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Dissertations / Theses on the topic 'Solid'
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1
Pradhan, Sulolit. "Solid state charge transfer in nanoparticle solids /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2008. http://uclibs.org/PID/11984.
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Harikrishna, Hari. "Nanoscale thermal transport through solid-solid and solid-liquid interfaces." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51160.
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This dissertation presents an experimental investigation of heat transport through solid- solid and solid-liquid interfaces. Heat transport is a process initiated by the presence of a thermal gradient. All interfaces offer resistance to heat flow in the form of temperature drop at the interface. In micro and nano scale devices, the contribution of this resistance often becomes comparable to, or greater than, the intrinsic thermal resistance offered by the device or structure itself. In this dissertation, I report the resistance offered by the interfaces in terms of interface thermal conductance, G, which is the inverse of Kapitza resistance and is quantified by the ratio of heat flux to the temperature drop. For studying thermal transport across interfaces, I adapted a non-contact optical measurement technique called Time-Domain Thermoreflectance (TDTR) that relies on the fact that the reflectivity of a metal has a small, but measurable, dependence on temperature.The first half of this dissertation is focused on investigating heat transport through thin films and solid-solid interfaces. The samples in this study are thin lead zirconate- titanate (PZT) piezoelectric films used in sensing applications and dielectric films such as SiOC:H used in semiconductor industry. My results on the PZT films indicate that the thermal conductivity of these films was proportional to the packing density of the elements within the films. I have also measured thermal conductivity of dielectric films in different elemental compositions. I also examined thermal conductivity of dielectric films for a variety of different elemental compositions of Si, O, C, and H, and varying degrees of porosity. My measurements showed that the composition and porosity of the films played an important role in determining the thermal conductivity.
The second half of this dissertation is focused on investigating heat transport through solid-liquid interfaces. In this regard, I functionalize uniformly coated gold surfaces with a variety of self-assembled monolayers (SAMs). Heat flows from the gold surface to the sulfur molecule, then through the hydrocarbon chain in the SAM, into the terminal group of the SAM and finally into the liquid. My results showed that by changing the terminal group in a SAM from hydrophobic to hydrophilic, G increased by a factor of three in water. By changing the number of carbon atoms in the SAM, I also report that the chain length does not present a significant thermal resistance. My results also revealed evidence of linear relationship between work of adhesion and interface thermal conductance from experiments with several SAMs on water. By examining a variety of SAM-liquid combination, I find that this linear dependency does not hold as a unified hypothesis. From these experiments, I speculate that heat transport in solid-liquid systems is controlled by a combination of work of adhesion and vibrational coupling between the omega-group in the SAM and the liquid.
Ph. D.
3
Lee, Jongho. "Solid modeling using implicit solid elements." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001254.
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Rice, Christopher S. (Christopher Scott). "Solid freeform fabrication using semi-solid processing." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/32166.
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Zhong, Xiaoguang Knowles James K. Knowles James K. "Continuum dynamics of solid-solid phase transitions /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10222007-135103.
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Quemin, Elisa. "Exploring solid-solid interfaces in Li6PS5Cl-based cathode composites for all solid state batteries." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS501.
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Les technologies de stockage énergétiques jouent un rôle crucial en accommodant le caractère intermittent des énergies renouvelable. Actuellement, les batteries lithium-ion prédominent le marché des appareils portables. Cependant, pour les véhicules électriques, des avancées sont nécessaires en termes de sécurité et de densité énergétique, conduisant à l'exploration de nouvelles technologies de batterie, notamment les batteries tout-solide. Cette thèse se concentre sur les obstacles entravant l'application pratique de ces batteries tout-solide, en mettant particulièrement en lumière le rôle des composites cathodes. L'attention s'est portée sur un composite couramment utilisé, composé de Li6PS5Cl comme électrolyte solide (SE) associé à un matériau actif de type NMC. Les mécanismes de dégradation se révèlent être influencés par deux interfaces : SE/additif carbone et SE/AM (matériau actif). Le cyclage en dessous de 3,6 V par rapport au Li-In/In montrent que la dégradation prédominante provient de l'interface SE/additif carbone, tandis qu'à 3,9 V, l'interface SE/AM devient le principal foyer de dégradation. A partir de là, l'effet des additifs de carbone dans le composite a été minutieusement étudié. Ainsi, une concentration de plus de 2 % en poids de VGCF a un impact négatif sur la conduction ionique des composites. De plus, une analyse in situ de la conductivité électronique des composites sans carbone révèle des changements induits par l'insertion/désinsertion du lithium dans le transport électronique, avec une réduction de la conductivité électronique à états de charge élevés, en particulier dans les NMC riches en nickel. Globalement, les résultats indiquent qu'une faible quantité d'additif carbone peut avoir des avantages significatifs, à condition que les réactions chimiques soient maitrisées. Ainsi, des stratégies minimisant les pertes de capacité à long terme ont été explorées, en examinant des paramètres tels que la pression d'assemblage, le loading, les cycles de formation, la température et les coating carbonate. En fusionnant les conditions optimales, un composite de cathode optimisé est présenté, ouvrant la voie à des avancées prometteuses dans la technologie des batteries tout-solideWhile Lithium-ion batteries dominate portable devices, growing safety and energy density demands in electric vehicle batteries have led to the exploration of "beyond Li-ion" technology. All-Solid-State Batteries (ASSBs) have emerged as a promising alternative to Li-ion batteries. Thus, this doctoral research focuses on overcoming challenges hindering the practical implementation of ASSBs, with a specific emphasis on cathode composites. The investigation revolves around a common composite comprising Li6PS5Cl solid electrolyte (SE) and NMC active material (AM). The research unveils the degradation mechanisms within ASSBs, governed by SE/Carbon additive and SE/AM interfaces. It is observed that capacity deterioration, occurring below 3.6 V vs. Li-In/In, is primarily attributed to SE/Carbon interfaces. Conversely, elevating the voltage to 3.9 V shifts the primary degradation source to SE/AM interfaces. Then, the adverse effects of carbon additives on the ionic conduction of composites are demonstrated, particularly when exceeding 2 wt. % VGCF. Moreover, the study delves into the electronic conductivity of carbon-free composites using innovative in situ monitoring. This reveals Li-induced alterations hindering electronic conductivity, especially at high charge levels, notably in high Ni-content NMC. Furthermore, the influence of particle size and morphology on electronic percolation is extensively examined, advocating for minimal VGCF to enhance kinetics and stability. Strategies for effectively incorporating carbon additives while mitigating long-term capacity loss are explored, encompassing assembly pressure, loading, formation cycles, temperature, and carbonate coating. By mixing these optimal conditions, an enhanced cathode composite is introduced, holding promising potential for the progression of All-Solid-State Battery technology
7
Tian, Jian Atwood J. L. "Molecular organic solids for gas adsorption and solid-gas interaction." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6882.
