Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"laser vaporization"”.
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Novel preparation of endohedral metallofullerenes via laser vaporization of fullerene/metal pellets
Electric-arc vaporization of graphite rod/metal (or metal oxide) mixtures in an inert He atmosphere has been the method of choice for the production of endohedral metallofullerenes (Am@C2n). However, yields of endohedral metallofullerenes have been limited to only a few percent of the total …
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Laser Vaporization Methods for the Synthesis of Metal and Semiconductor Nanoparticles; Graphene, Doped Graphene and Nanoparticles Supported on Graphene
… in this dissertation is the development of new laser vaporization methods for the synthesis of metal and semiconductor nanoparticles, graphene, B- and N-doped graphene, and metal and semiconductor nanoparticles supported on graphene. These methods include the Laser Vaporization Controlled …
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GROWTH MECHANISMS OF COMPLEX ORGANICS IN THE GAS PHASE AND ON METAL NANOPARTICLES GENERATED BY A LASER VAPORIZATION PROCESS
In this dissertation, the ion mobility mass spectrometry technique is used to study the possible mechanisms of formation of polyaromatic hydrocarbons (PAHs) and polyaromatic nitrogen-containing hydrocarbons (PANHs) via the ion-molecule reactions of acetylene neutrals with different aromatic …
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Intense laser matter interactions for explosives detection and tunable spectral blueshift
… shifts induced in metal surfaces by ultrafast laser pulses at intensities ranging from 1013 to 1014 W/cm2. These ~100 femtosecond (fs) pulses facilitate non-resonant vaporization of explosives, enabling non-contact sampling and detection. When coupled with electrospray post-ionization, fs laser …
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Synthesis and spectroscopy studies of fullerenes and discovery of macroscopic quantities of doped fullerenes
Synthesis techniques of carbon arc and laser vaporization in the furnace for production of fullerenes have been developed. The optimum conditions for the high yields of fullerenes were tested and studied. A fullerene growth model was proposed to explain the formation of the fullerenes and the …
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Carbon Monoxide Oxidation on Nanoparticle Catalysts and Gas Phase Reactions of Small Molecules and Volatile Organics with Metal Cations
… for CO oxidation. The method is based on the Laser Vaporization/Controlled Condensation (LVCC) technique. The first part of this dissertation presents the vapor phase synthesis and characterization of gold nanoparticles supported on a variety of oxide supports such as CeO2, TiO2, CuO and …
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Experimental Studies on Nucleation, Nanoparticle's Formation and Polymerization from the Vapor Phase
… the condensation of supersaturated TFE vapor on laser-vaporized magnesium nanoparticles has been studied under different experimental conditions, such as the supersaturation, the pressure and the electric field. In part II, the laser vaporization controlled condensation (LVCC) technique was used …
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Particle Size Dependence on the Luminescence Spectra of Eu3+:Y2O3 and Eu3+:CaO
… from the bulk to nanometer regime. The use of laser spectroscopy to probe two nanocrystalline structures, Eu3+:Y2O3 and Eu3+:CaO, was investigated. The nanocrystalline structures were prepared by the laser-vaporization-gas-phase condensation of the bulk oxides. The particle size distribution …
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Gas Phase Studies of Molecular Clusters Containing Metal Cations, and the Ion Mobility of Styrene Oligomers
… by benzene clusters have been studied using laser vaporization, cluster beam and time-of-flight mass spectrometry techniques. In this work strong magic numbers were observed for clusters containing 10, 13 and 14 benzene molecules depending on the nature of the metal cation involved. The metal …
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Applications and production of carbon nanotubes
… slowly and in small amounts by catalytic arc vaporization and catalytic laser vaporization of graphite. It is well known that nanotubes can be mass produced by catalytic chemical vapor deposition (CCVD), but the product consists only of large, defective multiwalled nanotubes. It has been found …
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Fluorescence Labeling of Surface Species as an Efficient Tool for Detection, Identification and Quantification of Oxygen Containing Functionalities on Carbon Materials
… results of the purification of arc-produced and laser vaporization grown SWCNT using dynamic oxidation are presented. Purity analysis of dynamically oxidized samples by UV-VIS-NIR and Raman spectroscopy, as well as transmission electron microscopy, explicitly demonstrate that dynamic oxidation …
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Laser Electrospray Mass Spectrometry: Mechanistic Insights and Classification of Inorganic-Based Explosives and Tissue Phenotypes Using Multivariate Statistics
… elucidates a greater understanding of the vaporization and electrospray post-ionization mechanisms when using femtosecond laser pulses for desorption of surface molecules and electrospray ionization for capture and mass analysis of the gas phase ions. The internal energy deposition from …
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BINDING ENERGIES AND SOLVATION OF ORGANIC MOLECULAR IONS, REACTIONS OF TRANSITION METAL IONS WITH, AND PLASMA DISCHARGE IONIZATION OF MOLECULAR CLUSTERS
In this dissertation, different approaches have been employed to address the quest of understanding the formation and growth mechanisms of carbon-containing molecular ions with relevance to astrochemistry. Ion mobility mass spectrometry and DFT computations were used to investigate how a second …