Amorphous silicon oxynitride (SiOxNy) thin films were grown by reactive high power impulse magnetron sputtering from a pure silicon target in Ar/N2O plasmas. The elemental composition of the films was shown to depend on the target surface conditions during the film deposition, as well as on the reactive gas flow rate. When the target was sputtered under poisoned surface conditions, the film composition was predominantly silicon oxide, whereas films deposited in the transition regime between poisoned and metallic target surface conditions showed higher nitrogen concentrations, as measured by X-ray photoelectron spectroscopy (XPS) and elastic recoil detection analysis (ERDA). The different target surface conditions were identified based on the evolution of the target current waveforms upon variation of the deposition parameters. The average electron temperatures during the peak target current were determined by Langmuir probe measurements, to assist with the explanation of the observed target current behavior and target poisoning characteristics. The chemical composition of the films was shown to range from silicon-rich to effectively stoichiometric silicon oxynitrides, where no Si–Si contributions were found in the XPS Si 2p core level spectra. The film optical properties, the refractive index n and the extinction coefficient k, were shown to depend on the film chemical bonding, with the effectively stoichiometric films displaying optical properties falling between those of SiO2 and Si3N4.

Generation of non-classical light is both of fundamental interest and a common condition for quantum information applications (QIA). One feasible type of single photon emitter for QIA is based on semiconductor quantum dots (QDs), due to their atomic-like energy structure and their possibility to be integrated with other semiconductor devices on the same chip. Sitecontrolled QDs with highly linear polarized emission are a prerequisite for certain QIA and a close to room temperature operation is demanded for widespread applications. III-nitride QD can have the deep connement potentials needed for high temperature operation, and the demonstration of single photon emission at room temperature was recently reported for a GaN QD [Nano Lett. 14, 982 (2014)]. Asymmetric III-nitride QD emits light with a high degree of linear polarization. To make site-controlled nitride-based QDs a promising approach is to deposit a thin layer of InGaN on top of hexagonal GaN micropyramids. QDs formed on the apex of the pyramids grown with this approach have been shown to exhibit single and sharp InGaN related emission lines with a high degree of linear polarization [Nano Lett. 11, 2415 (2011)]. A simple elongation of the pyramid base gives control of the polarization direction [Light: Sci. Appl. 3, e139 (2014)]. The work presented in this thesis deals with time correlation measurements, to measure, for the rst time, the single photon properties of these pyramidal QDs. A time correlated single photon spectroscopy (TCSPS) setup was assembled, tested and used to perform measurements on these pyramidal QDs. The TCSPS apparatus measures the time dierences between subsequent photons emitted from the sample. In the spectrally ltered light of one emission line in the emission spectra, e.g. exciton emission, of a QD two or more photons cannot be emitted simultaneously, i.e. the photons are sent out one by one. A histogram of the ensemble of measured time dierences (~106 events) will then for the ideal case have no events for τ = 0, and very few for close to zero. This histogram, when normalized, is under certain conditions equal to the second order coherence function g(2)(τ ). In reality, however, there are photons coming from other sources close to the QD, i.e. background emission, that reach the detector and reduce the dip in the correlation histogram for small τ. There is also an statistical uncertainty in the measured time dierences and nally the nite bin width used in the histogram that deteriorate the measured correlation function. To understand the in uence on g(2)(τ) from background emission, instrument response function and the bin width, on the measurement on excitonic emission, simulations and calculations were made. The crucial variables were, for our samples and setup, the level of the background emission and the instrument response function. A post growth process was developed to cover the lower parts of the pyramid sides as well as the area between the pyramids with a metal lm, to reduce the background emission. This reduces the background emission and largely improves the relative QD signal. As a result, signicant improved single photon characteristics were demonstrated. A measurement of the second order coherence function for the excitonic autocorrelation at a temperature of 12 K, gave for zero time delay ( = 0) a value of g(2)(0) = 0.24 and the residual value of the second order coherence function (0.24) could be in full explained by the three variables, background emission, instrument response function and bin width. The g(2)(0) value for correlation measurements at higher temperatures of 50 K and 80 K is also fully explained by the three variables, showing that the emission from the QD itself is ideal up to 80 K. This result underlines the great potential of these site controlled pyramidal dots as sources of fast polarized single photon emission, and provides the rst rigorous evidence of InGaN quantum dot formation on hexagonal GaN pyramids. We also show the rst proof of biexcitonic emission in this pyramidal QDs.

Optical material properties have been studied in a wide wavelength range. Theaim is future use of spectral design for camou age. The main characterization techniques used in this work are Refection Spectroscopy, Scatterometry (BRDF) and Mueller Matrix Ellipsometry. Six camouflage evaluation criteria based on reflection, emissivity, polarization, gloss, dynamic coloring and broadband properties, are to a greater or lesser degree related to the interaction between light and materia. Almost all are connected to the work of this thesis and are exemplied through dierent material categories with potential for use in camouföage applications. The included papers presents: a broad band (visible-infrared-microwave) study, two examples of dynamic optical properties of thin lms, and polarization and scattering properties of a natural surface.

Anodic stripping voltammetry (ASV) is an electroanalytical method used in the determination of trace metals in solutions volumes of 20 milliliters or less. Generally, 10-6 M concentrations are routinely analyzed. The analysis of Zn(II), Cd(II), and Cr(III) by ASV was Investigated, and the effects of introducing the bridging ligands, cyanide and thiocyanate into solutions of these metal ions was examined. These effects include a cathodic shift in the reduction potentials of the metals, and ASV signal changes ranging from small increases in peak currents to a total loss of peak-current signals, depending on the concentration of the ligand added.

