9,0 devido à interação com surfactantes iônicos, dodecil sulfato de sódio (SDS), cloreto de cetiltrimetilamônio (CTAC) e neutro, polioxietileno lauril éter (BRIJ - 35). A interação entre surfactantes e proteínas globulares tem sido estudada através de uma variedade de técnicas espectroscópicas visando à obtenção de informações relevantes com respeito à relação estrutura-atividade das proteínas. Os resultados de fluorescência mostraram que na presença dos surfactantes, há um aumento do rendimento quântico, sendo que o maior aumento é verificado na interação com o surfactante catiônico CTAC, sugerindo que a proteína apresenta uma quantidade maior de sítios específicos carregados negativamente, como os resíduos aniônicos, glutamil e aspartil. Na interação do monômero d da HbGp com CTAC ocorreu a formação de espécie pentacoordenada em ambos os pHs. Para o sistema monômero da HbGp-SDS em pH 7,0 e 9,0, foi observada a oxidação do monômero d, caracterizada pela formação da espécie hemicromo. A interação do monômero d em pH 7,0 e 9,0 com CTAC, analisada pelos espectros de dicroísmo circular, indicaram uma perda não muito significativa da estrutura secundária. No entanto, para os surfactantes SDS e BRIJ-35 foi possível constatar uma perda menos acentuada em relação ao CTAC. / The annelid hemoglobin (Hb) of the Glossoscolex paulistus is a giant extracellular hemoglobin (Hb). It is constituted by four polypeptide a, b, c and d chains containing the heme. The chains a, b and c form a trimer maintained by disulfide bond and the d chain is a monomer. In this work, the spectroscopic techniques of UV-Vís optical absorption, fluorescence and circular dichroism were used to monitor the changes induced by ionic detergents sodium dodecyl sulphate (SDS), cetyltrimethylammonium chloride (CTAC) and neutral, ether lauryl polioxitelene (BRIJ-35) in the structure of the d monomer in the oxi form of the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) in pH 7.0 and 9.0. The interaction between surfactants and globular proteins has been studied through a range of spectroscopic techniques targeting the obtaining of prominent information with regard to the relation structure-activity of the proteins. The fluorescence results showed that in the presence of the surfactants a quantum yield increases, and the CTAC promoted the more significant effect, suggesting that the protein presents a larger quantity of specific negative sites, as the anionic residues, glutamil and aspartil. In the interaction of d monomer of the HbGp with CTAC occurred the formation of pentacoordinated species in both pHs. For system monomer of HbGp-SDS at pH 7.0 and 9.0, was observed by oxidation of d monomer, characterized by the formation of the species hemichrome. The interaction of d monomer at pH 7.0 and 9.0 with CTAC, analyzed by circular dichroism spectra, indicates the loss of secondary structure. However, for SDS and BRIJ-35 surfactants it is possible to detect the lower loss of secondary structure in relation to CTAC.

An (e,2e) electron scattering spectrometer has been constructed and used for the first time to investigate the spectral momentum density of the valence bands of a solid target. This technique provides fundamental information about the electronic structure of both crystalline and amorphous solids. The three fundamental quantities, the band structure, electron density of states, and electron momentum distribution can be simultaneously derived from the measured (e,2e) cross section. A review of single electron and (e,2e) scattering theory is given with an emphasis on scattering from solids. The effects of multiple scattering are discussed and a method of deconvoluting those effects from the measured (e,2e) cross section is developed. There is a detailed description of the spectrometer design and operation with particular attention given to the electron optics and voltage distribution. The algorithms and software for computer aided data acquisition and analysis are also outlined, as is error analysis. The techniques employed in the preparation and characterization of extremely thin film samples of a-C and single crystal graphite are described An analysis of the data taken for a-C samples is complementary experiments and theory for graphite, diamond, and a-C which are given in a review of the literature. The existence of a definite dispersion relation ε(q) in amorphous carbon is demonstrated. The a-C band structure appears to be more similar to that of graphite than to that of diamond, however it differs significantly from both in some respects. The measured spectral momentum density seems compatible with a model of a-C based on small, randomly-oriented islands of quasi-2D graphite-like continuous random network structures. However, no definitive interpretations can be made until higher resolution experiments are performed on both a-C and single crystal graphite.

