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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 20 of 43 for “"vacuum system"”.
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High vacuum system and instrumentation for measuring the derivative of the current-voltage characteristic of a Langmuir probe
This study describes the construction of a high vacuum station and the instrumentation and testing of two methods for obtaining the first derivative of the current-voltage characteristic of a Langmuir Probe, which is needed to determine the electron speed distribution in rare gases. The theory …
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Measurement of the nitrogen(+) ((5)sulfide) state radiative lifetime
… results were non-reproducible at a higher vacuum system with a meshed wall ion trap. This is perhaps due to unknown impurity gases in Knight's vacuum system. This measurement will clarify the discrepancy between Knight's measurement and theoretical calculations. An accurate value for the …
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The Interaction of Simple Gases with Hot Metal Filaments
… filaments has been studied in a magnetron system. The interaction of two of these compounds, iodine and methyl iodide, with tantalum filaments has also been studied in an ultra high vacuum system. The study of the surface ionisation of iodine and the methyl compounds in the magnetron …
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A chirped, pulsed laser system and magneto-optical trap for rubidium
… to the preparation and assembly of the vacuum system. The MOT construction forms the first goal of the project, the second was to develop a laser system capable of producing custom programmable, amplitude modulated and frequency chirped pulses (on the tens of microseconds timescale) from …
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Extensions of quartz-enhanced photoacoustic spectroscopy
… of NH3 were generated through the use of a vacuum system, and absorption spectroscopy was performed on these samples. A tuning fork was also characterized. Photoacoustic signals were ultimately not realized, however, plans for future work are mentioned.
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Secondary Plasma Sources for Ionized Physical Vapor Deposition
The helicon antenna sits remotely outside the vacuum system, so all shadowing and contamination problems which the other two sources exhibit are eliminated. Ionization fractions to the substrate of 51 +/- 10% with a deposition rate of 847 +/- 42 A/min. are found. Without the antenna, the ionization …
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Competition between Reaction Channels in Electron Collisions of the Hydrogen Molecular Ion HD+
… from the dilute residual gas in the TSR vacuum system.
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Investigation of quasi-one-dimensional orthorhombic tantalum trisulfide using scanning tunneling microscopy
… on the microscope, and cleaned the microscope vacuum system to enable imaging at ultra-high vacuum. We achieved atomic-resolution imaging of TaS3 in order to better understand its crystal structure, which has been under investigation for decades. This thesis also involved the use of scanning …
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Hollow cathode sputtering system - installation, operation and theoretical background
… install and operate a hollow cathode sputtering system (HCSS). Therefore a complex vacuum system was built to create the right sputtering environment. The purpose of the HCSS is to develop advanced thin conducting oxides (TCOs) as well as high resistivity transparent (HRT) layers which are used …
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Building an apparatus for ultracold lithium-potassium Fermi-Fermi mixtures
In this thesis, I designed and built laser systems to cool, trap and image lithium-6 and potassium-40 atoms. I also constructed the vacuum system for the experiment and experimentally tested a new method to coat the chamber with a Titanium-Zirconium- Vanadium alloy that acts as a pump. The final …
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Characterisation of silicalite and post synthesis modified silicalite using adsorption
… widespread use of this type of technique. The system constructed was a flow system as opposed to the more commonly used vacuum system. The choice of a flow gravimetric system introduces a number of advantages: * The effect of the heat of adsorption is reduced * The system is better able to …
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Abdominal vacuum lift as an aid to diagnosing abdominal adhesions
… on a number of models of an external abdominal vacuum system which we believe will increase the accuracy and predictive values of measuring visceral slides under ultrasound using exaggerated respiration.
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Extraction and measurement of cosmogenic in situ 14C from quartz
… of carbon that can be extracted from quartz. The vacuum system that I have designed and built to extract carbon from quartz is based on that used at the University of Arizona (Lifton 1997), which uses resistance heating of samples to a temperature of approximately 1100ºC in the presence of lithium …
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Surface studies in ultra high vacuum
An ultra high vacuum system capable of attaining pressures of 10-12 mm Hg was used for thermal desorption experiments. The metal chosen for these experiments was tantalum because of its suitability for thermal desorption experiments and because relatively little work has been done using this metal. …
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A study of the physical adsorption of nitrogen gas on polished 347 stainless steel at very low pressures
… experiment was repeated in order to evaluate the vacuum system and dynamic technique used before studying the polished stainless steel. An error analysis of the dynamic technique indicated a maximum uncertainty of about ±40 percent.
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A System for Measuring Radiation Induced Chemical Products in Atmospheric Gases Using Optical Detection Methods
… is followed by a description of the optical and vacuum systems that were available and the modifications required to integrate the optical system into the vacuum chamber to achieve the ability to optically monitor the ozone levels in a controlled atmosphere. Both the ringdown data collection and …
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Modeling of high fluence Ti ion implantation and vacuum carburization in steel
… C was assumed to be gettered from the vacuum system in a one-to-one ratio with the surface Ti concentration up to a saturation point. Both Ti and C were allowed to diffuse. A series of experimental (Auger) concentration-versus-depth profiles of Ti implanted steel were analyzed using the …
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Design, performance, and analysis of a multi-level air permeability test
… and analysis of a soil vapor extraction system to identify zones most conductive to air transport and quantify kair in sequential soil layers is presented. A multi-level extraction well, with alternating solid and screened sections, was utilized to characterize multi-layered media. The …
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A new vibrational technique for measurement of stress variations in thin films
… of internal stress in thin films deposited in a vacuum system. The technique is based on a measurement of changes in the modal resonant vibrational frequencies of the substrate/film structure which are caused by stress-induced changes in curvature. The modal vibrations are induced by …
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Quantum Gas Microscopy of Bosonic Correlations in the Continuum
… adapted our apparatus to investigate bulk system behavior. A major part of this project involved upgrading the scientific apparatus and retrofitting the previous system. We introduced new optical components, including a high-NA objective, and improved the vacuum system for better optical …
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