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Dissertations / Theses on the topic 'Interfaces (Physical sciences)'
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1
Lee, Long. "Immersed interface methods for incompressible flow with moving interfaces /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/6789.
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Marmol, Leonardo. "Customized Interfaces for Modern Storage Devices." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3165.
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In the past decade, we have seen two major evolutions on storage technologies: flash storage and non-volatile memory. These storage technologies are both vastly different in their properties and implementations than the disk-based storage devices that current soft- ware stacks and applications have been built for and optimized over several decades. The second major trend that the industry has been witnessing is new classes of applications that are moving away from the conventional ACID (SQL) database access to storage. The resulting new class of NoSQL and in-memory storage applications consume storage using entirely new application programmer interfaces than their predecessors. The most significant outcome given these trends is that there is a great mismatch in terms of both application access interfaces and implementations of storage stacks when consuming these new technologies.
In this work, we study the unique, intrinsic properties of current and next-generation storage technologies and propose new interfaces that allow application developers to get the most out of these storage technologies without having to become storage experts them- selves. We first build a new type of NoSQL key-value (KV) store that is FTL-aware rather than flash optimized. Our novel FTL cooperative design for KV store proofed to simplify development and outperformed state of the art KV stores, while reducing write amplification. Next, to address the growing relevance of byte-addressable persistent memory, we build a new type of KV store that is customized and optimized for persistent memory. The resulting KV store illustrates how to program persistent effectively while exposing a simpler interface and performing better than more general solutions. As the final component of the thesis, we build a generic, native storage solution for byte-addressable persistent memory. This new solution provides the most generic interface to applications, allow- ing applications to store and manipulate arbitrarily structured data with strong durability and consistency properties. With this new solution, existing applications as well as new “green field” applications will get to experience native performance and interfaces that are customized for the next storage technology evolution.
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Leskovar, Michael. "The stability of interfaces between dissimilar materials /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9728.
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Chen, Chun-Chung. "Understanding avalanche systems through underlying interface dynamics /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9755.
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Millner, Amon Daran. "Hook-ups : how youth learn through creating physical computer interfaces." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32508.
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Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2005.Includes bibliographical references (p. 129-130).
The Hook-ups project introduces a new set of tools, materials, and activities intended to support children in creating physical computer input devices for computer programs they write. This project introduces a new approach to learning-through-design by providing opportunities for children to engage in both physical and computational design concurrently. This thesis describes the design of Hook-ups tools and materials, including the development of Scratch Patches - a new puzzle-piece-like set of technological building blocks used to build computer input devices. Also presented are classifications of the types of Hook-ups developed by youth, an analysis of what and how youth learned through Hook-ups design activities, and a roadmap for future work in the area of interaction design for children.
by Amon Daran Millner.
S.M.
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Follmer, Sean (Sean Weston). "Dynamic physical affordances for shape-changing and deformable user interfaces." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/97973.
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Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 207-222).
The world is filled with tools and devices designed to fit specific needs and goals, and their physical form plays an important role in helping users understand their use. These physical affordances provide products and interfaces with many advantages: they contribute to good ergonomics, allow users to attend to other tasks visually, and take advantage of embodied and distributed cognition by allowing users to offload mental computation spatially. However, devices today include more and more functionality, with increasingly fewer physical affordances, losing many of the advantages in expressivity and dexterity that our hands can provide. My research examines how we can apply shape-changing and deformable interfaces to address the lack of physical affordances in today's interactive products and enable richer physical interaction with general purpose computing interfaces. In this thesis, I introduce tangible interfaces that use their form to adapt to the functions and ways users want to interact with them. I explore two solutions: 1) creating Dynamic Physical Affordances through shape change and 2) user Improvised Physical Affordances through direct deformation and through appropriation of existing objects. Dynamic Physical Affordances can provide buttons and sliders on demand as an application changes, or even allow users to directly manipulate 3D models or data sets through physical handles which appear out of the data. Improvised Physical Affordances can allow users to squeeze, stretch, and deform input devices to fit their needs, creating the perfect game controller, or shaping a mobile phone around their wrist to form a bracelet. Novel technical solutions are needed to enable these new interaction techniques; this thesis describes techniques both for actuation and robust sensing for shape-changing and deformable interfaces. Finally, systems that utilize Dynamic Physical Affordances and Improvised Physical Affordances are evaluated to understand patterns of use and performance. My belief is that shape-changing UI will become increasingly available in the future, and this work begins to create a vocabulary and design space for more general-purpose interaction for shape-changing UI.
by Sean Weston Follmer.
Ph. D.
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Sanchez, Erik De Jesus. "Modeling of the Surface Plasmon Resonance (SPR) Effect for a Metal-Semiconductor (M-S) Junction at Elevated Temperatures." PDXScholar, 1993. https://pdxscholar.library.pdx.edu/open_access_etds/4624.
