Дисертації з теми "HTVS"

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1

Baghdadi, Mehdi. "Design and fabrication of the HTS synchronous motor using 2G-HTS stacked tapes." Thesis, University of Cambridge, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709482.

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2

Abomailek, Rubio Carlos. "Development of reduced-scale tests for HTLS substation connectors." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/663151.

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Power distribution networks face the upcoming challenge of managing the increase of power demand predicted worldwide. Power grid capacity is limited by the number of lines deployed and their characteristics, including conductor section, spacing, or number of phases, among others. Building new lines is costly and faces population opposition in many places. Therefore, a new conductor technology designed to upgrade the existing power lines has arisen. This technology, known as High Temperature Low-Sag (HTLS), permits the rise of capacity of existing power lines without modifying the supporting structures. Nowadays, the conductor technology is mature and under commercialization. But, there is the need to design and assess the behaviour of some auxiliary accessories needed to operate power lines equipped with HTLS conductors. Specifically, the substation connector industry is still developing HTLS substation connectors. From all the design process, the validation of the performance of these products is still a milestone. Currently, the tests performed to hardware for power lines are costly in terms of required infrastructures, testing time, power requirements, monetary cost and environmental affectation. Moreover, many of these tests can only be performed in few facilities all around the world. Furthermore, from an industrial scope, there is a growing interest to obtain the data of such tests in onsite industrial laboratories. Thus, this thesis develops a set of reduced-scale tests equivalent to the ones performed on full-scale connectors to validate the performance of the new designs. This thesis also performs a critical review of some of the methodologies that currently are being applied to assess products lifetime, and proposes the use of modern approaches. Concluding, this document aims to develop a series of test procedures that provide data about the validity of the newly required substation connectors designs in a cheaper, faster, and environmentally-friendlier way, whilst allowing to test the connectors in industrial laboratories, which have much less requirements than those of the full-scale test, since the later often require to be carried out in singular and scarce facilities.
Las redes de distribución y transmisión de potencia se enfrentan al reto de manejar el incremento de demanda eléctrica previsto mundialmente. La capacidad de la red eléctrica está limitada por el número de líneas instaladas y sus características. Esto incluye, la sección del conductor, espaciado o número de fases, entre otros. La construcción de nuevas líneas es cara y en muchos casos imposible debido a la enorme oposición a la que se enfrentan en muchos lugares del mundo. Por ello, en los últimos años una nueva tecnología de conductores ha empezado a tomar importancia. Estos conectores conocidos como HTLS (alta temperatura baja flecha), permiten el aumento de la capacidad de las líneas eléctricas existentes sin por ello tener que modificar las estructuras que las soportan. Hoy en día, esta tecnología está suficientemente madura para ser comercializada. Sin embargo, existe la necesidad de diseñar y validar el comportamiento de una serie de accesorios auxiliares para líneas eléctricas. Concretamente, la industria de los conectores de subestación está desarrollando sus productos para líneas HTLS. El proceso de validación de estos conectores es aún un hito por alcanzar. Por el momento, los ensayos realizados sobre aparamenta para líneas eléctricas son costosos en términos de infraestructuras necesarias, tiempo de ensayo, potencia requerida, coste económico e impacto medioambiental. Además, muchos de estos ensayos sólo pueden llevarse a cabo en unas pocas instalaciones disponibles en todo el mundo. Por lo tanto, desde un punto de vista industrial, existe un creciente interés en obtener estos datos en laboratorios industriales. Por ello, esta tesis desarrolla un conjunto de ensayos a escala reducida equivalentes con los que hoy en día se realizan a escala real, con el fin de validar el rendimiento de los nuevos diseños de conector. Esta tesis también realiza una revisión crítica de algunas de las metodologías que hoy en día se llevan a cabo para estudiar el envejecimiento de los conectores de subestación. A su vez, propone el uso de metodologías más modernas para realizar dichos estudios. En conclusión, este documento desarrolla una serie de procedimientos de ensayo para validar los diseños de los nuevos desarrollos de conectores de subestación de una manera barata, rápida y respetuosa con el medio ambiente a la vez que permite el ensayo de dichos productos en laboratorios industriales.
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3

Chalupa, Pavel. "Pevnostní kontrola nákladního přívěsu HTV 18." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231490.

