<p> </p><p><p> </p></p><p><p><p> </p></p></p><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 <em>ε(ω) = ε1(ω) + iε2(ω<em>). </em></em>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.</p>

Vibrational spectroscopy is used to elucidate the adsorption mechanisms of model volatile organic pollutants with a variety of mineral oxides. Vapor phase adsorption processes are particularly important in the vadose zone of an aquifer, where void spaces are filled with air and vapor transport is significant. Gaining a better understanding of the interactions occurring at the oxide-air interface is critical in developing or improving remediation strategies. In this work, Raman and infrared spectroscopy are used to obtain molecularly specific information concerning model pollutant-oxide adsorption processes. The choices of pollutants are varied to include several classes of compounds. The interactions of azaarenes, aromatics, chlorinated aromatics, trichloroethylene, and tributyl phosphate are investigated with several mineral types. Pure mineral phases such as silica, alumina, hydrated iron oxide, and montmorillonite clay are used to provide a basis set of interactions, which can be extended to more complex systems in the future. Pollutantoxide interactions, including weak physisorption, hydrogen bonding, Bronsted acid-base, and Lewis acid-base, were identified in this work and varied depending on the specific pollutant-oxide system. This research provides surface adsorption information on environmentally relevant contaminants and the techniques may be utilized to verify the accuracy of pollutant fate and transport models and to improve remediation strategies for such pollutants.

The study of spectroscopic binaries is by no means a new area of study. The Doppler shifting of spectral lines as the stars orbit around each other is now able to be measured very precisely. Binary stars give a reliable means of determining stellar parameters such as the mass. A star's mass is one of the most dominant factors in determining its evolution. Stars for study in this thesis were selected from SB9 (the ninth catalogue of spectroscopic binaries). They were chosen on criteria such as apparent visual magnitude, orbital period, orbital solution grade, equatorial velocity and position. Only stars with poor to average orbital solutions were chosen as it is these orbits which need the most work done. In total 6 spectroscopic binary systems were chosen for study in this thesis. Four single lined spectroscopic binaries (HD 70958, HD 110318, HD 122223 and HD 141544) and two double line spectroscopic binaries (HD 110317 and HD 148704). Unfortunate observing conditions meant that adequate phase coverage of HD 110317 and HD 110318 was not achieved. Adequate phase coverage of the star HD 122223 was also not achieved but this is likely a result of the period being about three years and not about 207 days as quoted in the catalogue. Observations were carried out with the HERCULES spectrograph and the 1-metre McLellan telescope at the Mt John University Observatory from December 2007 until September 2008. Radial velocities were than measured from these spectra with HRSP3 and then orbital solutions were derived. Orbital solutions have been derived for the single-lined systems HD 141544 and HD 70958. The precision of HD 141544 was much better than HD 70598. This is because HD 70958 is complicated by differential rotation and possible chromospheric activity. The orbital solution of the double lined system HD 148704 was obtained by using CARTopt and not TODCOR as is common, with good results. HD 122223 is included even though only six spectra were obtained as it will be evident that the current orbital solution should be rejected in favour of the previous solution obtained in 1936 by Christie. Although the amount of data was not as large as was hoped, significant improvements of the orbital solutions were obtained. The secondary component of HD 148704 had only previously being detected in a very few spectra but now has a good orbital solution. Errors on all parameters have been decreased and tighter limits have been placed on the secondary components of the single lined systems. The mass ratio of the components of HD 148704 was also determined very accurately and calculation of the inclination from photometry may allow accurate masses to be determined.