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The effect of temperature increase on the optical excitation of Surface Plasmon Resonance (SPR) at an Ag-Si metal-semiconductor (M-S) junction at a wavelength of 1 . 1 52 pm is investigated theoretically using computer modeling in Fortran. In order to accurately quantify the SPR, the temperature dependent optical constants for Ag and Si are obtained theoretically or semiempirically , using a Drude model for Ag and previous experimentally determined equations for Si (the behavior of the optical constants for crystalline Si and doped Si are found to have very little deviation between each other for our case). An improvement in the theoretical derivation for the optical constants of Ag is obtained, maintaining self-consistency. The optical constants are utilized to quantify the reflectance of an incident wave on an M-S junction, using Fresnel equations for a four layer system. The reflectivity of the M-S junction is indicative of the surface plasmon generation. There exists much industrial interest in increasing the amount of photocurrent generation in semiconductors for a given number of incident photons. This increase in photocurrent is often referred to as enhancing the quantum efficiency (Q). It has been previously shown by many groups that there can be an appreciable enhancement of Q due to the optical excitation of surface plasmons on a Schottky barrier junction (M-S junction), although all these previous studies were done at room temperature. Hence, the studies of temperature effect of SPR at the M-S junction could lead to interesting effects for the Q as well. In this thesis, we have studied qualitatively the effect of temperature increase on the optical excitation of SPR at an Ag-Si junction. From these results we have attempted to draw inference to the possibility of the enhancement of Q at elevated temperatures for such a diode junction.
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Wang, Chuandao Charlie, and 王传道. "Organic solar cells towards high efficiency: plasmonic effects and interface engineering." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48329654.
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Organic solar cells (OSCs) are promising candidates for solar light harvesting due to their standout advantages both in material properties and manufacturing process. During past decades, remarkable progress has been achieved. Efficiency for single-junction cells over 9% and tandem cells over 10% has been reported. For high performance OSCs towards commercialization, sufficient light absorption and high quality buffer layers are still two challenges, which are addressed in this thesis by investigating the plasmonic effects on OSCs and interface engineering.
Here, the mechanisms of plasmonic effects on OSC are explored by incorporating metallic Au nanoparticles (NPs) in individual anode buffer layer and active layer, respectively, and finally in both layers simultaneously. When Au NPs are incorporated into the buffer layer, surface plasmonic resonance (SPR) induced absorption enhancement due to incorporation of Au NPs is evidenced theoretically and experimentally to be only minor contributor to the performance improvement. The increased interfacial contact area between the buffer layer and active layer, together with the reduced resistance of the buffer layer due to the embedded Au NPs, are revealed to benefit hole collection and thus are main contributors to the performance improvement. When Au NPs are embedded in the active layer, Au NPs induced SPR indeed contributes to enhanced light absorption. However, when large amount of Au NPs are incorporated, the negative effects of NPs on the electrical properties of OSCs can counter-diminish the optical enhancement from SPR, which limits the overall performance improvement. When Au NPs are embedded into both layers, both advantages of incorporating NPs in individual layers can be utilized together to achieve more pronounced improvement in photovoltaic performance; as a result, accumulated enhancements in device performance can be achieved. The results herein are applicable to other metallic NPs such as Ag NPs, Pt NPs, etc. The study herein has clarified the degree of contribution of SPR effects on OSCs and revealed the mechanisms behind. It has also highlighted the importance of considering both optical and electrical effects when employing metallic NPs as strategies to enhance the photovoltaic performance of OSCs. Consequently, the study contributes both physical understanding and technological development of applying metallic NPs on OSCs.
Regarding interface engineering, we first propose a simple method to modify the substrate work function for efficient hole collection by using an ultra-thin ultraviolet-ozone treated Au. The method can be used in other situations such as modifying the work function of multilayer graphene as transparent electrode. Then we propose a general method to synthesize solution-processed transition metal oxides (TMOs). Besides high material quality, desirable electrical properties, and good stability, our method stands out particular in that the synthesized TMOs can be dispersed in water-free solvents and the TMO films require only low temperature treatment, which is very compatible with the organic electronics. Our method can also be used to synthesize other TMOs other than the demonstrated molybdenum oxide and vanadium oxide. The proposed method herein is applicable in semiconductor industry.published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
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Maeda, Nobuo. "Phase transitions of long-chain n-alkanes at interfaces." View thesis entry in Australian Digital Theses Program, 2001. http://thesis.anu.edu.au/public/adt-ANU20011203.151921/index.html.
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Failla, Roberto. "Random growth of interfaces: Statistical analysis of single columns and detection of critical events." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4550/.
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The dynamics of growth and formation of surfaces and interfaces is becoming very important for the understanding of the origin and the behavior of a wide range of natural and industrial dynamical processes. The first part of the paper is focused on the interesting field of the random growth of surfaces and interfaces, which finds application in physics, geology, biology, economics, and engineering among others. In this part it is studied the random growth of surfaces from within the perspective of a single column, namely, the fluctuation of the column height around the mean value, which is depicted as being subordinated to a standard fluctuation-dissipation process with friction g. It is argued that the main properties of Kardar-Parisi-Zhang theory are derived by identifying the distribution of return times to y(0) = 0, which is a truncated inverse power law, with the distribution of subordination times. The agreement of the theoretical prediction with the numerical treatment of the model of ballistic deposition is remarkably good, in spite of the finite size effects affecting this model. The second part of the paper deals with the efficiency of the diffusion entropy analysis (DEA) when applied to the studies of stromatolites. In this case it is shown that this tool can be confidently used for the detection of complexity. The connection between the two studies is established by the use of the DEA itself. In fact, in both analyses, that is, the random growth of interfaces and the study of stromatolites, the method of diffusion entropy is able to detect the real scaling of the system, namely, the scaling of the process is determined by genuinely random events, also called critical events.