<p>This thesis describes the research I have done, and partly will do, during my time as a PhD student in the laboratory of Applied Optics at Linköping University. Due to circumstances beyond the scope of this book, this incorporates three quite different projects. The first two, involving gas sensing and measuring on paper with ellipsometry, have been discontinued, whereas the third one, measuring fluorescence with a computer screen and web camera, is in full progress and will be until I complete my studies.</p><p>Thus the purpose of this work also has several aspects. Partly, it describes performed research and its results, as well as theoretical background. On the other hand, it provides practical and theoretical background necessary for future work. While the three projects are truly quite different, each of them has certain things in common with each of the other. This is certainly also true for the necessary theory. Two of them involve spectroscopic ellipsometry, for example, while another pair needs knowledge of color theory, etc. This makes it impossible to separate the projects, despite of their differences. Hopefully, these links between the different projects, connecting the different chapters, will make this work whole and consistent in its own way.</p> / Report code: LiU-TEK-LIC-200 4-19. On the day of the public defence the status of article I was: In press and the status of article III was: Manuscript and has a new title. The old title was Computer screen photo-assisted spectroscopic fluorimetry.

<p>In this work, a gradient of interpenetrating polymer networks, consisting of anionic</p><p>and cationic polymers, has been investigated with respect to protein resistant</p><p>properties and swelling characteristics at different pH and ionic strength</p><p>conditions.</p><p> </p><p>The swelling and protein adsorption have been studied using <em>in situ </em>spectroscopic</p><p>ellipsometry(SE) and imaging surface plasmon resonance(iSPR) respectively.</p><p>It has been shown that, by altering the buffer pH, the region of lowest</p><p>protein adsorption on the surface could be moved laterally. The swelling has</p><p>similarly been shown to respond to both changes in pH and ionic strength. Additionally,</p><p>the arise of surface charge and the polymer swelling in solution, both a</p><p>consequence of the ionisation of fixed charges on the polymer, have been indicated</p><p>to occur at different buffer pH.</p><p> </p><p>The studied polymer systems show promising properties for future applications</p><p>in, for example, the biosensor area, where the surface chemistry can be</p><p>tailor-made to work optimally in a given environment.</p>

MAX-phase materials are a new type of material class. These materials are potentiallyt echnologically important as they show unique physical properties due to the combination of metals and ceramics. In this project, spectroscopic ellipsometry in the spectral range of 0.06 eV –6.0 eV was used to probe the linear optical response of MAX-phases in terms of the complexd dielectric function ε(ω) = ε1(ω) + iε2(ω). Measured data were fit to theoretical models using the Lorentz and generalized oscillator models. Data from seven different samples of MAX-phase materials were obtained using two ellipsometers. Each sample dielectric function was determined, including their infrared spectrum.

Lead-tin telluride alloy, Pb1-xSnxTe, is a narrow band gap group IV–VI semiconductor with NaCl-like crystalline structure. This material has interesting electronic properties, which makes it suitable for designing infrared photo detectors, diode lasers, and thermo-photovoltaic energy converters. In this project, we used spectroscopic ellipsometry in the spectral range of 0.74–6.5 eV to probe the linear optical response of Pb1-xSnxTe alloys in terms of the complex dielectric function. A strong optical response in the range of 0.7-2.0 eV arising from optical absorption was found. We studied eleven different samples of Pb1-xSnxTe of p-type origin with x values in the range (0 ≤ x ≤ 1). They were prepared by means of molecular beam epitaxy (MBE) on BaF2 substrates with 15mm2 area.