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Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 24, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Jerry L. Atwood. Vita. Includes bibliographical references.
8
Collins, Kimberlee C. (Kimberlee Chiyoko). "Experimental investigations of solid-solid thermal interface conductance." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61600.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 70-84).
Understanding thermal interface conductance is important for nanoscale systems where interfaces can play a critical role in heat transport. In this thesis, pump and probe transient thermoreflectance methods are used to measure the thermal interface conductance between solid materials. Two experimental studies of thermal interface conductance are presented, each revealing the complexity of phonon interactions at interfaces which are inadequately captured by current models of phonon transmissivity. The first study considers interfaces of different metals with graphite, and finds that atomic-scale roughness at the interface could be appreciably influencing the heat transport due to the extreme anisotropy of graphite. The thermal interface conductance of graphite is found to be similar to that of diamond, suggesting that when estimating the thermal interface conductance between metal and multi-walled carbon nanotubes (MWCNTs), a reasonable assumption may be that the conductance with the side walls of the MWCNTs is similar to the conductance with the ends of the MWCNTs. The second study considered aluminum on diamond interfaces where the diamond samples were functionalized to have different chemical surface terminations. The surface termination of the diamond is found to significantly influence the heat flow, with oxygenated diamond, which is hydrophilic, exhibiting four times higher thermal interface conductance than hydrogen-treated diamond, which is hydrophobic. Microstructure analysis determined that the Al film formed similarly, independent of diamond surface termination, suggesting that differences in interface bonding likely caused the observed difference in thermal interface conductance, a phenomenon which is not captured in current models of solid-solid phonon transmissivity.
by Kimberlee Chiyoko Collins.
S.M.
9
Marander, Sanna. "solid objects." Thesis, Konstfack, Institutionen för Konst (K), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-3615.
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solid objects is a collection of objects and its cultural life, where the roles of the object, artist, collector, museum, writer, publisher and curator are suspended to reemerge in other possible forms. In this work the text becomes an object, the pocket a museum, the collection a persona, the artist its curator, the writer a sign.
10
Azrak, Edy Edward. "Croissance et caractérisation des Nanofils GeSn et SiSn obtenue par le mécanisme Solide-liquide-Solide." Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR135/document.
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L’alliage germanium-étain est un semiconducteur qui suscite une grande attention en raison de ses propriétés électriques et optiques. L’incorporation de Sn dans le germanium permet d’ajuster la largeur de bande interdite (gap) et d’améliorer la mobilité des électrons et des trous, et pour une quantité suffisante d’étain, le matériau passe d’un gap indirect à direct. Cet alliage est versatile parce qu’il peut être intégré d’une façon monolithique sur le Si, c’est ce qui en fait un matériau idéal dans les domaines de l'optoélectronique à base de silicium. Cette thèse est sur la fabrication et la caractérisation de nanofils cristallins Ge1-xSnx à haute concentration en Sn. Des nouvelles stratégies ont été employées pour fabriquer de nombreux types de nanofils GeSn. Les résultats ont été expliqués en fonction des modèles cinétiques existants. Un nouveau mécanisme de croissance y est décrit: le mécanisme solide-solide-solide – SSS. Il consiste à faire croître des nanofils de GeSn dans le plan du substrat à l’aide de catalyseurs d’étain à une température inférieure au point de fusion de Sn. Quatre modèles de transport de masse sont proposés pour le mécanisme de croissance du SSS. Diverses caractérisations (par exemple TEM et APT) ont été effectuées pour étudier les propriétés physiques, et chimiques des nanofilsGermanium-Tin alloy is a unique class semiconductor gaining a strong attention because of its significant electrical and optical properties. Sn incorporation in Ge allows straightforward band-gap engineering enabling to enhance the electron and hole mobilities, and for a sufficient Sn amount an indirect-to-direct band-gap transition occurs. Its versatility rises due the possible monolithic integration on Si-platforms making it an ideal material in domains of optoelectronics, and high speed electronic devices. This thesis has focused on the fabrication and characterization of crystalline Ge1-xSnx nanowires with high Sn concentrations. New strategies were designed to fabricate many types of GeSn nanowires. The results have been explained as function of the existing kinetic models. A new growth mechanism was reported (i.e. Solid-Solid-Solid mechanism – SSS), it consists of growing in-plane GeSn nanowires using Sn catalysts below the melting point of Sn. Four mass transport models were proposed for the SSS growth mechanism. Various characterizations (e.g. TEM and APT) were done to investigate the physical and chemical properties of the obtained nanowires
11
Bauer, Rico [Verfasser]. "Solid-solid phase transformation kinetics / vorgelegt von Rico Bauer." Stuttgart : Max-Planck-Inst. für Metallforschung, 2010. http://d-nb.info/100971175X/34.
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Chien, Chang-Yin. "Methane and Solid Carbon Based Solid Oxide Fuel Cells." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1299670407.
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Bockhold, Steven. "Copper (I) coordination networks synthesized with solid-solid reactions." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5612.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2008.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 June 2, 2009). Vita. Includes bibliographical references.
14
Wang, Fuming M. "XAFS study of solid-solid transitions under high pressure /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9655.
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Heidarian, Höckerfelt Mina. "On the chemical and processing stability of pharmaceutical solids : Solid form dependent water presenting capacity and process induced solid form transformation." Doctoral thesis, Uppsala universitet, Institutionen för farmaci, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-261785.