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The subject of this master's thesis is the strength analysis of the cargo trailer HIPOCAR HTV 18 and proposed modifications. For the strength analysis was selected finite element method. The frame model was modified by the results of the strength analysis. After that has been carried out the strength analysis of the modified frame.
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4

Capelli, Francesca. "Development of high-capacity substation connectors compatible with HTLS technology." Doctoral thesis, Universitat Politècnica de Catalunya, 2017. http://hdl.handle.net/10803/404412.

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The advent of HTLS (High Temperature, Low Sag) conductors imposes more severe operating conditions on devices such as substation connectors intended for transmission and distribution systems, which are subjected to higher loads and have to operate at higher temperatures. The main objective of this thesis is the development of a new family of high-capacity substation connectors compatible with the HTLS technology. The first aspect that has been analyzed is the selection of the base material. At present, substation connectors are manufactured by using A356 cast aluminum alloy due to its good castability and physical properties. However, due to the new operating conditions introduced by the HTLS technology, A356 alloy needs to be further improved. A chemical treatment (modification) has been proposed to fulfill the requirements of high-capacity substation connectors' material. Experimental measurements of electrical, thermal and mechanical properties have been carried out to characterize and compare properties of both un-modified and modified alloys. Moreover, their electrical resistivity has been evaluated from cryogenic up to 200ºC, to find out the temperature coefficient of resistivity. Experimental measurements prove that chemical modification improves mechanical, electrical and thermal properties of A356.0 alloy. Moreover, to design the new family of connectors it is necessary to take into account the contact resistance. The contact resistance defines the energy-efficiency, the stable performance and the long-term service of an electrical connection. To reduce the contact resistance a new installation procedure has been proposed in this thesis. Thermal behavior of connectors installed with the new procedure has been compared with the traditional one, through standardized temperature rise, thermal cycle and short-circuit tests. Results show a lower operating temperature and degradation rate for connectors installed with the new procedure. Moreover, the temperature coefficient of contact resistance has been determined through an experimental test. To accurately predict the thermal behavior of substation connectors, it is important to estimate the electrical constriction resistance (ECR). Different ECR models have been compared with experimental measurements. The fractal model for rough surfaces shows closer agreement with experimental data, however, they are based on several parameters dependent on the surfaces' roughness, whose values need to be tuned for each application. A software tool based on a genetic algorithm approach has been developed to obtain an accurate prediction of the contact resistance. Furthermore, advanced 3D-FEM modelling tools to perform realistic simulations of the short-time and peak withstand current and temperature rise tests have been developed. Substation connectors must pass these compulsory tests, which require high-power laboratory facilities, are very power-consuming and thus very expensive. The development of a realistic simulation tool is essential for anticipating the results of the mandatory laboratory tests in a fast and inexpensive way. In this thesis electromagnetic-thermal multiphysics 3D-FEM tools to simulate the transient thermal behavior of substation connectors during the standard short-circuit and temperature rise tests have been developed. Finally the thesis deals with the loop inductance. The estimation of the loop inductance is very important as it determines voltage drop in conductors. Inductance estimation provided by formulas has been compared with FEM simulations and experimental measurements. Furthermore, a simple setup to reduce the reactive power consumption when conducting short-circuit tests, based on placing a conductor forming a closed inner loop concentric with the testing loop, has been proposed and optimized trough 3D-FEM simulations.
La tecnología de conductores HTLS (alta temperatura, baja flecha) impone condiciones operativas muy severas en los dispositivos eléctricos, como los conectores subestación para sistemas de transmisión y distribución, los cuales están sometidos a corrientes más altas y tienen que operar a temperaturas más elevadas. El objetivo principal de esta tesis es el desarrollo de una nueva familia de conectores de subestación de alta capacidad compatibles con la tecnología HTLS. El primer aspecto que se ha analizado es la selección del material de base. En la actualidad, los conectores de subestación se fabrican con la aleación de aluminio de fundición A356, debido a sus buenas propiedades físicas. Sin embargo, debido a las condiciones operativas más estrictas introducidas por la tecnología HTLS, la aleación estándar se debe mejorar. Para cumplir con los requisitos de la aplicación, se ha propuesto un tratamiento químico (modificación). Se han caracterizado las propiedades eléctricas, térmicas y mecánicas de la aleación estándar y modificada, además la resistividad eléctrica se ha evaluado desde temperaturas criogénicas hasta 200 ºC, para determinar el coeficiente de temperatura de resistividad. Las medidas experimentales han demostrado que la modificación química mejora las propiedades mecánicas, eléctricas y térmicas de la aleación A356. Por otra parte, para el diseño de la nueva familia de conectores, se debe tener en cuenta la resistencia de contacto, la cual define la eficiencia energética y la vida útil de una conexión eléctrica. Para reducir la resistencia de contacto se ha propuesto un nuevo procedimiento de instalación para conectores. El comportamiento térmico de los conectores instalados con el nuevo procedimiento se ha comparado con el tradicional, a través de ensayos de calentamiento, de ciclos térmicos y de cortocircuito. Los resultados muestran una menor temperatura de funcionamiento y degradación de los conectores instalados con el nuevo procedimiento. Además, el coeficiente de temperatura de la resistencia de contacto se ha determinado a través de una medida experimental. Para predecir el comportamiento térmico de los conectores de subestación, es importante poder estimar la resistencia eléctrica de constricción (ECR). Diferentes modelos ECR se han comparado con medidas experimentales. Los modelos fractales muestran una mejor correspondencia con los datos experimentales; sin embargo, estos modelos se basan en varios parámetros que dependen de la rugosidad de las superficies, cuyos valores necesitan ser calibrados para cada aplicación. Se ha desarrollado un programa basado en un algoritmo genético para obtener una predicción precisa de la resistencia de contacto en conectores de subestación. Además, se han desarrollado herramientas avanzadas de modelado 3D-FEM para realizar simulaciones de ensayos de cortocircuito y de calentamiento para conectores eléctricos. El desarrollo de herramientas de simulación es esencial para anticipar los resultados de los ensayos estándar, de una manera rápida y barata. En esta tesis se han desarrollado herramientas 3D-FEM multifísicas electromagnéticas-térmicas para simular el comportamiento térmico transitorio de los conectores en los ensayos estandarizados de cortocircuito y de calentamiento. Por último, la tesis trata de la inductancia del bucle de ensayo. La estimación de la inductancia del bucle es muy importante, ya que determina la caída de tensión en los conductores. La estimación de la inductancia proporcionada por las fórmulas ha sido comparada con simulaciones FEM y medidas experimentales. Por otra parte, se ha propuesto y optimizado una configuración sencilla para reducir el consumo de energía reactiva durante los ensayos de cortocircuito, basada en la adición de un conductor que forma un bucle cerrado concéntrico interno al bucle de ensayo.
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5