The objectives of this efforts was to develop spectroscopic ellipsometry method for investigation of optical properties: (i) of multi-layered nanostructures used for Bovine leukaemia virus glycoprotein gp51 recognition, (ii) nanostructures consisting of monomeric (mGCSF) and dimeric (dGCSF) granulocyte colony stimulating factor and its receptor (GCSF-R) and (iii) Al2O3/ZnO nanolaminates designed by atomic layer deposition method. In particular, focusing on the investigation of: • biological recognition layers of immunosensors by means of comparison of analytical sensitivities of ellipsometric parameters Δ and Ψ in order to estimate differences in orientation of immobilized intact- and fragmented-antibodies against bovine leukemia virus antigen gp51; • the kinetics of biosensing layer formation, which was based on the immobilization of fragmented and intact antibodies, kinetics of antigen interaction with the immobilized antibodies and interactions of monomeric (mGCSF) and dimeric (dGCSF) granulocyte colony stimulating factor and its receptor (GCSF-R) immobilized on a thin gold layer; • kinetic coefficients of monomolecular biological layer formation process using model which takes into consideration partial reversibility (residence time) effect; • optical constants of Al2O3 and ZnO monolayer as well as Al2O3/ZnO nanolaminates prepared by atomic layer deposition method in order to investigate possibilities to apply these nanolaminates for optical biosensors. / Spektroskopinės elipsometrijos metodas išvystytas ir pritaikytas (i) daugiasluoksnių nanostruktūrų, skirtų galvijų leukemijos viruso (GLV) antigeno gp51 aptikimui, (ii) nanostruktūrų, sudarytų iš monomerinio ir dimerinio granuliocitų kolonijas stimuliuojančio faktoriaus bei jų receptoriaus ir (iii) Al2O3/ZnO nanolaminatų, pagamintų atominių sluoksnių nusodinimo metodu, optinių savybių tyrimams • Tiriant elipsometrinių parametrų Δ ir Ψ jautrumą biojutikliuose, sudarytuose iš biologiškai aktyvių sluoksnių, nustatyti biomolekulių orientacijos skirtumai tarp sluoksnių, sudarytų iš imobilizuotų skaldytų ir neskaldytų antikūnų prieš GLV antigeną. • Ištirti biologiškai aktyvūs sluoksniai, sudaryti iš imobilizuotų skaldytų ir neskaldytų antikūnų prieš GLV antigeną sąveikos su antigenu gp51 ir granuliocitų kolonijas stimuliuojančio faktoriaus (GCSF) receptoriaus imobilizuoto ant aukso paviršiaus, sąveikos su GCSF monomeru ir dimeru formavimosi kinetikos. • Pritaikant modelį, įskaitantį negrįžtamos imobilizacijos reiškinį, nustatytos monomolekulinių biologinių sluoksnių iš antikūnų prieš GLV ir antigeno gp51 bei GCSF ir jo receptoriaus formavimosi kinetinės konstantos. • Nustatytos Al2O3 ir ZnO sluoksnių bei Al2O3/ZnO nanolaminatų, suformuotų naudojant atominių sluoksnių nusodinimo metodą, optines konstantos ir ištirtos galimybes šias struktūras panaudoti biojutikliuose.

This thesis is made as it is submitted as a sum of published papers by the candidate. Aluminium hydroxides including gibbsite, boehmite and diaspore, are the major components, while iron hydroxides/oxides and kaolinite are the major impurities in bauxite. The dehydroxylation pathways during thermal activation of bauxite have been debated for decades. Phase transformation during thermal activation or calcination of bauxite to achieve high yields of alumina has been an important goal for the refining industry. This study deals with natural and synthetic aluminium and iron hydroxides using vibrational spectroscopy in conjunction with X-ray diffraction and electron microscopy, followed by the characterisation of the phase transformation in activated bauxite. In the Raman spectra, gibbsite shows four bands at 3617, 3522, 3433 and 3364 cm-1, and bayerite shows seven bands at 3664, 3652, 3552, 3542, 3450, 3438 and 3420 cm-1 in the hydroxyl stretching region. Five bands at 3445, 3363, 3226, 3119 and 2936 cm-1 for diaspore and four at 3371, 3220, 3085 and 2989 cm-1 for boehmite are present. The far infrared spectrum of boehmite resembles that of diaspore in the 300-400 cm-1 region. Boehmite has two characteristic bands at 366 and 323 cm-1 while diaspore has five at 354, 331, 250, 199 and 158 cm-1. The far infrared spectrum of gibbsite resembles that of bayerite in the 230-300 cm-1 region. Gibbsite shows three characteristic bands at 371, 279 and 246 cm-1 whereas bayerite shows six at 383, 345, 326, 296, 252 and 62 cm-1. The far infrared spectra are in-harmony with the FT-Raman spectra, allowing the study and differentiation of the stretching of AlO4 units to characterize these four alumina phases. The surface properties of kaolinite and gibbsite are studied using Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The FTIR-PAS spectra of kaolinite are recorded at mirror velocities of 0.05, 0.1, and 0.2 cm s-1, and compared to the gibbsite spectra recorded at mirror velocity of 0.2 cm s-1. It is found that the hydroxyl surface spectra are a function of depth. For the FTIR spectroscopy of thermal dehydroxylation of goethite to form hematite, the intensity of hydroxyl stretching and bending vibrations decreased with the extent of dehydroxylation of goethite. Infrared absorption bands clearly show the phase transformation between goethite and hematite, in particular the migration of excess hydroxyl units from goethite to hematite. Data from the band component analysis of FT-IR spectra indicate that the hydroxyl units mainly affect the a- plane in goethite and the equivalent c- plane in hematite. A larger amount of non-stoichiometric hydroxyl unit is found to be associated with a higher aluminium substitution. A shift to a higher wavenumber of bending and hydroxyl stretching vibrations is attributed to the effects of aluminium substitution associated with non-stoichiometric hydroxyl units on the a-b plane relative to the b-c plane of goethite. The dehydroxylation pathways of both the aluminium hydroxides and the impurities are intensively studied. Gibbsite completely decomposed at 250 °C, followed by boehmite and kaolinite at 500 °C. No phase transformations were observed for hematite, anatase, rutile or quartz up to 800 °C. Small amounts of gibbsite transformed to boehmite but the majority transformed to chi (χ) alumina, a disordered transition alumina phase, after dehydroxylation at 250 °C. The dehydroxylation pathways of crystalline gibbsite follow the orders: (a) gibbsite (&lt250 °C) to boehmite (250-450 °C) to gamma alumina (γ) (500-800 °C); or (b) gibbsite (&lt250 °C) to chi alumina (χ) (250-800 °C) to chi (χ) + kappa alumina (κ) (700-800 °C). Boehmite completely altered to gamma alumina (γ), while kaolinite altered to metakaolinite at 500 °C. The vibrational spectroscopy including FT-IR and FT-Raman, is a rapid, accurate and non-destructive technique in characterising both single and mixed mineral phases. In particular, the vibrational spectroscopy has shown its advantages over other techniques in terms of its sensitivity to hydroxyl groups. Future work on the simulation of bauxite dehydroxylation with emphasis on the studies of transition aluminas is proposed. The application of the advanced technique synchrotron x-ray spectroscopy, in addition to those techniques used in the present study, is recommended.