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There is a need for improving our knowledge and understanding about formation mechanisms and nature of amorphous state in order to prevent the unintended presence of disorder in solid pharmaceutical products and reduce the related stability issues. The suggested theory that water binding capacity of amorphous cellulose affects the chemical stability of hydrolysis sensitive drugs in formulations with cellulose based excipients needs a clarification and water-cellulose interaction profiles need to be examined. This thesis has addressed these questions. Chemical, mechanical and thermal methods have been used to create partially or predominantly amorphous solids. Mechanisms and the pathways for transformation to amorphous phase and the characteristic qualities of this phase is studied in order to give some tools to predict, to control or prevent the creation of disorder in a crystalline structure. The water interaction with amorphous pharmaceutical materials has been studied to improve stability of hydrolysis sensitive drugs. The transition to amorphous state during handling of pharmaceutical material, referred to as mechanical activation in processes like blending, mixing and compression is substantially a consequence of vitrification. The process is described as creation of hot spots where friction caused by particle sliding raise the temperature above the melting point of the material. The fast cooling process promotes creation of a local disordered molecular arrangement. It is possible to decrease the degree of amorphisation and undesired stability problems by reducing the friction and inhibit the creation of crystal defects during processing. The glass-forming propensity is an inherent material characteristic related to molecular size and structure and is not process dependent. Molecules with a couple of aromatic rings are often poor glass-formers. Less symmetrical, branched molecular structures with presence of electronegative atoms are more readily transformed to and exist in amorphous state when handled and stored at temperatures below their glass transition temperature. The interaction profile of cellulose with water is strongly dependent on solid state structure of cellulose. Crystallinity is the key parameter in water presenting capacity of cellulose. Amorphous regions have a capacity to bind the water and decrease water mobility and in that way reduce cellulose water presenting capacity despite higher moisture content in partially amorphous cellulose compared to crystalline cellulose. The fact that higher amorphous content decreases cellulose water presenting capacity is a promising lead to improve stability of hydrolysis sensitive drugs in compositions with cellulose. This knowledge could be applicable to other pharmaceutical materials as the differences between crystalline and amorphous states of material are generally the same for different kind of materials.
16
Koç, Tuncay. "In search of the best solid electrolyte-layered oxide pair in all-solid-state batteries." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS535.
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Les batteries à l'état solide (ASSB) qui reposent sur l'utilisation d'électrolytes solides (SE) à conductivité ionique élevée sont le Saint-Graal de la future technologie des batteries, car elles pourraient théoriquement permettre une augmentation de près de 70 et 40 % des densités d'énergie volumétrique (Wh/l) et gravimétrique (Wh/kg), respectivement, ainsi qu'une sécurité accrue par rapport à la technologie des batteries au lithium-ion. À cette fin, la dernière décennie a vu le développement des ASSB, principalement grâce à des SE à base de sulfure, en raison de leurs propriétés intrinsèques favorables. Toutefois, ces progrès n'ont pas permis de mettre au point des ASSB pratiques et performants en raison des réactions complexes de décomposition interfaciale qui se produisent aux électrodes négative et positive et qui entraînent une détérioration de la durée de vie des cycles. En se concentrant sur l'électrode positive, cela nécessite une meilleure compréhension de la compatibilité électrochimique/chimique des SE qui est cruellement nécessaire pour les applications du monde réel.Ce travail vise à fournir des réponses concernant la meilleure paire d'oxyde en couche SE dans la cathode composite pour les ASSB. En menant une étude systématique sur l'effet de la nature des SE sur les performances des batteries, nous montrons que les performances de Li6PS5Cl rivalisent avec celles de Li3InCl6, surpassant toutes deux celles de β-Li3PS4 et ce, indépendamment de la voie de synthèse. Ces performances sont préservées lors de l'assemblage de piles à l'état solide, puisque l'appariement de Li6PS5Cl avec une cathode en oxyde stratifié présente la meilleure rétention en cas de cyclage. Cette étude révèle également que les halogénures réagissent avec les sulfures dans les cellules hétérostructurées, ce qui entraîne une diminution rapide de la capacité en cas de cyclage en raison de réactions de décomposition interfaciales. Pour éliminer ce processus de dégradation interfaciale, nous proposons une stratégie d'ingénierie de surface qui permet d'atténuer la détérioration de la surface et de débloquer des ASSB très performants. Enfin, l'analyse électrochimique, structurelle et spectroscopique combinée démontre que Li3InCl6 ne peut pas résister à des potentiels d'oxydation plus élevés, ce qui entraîne des produits de décomposition contrairement à ce que les calculs théoriques prévoyaientAll-solid-state batteries (ASSBs) that rely on the use of solid electrolytes (SEs) with high ionic conductivity are the holy grail for future battery technology, since it could theoretically enable achieving nearly 70 and 40 % increase in volumetric (Wh/l) and gravimetric (Wh/kg) energy densities, respectively, as well as enhanced safety compared to lithium-ion battery technology. To this end, the last decade has witnessed the development of ASSBs mainly through sulfide-based SEs pertaining to their favorable intrinsic properties. However, such advancements were not straightforward to unlock high-performing practical ASSBs because of complex interfacial decomposition reactions taking place at both negative and positive electrodes, leading to a worsening cycling life. Focusing on the positive electrode, this calls for a better understanding of electrochemical/chemical compatibility of SEs that is sorely needed for real-world applications.This work aims to provide answers regarding the best SE-layered oxide pair in composite cathode for ASSBs. By conducting a systematic study on the effect of nature of SEs in battery performances, we show that Li6PS5Cl performances rival that of Li3InCl6, both outperforming β-Li3PS4 and this, independently of the synthesis route. This is preserved when assembling solid-state cells since Li6PS5Cl pairing with layered oxide cathode shows the best retention upon cycling. This study also unravels that halides react with sulfides in hetero-structured cell design, hence resulting in a rapid capacity decay upon cycling stemming from interfacial decomposition reactions. To eliminate such interfacial degradation process, we suggest a surface engineering strategy that helps to alleviate the surface deterioration, unlocking highly performing ASSBs. Eventually, combined electrochemical, structural and spectroscopic analysis demonstrate that Li3InCl6 cannot withstand at higher oxidation potentials, resulting in decomposition products in contrast to what the theoretical calculations predicted
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Knox, David Andrew. "High resolution gas phase spectroscopy at solid/solid interfacial regions." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/high-resolution-gas-phase-spectroscopy-at-solid--solid-interfacial-regions(b5dfd0d0-7c6a-4b50-ad78-39c10c33b3ac).html.
