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The Influence of Fredrik Melius Christiansen on Six Minnesota Conductor-ComposersArmendarez, Christina Marie 05 1900 (has links)
F. Melius Christiansen was very influential in the a cappella choral tradition. He started his career in Norway and brought his expertise to the American Midwest. Christiansen established a name for himself while working at St. Olaf Lutheran College as the head of the music department. It was the blended choral sound and precision he was able to achieve and display with his new choir in 1912 that caught everyone's ear. He continued to succeed with national and international tours, allowing him to spread his new "St. Olaf" choral sound through his music, compositions, and conducting school. This study explores the influence of F. Melius Christiansen (1871-1955) and the Minnesota choral tradition on six subsequent conductor-composers' compositions and conducting styles, including: Olaf Christiansen (1901-1984), Paul J. Christiansen (1914-1997), Kenneth Jennings (b. 1925), Robert Scholz (b. 1940), René Clausen (b. 1953), and Kenneth Hodgson (b. 1939) using Schenkerian analysis.
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Synthesis, characterization and self-assembly of liquid-crystalline ambipolar semi-conductors / Synthèse, caractérisation et auto-assemblage de cristaux liquides semi-conducteurs ambipolairesDebever, Olivier 22 March 2011 (has links)
These days, organic photovoltaic devices (OPV) have received a large interest from both academic and industrial researchers as alternative energy source to replace petroleum and nuclear fission. New organic semi-conductors (OSC) are actively researched since these materials can be purified and processed by solution techniques that are cheaper than those required for silicon. The current record efficiency is 8.3%. Further improvement of the OPV performances is desired in order to decrease both the pay-back time of the device and the price of the energy produced. On that purpose, academic research is focused on two main axes: (i) develop new organic materials characterized by high charge mobilities for both p-type (holes) and n-type (electrons) semi-conduction and (ii) increase as much as possible the contact surface between both p-type and n-type OSC (p-n junction), where the electric charges are created. <p>In the frame of this PhD thesis, we proposed to investigate this second aspect by building the interface at a nanoscopic scale, creating a molecular heterojunction. Liquid crystalline (LC) materials composed of donor-acceptor dyads were chosen as OSC since they can lead to complex supramolecular structures made of two interpenetrated networks: the first one is related to the donor and provides holes transport, while the second one is related to the acceptor and affords electrons conduction. In this context, we decided to synthesize new donor-acceptor molecules composed of a phthalocyanine (donor) covalently connected to a fullerene (acceptor) through a non-conjugated bridge and to investigate their supramolecular assembly in solution and solid state. This specific molecular structure was inspired from a mesogenic phthalocyanine developed earlier in our laboratory and the very popular fullerene derivative referred to as PCBM. <p>Four dyads with different bridge lengths were prepared via multi-step synthesis. Two key steps are: (i) the formation of low-symmetry A3B phthalocyanines bearing three mesogenic substituents and one hydroxyl-terminated chain and (ii) the esterification of these phthalocyanines with the carboxylic acid homologue of PCBM.<p>In solution, no electron transfer from the phthalocyanine to the fullerene is evidenced in the ground state. On the contrary fluorescence quenching indicates that a photo-induced charge transfer takes place. Also, cyclic voltammetry measurements confirmed that both phthalocyanine and fullerene moieties act as independent & / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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Přeizolace vedení 110 kV / Reconstruction of overhead power lines 110 kVKrejčí, Tomáš January 2015 (has links)
The master’s thesis deals with the topic new isolation lines of 110 kV. The aim is to propose new insulator hangers. The first, theoretical part focuses on the development of insulators, cutting and possibilities of application. They are the different materials that are used for the production of insulators HV, advantages and disadvantages long rod and cap and pin insulators. There are also described insulator hangers. The theoretical work is to describe thefittings for overhead transmission lines, which are, used to construct a insulator hanger. The last part of the theoretical work is intended distribution towers for overhead lines HV. The practical part deals with the design of new insulator suspensions for specific lines of 110 kV. The results are drawings newly designed hangers and a list of materials (fittings) for individual towers and the total amount of material. The practical part is calculating the differences in the conductor sag using old and new insulators hangers.