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Vink, Luke (Luke Alexander Jozef). "Materiality in suspense : exploring radical interfaces capable of representing multiple physical property transformations to enable computational, physical material perception." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107548.
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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, September 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 86-89).
Years after the inception of the Radical Atoms vision, significant advances in technology have seen to dynamic tangible interfaces that bridge the biological and micromechanical to enable radical physical interaction with computation. With an increasing multi-modal complexity in such interfaces, this thesis explores a new methodologies and frameworks to designing input/output coincident and physically embodied computers. New types of Shape Changing Interfaces introduce physical perception of material properties to dynamic shape with physically accurate force feedback and introduce Radical Materiality as a way to afford physical interactions with a rendered object. Finally, the Radical Reality Test is proposed as an objective for such interfaces to eventually become indistinguishable from the physical entity or behavior they are computationally and dynamically imitating.
by Luke Vink.
S.M.
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Szabo, Tamas. "Energy transfer at gas-liquid interface towards energetic materials /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4797.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on February 29, 2008) Vita. Includes bibliographical references.
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Schuerg, Frank. "Fractal geometry of iso-surfaces of a passive scalar in a turbulent boundary layer." Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180358/unrestricted/schuerg%5ffrank%5f200312%5fms.pdf.
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Chung, Paular Wai Kwan. "Interfacial adhesion between epoxy molding compound and copper leadframe under different thermal conditions /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?MECH%202002%20CHUNGP.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 111-114). Also available in electronic version. Access restricted to campus users.
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Schoessler, Philipp. "Shape synthesis : physical object augmentation and actuation for display and interaction on shape changing interfaces." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98619.
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Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 81-87).
Pin based shape displays can not only give physical form to digital information, but they have the inherent ability to accurately move and manipulate objects that are placed on top of them. This document presents ways and ideas that show how a shape display's dynamic shape changing ability can work in unison with physical objects that are placed on top of it. First, we introduce the idea of shape synthesis, which is the physical augmentation of inert physical objects with the dynamic shape to create a seemingly new object. This synthesized object combines the advantages of the inert object's natural affordances with the computational power of dynamic shape change. In so doing, we can substitute for passive objects, complement passive objects and enable easier interactions with a shape display. We then show that a shape display can be used to assemble, disassemble and reassemble structures from simple passive building blocks through stacking, scaffolding and catapulting. Then, we introduce special unpowered kinematic modules that can be driven and sensed through the underlying pins. These modules can translate the vertical pin movement into other degrees of freedom like rotation or horizontal movement. This suggests that a shape display can be regarded as a versatile physical control platform that can drive and control a variety of useful mechanisms and objects.
by Philipp Schoessler.
S.M.
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Bruant, Robert Gilbert. "Adsorption of volatile hydrophobic organic compounds at the vapor/water interface." Diss., The University of Arizona, 2000. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_2000_292_sip1_w.pdf&type=application/pdf.
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Mathew, Anoop. "Study of interfacial phenomena in thin films using photoelectron spectroscopy." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 2.05 Mb., 74 p, 2006. http://wwwlib.umi.com/dissertations/fullcit/1435840.
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Le, Roux Sébastien. "Effet Marangoni aux interfaces fluides." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S060/document.
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Nous présentons au cours de ce manuscrit diverses expériences de dépôt de tensioactifs solubles dans l'eau à l'interface entre deux fluides. Après quelques développements théoriques, nous étudions l'étalement de tensioactifs solubles déposés à une interface eau/air. Nous présentons au cours de cette partie deux configurations expérimentales dans lesquelles ces molécules exhibent une vitesse caractéristique d'écoulement induit ainsi qu'une distance finie d'étalement dépendant de la CMC du surfactant utilisé, qui se traduit par l'apparition d'une tache centimétrique à la surface de l'eau. Nous mettons alors au point un protocole de mesure simple et rapide de CMC utilisant notre dispositif expérimental. À cet étalement s'ajoutent une déformation verticale de l'interface, la mise en place d'une double recirculation toroïdale, ainsi qu'une instabilité hydrodynamique de surface tout autour de la tache. La deuxième expérience porte sur l'étalement de tensioactifs solubles à une interface eau/huile. Dans cette expérience, les déformations verticales induites par l'étalement peuvent devenir très importantes, si bien que sous certaines conditions cette déformation crée un trou dans la couche d'huile. Nous nous penchons donc sur l'étude de ces déformations verticales, ainsi que sur les caractéristiques de ce cratère. Enfin, la dernière partie traite du dépôt d'une goutte de Triton X-100 à la surface de l'eau. Ce tensioactif possède la propriété de gélifier lorsqu'il est hydraté, ce qui lui permet de flotter. On observe alors un phénomène d'auto-propulsion de la goutte. Nous nous intéressons plus particulièrement à la structure microscopique de cette phase gel, ainsi qu'aux trajectoires erratiques empruntées par la goutteWe report experiments about the deposition of water soluble surfactants at the interface between two fluids. After some theoretical developments, we study the spreading of water soluble amphiphiles at the water/air interface. In this part, we present two experimental setups where these molecules show a typical induced flow velocity, and a finite spreading distance, depending on the CMC of surfactant we use, which results in the apparition of a coronna on the surface of the liquid. We then set up a fast and simple CMC measurement protocole using our experimental setup. This spreading induces also a vertical deformation of the interface, a double toroidal recirculation in the bulk, and a beatiful hydrodynamic surface instability all around the coronna. The second experiment is about the spreading of amphiphiles at the interface between oil and water. In this experiment, the vertical deformations induced by the spreading can become so important that under certain circumstances, we manage to create a hole in the oil layer. We focus on the study of these vertical deformations and on the caracteristics of this hole. Finally, the last experiment is about the deposition of a Triton X-100 drop at the water/air interface. This molecule has the ability to gelify when it gets hydrated, allowing him to float. Then we can observe the self propulsion of the droplet. We focus on the microscopic structure of this gel phase, and also on the erratic trajectories followed by the drop
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Zheng, Jie. "Effects of capillarity on the mechanical stability of small-scale interfaces." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-11212004-180952/unrestricted/zheng%5Fjie%5F200412%5Fphd.pdf.