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Understanding the behaviour of polymers which are located in the presence of nuclear materials is important in order to predict the lifespan of the materials. Artificial ageing experiments are undertaken at elevated temperatures to infer how the materials may age. This study was concerned with the monitoring of trace gases (H2O, CO2, CO and acetic acid) within a materials ageing vessel which contained ethylene-vinyl acetate (EVA) polymer and uranium in order to deduce the rate of polymer degradation and/or uptake of the gases by uranium. A novel circular multi-reflective (CMR) cell was designed, developed and deployed in situ in order to extend the optical pathlength within the vessel to improve detection limits of the trace gases. One cell was located at the 6 millimetre solid/solid interfacial region between cylindrical coupons of the EVA polymer and uranium, to enable representative sampling in proximity to where the gases were evolved, adsorbed or reacted. The unique planar star-like beam profile of the CMR cell was crucial in enabling detection within this narrow interfacial region. A second CMR cell was incorporated within the vessel headspace, above the two material coupons, to address a specific research problem which aimed to ascertain whether differences in the gaseous composition existed between the two regions, which would indicate poor gas mixing. Two spectroscopic techniques were employed in conjunction with the CMR cells to monitor the trace gases: these comprised broadband absorption spectroscopy (BBAS) and tunable diode laser absorption spectroscopy (TDLAS). Near-infrared (IR) radiation sources, in the form of diode lasers, a superluminescent light emitting diode (SLED) and supercontinuum (SC) source were utilised in BBAS experiments. TDLAS was used for the detection of CO2, CO and H2O, whilst BBAS was used for the detection of acetic acid, and other potential unknown species. The requirement for using near-IR radiation was a consequence of using flexible silica-based optical fibres to remotely monitor the vessel which was located within a temperature controlled chamber. As a result, this was the first demonstration of CMR cells being used in conjunction with near-IR radiation sources. An optical pathlength of 69 cm was achieved within the materials ageing vessel, which led to the following limits of detection at 75 °C, 150 Torr with a 10 second averaging time: H2O = 3 ppm; acetic acid = 157 ppm; CO2 = 596 ppm and CO = 37500 ppm. Manufacturing issues with the cell optics, coupled with monitoring weak ro-vibrational absorption features led to considerably higher limits of detection than expected. The CMR spectroscopic system was used successfully to observe the outgassing trend of partially cured EVA polymer, which was shown to depend on cure time. A key finding of this research, however, was the observation of a difference between the interfacial gaseous composition versus the headspace gas in a system that contained both a source and sink material (i.e. one that evolved, and one that adsorbed gases). This was only made possible by using the CMR spectroscopic system. This observation was also supported by a computational fluid dynamic (CFD) model.
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Mackin, Gail S. "On an Order-Parameter Model of Solid-Solid Phase Transitions." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30676.
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We examine a model of solid-solid phase transitions that includes
thermo-elastic effects and an order parameter. The model is derived
as a special case of the Gurtin-Fried model posed in one space
dimension with a symmetric triple-well free energy in which the
relative heights of the wells vary with temperature. We examine the
temperature independent case, showing existence of a unique classical
solution of a regularized system of partial differential equations
using semigroup theory. This is followed by numerical study of a
finite element algorithm for the temperature independent model.
Finally, we present computational material concerning the
temperature dependent model.Ph. D.
19
Pecorari, Claudio Vinicio. "Scattering of ultrasonic waves from rough imperfect solid-solid interfaces /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487779120908438.
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Silva, Ellen Mae. "A gas-solid spouted bed bioreactor for solid state fermentation /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487945320759412.
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Ghosh, Supriyo. "Effects of solid-solid boundary anisotropy on directional solidification microstructures." Palaiseau, Ecole polytechnique, 2015. http://www.theses.fr/2015EPXX0043.
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Vitorica, Inigo. "Solid state supramolecular chemistry : gas-solid reactions and intermolecular interactions." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/3926/.
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Hama, Tetsuya. "Photodissociation dynamics of amorphous solid water and amorphous solid methanol." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120883.
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廖家敏 and Ka-man Liu. "Kitchen solid waste." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41549430.
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Денисова, Людмила Анатоліївна, Людмила Анатольевна Денисова, Liudmyla Anatoliivna Denysova, and Y. V. Miroshnichenko. "Municipal solid waste." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/13478.
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People produce a large variety of waste during their life. The sharp rise in consumption has led to an increase of solid waste throughout the world.
Mankind produces 450-500 million tons of municipal solid waste every year. In the developed countries there is from 1 to 3 kg of household waste per capita per day.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/13478
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Liu, Ka-man. "Kitchen solid waste." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41549430.
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Fontana, Christian. "Solid State Transformer." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3424940.
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The Solid State Transformer (SST) is an emerging solution that can advantageously substitute the conventional transformer, thanks to its capabilities. Furthermore, it is a multi-functional equipment that offers:
- conditioning of the power flow, whether of DC or AC form;
- reduced size and weight thanks to the high frequency transformer;
- good voltage regulating capabilities;
- no diffusion of voltage swell or sag thanks to the DC link (if any);
- power factor correction;
- fast fault detection and protection;
- capability to maintain the output feed for a time (hold up time) thanks to the DC link capacitors;
Moreover, it offers the conventional transformer properties:
- galvanic isolation between input and output;
- step up/down of the input voltage;
The SST capabilities make this technology an important solution to solve the current and future issues of the grid. The reduced weight and size allow getting high performances in the traction systems. The bidirectional power flow capabilities allow the connection and management of renewable energy sources (RES) with the grid and different loads, connected to AC side or, if present, to DC link.Il trasformatore a stato solido (SST) è un emergente tecnologia che può sostituire i trasformatori convenzionali, apportando notevoli vantaggi grazie alle sue potenzialità e funzionalità. Tra le più importanti abbiamo: -condizionamento del flusso di potenza, sia DC che in AC; -ridotte dimensioni e peso, grazie all'uso di un trasformatore in alta frequenza; -ottima regolazione della tensione; -limita diffusione di buchi di tensione; -correzione del fattore di potenza; -hold up time funzionalità; -isolamento galvanico. Grazie a queste funzionalità questa tecnologia diventa molto importante per poter affrontare problemi, presenti e futuri, legati alla gestione della rete elettrica. La possibilità di gestire il flusso di energia e la bidirezionalità del flusso di potenza consentono di facilitare l'integrazione delle risorse rinnovabili con la rete elettrica. Inoltre, la riduzione dipeso e dimensioni consentono di ottenere alte performance in sistemi usati per la trazione.