Jablonski, Jens. "Cumarine als präzipitierende Fluorophore für HTS-Anwendungen." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971955603.

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6

Zimmermann, Marc [Verfasser]. "Rechnerunterstützte Analyse von HTS-Daten / Marc Zimmermann." Aachen : Shaker, 2004. http://d-nb.info/1170529941/34.

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7

Malde, Nishil. "Raman spectroscopy of manganite (CMR) andcuprate (HTS) oxides." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270622.

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8

Hirose, M., T. Masuda, Y. Ashibe, F. Endo, H. Kojima, S. Ueyama, and N. Hayakawa. "Quench-induced Partial Discharge Characteristics of HTS Cables." IOP Publishing, 2008. http://hdl.handle.net/2237/20717.

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9

Johnstone, Adam Paul. "Quench propagation in conduction cooled HTS pancake coils." Thesis, University of Southampton, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417976.

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10

Geng, Jianzhao. "Flux pumping for high-Tc superconducting (HTS) magnets." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268221.

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High Tc superconductors are enabling in the generation of extremely high magnetic fields. Flux pumping is a promising technology which can be used to operate HTS magnets without significant loss. In this decade, several HTS flux pumps based on travelling magnetic waves have been developed, yet their physics is still unclear. This thesis established a framework in the area of flux pumping for HTS coils. It revealed the underlying physics of existing travelling wave flux pumps, which is an important theoretical contribution. Based on the thorough understanding of flux pumping mechanism, the author proposed two novel types of flux pumps. The new inventions make flux pumping much easier, more controllable, and much less energy consuming. These flux pumps may promote the future applications of HTS magnets. This thesis can be a guidebook for researchers and engineers in developing flux pumps.
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11

Шинкус, Є. В., М. В. Кругляк, Олександр Олександрович Ляпощенко, Александр Александрович Ляпощенко та Oleksandr Oleksandrovych Liaposhchenko. "Оптимізаційне автоматизоване проектування блоків теплообмінників у Aspen HYSYS з модулем Aspen HTFS". Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40016.