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Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2005.J. Carson Meredith, Committee Member ; J. Carlos Santamarina, Committee Member ; G. Paul Neitzel, Committee Member ; Richard F. Salant, Committee Member ; Jeffrey L. Streator, Committee Chair. Includes bibliographical references.
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Le, Jiabo. "Simulating electric double layers at transition metal-water interfaces from density functional theory based molecular dynamics." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=235395.
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This PhD project aims at understanding the electric double layers (EDLs) at transition metal-water interfaces with density functional theory based molecular dynamics (DFTMD). We plan to develop a method for computationally determining the electrode potential of an interface, which bridges experiments and theoretical computation. After that, we will investigate the microscopic structure of the EDLs, including ion distribution, water orientation, hydrogen bonding and so on. Furthermore, we are interested in the charge transfer between metal surface and water at different configurations, and some consequences this may lead to. In the first part, we have simulated Pt(111)-, Au(111)-, Pd(111)- and Ag(111)-water interfaces at a well-defined condition, potential of zero charge (PZC), by DFTMD. We find the water coverage of the metal surface is ⇠0.8ML, and there is no ordered pattern formed at room temperature. Moreover, we have characterised three configurations (watA, watB-down and watB-up) from the surface water layer, and revealed their hydrogen bonding networks. In the second part, we have developed a computationally efficient scheme for determining the electrode potential of the metal-water interfaces with respect to standard hydrogen electrode (SHE), and obtained the PZC values of Pt(111), Au(111), Pd(111) and Ag(111)-water interfaces within a good accuracy. Furthermore, we find that the interface dipole potentials are almost entirely caused by charge transfer from water and to the metal surfaces, the magnitude of which depends on the bonding strength between water and the metals, while water orientation hardly contributes at the PZC condition. In the third part, we have calculated the vibrational spectrum of the chemisorbed water on Pt(111) and Au(111), and found their peak positions of the stretch vibrational frequency are red-shifted, the magnitude of which is dependent to the strength of the metal-water interaction and the local hydrogen bonding. We have also suggested that the chemisorbed water is the source of the peaks at 2850-3000 cm-1 observed in experiments. In the last part, we have simulated a series of EDLs at Au(111)-water interfaces, their reliability is confirmed by comparing the differential capacitance with experimental values. We find the Stern layer gets compressed and the partial solvation layer of the ion is peeled off at a negatively charged surface. Moreover, we find the configuration of the interfacial water is reoriented from 'parallel water', to 'H-downwater', then further to 'perpendicular water' when the metal surface is progressively charged with electrons.
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Ramrus, Daniel A. "The creation and adhesion testing of patterned silane surfaces /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/9838.
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Abshere, Travis Arthur. "A picosecond photoluminescence and electrochemical study of the n-GaAs/elctrolyte interface in a nonaqueous photoelectrochemical cell /." view abstract or download file of text, 2000. http://wwwlib.umi.com/cr/uoregon/fullcit?p9978241.
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Thesis (Ph. D.)--University of Oregon, 2000.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 122-126). Also available for download via the World Wide Web; free to University of Oregon users.
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Webster, Robert Samuel. "A numerical study of the conjugate conduction-convection heat transfer problem." Diss., Mississippi State : Mississippi State University, 2001. http://library.msstate.edu/etd/show.asp?etd=etd-04102001-144805.
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Lei, Siu Long. "Phase-field simulations of two-phase flows /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?MATH%202009%20LEI.
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Bansal, Dinesh Gur Parshad. "Tribological investigation of electrical contacts." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31749.
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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Streator, Jeffrey; Committee Member: Blanchet, Thierry; Committee Member: Cowan, Richard; Committee Member: Danyluk, Steven; Committee Member: Neu, Richard; Committee Member: Thadhani, Naresh. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Shu, Shu. "Engineering the performance of mixed matrix membranes for gas separations." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/26626.