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Mukherjee, Manas. "Bubble Solid Interaction." Thesis, Indian Institute of Science, 2004. https://etd.iisc.ac.in/handle/2005/78.
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The interaction of a bubble with solid surfaces, hydrophobic and hydrophilic, was investigated. When a bubble approaches towards a solid surface, a thin liquid film forms between them. The liquid in the film drains until an instability forms and film ruptures resulting in a three phase contact (TPC). Following rupture, the TPC line spreads on the solid surface. In the present study, glycerol-water solutions with varying percentages of water were used to investigate the effect of viscosity. Experiments were carried out with varying bubble size. The rupture and TPC line movement were recorded by high-speed digital video camera. The dependence of the TPC line movement on different parameters was investigated. The experimental results were compared with the existing theories for the TPC line movement. An empirical equation was developed to predict the TPC line movement. Formation or rupturing of the intervening film in case of a hydrophilic surfaces, which were glass surface cleaned by six cleaning techniques, was investigated. It was shown that a stable film forms for acid or alkali cleaning.
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Mukherjee, Manas. "Bubble Solid Interaction." Thesis, Indian Institute of Science, 2004. http://hdl.handle.net/2005/78.
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The interaction of a bubble with solid surfaces, hydrophobic and hydrophilic, was investigated. When a bubble approaches towards a solid surface, a thin liquid film forms between them. The liquid in the film drains until an instability forms and film ruptures resulting in a three phase contact (TPC). Following rupture, the TPC line spreads on the solid surface. In the present study, glycerol-water solutions with varying percentages of water were used to investigate the effect of viscosity. Experiments were carried out with varying bubble size. The rupture and TPC line movement were recorded by high-speed digital video camera. The dependence of the TPC line movement on different parameters was investigated. The experimental results were compared with the existing theories for the TPC line movement. An empirical equation was developed to predict the TPC line movement. Formation or rupturing of the intervening film in case of a hydrophilic surfaces, which were glass surface cleaned by six cleaning techniques, was investigated. It was shown that a stable film forms for acid or alkali cleaning.
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Valkov, Boris Ivanov. "A blurred interface formulation of The Reference Map Technique for Fluid-Solid Interactions and Fluid-Solid-Solid Interactions." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92123.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 143-144).
In this work we present a blurred interface method for Fluid-Solid Interactions (FSI) and multiple solids immersed in a fluid or FSSI (Fluid-Solid-Solid Interactions) based on the reference map technique as presented by Kamrin and Rycroft. I will follow the chain of thought which lead from the initial sharp interface technique to the newer blurred interface one. We will present its capabilities of doing fully-coupled simulations of a compressible Navier-Stokes fluid and highly non-linear solid undergoing large deformations all performed on a single Eulerian grid with no Lagrangian particles whatsoever. The Reference Map Technique (RMT) provides an Eulerian simulation framework allowing to compute fully coupled fluid/soft-solid interactions. However, due to the extrapolations inherent to the Ghost Fluid Method (GFM) for fluid/fluid interactions, on which the RMT is based, numerical artifacts get created in the resulting pressure and velocity fields whenever the levelset defining the interface crosses a gridpoint from the fixed cartesian grid utilized in this method. We will therefore follow the creation and propagation of these artifacts as well as analyze how the blurred technique solves or avoids these problems.
by Boris Ivanov Valkov.
S.M.
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Mitchell, Martin R. "Investigation of structure and disorder in inorganic solids using solid-state NMR." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3367.
Full textAbstract:
The use of solid-state NMR and DFT calculations to study Y₂Sn[subscript(x)]Ti[subscript(2-x)]O₇, Y₂Sn[subscript(x)]Zr[subscript(2-x)]O₇ and Y₂Ti[subscript(x)]Zr[subscript(2-x)]O₇, materials with applications for the safe encapsulation of radioactive actinides is investigated. As a result of cation or anion disorder in these materials, NMR spectra are often complex and difficult to interpret. Therefore, an investigation using a range of NMR active nuclei and measurement of a variety of NMR parameters (isotropic chemical shift, δ[subscript(iso)]; span, Ω and quadrupolar coupling, C[subscript(Q)]) were used to provide a full and detailed picture of each material. The measurement of Ω in these disordered compounds with multiple resonances in the NMR spectra, required the use of 2D CSA-amplified PASS (CAPASS) experiments to enable the separation of each of the spinning sideband manifolds. An experimental assessment of the CAPASS experiment showed that although low ν₁/Ω[subscript(Hz)] ratios (as found in ⁸⁹Y NMR) resulted in distortions in the spectra obtained, a modified fitting procedure could be utilised to compensate for this fact, which allowed the accurate measurement of Ω. Despite the difficulties in acquiring the ⁸⁹Y NMR spectra, they were found to be the most informative of the NMR-active nuclei available. ¹¹⁹Sn NMR spectra, although much easier to acquire than ⁸⁹Y, were more complex and harder to analyse, owing to the overlapping resonances. Therefore, ¹¹⁹Sn NMR could only be used to confirm or support the results obtained using ⁸⁹Y NMR. Although ¹⁷O NMR was found to be useful, a full study could not be implemented due to the lack of ¹⁷O enriched samples; an area where future investigation may prove fruitful. Finally, [superscript(47/49)]Ti and ⁹¹Zr NMR spectra were found to be the most difficult to acquire due to their low receptivities and the quadrupolar broadened lineshapes, and as a result, little additional information was obtained. As a result of this analysis, for the Y₂Sn[subscript(x)]Ti[subscript(2-x)]O₇ pyrochlore solid solution, using primarily ⁸⁹Y δ[subscript(iso)] and Ω, and additionally confirmed with ¹¹⁹Sn δ[subscript(iso)], it was found that the Sn and Ti cations were randomly ordered throughout the B-sites. Additionally, ⁸⁹Y Ω could be used to obtain approximate Y-O[subscript(48f)] and Y-O[subscript(8b)] bond lengths for each type of Y environment. The study of Y₂Sn[subscript(x)]Zr[subscript(2-x)]O₇ using ⁸⁹Y NMR showed that although the end members were single phase, pyrochlore (Y₂Sn₂O₇) or defect fluorite (Y₂Zr₂O₇), the intermediate compositions were mostly two phase mixtures, consisting of an ordered pyrochlore (with an average formula of Y₂Sn₁.₈Zr₀.₂O₇) and a disordered phase, where the proportions of the pyrochlore and disordered phases decreased and increased, respectively, with the Zr content. Additionally, although the coordination states of the Y and Sn cations were easily determined using ⁸⁹Y and ¹¹⁹Sn NMR, respectively, the coordination states of the Zr cations could not be confirmed directly by ⁹¹Zr NMR. However, using indirect analysis from results obtained with ⁸⁹Y and ¹¹⁹Sn NMR, it was determined that 6 coordinate Zr was present in each composition, and it was always present in a greater proportion than 8 coordinate Zr. Finally, although ⁸⁹Y NMR spectra of Y₂Ti[subscript(x)]Zr[subscript(2-x)]O₇ were extremely difficult to analyse, it was tentatively proposed that they could be similar to Y₂Sn[subscript(x)]Zr[subscript(2-x)]O₇ due to some similarities observed between the spectra.