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Strombegrenzende Mechanismen YBa2Cu3O7-[delta]-Dünnschichten und -QuasimultilagenHänisch, Jens 20 October 2005 (has links)
In this work, electrical transport properties and the maximum current carrying capability of YBa2Cu3O7-[delta] thin films and so called quasi-multilayers are investigated. These samples are prepared with pulsed laser deposition on single-crystalline substrates (SrTiO3) as well as on biaxially textured Ni tapes. The critical current density of coated conductors is limited by small-angle grain boundaries in low magnetic fields, but by the intra-grain pinning properties in higher magnetic fields. Accordingly, these investigations are divided into two parts: In the first part, the limitation of the critical current density by grain-boundaries and grain boundary networks is investigated with the main focus on the influence of geometrical factors such as the conductor width or the grain aspect ratio. In the second part, a possible enhancement of the critical current density due to different doping types (atomar doping using Zn and precipitate doping using BaMO3 where M is a transition metal) will be discussed. Here, not only the irreversibility field but also the pinning behaviour in very low magnetic fields is of interest to better understand the pinning mechanism of thin films. / In der vorliegenden Arbeit werden elektrische Transporteigenschaften und die maximale Stromtragfähigkeit von YBa2Cu3O7-[delta]-Dünnschichten und -Schichtsystemen, die mit Hilfe der gepulsten Laserdeposition sowohl auf einkristallinem Substrat, SrTiO3, als auch auf biaxial texturierten Ni-Bändern deponiert wurden, untersucht. Da in kleinen Magnetfeldern Kleinwinkelkorngrenzen die kritische Stromdichte in Bandleitern begrenzen, in höheren jedoch die Pinningeigenschaften der Körner, gliedern sich diese Untersuchungen in zwei Teile: Im ersten wird die Limitierung der kritischen Stromdichte jc durch Korngrenzen und Korngrenzennetzwerke näher untersucht, wobei besonders Geometrieeinflüsse, wie die Leiterbahnbreite oder das Aspektverhältnis der Körner, interessieren. Im zweiten wird eine mögliche Erhöhung der kritischen Stromdichte durch verschiedene Dotierungen (atomare Dotierung: Zn, Ausscheidungsdotierung: BaMO3, M Metall) erörtert. Dabei ist nicht nur das Irreversibilitätsfeld interessant, sondern auch das Pinningverhalten in sehr kleinen Magnetfeldern, da so die Pinningmechanismen in Dünnschichten besser verstanden werden können.
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First Principles Modelling of Clean Energy MaterialsŽguns, Pjotrs January 2015 (has links)
This licentiate thesis presents the density functional theory study on clean energy materials relevant for catalysis applications, and for solid oxide fuel cells. In the first part of the thesis the metal supported ultrathin films, namely ScN/Mo, MgO/Mo and NaF/Mo are considered, and the Cu atom adsorption and charging on them is explored.The comparative study of these different films allows us to provide recommendations regarding the choice of materials, in order to promote adatom charging. The modulation of the adatom charge, by changing the material of the film, also paves the way for the design of novel catalysts. Moreover, the detailed investigation of the Cu/NaF/Mo caseshows a correlation between the charge redistribution upon the adsorption and the anharmonicity of the accompanying distortion. Overall, the research commands a fresh view on the adatom charging mechanism. In the second part of the thesis the gadolinium doped ceria, used asoxide electrolyte in solid oxide fuel cells, is studied. The employment of the cluster expansion method together with the density functional theory calculations provides the description of the configurational energy spectrum of dopants and oxygen vacancies in terms of effective pair and three site interactions. The chosen method allows one to predict the energy of anarbitrary configuration. Moreover, the effect of volume change on the strength of interactions is investigated, which is relevant for the modelling ofoxide electrolytes at operating temperatures of solid oxide fuel cells,i.e. when volume expansion is notable. / <p>QC 20150521</p>
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EXPERIMENTAL INVESTIGATION TO STUDY THE FEASIBILITY OF FABRICATING ULTRA-CONDUCTIVE COPPER WIREPallikonda, Mahesh Kumar 15 December 2021 (has links)
No description available.