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Необхідність обміну енергетичною складовою між потоками, зокрема тепловою енергією, виникає на багатьох технологічних стадіях та установках, починаючи від потужних енергетичних об’єктів (ТЕЦ) і закінчуючи простими допоміжними системами (установки охолодження мастила насосних агрегатів).
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12

Reppel, Michael. "Novel HTS microstrip resonator configurations for microwave bandpass filters." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960169245.

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13

Fleiter, Jérôme. "Development of high Tc superconducting cables for applications in CERN." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00933352.

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En physique des particules, les grands accélérateurs permettent de sonder la matière en produisant des collisions de faisceaux à haute énergie. Dans un accélérateur circulaire, l'énergie maximale de collision dépend directement de l'intensité du champ magnétique dipolaire servant à guider les particules le long de leur orbite. Dans le large collisionneur de hadrons installé au CERN, l'énergie de collision maximale est de 14 TeV dans le centre de masse. Réaliser des collisions à plus haute énergies nécessitera alors l'utilisation de matériaux supraconducteurs à haute température critique (HTS). Dans cette perspective, les propriétés électromécaniques des différents conducteurs HTS sont caractérisées et paramétrées à 4.2 K sous des inductions allant jusqu'à 12 T. Dans les aimants supraconducteurs d'accélérateur, le câble doit être à fort ampérage et à haute densité de courant (15 kA-400 A/mm2). Il consistera en plusieurs conducteurs HTS connectés en parallèle. La caractérisation et la modélisation des performances de tels câbles dans leurs futures conditions opérationnelles sont exposées dans cette thèse.
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14

Hayakawa, N., M. Nagino, H. Kojima, M. Goto, T. Takahashi, K. Yasuda, and H. Okubo. "Dielectric characteristics of HTS cables based on partial discharge measurement." IEEE, 2005. http://hdl.handle.net/2237/6772.

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15

Kojima, Hiroki, Xin Chen, Naoki Hayakawa, Fumihiro Endo, and Hitoshi Okubo. "Dynamic Thermal Characteristics of HTS Coil for Conduction-Cooled SMES." IEEE, 2009. http://hdl.handle.net/2237/13940.

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16

Okubo, Hitoshi, Masahiro Hanai, Hiroki Kojima, and Naoki Hayakawa. "Recent Progress in Electrical Insulation Techniques for HTS Power Apparatus." Elsevier, 2012. http://hdl.handle.net/2237/20731.

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17

Orso, Giuliano. "Spin-Charge Gauge Approach to HTS Cuprates: Theory Versus Experiments." Doctoral thesis, SISSA, 2003. http://hdl.handle.net/20.500.11767/4161.

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18

Shen, Boyang. "Study of second generation high temperature superconductors : electromagnetic characteristics and AC loss analysis." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/276688.