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Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2008.Committee Chair: Koros William; Committee Member: Hess Dennis; Committee Member: Jones Christopher; Committee Member: Meredith Carson; Committee Member: Wong CP. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Schwartz, Nicholas Edward. "P300-Based BCI Performance Prediction through Examination of Paradigm Manipulations and Principal Components Analysis." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etd/1775.
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Severe neuromuscular disorders can produce locked-in syndrome (LIS), a loss of nearly all voluntary muscle control. A brain-computer interface (BCI) using the P300 event-related potential provides communication that does not depend on neuromuscular activity and can be useful for those with LIS. Currently, there is no way of determining the effectiveness of P300-based BCIs without testing a person's performance multiple times. Additionally, P300 responses in BCI tasks may not resemble the typical P300 response. I sought to clarify the relationship between the P300 response and BCI task parameters and examine the possibility of a predictive relationship between traditional oddball tasks and BCI performance. Both waveform and component analysis have revealed several task-dependent aspects of brain activity that show significant correlation with the user's performance. These components may provide a fast and reliable metric to indicate whether the BCI system will work for a given individual.
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Yao, Qizhou. "Modeling and characterization of interfacial adhesion and fracture." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17691.
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DeJong, Jason Theodore. "Investigation of particulate-continuum interface mechanisms and their assessment through a multi-friction sleeve penetrometer attachment." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/21536.
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Schroeder, Brett. "Surface modification enhanced semiconductor-on-insulator heteroepitaxy /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/9808.
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Adams, Jonathan A. "A surface and interface study of aluminum selenide on silicon : growth and characterization of thin films /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/9797.
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Eriksson, Martin. "Nanoscale electrical properties of heterojunction interfaces for solar cells : modeling and experiments." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-72505.
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A numerical model have been developed in order to describe and achieve deeper understanding of experimentally obtained I-V curves from Cu2O/ZnO p-n heterojunctions for potential use as future solar cell material. The model was created using the simulation software COMSOL Multiphysics® and their semiconductor module. To experimentally study the samples two approaches were taken: (1) macro-electrical measurements and (2) local I-V measurements using conductive AFM. The final model is one-dimensional, time dependent and with the ability to study photovoltaic effects of samples with different layer thickness at different voltage ramping speeds and different light irradiance. The model is also able to study the effects of using different contact materials by treating the contacts as ideal Schottky contacts. The dynamic behavior of a Cu_2O/ZnO heterojunction was studied by considering the systems response to a voltage step and the effect of changing the voltage ramping speed. The output from the step response, the current as a function of time, is varying a short time after a step has occurred before settling on to a steady value. The response also shows an overshoot of the current in the direction of the voltage step and the final steady value depends on whether the junction is conducting or not. The effects of this behavior on the shape of the I-V curves are witnessed when studying the different voltage ramping speeds. The voltage is ramped from 2 V to -2 V and back again for different speeds (V/s). The I-V curves have different shapes when sweeping the voltage in different directions and the magnitude increases with increasing speed. The photovoltaic effects were studied by applying different light irradiances. The behavior of the model agrees well with the theory for an ideal diode solar cell. An investigation was done of how the work function of the metal in contact with the Cu_2O affects the shape of the I-V curve under dark and illuminated conditions. The metal work function was changed from 4.5 eV to 6.5 eV in steps of 0.4 eV and does not affect the shape of the I-V curves much in dark after increasing it above 4.5 eV. The effects are more visible under illuminated conditions where a "step"-behavior appears for the lower values of the work function. Only one of the physical samples show a noticeable light effect. The macro-electrical measurement on this sample is compared with simulated results and are in qualitative agreement with each other. The agreement between the local electrical measurements and the simulated results is not as good with the current model.
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Beerman, Michael. "Transverse freezing of thin liquid films /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/10573.
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Aston, David Eric. "Quantifying single oil-particle interactions in aqueous media /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/9898.
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Tillman, Matthew Scott. "Analysis and development of interphase matrices for use in thermosetting composites and adhesives /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/9921.
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Camargo, Bruno Cury 1988. "Efeitos quânticos em semimetais de Dirac e heteroestruturas relacionadas." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276954.