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Design and Fabrication of 1550 nm Photonic Crystal Surface Emitting LasersMartins de Pina, João January 2018 (has links)
In this study, the design and fabrication of a monolithic InP-based 1550-nm photonic-crystal surfaceemitting laser (PCSEL) is reported. The device is composed by an InGaAsP multi-quantum well (MQW) active layer and InP photonic crystal (PhC) formed by metal organic chemical vapour deposition (MOCVD). A theoretical study based mainly on the Fourier modal method using Stanford Stratified Structure Solver (S 4) and finite element analysis using COMSOL Multiphysics was carried out in order to optimize the emission at 1550 nm due to the two-dimensional band-edge resonance effect at the Γ point.The device design and modeling, materials testing (annealing and MOCVD regrowth), process optimization and the fabrication of light emitting diodes (LEDs) based on the same structure as the PCSELs (without the PhC) is reported. The fabricated devices show a low series resistance of 8.19 Ω and a turn-on voltage of 0.84 V. The average differential output power is 41 mW/A with an electroluminescent peak at 1511 nm. The full assembly of the final PCSEL devices is beyond the scope of the present thesis and corresponds to an ongoing project expected to be finalized within the coming year. However, detailed guidelines and fabrication instructions, including the manufacturing of an appropriate lithographic mask set, are provided. / Föreliggande examensarbete rapporterar designen och tillverkningsprocessen för en monolitisk InPbaserad 1550-nm så kallad Photonic-Crystal Surface-Emitting Laser (PCSEL). Komponenten bestå r av en aktiv kvantbrunnsstruktur i InGaAsP och ett fotoniskt-kristall (PhC)-lager i InP, bägge odlade med hjälp av metalorganisk gasfasepitaxi (MOCVD). En teoretisk studie baserad på Fourier-modalmetoden med användning av Stanford Stratified Structure Solver (S4) och finit elementanalys-metoden med med hjälp av av COMSOL Multiphysics utfördes för att optimera emissionen vid 1550 nm genom en tvådimensionell bandkantsresonanseffekt vid Γ punkten.Rapporten går igenom komponentdesign och modellering, materialtestning (värmebehandling och MOCVDåterväxt), processoptimering och tillverkning av lysdioder (LED) baserade på samma struktur som PCSELkomponenterna (men utan PhC-strukturering). De tillverkade lysdioderna uppvisar en låg serieresistans på 8.19 Ω och en framspänning på 0.84 V. Den genomsnittliga differentiella utgångseffekten är 41 mW/A med en luminescenstopp vid 1511 nm. Den slutliga tillverkningen av färdiga PCSEL-enheter ligger utanför ramen för detta examensarbete och motsvarar istället ett pågående projekt som förväntas bli slutfört inom det kommande året. Däremot ges detaljerade riktlinjer och tillverkningsinstruktioner, för vilket ett fotolitografiskt mask-set även tagits fram.
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A Study of Interface Reaction of Li0.35La0.55TiO3-Li2CO3 and Its Effect on Potentiometric CO2 Gas SensorsYoon, Junro 20 December 2012 (has links)
No description available.
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New solid state oxygen and hydrogen conducting materials. Towards their applications as high temperature electrochemical devices and gas separation membranesBalaguer Ramírez, María 02 September 2013 (has links)
Los materiales conductores mixtos de electrones e iones (oxígeno o
protones) son capaces de separar oxígeno o hidrógeno de los gases de combustión
o de corrientes de reformado a alta temperatura. La selectividad de este proceso
es del 100%. Estos materiales, óxidos sólidos densos, pueden usarse en la
producción de electricidad a partir de combustibles fósiles, así como formar parte
de los procesos que forman parte del sistema de captura y almacenamiento de
CO2. Las membranas de transporte de oxígeno (MTO) se pueden utilizar en las
plantas energéticas con procesos de oxicombustión, así como en reactores
catalíticos de membrana (RCM), mientras que las membranas de transporte de
hidrógeno (MTH) se aplican en procesos de precombustión. Además, estos
materiales encuentran aplicación en componentes de sistemas energéticos, como
electrodos o electrolitos de pilas de combustible de óxido sólido, de ambas clases
iónicas y protónicas (SOFC y PC-SOFC).
