Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto, Department of Chemical Technology. Lappeenranta University of Technology. 2009

Graduation date: 1994

Thesis (M.S.)--Oregon Graduate Center, 1976.

Thesis (Ph. D.)--Oregon Graduate Center, 1979.

M.S. / Applied Physics / This monograph summarizes the theory and construction of a tunable continuous wave (CW) Rhodamine 6G dye laser longitudinally pumped by an argon laser. (from Introduction; no abstract available)

Graduation date: 1991

Graduation date: 1991

The above-ground organs of plants are covered by a protective cuticle, an extracellular membrane performing important physiological and ecological functions, that consists of cuticular wax and the fatty acid-derived polymer cutin. Until the past decade, the cuticular wax was thought to be a homogenous mixture. Hence, previous interpretations relating the chemical composition and biological functions of the cuticular wax were based on the total wax composition, an average taken over the entire area and depth of the cuticle. However, recent selective sampling experiments showed a heterogeneity of the chemical composition between different wax layers. The finding of this heterogeneity imposes the need for a more accurate description of the cuticle in order to understand how the chemical composition determines the biological function. This thesis is aimed at mapping the lateral patterns of cuticular waxes on Prunus laurocerasus leaf surfaces with microscopic resolution to provide spatially resolved chemical information in the interest of describing the cuticle more accurately. Firstly, this thesis examines the post-acquisitional data processing and analysis techniques followed by the investigation of the potential of Raman microspectroscopy for the simultaneous detection of structurally similar triterpenoids in plant cuticles. Relative composition analysis was performed on artificial triterpenoid mixtures and the resulting calculated triterpenoid ratios were consistent with the expected values. Qualitative and quantitative analysis of the linear near infrared (NIR) Raman, coherent anti-Stokes Raman scattering (CARS), and third harmonic generation (THG) spectra of isolated adaxial and abaxial P. laurocerasus cuticles demonstrated the in situ detectability of the triterpenoids using this approach. Raman maps of the adaxial cuticle showed that the triterpenoids accumulate to relatively high concentrations over the periclinal regions of the pavement cells, while the very long chain aliphatic wax constituents are distributed fairly evenly across the entire adaxial cuticle. In the analysis of the abaxial cuticles, the triterpenoids were found to accumulate in greater amounts over the guard cells relative to the pavement cells. The very long chain aliphatic compounds accumulated in the cuticle above the anticlinal cell walls of the pavement cells, and were found at low concentration above the periclinals and the guard cells. The main research contributions include evaluating various data processing techniques as candidates for automated implementation and applying different imaging techniques to obtain chemical information about the lateral concentration gradient of the triterpenoid components in the cuticles, with high spatial resolution. This thesis also provides the first direct (i.e. in situ) evidence for lateral spatial heterogeneity of triterpenoids in the cuticle of a model species, P. laurocerasus. This work is expected to impel further structure-function investigation of the cuticular membranes of plants.

No description available.

Diamond-Like carbon (DLC)films have received a considerable amount ofwear resistant overcoat and biocompatible coatings. attention recently due to their chemical stability, high optical transparency and hardness. These properties make the films suitable for a number of applications such as protective and anti-reflection coating. Due to environmental pollution, double or multilayered coatings were recently developed as a new generation of protective coating. The present development hybrid coating system HBS900,is combination of hard coatings titanium nitride (TiN) and titanium carbonitride (TiCN) as multilayer are generated by cathode arc vaporization and magnetron sputtering, then on it following is high quality of diamond-like carbon film deposited by high degree of ionization, high densities of ions of electron cyclotron resonance plasma in the same recipient. It made the tools longer lifetime combination of outer lubrication layer. Not only using the high resistance and wear out of the inter multilayer, but also increasing the adhesion of DLC. The structural characteristics of DLC films were investigated by Raman spectroscopy, standard scratch, pin-on-disk test and microhardness. It made the film more graphite-like by higher substrate bias, higher process pressure, and higher ECR power The characteristics of the back stamper surface coated by DLC film were improved, and the productivity of an optical disk per stamper was estimated at about 1.7 times more than obtained. The properties of DLC films coating on the tamper were obtained and summarized as follows: excellent adhesion 65N, and coefficients of friction less than 0.15. As a result of adapting a microdrill coated with DLC film, the drilling lifetime was significantly improved to reach about 2.5 times than that of the uncoated one. The purpose of this research was to deposit the protective diamond-like carbon (DLC) films on polycarbonate substrates for optical applications. The oxygen plasma pretreatment of the substrate surface, silicon-incorporated diamond-like carbon films (DLC-Si), and the coating deposition conditions can enhance the adhesion of the DLC film. The coated DLC film showed better adhesion on the PC substrate surface under three tests as the alcohol rub test, a tape pull test, and a thermal shock test. The reactive CH4 (30sccm), the substrate bias (-100 V), the RF power (300 W), and In experiments, it is preceded being focus on the analysis of Raman spectrum for the films grown at various CH4 gas fluxes, substrates bias voltages, and higher si-doping concentrations made the film the better characteristics, the lower surface roughness, and higher hardness and adhesion. At least, the properties of diamond-like carbon (DLC) film coatings on phase-change recording media were characterized by Raman spectroscopy, atomic force microscope (AFM), UV-visible spectrometer and disc testers. The dependence of mechanical, optical and structural properties of DLC films included the characteristics of surface roughness, hardness, transmittance and electrical signals of discs on serveral DLC film thicknesses were investigated. Our experimental results indicate that DLC films provide a suitable coating to protect PC substrate and make it no difference for data stored on phase-change optical discs.