This thesis presents the results of a single-crystal electron paramagnetic resonance (EPR) spectroscopic investigation of defect centers in selected borates and borosilicates (i.e., datolite, danburite, and jeremejevite). The research brings new complementary data to the current understanding of defect structures in minerals, which are not only important to Earth Sciences but also directly relevant to environmental applications (e.g., nuclear waste disposal) and materials science. Single-crystal EPR spectra of a gamma-ray-irradiated datolite from Bergen Hill, New Jersey, USA, reveal the presence of a boron-oxygen hole center (BOHC). Spin-Hamiltonian parameters obtained from single-crystal EPR spectra and radiation-dose-dependence experiments allow us to confirm the BOHC center in datolite as the [BO4]0 type, involving hole trapping on the hydroxyl oxygen atom after the removal of the hydrogen atom: via a reaction O3BOH --> O3BO• + H0, where • denotes the unpaired electron. Density functional theory (DFT) calculations support the proposed structural model, and the calculated 11B hyperfine coupling constants are in excellent agreement with the experimental results. Also, isochronal and isothermal annealing experiments provide information about the thermal stability and decay kinetics of the [BO4]0 center in datolite. The confirmation of the [BO4]0 center and its formation from the O3BOH precursor in datolite are compared with other BOHCs in minerals and are discussed with relevance to the implications for not only understanding of BOHCs in alkali borosilicate glasses but also their applications to nuclear waste disposal. A combined study by use of synchrotron X-ray absorption spectroscopy (XAS), single-crystal EPR and pulse electron spin echo envelope modulation (ESEEM) spectroscopy provides compelling evidence for lattice-bound arsenic in danburite from Charcas, San Luis Potosi, Mexico. Arsenic K-edge X-ray absorption near-edge (XANES) spectra show that the dominant oxidation state is +3, and modeling of the extended X-ray absorption fine structure (EXAFS) spectra suggests that As3+ mainly occupies the Si site. Detailed single-crystal EPR spectra, measured before and after gamma-ray irradiation, reveal three arsenic-associated paramagnetic electron centers (I, II and III). Centers I and II are varieties of the [AsO2]2 radicals, formed from electron trapping on a substitutional As3+ ion at the Si site. This model is also supported by the 11B superhyperfine structures determined by ESEEM spectra at 80 K. Center III is the [AsO3]2 radical, originated from electron trapping on a [AsO4]3¬ group after removal of the O4 atom during gamma-ray irradiation. Therefore, arsenic in danburite is present in both the +3 and +5 oxidation states and preferentially occupies the Si site. Single-crystal EPR spectra of jeremejevite from Cape Cross, Namibia, reveal an S = 1/2 hole center characterized by a hyperfine structure arising from interaction with two equivalent 27Al nuclei. Our results suggest that this aluminum-associated oxygen hole center represents hole trapping on a hydroxyl oxygen atom linked to two equivalent octahedral Al3+ ions, after the removal of the proton (i.e., a VIAl−O−−VIAl center). Periodic ab initio UHF and DFT calculations confirmed the experimental 27Al hyperfine coupling constants and directions, supporting the proposed structural model. Also, isochronal annealing experiments provide information about the thermal stability of the VIAl−O−−VIAl center. These data obtained from the VIAl−O−−VIAl center in jeremejevite provide new insights into analogous defects that have been documented in several other minerals.

Magnetic Resonance Spectroscopy (MRS) can be applied to probe noninvasively the concentrations and distribution of metabolites of human tissue in vivo. As the improving of hardware and localization techniques, MRS becomes more and more important in clinical applications. Furthermore, some post-processing software, like LCModel, provide a graphical user interface for efficient and convenient analysis of MR spectroscopic imaging and thus increase the value of MRS applications. Although LCModel provides an efficient analysis and produces stable results, it can not provide metabolite map to observe the distribution of metabolite concentrations. For this reason our study processes the output data of LCModel and Digital Imaging and Communications in Medicine (DICOM) format MR images for 2D/3D metabolite map displaying. Users can use this software to observe the metabolic distribution in AP, SI and RL slice of brain tissue. In the meanwhile, as the absolute quantification of MRS has played more and more important role in clinical applications, this study also provides the LCModel end users an easy way for interpretation.