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Cockroft, Nigel J. "Solid state spectroscopy : laser selective excitation of erbium ions in crystalline solids." Thesis, University of Canterbury. Physics, 1987. http://hdl.handle.net/10092/8056.
Full textAbstract:
Optical absorption and laser selective excitation (l.s.e.) spectroscopy have been used to study Er³⁺ ions in the CsCdBr₃ and hydrogenated CaF₂ and SrF₂ crystalline lattices. Sixteen hydrogenic charge compensation sites for both the H- and D- isotopes were found in CaF₂:0.05%Er³⁺, and nine new D- ion sites in SrF₂ :0.05%Er3³⁺. The relative occurrence of these sites can be controlled by variation of the duration of hydrogenation. For SrF₂:Er³⁺, this results in a change of the principal D- ion charge compensation arrangement. Classification of local-mode vibronic fluorescence transitions and consideration of isotope shifts of electronic transitions enabled the assignment of model configurations to several sites. Most hydrogenic sites were classified into one of two distinct families. A new effect, reversible polarised bleaching was observed, whereby hydrogenic ion migration in Er³⁺ ion site configurations can be controlled by l.s.e. with polarised light in oriented crystals. One hydrogenic site was found to consist of two photo-induced interconvertible components. Five new fluoride ion sites in CaF₂:Er³⁺ and nine in SrF₂:Er³⁺ were also determined. For <100> and <111> oriented crystals, the fluorescence spectra of several sites exhibited well defined polarisation which may be used to determine the Er³⁺ ion symmetry. Trigonal symmetry of the F- B site of CaF₂:Er³⁺ was confirmed by this means. Crystal field analysis of tetragonal and trigonal symmetry sites is also reported. An infra-red study revealed local mode lines of seven new sites in hydrogenated CaF₂:Er³⁺ and enabled correlation of some sites to those observed in the optical spectra. Reduction of Er³⁺ ions by the short range beta decay of tritium in the lattice was identified by local mode absorption. Erbium ions in CsCdBr₃ exhibited efficient upconverted fluorescence consistent with the formation of a dominant dimer site. Detailed spectroscopy resulted in the assignment of energy levels from twelve groups of transitions. Several of these transitions, studied by absorption and l.s.e., were found to consist of two components.
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Mujaji, Marjorie. "Solid state spectroscopy : laser selective excitation of holmium ions in crystalline solids." Thesis, University of Canterbury. Physics, 1992. http://hdl.handle.net/10092/8145.
Full textAbstract:
The technique of laser selective excitation has been used to study the spectra of 23 Ho³⁺centres present in CaF₂ and SrF₂ crystals, in mixed Ca₀.₉₉Sr₀.₀₁F₂ and Ca₀.₉₉Ba₀.₀₁F₂ crystals and in CsCdBr₃ crystals.
The polarisation of the fluorescence from < 100> and < 111> oriented crystals has been used to assign specific Ho³⁺ site symmetries to the various centres and to label the crystal-field energy levels of each centre by their group irreps.
The two principal Ho³⁺ centres (A and B) observed in both CaF2:Ho³⁺and SrF2:Ho³⁺ crystals have been shown to be of C₄ᵥ and C₃ᵥ symmetry respectively. The four new centres identified in Ca₀.₉₉Sr₀.₀₁F₂:Ho3³⁺ and Ca₀.₉₉Ba₀.₀₁F₂:Ho³⁺ crystals, are derived from the parent CaF₂ C₄ᵥ symmetry (A) centre by an on-axis and an off-axis placement of a dopant cation, Sr²⁺+ or Ba²⁺, in the vicinity of the Ho³⁺ - F- pair. The three additional centres found in SrF₂:Ho³⁺ crystals are from similar Ca²⁺and Ba²⁺ substitutions in the SrF₂ lattice.
Seven centres associated with n- charge compensation were observed in deuterated CaF₂:Ho³⁺ and SrF₂:Ho³⁺ crystals, with no C₄ᵥ symmetry centre being apparent.
For the CsCdBr3:Ho³⁺ system, spectra of the principal dimer centre and three other minority centres are reported. Strong upconversion fluorescence was observed for the principal dimer centre, enabling crystal-field energy levels for 18 Ho³⁺ multiplets to be determined. Low symmetry crystal-field splittings and pair splittings were observed on some of the sharper transitions.
Crystal-field analyses performed for all the C₄ᵥ and C₃ᵥ symmetry centres in CaF2:Ho³⁺, SrF2:Ho³⁺ and CsCdBr3:Ho³⁺ crystals are reported and the resulting crystal-field parameters discussed. Fluorescence lifetimes determined for the major Ho³⁺ centres are also presented.
The high resolution and ODNMR results for the C₄ᵥ symmetry A and SB1 centres in SrF2:Ho³⁺ crystals confirm the centre symmetry assignments and the model configurations proposed on the basis of the polarisation ratio measurements. The superhyperfine ODNMR frequencies correlate well with the changes in the crystal-field parameters between the two centres.