The study of spectroscopic binaries is by no means a new area of study. The Doppler shifting of spectral lines as the stars orbit around each other is now able to be measured very precisely. Binary stars give a reliable means of determining stellar parameters such as the mass. A star's mass is one of the most dominant factors in determining its evolution. Stars for study in this thesis were selected from SB9 (the ninth catalogue of spectroscopic binaries). They were chosen on criteria such as apparent visual magnitude, orbital period, orbital solution grade, equatorial velocity and position. Only stars with poor to average orbital solutions were chosen as it is these orbits which need the most work done. In total 6 spectroscopic binary systems were chosen for study in this thesis. Four single lined spectroscopic binaries (HD 70958, HD 110318, HD 122223 and HD 141544) and two double line spectroscopic binaries (HD 110317 and HD 148704). Unfortunate observing conditions meant that adequate phase coverage of HD 110317 and HD 110318 was not achieved. Adequate phase coverage of the star HD 122223 was also not achieved but this is likely a result of the period being about three years and not about 207 days as quoted in the catalogue. Observations were carried out with the HERCULES spectrograph and the 1-metre McLellan telescope at the Mt John University Observatory from December 2007 until September 2008. Radial velocities were than measured from these spectra with HRSP3 and then orbital solutions were derived. Orbital solutions have been derived for the single-lined systems HD 141544 and HD 70958. The precision of HD 141544 was much better than HD 70598. This is because HD 70958 is complicated by differential rotation and possible chromospheric activity. The orbital solution of the double lined system HD 148704 was obtained by using CARTopt and not TODCOR as is common, with good results. HD 122223 is included even though only six spectra were obtained as it will be evident that the current orbital solution should be rejected in favour of the previous solution obtained in 1936 by Christie. Although the amount of data was not as large as was hoped, significant improvements of the orbital solutions were obtained. The secondary component of HD 148704 had only previously being detected in a very few spectra but now has a good orbital solution. Errors on all parameters have been decreased and tighter limits have been placed on the secondary components of the single lined systems. The mass ratio of the components of HD 148704 was also determined very accurately and calculation of the inclination from photometry may allow accurate masses to be determined.

Thesis (Ph.D.)--Tufts University, 2004. / Adviser: Sergio Fantini. Submitted to the Dept. of Electrical Engineering. Includes bibliographical references (leaves 201-202). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

<p> A number of complexes FeX2Ln (X = Cl, Br; L = formamide, N-methylformamide, N,N-dimethylformamide, acetamide, benzamide, isobutyramide, urea, N-methylurea, N,N'-dimethylurea, thioacetamide, thiourea, N-methylthiourea, N,N'-dimethylthiourea, benzothiazole, aniline) have been prepared and investigated by means of Mossbauer and infrared spectroscopy and magnetic measurements. It has been possible to distinguish firstly between 4-coordinate and 6-coordinate complexes and secondly between a number of different types of 6-coordinate complexes.</p> / Thesis / Master of Science (MSc)

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