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Orientador: Iakov Veniaminovitch KopelevitchTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Neste trabalho serão apresentados os principais resultados obtidos peloautor no decorrer de seu doutorado. Os sistemas estudados eram compostos por grafite, grafeno, antimônio e interfaces de grafite/silício. Uma das partes do trabalho consistiu no estudo de efeitos de desordem estrutural sobre oscilações quânticas em grafite. O estudo revelou que a mosaicidade da grafite estudada, largamente utilizada para se determinar a qualidade de amostras de grafite pirolítico altamente orientado (HOPG), não apresenta correlação com a amplitude das oscilações quânticas no material. Ao invés disso, os experimentos mostraram uma clara correlação entre a rugosidade superficial, a mobilidade eletrônica média e a amplitude do efeito de Haas van Alphen no material. Os resultados indicam que deformações da superfície da grafite afetam fortemente a mobilidade eletrônica do material (reduzindo a amplitude de oscilações quânticas) sem reduzir sua anisotropia. No trabalho, também é discutida a possibilidade de que as oscilações quânticas em grafite estejam relacionadas com a existência de interfaces bem definidas na estrutura interna do material. Também foram estudadas propriedades de transporte elétrico interplanar em grafite no limite ultraquântico. Medidas de magnetorresistência interplanar para campos magnéticos de até 60 T acusaram a ocorrência de uma região de magnetorresistência positiva seguida de magnetorresistência negativa (MRN) para campos magnéticos suficientemente altos. O efeito persistia até temperatura ambiente. Ele é explicado considerando-se o tunelamento de férmions de Dirac entre níveis fundamentais de Landau de planos de grafeno adjacentes dentro da grafite. A região de MRN é mais pronunciada em grafites com menor mosaicidade, o que sugere que o alargamento de níveis de Landau seja responsável pela magnetorresistência positiva observada nas medidas ao longo do eixo c da grafite. Além disso, experimentos de magnetorresistência interplanar com campos magnéticos orientados paralelamente à direção dos planos da grafite apresentaram indícios de que o material se torna mais tridimensional com a redução da temperatura. Os resultados sugerem que a integral de overlap interplanar em grafite possui valor ?1 < 7 meV. Esse valor é muito inferior àqueles reportados na literatura considerando-se o modelo mais bem aceito para grafite, segundo o qual ?1 ? 380 meV. Nesta tese também são apresentados resultados inéditos obtidos pelo autor relacionados a efeito Hall quântico em grafeno crescido epitaxial mente sobre substratos de carbeto de silício, efeitos de desordem estrutural sobre as propriedades de transporte elétrico basal da grafite, supercondutividade em heteroestruturas de grafite e silício e supercondutividade em compósitos de antimônio-ouro
Abstract: In this thesis, experimental results obtained by the author during his PhD will be presented. The work consisted on the study of electrical and magnetic properties of Dirac semimetals and related heterostructures. Namely: graphite, graphene, graphite/silicon interfaces and antimony. Part of the work about graphite consisted on the study of the effects of structural disorder on the quantum oscillations in the material. Experimental results in the literature widely regard the mosaic spread in graphite as a good disorder parameter. However, in the present work, we report that the mosaicity of graphite samples does not correlate with their quantum oscillations¿ amplitude. Experiments have revealed a clear relation of surface roughness to the electronic mobility and the amplitude of the deHaas van Alphen effect in the material. The possibility that quantum oscillations in graphite are affected by the presence of sharp interfaces within its stacking structure is also discussed. We have also studied out-of-plane magnetoresistance properties in ultraquantum graphite. Experiments performed at magnetic fields B//c up to 60 T have shown the occurrence of positive c-axis magnetoresistance followed by a region of negative magnetoresistance (NMR). The NMR persists up to room temperature and has been explained in terms of the tunneling of electrons between zero-energy Landau levels of adjacent graphitic layers. The NMR is more evident in samples with low mosaicity, suggesting the positive c-axis magnetoresistance is induced by means of broadening of LL¿s by disorder. In addition, c-axis magnetoresistance measurements with magnetic fields perpendicular to c-axis (B?c) suggest that our samples undergo a 2D to 3D transition with the reduction of temperature. Based on our results, we estimate a value for the interplane hopping energy parameter ?1 < 7 meV. This value is at odds with the most accepted model for graphite, for which ?1 ? 380 meV. In this thesis, we also present unpublished results on the occurrence of quantum Hall effect in graphene grown epitaxially in silicon carbide substrates, on the effects of structural disorder in the basal electric properties of graphite
Doutorado
Física
Doutor em Ciências
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Minus, Marilyn Lillith. "The study of crystallization and interfacial morphology in polymer/carbon nanotube composites." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29773.
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Thesis (Ph.D)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009.Committee Chair: Kumar, Satish; Committee Member: Garmestani, Hamid; Committee Member: Graham, Samuel; Committee Member: Griffin, Anselm; Committee Member: Shofner, Meisha. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Gomes, Wyllerson Evaristo 1983. "Estudo da interface sólido/líquido aplicando a microbalança de cristal de quartzo com eletrodos funcionalizados." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276941.