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Zatari, Taha Mohammed. "High solids anaerobic digestion of the putrescible fraction of municipal solid waste." Thesis, University of Newcastle Upon Tyne, 1996. http://hdl.handle.net/10443/389.
Full textAbstract:
Anaerobic digestion is increasingly becoming essential for treating the organic fraction of municipal solid waste (MSW) according to the growing 'energy from waste' recycle concept. Over the last decade, efforts have been made to control the anaerobic digestion of the putrescible fraction of municipal solid waste in engineered reactors, rather than continuing with 'free' digestion in landfill sites. This way of increasing treatment efficiency can be achieved with significantly reduced retention time (days rather than years) and enables the recovery of valuable energy from waste without biogas emissions into the atmosphere, which cause adverse greenhouse effects. Three basic approaches have been explored for the anaerobic treatment of MSW: (a) conventional 'low solids' slurry digestion; (b) two-phase digestion; and (c) high solids 'dry and semi-dry' digestion. The advantages of high solids digestion processes include high loading rates, and high yields of biogas and methane. Anaerobic digestion at high solids content is also reported to reduce capital and operating costs through smaller reactor volume. Different reactor design configurations have been applied at full-scale and their performance evaluated. Commercial plants which use a high solids digestion process, recycle a portion of the digested solids residue in addition to the liquid from the digested residue. However, the exact recycling ratio and data concerning the recycling impact on the stability and performance of the digestion process, are not well documented in the literature. Also, it is recognised that mixing is important to enhance anaerobic digestion but little research has concentrated on the impact of mixing on continuous or semi-continuous high solids anaerobic digestion systems. The main aim of this research was to evaluate the potential methane production in the stabilisation of the putrescible fraction of MSW using two novel reactor designs. A vertical sequential reactor (VSR) was used to assess the effects of digested recycle ratio (DRR) and leachate recycling (LR) and a horizontal rotary reactor (I-IRR) was used to evaluate the impact of mixing on the digestion of the PFMSW. Experiments were conducted in both batch and semi-continuous mode using three 70 1 reactors, under mesophilic conditions (3 5°C) and high total solids content. Process performance was assessed using various waste parameters for solid waste and leachate treatment. Regarding solid waste treatment, VS removal, biogas and methane production and yields were the main parameters used for assessment, among several others. Accordingly, COD, VFA, pH, alkalinity, N1H3-N, TKN etc. have been some of the parameters used to monitor leachate quality. Furthermore, internal biological activity in the VSR was assessed using the observed VFA concentrations and degradation under different operational conditions (DRR and LR). Initially, batch experiments were carried out in order to evaluate the first start-up of high solids digestion. Furthermore, they provided seed digested residues for the subsequent semi-continuous studies, in addition to providing essential information regarding ultimate process efficiency in terms of methane yield and VS removal. Also, rapid start-up batch experiments were used to determine the required RT for semi-continuous studies. Optimum DRR and LR were determined with the use of the VSR semicontinuous process. A DRR of 0.5 was found to be optimum in terms of volumetric methane production, while LR2 (3.5 £ leachate recycle) provided a desirable economical option, because of its lower liquid requirements. I-IRR gave limited indicatory results expressing high treatment potential for high solids anaerobic digestion of the putrescible fraction of MSW. Finally, a mathematical model was developed for optimising the VSR operational conditions, utilising data produced under semi-continuous conditions.
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Caiti, Massimiliano. "Mechanochemistry: a new approach to depolymerize cellulose via solid-solid reaction." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14434/.
Full textAbstract:
Cellulose is both insoluble in water and resistant against hydrolysis. These features pose major problems for its conversion into platform chemicals, first of all glucose. Herein, is demonstrated that the combination of mechanical forces and the presence of solid acid catalysts leads to the full conversion of cellulose into oligosaccharides. In this way mechanochemistry results an available route to depolymerize cellulose via solid-solid reaction. In this work is described the whole developed methodology which permits to obtain a quantifiable final products from the milling of a cellulosic substrate. Furthermore is reported the analytic method constructed thanks to which it is possible to determine the cellulose conversion and thus compare the performances of various solid acids tested. This study has moreover allowed to understand important catalyst features that enhance the depolymerization rate, such as the distribution of the acid sites on a inert support. Amberlyst 15, producing 100% of oligosaccharides in 15 hours of milling at 500rpm, is resulted the more active catalysts among those studied. Thanks to its high activity were performed performances comparison of the different ball mills employed.
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Fu, Qi. "Theoretical Study and Computer Simulation of Generalized Solid-on-solid Models." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/261.
Full textAbstract:
The subject of this thesis is investigation of the morphology of a crystal surface by means of statistical mechanics and Monte Carlo simulations. We employ solid-on-solid models, modified to include the effects of corner and edge energies of faceted surfaces. We also account for surface configurational entropy associated with various surface configurations (colonies of facets). This is an extension of the work of Herring who ignored corner and edge energies and effectively treated periodic hill-and-valley structures, which have no configurational entropy. The excess energies from the corners and edges of a surface also affect the equilibrium shape of very small crystals. These and other related effects are studied on solid-on-solid models for nearest-neighbor forces with central symmetry and additive bond energies. We obtain theoretical formulae for configurational entropy and theoretical distributions of the heights and lengths of facets on one-dimensional crystal surfaces (two-dimensional crystals). These results are tested by comparison with simulation data and good agreement results. A modified solid-on-solid model with nearest neighbor energy proportional to the nearest neighbor height difference raised to a power p is used to account for effects of corner and edge energies for two-dimensional surfaces (three-dimensional crystals). On an initially flat (100) surface, a slight change of p-value has a significant effect on surface morphology. Especially for p = 0:9, which corresponds to positive corner energies, a “macroscopic smoothing” transition from a faceted surface at low temperatures to a non-faceted surface at high temperatures is observed. This transition is only evident for surfaces that are initially tilted with respect to a close-packed surface. We also develop a symmetric solid-on-solid model that preserves crystal symmetry. For this symmetric model, the “macroscopic smoothing” transition for p = 0:9 is still observed on (111) and (112) surfaces, but now the surface structure is consistent with crystal symmetry. We find a hysteresis effect in these transitions, which is less pronounced for large systems. We calculate the correlation time of the surface by several different measures to study the relaxation of the system. A discrete Fourier analysis of the surface is implemented and we verify that there exists a long-wave fluctuation in the surface. We also study the distribution of facet areas and facet heights, which turns out to be exponential. A histogram method is employed to extend results at a given temperature to nearby temperatures.