1-(9-Anthry1)-2-nitropropene and 1-(3-pyridy1)-2-nitropropene were prepared and irradiated with ultraviolet light. Irradiation of 1-(9-anthry1)-2-nitropropene, in which the ethylene group was twisted out of the plane of the aromatic ring and the resonance stabilization between the ethylene group and the aromatic ring was limited , gave only cis-trans isomerization. Irradiation of 1-(3-pyridy1)-2-nitropropene gave an oxime. The effect of added HC1 on the reactivity of 1-(3-pyridy1)-2-nitropropene showed that the rate for the formation of oximinoketone was decreasing., while irradiation of 1-phenyl-2-nitropropene with HC1 showed that the rate for the formation of oximinoketone was increasing. From these observation, steric factors and resonance factors are postulated to have a rather large influence on the nitro-nitrite rearrangement and the extent to which it will occur.

Edible oils are easily oxidized when used for frying. Oxidation originates with double bonds present in unsaturated fatty acids. A new NMR method is presented which offers potential for determining the products of oil oxidation. High resolution fourier transform nuclear magnetic resonance (FT-NMR) and fourier transform infrared (FT-IR) spectroscopy have found increasing use in biochemistry. One pure fat, trioleoylglycerol, was heated at 160°C in the presence of air Samples were taken for FT-NMR and FT-IR analyses at 4, 10. 20. 25, 35, 50, 70 and 100 hours. Proton, Carbon-13 and several types of two-dimensional FT-NMR spectra were obtained using a JEOL 270 Mhz instrument. The spectra suggest initial oxidation occurs by an allyl free radical mechanism facilitating the formation of epoxide and peroxide products.

It has been postulated that acetone is the best solvent for the photochemical rearrangement of β-methy1-β-nitrostyrene to 1-phenyl-1, 2-propanedione-1-oxime and it has been postulated to be a sensitizer for this rearrangement. It has also been suggested that the methyl group on the beta-carbon is required for the proper orientation of the nitro group for rearrangement. The irradiation of β-methyl-β-nitrostyrene in several solvents has been studied and the yield of oxime has been recorded. It has been found that several solvents gave yields of oxime higher than that recorded for acetone. We do not, therefore, believe acetone to be necessary to sensitize the rearrangement. The fact that essentially quantitative yields of 1-phenyl-1, 2-propanedione-1-oxime were obtained in aqueous acetone, ethanol and methanol (the yield of oxire in diethyl ether was increased from 45% to 85.6% by the addition of 1% of water prior to irradiation) leads us to believe that water plays an important role in the formation of the oxime. The role of the s-methyl group was verified and the effect of oxygen on the rearrangement was investigated. Irradiation of β-methyl-β-nitrcstyrene in aqueous ethanol under an oxygen stream gave benzaldehyde, benzoic acid and 1-phenyl-1, 2-propanedione as the major products. c oxire could be detected in the reaction mixture.

Within the past few years kinetic studies of NADP+- specific isocitrate dehydrogenase have been conducted extensively following isolation from bacteria, yeast and vertebrates. However, the kinetic properties of NADP+ - specific isocitrate dehydrogenase have not been adequately characterized in filamentous fungi. Therefore, the present study was undertaken to examine the kinetic behavior of partially purified NADP+ - specific isocitrate dehydrogenase enzyme isolated from Phycomyces blakesleeanus. During this study Michaelis constants (Km) and maximum velocities (Vmax) were determined for threo-Ds-isocitrate, NADP+, and Mn2+ as well as the number of binding sites of these components to the enzyme. The order of reaction with respect to enzyme was also established. The effects of ionic strength, metal ions, coenzymes, coordinating ligands, and some inhibitors on the rate of reaction were investigated. Some experiments were performed to elucidate a possible reaction mechanism for the conversion of D-isocitric acid to α-ketoglutaric acid in the presence of coenzyme, NADP+, and Mn2+.

A total of twelve α ,β - unsaturated nitro compounds of the form Ar-C=C-NO2 | | H R (where Ar=phenyl, o-methylphenyl, mesityl, α - naphthyl, and β - naphthyl; R=hydrogen, methyl, ethyl, and phenyl) were prepared and irradiated with ultraviolet light. When the corresponding α - oximinoketone was formed, it was recovered and identified. Six of the α , β - unsaturated nitro compounds and one α - oximinoketone had not been previously reported. Yields of irradiation products were determined and a kinetic study performed on these. The effect of substituents size at the β - position of α , β - unsaturated nitro compounds was investigated. No rearrangement of the α - oximinoketone occurred in β - nitrostyrene where as the oxime was recovered for β - methyl, β - ethyl, and β - phenyl α , β - unsaturated nitro compounds. The rate of rearrangement was not largely affected by the substituent size, although some increase in rate was noted for the β - ethyl compound. The rearrangement was found to be highly dependent on steric interference by ortho substituents on the aromatic ring. One o-methyl group slowed down the reaction rate and two o-methyl groups completely halted rearrangement to the oxime. Rearrangement of 1-(α - naphthyl) - 2-nitropropylene appeared to be hindered by adjacent hydrogens whereas 1-(α - naphthyl) - 2-nitropropylene rearranged to the oxime at a rate 1.68 times the rate of β-methyl-β-nitrostyrene. An explanation for these observations is proposed in terms of structural considerations.

The Potentiodynamic corrosion measuring technique is an electrochemical analytical method which measures corrosion rates of a metal exposed to a corrosive environment. The corrosion characteristics of carbon steel A1044 in aqueous solutions of aniline hydrochloride,simulating a coal liquid wash water, were determined by this method. The effects of solution velocity and oxygen concentration on the system were also determined. A bimodal corrosion rate effect was observed in deaerated solutions of 1000 and 5000 ppm chloride as aniline hydrochloride. This effect was interpreted to be the result of the formation of a film on the surface of the specimen.