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Orientador: David Mendez SoaresTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Neste trabalho, pesquisamos o uso de filmes autoorganizados sobre o eletrodo de ouro da microbalança de cristal de quartzo eletroquímica, EQCM. Focamos a pesquisa na interação física da superfície sólida funcionalizada com o meio líquido. Desenvolvemos uma metodologia para compreender a dinâmica de variação dos parâmetros medidos, pela EQCM durante um experimento (perturbação) em meio líquido. Introduzimos a representação bidimensional da variação da freqüência de ressonância e da resistência de ressonância do cristal de quartzo da EQCM, ?f e ?R respectivamente, durante uma perturbação, usando o tempo como parâmetro. A metodologia foi utilizada para soluções aquosas de sais, álcool, líquidos apolares como ciclohexano, n-hexano, soluções de sacarose. Mostramos que líquidos reais apresentam viscoelasticidade. Também testamos a perturbação causada pela aplicação de campo elétrico nas interfaces sólido/soluções iônicas em condições em que o eletrodo é polarizável. Mostramos a possibilidade de formação de nanoestruturas gasosas, nanobolhas. Estendemos a pesquisa para a superfície do ouro funcionalizado com filmes de tiol, S-layers (proteínas de membrana de bactéria), e adsorção de lipossomos zwiteriônicos. A interface sólido/líquido também foi estudada relativamente às características hidrofóbicas da funcionalidade devido à sua microestrutura superficial (superfície superhidrofóbica). Usamos as técnicas de microscopia de força atômica, AFM, e de Raman confocal, paralelamente às nossas pesquisas com a EQCM. Para complementar o estudo de campos elétricos aplicados a interfaces, estudamos também os efeitos macroscópicos da aplicação desses campos a líquidos dielétricos como a água. Pesquisamos o fenômeno da ponte líquida usando líquidos dielétricos isolantes apróticos
Abstract: In this work, we have studied the use of self-assembling films onto gold electrode of the electrochemical quartz crystal microbalance, EQCM. The main objective is to understand the physical interaction of the functionalized solid surface with the liquid medium. We have developed a methodology to understand the dynamics of variation of the parameters measured by the EQCM in liquid medium. We also have introduced the two-dimensional representation of the variation of resonance frequency and resonance resistance of the quartz crystal of the EQCM, ?f and ?R respectively. The measurements were taken during a perturbation, using time as parameter. The methodology was used for aqueous salt solutions, alcohol, nonpolar liquids such as cyclohexane, n-hexane and sucrose solutions. We showed that real liquids exhibit viscoelasticity. We also tested the perturbation caused by the application of electric field at solid interfaces/ionic solutions, under conditions in which the electrode is polarizable. We showed the possibility of formation of gaseous nanostructures, nanobubbles. We extended the study to gold electrode thiol-functionalized surfaces, gold surfaces covered by S-layers films (membrane proteins of bacteria), and then adsorption of zwitterionic liposomes. The solid/liquid interface was also studied in relation to hydrophobic functionality due to its surface microstructure (superhydrophobic surface). We use the atomic force microscopy, AFM, and confocal Raman techniques, parallel to our research with EQCM. In addition to the study of electric fields applied to interfaces, we also studied the macroscopic effects of the application of these fields to the dielectric liquids like water. We researched the phenomenon of liquid bridge using insulating dielectric aprotic liquids
Doutorado
Física
Doutor em Ciências
2010/140031-3
CNPQ
39
Kim, Young Shin. "Investigating Langmuir films at the air-water interface using a planar array infrared reflection-absorption spectrograph." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 127 p, 2008. http://proquest.umi.com/pqdweb?did=1601522541&sid=5&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Sills, Scott E. "Interfacial nanorheology : probing molecular mobility in mesoscopic polymeric systems /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/9832.
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Bhattacharya, Paromita. "A Case Study of the Effects of a Web Interface Redesign Based on Usability Guidelines." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1320.
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Usability guidelines for user interface (UI) design formulated by Nielsen and other authorities were used to redesign the web interface for a web based distance education course. The website's original UI, as judged by a group of web design professionals, violated standard guidelines for usability, readability, learnability, consistency, efficiency of use and flexibility. The original and redesigned UIs were tested using thinking aloud testing, a user satisfaction survey, and usability inspection. The results of user testing and heuristic evaluation suggest that the use of these guidelines in website redesign had a positive impact on user performance. A more conclusive result would have required a larger sample size and a redesigned testing protocol that varied the order in which participants worked with the old and redesigned interfaces.
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Price, Alan. "A Secure Behavior Modification Sensor System for Physical Activity Improvement." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cgu_etd/5.
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Today, advances in wireless sensor networks are making it possible to capture large amounts of information about a person and their interaction within their home environment. However, what is missing is how to ensure the security of the collected data and its use to alter human behavior for positive benefit.
In this research, exploration was conducted involving the "infrastructure" and "intelligence" aspects of a wireless sensor network through a Behavior Modification Sensor System. First was to understand how a secure wireless sensor network could be established through the symmetric distribution of keys (the securing of the infrastructure), and it involves the mathematical analysis of a novel key pre-distribution scheme. Second explores via field testing the "intelligence" level of the system. This was meant to support the generation of persuasive messages built from the integration of a person's physiological and living pattern data in persuading physical activity behavior change associated with daily walking steps. This system was used by an elderly female in a three-month study.
Findings regarding the "infrastructure" or the novel key pre-distribution scheme in comparison to three popular key distribution methods indicates that it offers greater network resiliency to security threats (i.e., 1/2^32 times lower), better memory utilization (i.e., 53.9% less), but higher energy consumption (i.e., 2% higher) than its comparison group.
Findings from the "intelligence" level of the research posit that using a person's physiological and living pattern data may allow for more "information rich" and stronger persuasive messages. Findings indicate that the study participant was able to change and improve her average daily walking steps by 61% over a pre-treatment period. As the study participant increased her physical activity, changes in her living pattern were also observed (e.g., time spent watching television decreased while time spent engaged in walking increased by an average of 15 minutes per day). Reinforcement of these findings were noted between a pre and post-study survey that indicated the study participant moved from a contemplation stage of change where physical activity engagement was intended but not acted upon to an action stage of change where physical activity engagement dominated the new behavior.
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Rhamdhani, Muhammad Akbar Brooks Geoffrey. "Reaction kinetics and dynamic interfacial phenomena in liquid metal-slag systems." *McMaster only, 2005.
