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 19 of 19 for “"ion emission"”.
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High Current Ion Emission in Electrohydrodynamic Spraying
Made available in DSpace on 2015-05-13T15:21:59Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7607008.PDF: 3915500 bytes, checksum: 19a77b91d89e61fb52b7e048b73c6dd7 (MD5) Previous issue date: 1975
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High current ion emission in electrohydrodynamic spraying
The electrohydrodynamic spraying of ions from conducting liquids at a capillary tip has traditionally been explained as field evaporation at room temperature from a very small liquid tip, of the order of 10 -20 i. Consideration of the effect of space charge on the fields and force balance at the …
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Aircraft charging using ion emission for lightning strike mitigation : an experimental study
… field is magnified. This can result in bidirectional leaders which extend from opposite polarity aircraft extremities. These can connect to oppositely charged regions in a cloud or the ground, resulting in a lightning strike. Current methods to avoid lightning are limited to avoiding …
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Molecular dynamics modeling of ionic liquids in electrospray propulsion
Micro-propulsion has been studied for many years due to its applications in small-to-medium sized spacecraft for precise satellite attitude control. Electrospray thrusters are promising thrusters built upon the state of the art in micro-technology and with flexible performance in terms of their …
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A comprehensive numerical procedure for solving the Taylor-Melcher leaky dielectric model with charge evaporation
Electrosprays in the pure-ion mode are of particular interest to space propulsion because of its ability to produce high specific impulse and efficient electrical-to-kinetic energy transformation, together with its simplicity and compactness. Unlike electrospray emitters operating in the droplet …
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Emission Capabilities of Nafion-Based Emitting Geometries
The propulsion field is home to numerous technological advancements, ranging from the mechanisms of their operation to the propellants used. All of these have enabled numerous space missions, either for technological demonstrations, or for other commercial, and even government use. Fortunately, …
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Analysis of ion emitting jet structures during ionic liquid electrospraying
<p>"The ionic liquid [Bmim][DCA] is a propellant candidate for a standalone electrospray thruster or a dual-mode propulsion system. Characterization of positive polarity ions produced by [Bmim][DCA] capillary emitters with a nominal extraction voltage of 2.0 kV within a quadrupole and …
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Active Thermal Augmentation and Ultra Dense MEMS-Based Electrospray Thrusters
Ionic liquid electrospray thrusters, a highly efficient form of electric space propulsion, have several advantages over traditional chemical forms of space propulsion as well as competing forms of electric propulsion, including their unique scalability down to extremely small sizes, their use of …
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Fabrication and characterization of porous metal emitters for electrospray applications
… less than 1000s to over 4000s. The miniaturization and clustering of many emitters together is essential to increase the thrust density of electrospray devices in order to increase their domain of applicability in space. Electrospray emitter arrays have many advantages over existing electric …
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A Fundamental Study on the Relocation, Uptake, and Distribution of the Cs⁺ Primary Ion Beam During the Secondary Ion Mass Spectrometry Analysis
… bombardment with positive secondary molecular ion detection (MCs+) can extend the analysis capability of Secondary Ion Mass Spectrometry (SIMS) from the dilute limit (<1%) to matrix elements. The MCs+ technique has had great success in quantifying the sample composition of III-V semiconductors …
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Use of molecular dynamics simulations to study the impact of weak to strong non-covalent chemical interactions
… the role of van der Waals and Coulomb interactions on two fundamental processes, namely, gas-surface interactions and electrospray propulsion, respectively. For the gas-surface interaction work, we proved that conventionally used gas surface interaction models were not adequate in reproducing …
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A fully microfabricated two-dimensional electrospray array with applications to space propulsion
This thesis presents the design, fabrication and testing of a fully-integrated planar electrospray thruster array, which could lead to more efficient and precise thrusters for space propulsion applications. The same techniques could be used for making arrays to increase throughput in many other …
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Processes for the Fabrication of SU-8 Structures and Sputtered Materials on Porous Glass for Electrospray Thruster Manufacturing
Electrospray thrusters are electric propulsion devices that generate thrust through the use of an electric potential between the emitter, a concentrated point at which a propellant is flowed to, and downstream extractor electrodes that generates a high electric field at the emitter causing the …
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MBE growth and investigation of (001) GaAs surfaces using SIMS
… been designed and constructed. After identification and elimination of various problems, high mobility, Si-doped , n-tYfe GaAs has been grown with electron concentration from ~ 5 x 10[to the power of]15 cm[to the power of]-3 (u 77 ~ 30,000 cm[squared]/Vs) to a solubility limit at ~ 7 x 10[to the …
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The role of nanostructured targets in Laser-Produced Plasmas for Nuclear Astrophysics studies
… study of plasmas produced from the interaction of a high-power laser in ns domain with nanostructured materials compared with ordinary bulk target. The study is focused on the effect of solid targets with different physical and geometric characteristics, and has the purpose to asses the …
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Debris Characterization And Mitigation Of Droplet Laser Plasma Sources For Euv Lithography
… ultraviolet lithography (EUVL) is a next generation lithographic techniques under development for fabricating semiconductor devices with feature sizes smaller than 32 nm. The optics to be used in the EUVL steppers is reflective optics with multilayer mirror coatings on each surface. The …
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Triboemission From Ceramics: Charge Intensity and Energy Distribution Characterizations
Lubrication of ceramics is a difficult and not completely solved problem. Ceramics do not respond to conventional lubricants which are designed to function by a chemical reaction with the surface. There is, accordingly, increased interest in the development of lubrication alternatives for ceramics, …
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Development of a ferroelectric plasma source through material degradation studies and characterization of volume and surface discharges
… – 10^5 A/cm2), is pulsed to emit electrons and ions. The ferroelectric material uniquely affects emission, which in turn uniquely affects the ferroelectric surface. Lifetimes are typically limited to 10^4 to 10^5 emissions due to poorly understood degradation mechanisms. Understanding the causes …