Los procesos mencionados implican condiciones de operación muy
severas, como altas temperaturas y grandes gradientes de presión parcial de
oxígeno (pO2), probablemente combinadas con la presencia de CO2 and SO2. Los
materiales más que mayor rendimiento de separación presentan y más
ampliamente investigados en este campo son inestables en estas condiciones. Por
tanto, existe la necesidad de encontrar nuevos materiales inorgánicos estables que
proporcionen alta conductividad electrónica e iónica.
La presente tesis propone una búsqueda sistemática de nuevos
conductores iónicos-electrónicos mixtos (MIEC, del inglés) con diferente
estructura cristalina y/o diferente composición, variando la naturaleza de los
elementos y la estequiometría del cristal. La investigación ha dado lugar a materiales capaces de transportar iones oxígeno, protones o cargas electrónicas y
que son estables en las condiciones de operación.
La caracterización de una amplia serie de cerias (CeO2) dopadas con
lantánidos proporciona una comprensión general de las propiedades estructurales
y de transporte, así como la relación entre ellas. Además, se estudia el efecto de la
adición de cobalto a dicho sistema. Se ha completado el análisis con la
optimización de las propiedades de trasporte a partir de la microestructura. Todo
esto permite hacer una clasificación inicial de los materiales basada en el
comportamiento de transporte principal y permite adecuar la estructura y las
condiciones de operación para obtener las propiedades deseadas para cada
aplicación.
Algunos de los materiales extraídos de este estudio alcanzaron las
expectativas. Las familias de materiales basadas en Ce1-x
Tbx
O2-¿
y Ce1-x
Tbx
O2-¿
+2 mol% Co proporcionan flujos de oxígeno bajos pero competitivos, ya que son
estables en atmósferas con CO2. Además, la inclusión de estos materiales en
membranas de dos fases aumenta el flujo de oxígeno. La combinación con una
espinela libre de cobalto y de metales alcalinotérreos como es el Fe2
NiO4, ha
dado lugar a un material prometedor en cuanto a flujo de oxígeno y estabilidad en
CO2 y en SO2, que podría ser integrado en el proceso de oxicombustión.
Por otra parte, se ha añadido metales como codopantes en el sistema
Ce0.9-x
Mx
Gd0.1O1.95. Estos materiales, en combinación con la perovskita La1-
x
Srx
MnO3 usada comúnmente como cátodo de SOFC, han sido capaces de
disminuir la resistencia de polarización del cátodo. La mejora es consecuencia de
la introducción de conductividad iónica por parte de la ceria.
Las perovskitas dopadas basadas en CaTiO3 forman el segundo grupo de
materiales investigados. La dificultad de obtener perovskitas estables y que presenten conducción mixta iónica y electrónica se ha hecho evidente. De entre
los dopantes utilizados, el hierro y la combinación hierro-magnesio han sido los
mejores candidatos. Ambos materiales presentan conductividad principalmente
iónica a alta temperatura, mientras que a baja predomina la conductividad
electrónica tipo p. CaTi0.73Fe0.18Mg0.09O3-¿ se ha mostrado como un material
competente en la fabricación de membranas de oxígeno, que proporciona flujos
adecuados a la par que estabilidad en CO2.