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Gu, Xue Fan 1956. "Shear behaviour of sandstone-concrete joints and pile shafts in sandstone." Monash University, Dept. of Civil Engineering, 2001. http://arrow.monash.edu.au/hdl/1959.1/8856.
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Crozier, Paul S. "Slab-geometry molecular dynamics simulations : development and application to calculation of activity coefficients, interfacial electrochemistry, and ion channel transport /." Diss., CLICK HERE for online access:, 2001. http://contentdm.lib.byu.edu/ETD/image/etd15.pdf.
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Ryan, David B. "Improving Brain-Computer Interface Performance: Giving the P300 Speller Some Color." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1328.
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Individuals who suffer from severe motor disabilities face the possibility of the loss of speech. A Brain-Computer Interface (BCI) can provide a means for communication through non-muscular control. Current BCI systems use characters that flash from gray to white (GW), making adjacent character difficult to distinguish from the target. The current study implements two types of color stimulus (grey to color [GC] and color intensification [CI]) and I hypotheses that color stimuli will; (1) reduce distraction of nontargets (2) enhance target response (3) reduce eye strain. Online results (n=21) show that GC has increased information transfer rate over CI. Mean amplitude revealed that GC had earlier positive latency than GW and greater negative amplitude than CI, suggesting a faster perceptual process for GC. Offline performance of individual optimal channels revealed significant improvement over online standardized channels. Results suggest the importance of a color stimulus for enhanced response and ease of use.
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Wan, Peng. "Orientational structure of water molecules near the silica/water interface probed with second harmonic generation." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=117&did=1874088951&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270487476&clientId=48051.
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Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Includes bibliographical references (leaves 96-102). Issued in print and online. Available via ProQuest Digital Dissertations.
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Rykaczewski, Konrad. "Electron beam induced deposition (EBID) of carbon interface between carbon nanotube interconnect and metal electrode." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31773.
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Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2010.Committee Chair: Dr. Andrei G. Fedorov; Committee Member: Dr. Azad Naeemi; Committee Member: Dr. Suresh Sitaraman; Committee Member: Dr. Vladimir V. Tsukruk; Committee Member: Dr. Yogendra Joshi. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Moakes, Greg. "Study of Lithium Solvation Environments in Water-saturated Nitrobenzene." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14105.
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It was found that there exist three major water environments when water is dissolved in nitrobenzene. 2H NMR has proved that these solvatomers exist irrespective of whether lithium salt is added to the system. 7Li NMR experiments suggested that the first solvatomer is majority nitrobenzene, the second a mixed solvation shell consisting of nitrobenzene and water and the third solvatomer is a large water aggregated at the glass surface. The mixed solvation state is short lived and is promoted by addition of water of by supersaturating the system upon cooling. This is a high energy state and decays either into the homogenous bulk NB state or to the surface of the glass wall, depending on if glass surface is present. In the 7Li NMR experiments, the hydrophobicity of the salt, determined by the anion, affects the relative intensity of the three 7Li resonances.
Addition of lithium serves to promote hydrogen bonding in the majority nitrobenzene solvatomer, as confirmed by FTIR and neutron diffraction studies. There is no evidence that it has an effect on the size of the mixed solvatomer or the water aggregate immobilized on the glass surface. A reasonable hypothesis is that lithium exchanges between the water species which are formed independent of lithium involvement. The system is summarized as follows:
Below critical water concentration (~200mM) nitrobenzene/water is a homogeneous distribution of water molecules in nitrobenzene. Addition of lithium salt to such a system has two main affects. First, the lithium promotes hydrogen bonding between the dissolved water molecules, as confirmed by FTIR and neutron scattering. Second, the hydrogen bonded water may precipitate causing microheterogeneity of the system, leading to a second resonance observed in both the 2H and 7Li NMR spectra (LiNB/W). In the presence of glass, a third solvation state can nucleate at the glass surface; this solvation state has character even closer to that of bulk water (LiW). These two supplementary solvation states can be artificially induced by either adding aliquots of water or cooling.
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Malec, Christopher Evan. "Transport in graphene tunnel junctions." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41140.
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It has been predicted that gold, aluminum, and copper do not fundamentally change the graphene band structure when they are in close proximity to graphene, but merely increase the doping. My data confirms this prediction, as well as explores other consequences of the metal/graphene interface. First, I present a technique to fabricate thin oxide barriers between graphene and aluminum and copper to create tunnel junctions and directly probe graphene in close proximity to a metal. I map the differential conductance of the junctions versus tunnel probe and back gate voltage, and observe mesoscopic fluctuations in the conductance that are directly related to the graphene density of states. I develop a simple theory of tunneling into graphene to extract experimental numbers, such as the doping level of the graphene, and take into account the electrostatic gating of graphene by the tunneling probe. Next, results of measurements in magnetic fields will also be discussed, including evidence for incompressible states in the Quantum Hall regime wherein an electron is forced to tunnel between a localized state and an extended state that is connected to the lead. The physics of this system is similar to that encountered in Single Electron Transistors, and some work in this area will be reviewed. Finally, another possible method of understanding the interface between a metal and graphene through transport is presented. By depositing disconnected gold islands on graphene, I am able to measure resonances in the bias dependent differential resistance, that I connect to interactions between the graphene and gold islands.