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This thesis presents a novel study on Second Generation High Temperature Superconductors, which covers their electromagnetic characteristics and AC loss analysis. Lorentz Force Electrical Impedance Tomography (LFEIT) is one of the most promising hybrid diagnostic scanners with burgeoning potential for biological imaging, particularly in the detection of cancer and internal haemorrhages. The author tried a novel combination of superconducting magnets together with the LFEIT system. The reason is that superconducting magnets can generate a magnetic field with high intensity and homogeneity, which could significantly enhance the electrical signal induced from a sample, thus improving the Signal-to-Noise Ratio (SNR). The author developed four magnet designs for the LEFIT system using the Finite Element Method (FEM) package, COMSOL Multiphysics, and found that a Superconducting Halbach Array magnet can achieve all the requirements (magnetic field properties, geometry, portability, etc.) for the LFEIT system. The optimization study of the superconducting Halbach Array magnet has been carried out on the FEM platform of COMSOL Multiphysics, with 2D models using H-formulation based on B-dependent critical current density and bulk approximation. Optimization focused on the location of the coils, as well as the geometry and number of coils on the premise of maintaining the total amount of superconducting material used in the design. The optimization results showed that the Halbach Array configuration based superconducting magnet is able to generate a magnetic field with an intensity of over 1 Tesla and improved homogeneity. In order to efficiently predict the optimization performance, mathematical formulas were developed for these optimization parameters to determine the intensity and homogeneity of the magnetic field. The mathematical model for the LFEIT system was built based on the theory of the magneto-acousto-electric effect. Then the basic imaging of the electrical signal was developed using Matlab. The magnetic field properties of the magnet design were imported into the LFEIT model. The LFEIT model simulated two samples located in three different magnetic fields with varying magnetic strength and homogeneity. Even if there are no actual alternating currents involved in the DC superconducting magnets mentioned above, they have power dissipation during normal operation (e.g. magnet ramping) and under different background fields. This problem generally goes under the category of “AC loss”. Therefore, the AC loss characteristics of HTS tapes and coils are still fundamentally important for HTS magnet designs, even if they are normally operating in DC conditions. This thesis starts with the AC loss study of HTS tapes. The investigation and comparison of AC losses on Surround Copper Stabilizer (SCS) Tape and Stabilizer-free (SF) Tape have been carried out, which includes AC loss measurement using the electrical method, as well as the real geometry and multi-layer HTS tape simulation using the 2D H formulation by COMSOL Multiphysics. Hysteresis AC losses in the superconducting layer, and eddy current AC losses in the copper stabilizer, silver overlayer and substrate were concerned in this investigation. The measured AC losses were compared to the AC losses from the simulation, using 3 cases of different AC frequency: 10 Hz, 100 Hz, and 1000 Hz. The frequency dependence of AC losses from Stabilizer free Tape and Copper Stabilizer Tape were compared and analysed. A comprehensive AC loss study of a circular HTS coil has been fulfilled. The AC losses from a circular double pancake coil were measured using the electrical method. A 2D axisymmetric H-formulation model using FEM package COMSOL has been established, which was able to make consistency with the real circular coil used in the experiment. To model a circular HTS coil, a 2D axisymmetric model provided better accuracy than a general 2D model, and was also more efficient than a 3D model. Three scenarios were analysed: (1) AC transport current and DC magnetic field, (2) DC transport current and AC magnetic field, (3) AC transport current and AC magnetic field. The angular dependence analysis on the coil under the magnetic field with the different orientation angle  was carried out for all three scenarios. For scenario (3), the effect of the relative phase difference ∆ between the AC current and the AC field on the total AC loss of the coil was investigated. To summarise, a current/field/angle/phase dependent AC loss (I, B, , ∆) study of circular HTS coil has been carried out, which could potentially benefit the future design and research of HTS AC systems. The AC losses of horizontally parallel HTS tapes have been investigated. The AC losses of the middle and end tape of three parallel tapes have been measured using the electrical method, and compared to those of an individual isolated tape. The effect of the interaction between tapes on AC losses has been analysed, and compared with finite element method (FEM) simulations using the 2D H formulation implemented in COMSOL Multiphysics. The electromagnetic induction around the three parallel tapes was monitored using COMSOL simulation. The electromagnetic induction and AC losses generated by a conventional three turn coil were simulated as well, and then compared to the case of three parallel tapes with the same AC transport current. The analysis demonstrated that HTS parallel tapes could be potentially used in wireless power transfer systems, which could have lower total AC losses than conventional HTS coils. By using FEM simulations, cases of increasing number of parallel tapes was considered, and the normalised ratio between the total average AC losses per tape and the AC losses of an individual single tape have been calculated for different gap distances. A new parameter is proposed, Ns, a turning point the for number of tapes, to divide Stage 1 and Stage 2 for the AC loss study of horizontally parallel tapes. For Stage 1, N < Ns, the total average losses per tape increased with the increasing number of tapes. For Stage 2, N > Ns, the total average losses per tape started to decrease with the increasing number of tapes. The analysis demonstrates that horizontally parallel HTS tapes could be potentially used in superconducting devices like HTS transformers, which could retain or even reduce the total average AC losses per tape with large numbers of parallel tapes.
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19

De, Silvestri Federica. "Investigation of the magnetic levitation between HTS bulks and permanent magnets." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

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Lo scopo di questa ricerca è lo studio della levitazione magnetica risultante dall'interazione fra bulk di superconduttori ad alta temperatura critica e magneti permanenti. E' stato realizzato un modello numerico 2D in Comsol che simula l'interazione fra i due componenti, per studiare la forza di levitazione ottenuta. Il modello è stato successivamente validato con i risultati sperimentali ottenuti nei laboratori del dipartimento di Ingegneria dell'Energia Elettrica dell'Università di Bologna, ottenendo un buon riscontro sia per quanto riguarda i valori della forza sia per quanto riguarda le distribuzioni di campo e di corrente.
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20

Cheong, Hoon Sin. "Cryogenically-cooled high temperature superconducting (HTS) coils for low field MRI." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.575382.