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Wilkinson, E. T. "Stochastic models for certain solid classification and solid fluid separation processes." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384086.
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Stelmack, Patricia Louise. "Effects of surfactants on microbial adhesion to solid and semi-solid surfaces." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq21211.pdf.
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Song, Jiasen. "Solid-liquid mass transfer and solid dynamics in three-phase fluidized beds." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0020/MQ49687.pdf.
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Alesso, Sonia Maria. "Synthesis and evaluation of new solid supports for solid phase organic synthesis." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270385.
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Lee, Rhonda Joy. "Studies of solid-solid interaction forces and the pneumatic handling of powders /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487848078451112.
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De, Vos Wouter Phillip. "The effect of particle shape on solid entrainment in gas-solid fluidisation." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-08282008-144243/.
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Rovnyak, David S. (Davis Sherman) 1971. "Solid-state nuclear magnetic resonance of quadrupolar nuclei with applications to biological solids." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85294.
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L'Hereec, Frederic. "Solid state chemical electronics." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/5341.
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Malus, Shem. "Gas-solid reaction analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ64402.pdf.
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Lancaster, Norman Llewellyn. "Solid-supported aromatic nitrations." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302641.
Full textAbstract:
The efficacy of the claycop system in the nitration and the dinitration of toluene has been investigated.Comparison of regioselectivity and of rate constant with homogeneous nitric acid nitration was made. The use of ion-exchanged montmorillonite clay as a catalyst for acetyl nitrate nitration was studied. The system was found to enhance Para selectivity in the nitration of toluene and to catalyse the reaction. Additionally, the catalyst was shown to be recyclable. The reaction of toluene was too fast to allow kinetic study. However, kinetic study was possible,using chlorobenzene as substrate.Again, the system was found to decrease both the reaction time and the o-/ p- ratio. It was possible to demonstrate a dependence of rate constant upon mass of clay. The effect of the counter ion was investigated and the use of trifluoroacetyl anhydride was studied. A new system for aromatic nitration has been developed in this work using zeolite with dinitrogenp entoxide.A series of zeolites were screened in the nitration of onitrotoluene, with the H-faujasites showing the quickest reaction times and highest degree of regioselectivity. The silica/ alumina ratio of the faujasite used was varied and this was shown to have an effect on regioselectivity. However, reactions were too fast for kinetic study. The faujasite/ dinitrogen pentoxide system was used in the nitration of some deactivated benzenes using these substrates allowed kinetic studies to be made and the order in each component to be determined. It was found that nitration was zeroth order in dinitrogen pentoxide, that the reaction obeyed a first order rate law, and that the first order rate constant was proportional to the mass of zeolite used. Comparison of the relative rates of nitration of 1-chloro-2-nitrobenzene1, -chloro-4-nitrobenzene and nitrobenzeneb y this system to the relative rate constants of nitronium ion nitration was made. The similarity suggested that the mechanism of nitration by faujasite/d initrogen pentoxide might involve nitronium ion transfer.Amongst the H-faujasites of different silica/ alumina ratio, the rate constant was shown to increase with the aluminium content. A mechanism is proposed in which zeolite protons (present in proportion to the aluminium atoms) are first replaced by nitronium ions. The latter are transferred to the aromatic in the rate-determining step. The use of non-chlorinated solvents and the recycling of zeolite were both studied, and the nitration of 2,6-dinitrotoluene was attempted. The use of the faujasite/ dinitrogen pentoxide system was extended to the nitration of nitrogen containing aromatic heterocycles direct C-nitration of quinolone was not possible, only N-nitration. However, pyrazole was converted to 1,4-dinitropyrazole quickly and cleanly under mild conditions. It was shown that the N-nitration occurred instantly, followed by slower C-nitration. The kinetics of the second nitration were studied and comparison with deactivated benzenes was made.
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Adamson, R. "Solid phase peptide synthesis." Thesis, University of Bradford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371460.
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Hodgins, Diana. "Vibrating solid-state sensors." Thesis, University of Hertfordshire, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314742.
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Jelfs, A. M. P. "Novel solid electrolyte systems." Thesis, De Montfort University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379174.
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Aldrich, Matthew (Matthew Henry). "Dynamic solid state lighting." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58000.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 142-148).
Energy conservation concerns will mandate near-future environments to regulate themselves to accommodate occupants' objectives and best tend to their comfort while minimizing energy consumption. Accordingly, smart energy management will be a needed and motivating application area of evolving Cyber-Physical Systems, as user state, behavior and context are measured, inferred, and leveraged across a variety of domains, environments, sensors, and actuators to dynamically mitigate energy usage while attaining implicit and explicit user goals. In this work, the focus in on the efficient control of a LED-based lighting network. This thesis presents a first-of-its-kind pentachromatic LED-based lighting network that is capable of adjusting its spectral output in response to ambient conditions and the user's preferences. The control of the intensity is formulated as a nonlinear optimization problem and the mathematics governing sensed illuminance, color, and corresponding control (feedback and adjustment) are formally defined. The prototype adjustable light source is capable of maintaining an average color rendering index greater than 92 (nearly the quality of daylight) across a broad adjustable range (2800 K - 10,000 K) and offers two modes of control, one of which is an energy efficient mode that reduces the total power consumption by 20%. The lighting network is capable of measuring the illuminance and color temperature at a surface and adjusting its output with an overall update rate of 11 Hz (limited by the MATLAB kernel). The sensor node features an optical suite of sensors with a dynamic range of 10000 : 1 lx (rms error: 2 lx). The sensor node measures the color temperature of daylight within ±500 K (kelvin). Device testing and validation were performed in a series of experiments in which the radiant power was collected using a radiometrically calibrated spectrometer with an expanded uncertainty (k = 2) of 14% and validated against a model derived by measuring the individual spectra of the system using custom MATLAB tools. A digital multimeter measured the current in the experiments. The work concludes by estimating the energy savings based on the measured optical and electrical data. In environments with moderate ambient lighting, the networked control reduces power consumption by 44% with an additional 5-10% possible with spectral optimization.
by Matthew Aldrich.
S.M.