Finalmente, la perovskita La0.87Sr0.13CrO3 (LSC) ha sido dopada con el
objetivo de aumentar la conductividad mixta protónica electrónica. Este estudio
ha llevado al desarrollo de una nueva generación de ánodos para PC-SOFC
basadas en electrolitos de LWO. Las perovskitas dopadas con Ce en el sitio del
La (LSCCe) y con Ni en el sitio del Cr (LSCN) son estables en condiciones de
operación reductoras, así como en contacto con el electrolito. El uso de ambos
materiales como ánodo disminuye la resistencia de polarización con respecto al
LSC. El LSCCe está limitado por los procesos que ocurren a baja frecuencia
(BF), relacionados con los procesos superficiales, y que son atenuados en el caso
del LSCN debido a la formación de nanopartículas de Ni metálico en la
superficie. La infiltración posterior con nanopartículas de Ni permite disminuir la
resistencia a BF lo que sugiere que la reacción superficial de oxidación del H2
está siendo catalizada. La infiltración más concentrada en Ni (5Ni) elimina
completamente la resistencia a BF en ambos ánodos, de forma que los procesos
que ocurren a altas frecuencias son ahora limitantes. El ánodo constituido por
LSCNi20+5Ni dio una resistencia de polarización de 0.26 ¿·cm
2
at 750 ºC en H2
húmedo. / Mixed ionic (oxygen ions or protons) and electronic conducting materials
(MIEC) separate oxygen or hydrogen from flue gas or reforming streams at high
temperature in a process 100% selective to the ion. These solid oxide materials
may be used in the production of electricity from fossil fuels (coal or natural gas),
taking part of the CO2 separation and storage system. Dense oxygen transport
membranes (OTM) can be used in oxyfuel combustion plants or in catalytic
membrane reactors (CMR), while hydrogen transport membranes (HTM) would
be applied in precombustion plants. Furthermore, these materials may also be
used in components for energy systems, as advanced electrodes or electrolytes for
solid oxide fuel cells (SOFC) and proton conducting solid oxide fuel cells (PCSOFC)
working at high and moderate temperature.
The harsh working conditions stablished by the targeted processes
include high temperatures and low O2 partial pressures (pO2), probably
combined with CO2 and SO2 containing gases. The instability disadvantages
presented by the most widely studied materials for these purposes make them
impractical for application to gas separation. Thus, the need to discover new
stable inorganic materials providing high electronic and ionic conductivity is
still present.
This thesis presents a systematic search for new mixed ionic-electronic
conductors. It includes different crystalline structures and/or composition of the
crystal lattice, varying the nature of the elements and the stoichiometry of the
crystal. The research has yielded new materials capable to transport oxygen ions
or protons and electronic carriers that are stable in the working condition to
which they are submitted. / Balaguer Ramírez, M. (2013). New solid state oxygen and hydrogen conducting materials. Towards their applications as high
temperature electrochemical devices and gas separation membranes [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31654 / Premios Extraordinarios de tesis doctorales
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The Impact of American Conductors on the Development of Japanese Wind Band Repertoire as Evidenced in the Programming of Tokyo Kosei Wind Orchestra, Musashino Academia Musicae, Showa Academia Musicae, Senzoku Gakuen School of Music, and Tokyo University of the ArtsLo, Albert 12 1900 (has links)
The wind bands in Japan are considered by many scholars and wind band conductors to be among some of the finest ensembles in today's wind ensemble medium. The literature and repertoire of Japanese ensembles have evolved from orchestral transcriptions, patriotic music, and military marches to original compositions by European, American, and Japanese composers. British conductor Timothy Reynish states that Japanese wind band music has looked traditionally towards the United States and occasionally United Kingdom for inspiration and repertoire. This phenomenon can be attributed to the many collegiate American and the few English wind band conductors who traveled to Japan as guest conductors, and in some cases, became residents of Japan. The focus of this study is to closely examine this significant impact of American collegiate wind band conductors, their influence on Japanese programming and how that programming has affected the collegiate repertoire. This study includes surveys of repertoire, concert programs, discographies of recordings, and interviews with prominent American conductors currently conducting in Japan. This research documents the impact that American wind band conductors have had on the programming of Japanese wind bands and how their influence have altered the collegiate repertoire. Evidence of this impact is documented by Toshio Akiyama, who states that "The influence of visiting musicians from abroad must be measured as one of the most influential aspects affecting Japanese band growth. Although the effect of Japanese musicians traveling to the United States or Europe has been beneficial, the overall impact on large numbers of people has been more directly due to the visitors from abroad."
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