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In low field MRl (<0.5T), the signal-to-noise ratio (SNR) is predominantly degraded by thermal noise of the imaging coil when the sample loading is minimized. This means surface coils made of high temperature superconductors (HTS) should have an SNR significantly higher than their room-temperature copper equivalents due to the reduction in resistivities. While this hypothesis has been reportedly validated, the actual efficacy of HTS coils is still debatable as the benchmark setups in the prior art had an unfavorably large coil-to-sample separation which diminished the SNR yield. This thesis is intended to perform a quantitative validation on the said hypothesis against a novel benchmark setup where the equivalent room-temperature copper coil was placed directly next to the sample to achieve the best SNR sensitivity. The HTS coil used was an YBCO surface coil having a l0-tum, 70mm-circular spiral layout. For sufficient thermal insulation, there was a 10mm gap between the YBCO coil and the sample while the sample separation for the copper coil was merely I mm. By studying the simulated B1 sensitivity profile of the designated layout, the sample loss and intrinsic resistance of both coils were calculated to allow a theoretical evaluation on the research hypothesis. Each coil was then fabricated and configured with an inductively-coupled matching circuit. The quality factors (Q) of the coils in different loading conditions were measured to allow an empirical estimation on the SNR advantage of the YBCO coil. Both coils were then tested on a saline phantom in a 0.17T MRI system where in-vivo hand images were also acquired. The results showed that the YBCO coil had an SNR gain of 2.0 over the proposed benchmark setup. Such a finding is a valuable addition to the prior art as the efficacy of HTS coils for low field MRl was conclusively proven.
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21

Zhang, Heng. "Magnetization of stacked high-Tc superconducting (HTS) tapes using flux pumping." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/276477.

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Stacked commercial second generation (2G) high temperature superconducting (HTS) tapes has been demonstrated to have great field trapping ability, with superior mechanical, thermal properties and crossed-field performance to HTS bulks. HTS stacks are considered as a very promising candidate for superconducting permanent magnets, which can be used for many applications like superconducting machines and levitation devices. However, the current magnetization methods for HTS stacks are the conventional magnetization methods developed for HTS bulks decades ago, which have various limitations. On the other hand, the recent progress on HTS flux pumping technology enables HTS coils to be successfully magnetized in an effective and efficient way. In this thesis, these two concepts were combined for the first time. Flux pumping for HTS stacks was proposed and developed as a new magnetization technique. I employed two types of flux pumps, the rotating magnet flux pump and the rectifier type flux pump, to magnetize the modified HTS stacks. The design of the flux pumps, the experimental results and the analysis of the observed behaviours are presented in the thesis. This research provides a new direction in the magnetization of HTS permanent magnets, which has the potential to make HTS permanent magnets more practical with lighter, more compact and efficient magnetization setups.
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22

Landry, Sébastien. "Caractérisation et régulation de la transcription antisens chez le VIH-1 et les rétrovirus HTLVs." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26531/26531.pdf.

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23

Wegener, Dennis. "Entwicklung eines HTS-geeigneten Enzymtests für Histondeacetylasen zur Entwicklung von HDAC-Inhibitoren." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=972620621.

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24

Garbom, Sara. "A strategy to identify novel antimicrobial compounds : a bioinformatics and HTS approach." Doctoral thesis, Umeå : Department of Molecular Biology, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-900.

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25

Okubo, H., H. Kojima, F. Endo, K. Sahara, R. Yamaguchi, and N. Hayakawa. "Partial Discharge Activity in Electrical Insulation for High Temperature Superconducting (HTS) Cables." IEEE, 2008. http://hdl.handle.net/2237/12061.

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26

Hayakawa, N., S. Ueyama, H. Kojima, F. Endo, T. Masuda, and M. Hirose. "Electrical Insulation Characteristics of HTS Cables Under Quench-Induced Thermal Stress Condition." IEEE, 2007. http://hdl.handle.net/2237/9462.

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27

Purnell, Adrian Jason. "Non linear behaviour in HTS and MgB2, superconductors of high microwave power." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412290.

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28

Hayakawa, N., A. Ishiyama, N. Amemiya, T. Hasegawa, T. Saitoh, M. Yagi, S. Mukoyama, et al. "Development of 66 kV and 275 kV Class REBCO HTS Power Cables." IEEE, 2013. http://hdl.handle.net/2237/20737.

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29

Gambaccini, Michele. "Pairing and superconductivity in a spin-charge gauge approach to HTS cuprates." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3427543.

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This thesis deals with different aspects of high temperature superconductivity in hole-doped cuprates. We assume the t - J model to describe the CuO2 planes of cuprates and we use a spin-charge gauge approach with spin-charge separation to describe holes in terms of a spinless fermion carrying the charge (holon) and a neutral boson carrying spin 1/2 (spinon), coupled by a slave-particle gauge field. In this framework we consider the effects of the presence of a finite density of incoherent holon pairs in the normal state as a precursor of superconductivity. We show that it is possible to take such pairs into account through a strongly direction dependent spectral weight for holons, which suppresses quasi-particles starting from the anti-nodal directions, and a wave function renormalization for the slave particle gauge field. In this way we prove that, when temperature is reduced, the formation of holon pairs causes both the deviation from linearity of the resistivity and the deviation from the constant value of the Knight shift. Moreover we point out the need for a negative next-nearest-neighbor hopping term ((t - t' - J model) to get a good continuum limit and to evaluate the Knight shift. These results are obtained through a Green's function, which follows naturally from the formalism and analytically interpolates between a Fermi liquid-like behavior and a d-wave superconductor when the coherence length of the holon pair order parameter is increased. The system preserves a finite Fermi surface until the superconducting transition, where it reduces to four nodes. Finally when, at lower temperatures, both the holon pairs and the RVB spinon pairs condense we enter the superconducting phase. In this phase we study the magnetic excitations showing how to extend to spin waves the hourglass-shape dispersion, found for spinons near the antiferromagnetic vector, if a suitable local mechanism of attraction between spinon and anti-spinon is assumed. The resulting spin wave Green's function, whose imaginary part is directly comparable with experiments, generates the hourglass with a finite gap between the two branches. Since the U(1) slave-particle gauge field gains mass in the superconducting phase via Anderson-Higgs mechanism, we propose the necessary mechanism of attraction comes from the unbroken Z2 subgroup of the U(1) gauge group.
Questa tesi riguarda diversi aspetti della superconduttività nei cuprati drogati con lacune trattati con una variante del formalismo di "slave-particle", lo "spin charge gauge approach". Si assume il modello t - J in due dimensioni per descrivere i piani CuO2 e si utilizza l'approccio di gauge "slave particle" con separazione di spin e carica, riscrivendo le lacune in termini di una eccitazione fermionica carica ma priva di spin (l'holone) ed una neutra con spin 1/2 (lo spinone) accoppiate dal campo di gauge. In tale ambito si studia l'effetto della formazione di coppie incoerenti di holoni nella fase normale. Si mostra come si possa tenere conto dell'effetto di quaste coppie tramite un peso spettrale per gli holoni fortemente dipendente dalla direzione che sopprime i modi a partire dalle direzioni antinodali. Si mostra poi come alla formazione di queste coppie sia imputabile, al decrescere della temperatura, sia la deviazione dalla linearità della resistività che la deviazione dal valore costante del Knight shift (per il modello con secondi vicini t-t'-J). Tali risultati sono ottenuti tramite una funzione di Green che appare naturalmente nel formalismo ed interpola analiticamente tra un comportamento di tipo liquido di Fermi ed uno superconduttivo d-wave al decrescere della temperatura. Infine si studiano le eccitazioni magnetiche nella fase superconduttiva, che compare quando, diminuendo la temperatura, sia le coppie di holoni che le coppie di singoletto (RVB) di spinoni condensano. Si mostra come, assumendo un meccanismo di attrazione locale tra spinoni, sia possibile estendere al magnone la dispersione trovata in precedenza per gli spinoni che, in prossimità del vettore antiferromagnetico, è caratterizzata da due rami, uno crescente ed uno decrescente. La dispersione per i magnoni è direttamente comparabile con i dati sperimentali sulle eccitazioni magnetiche (il cosidetto "hourglass"). Si congettura che il meccanismo di attrazione tra spinoni possa essere originato dal sottogruppo Z2 del gruppo U(1) di gauge "slave-particle" che rimane non rotto nella fase superconduttiva.
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30

MEZZASALMA, VALERIO. "Food molecular identification and characterization: towards geographical traceability." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2018. http://hdl.handle.net/10281/198936.

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La sicurezza e la qualità degli alimenti dipendono dalle caratteristiche delle materie prime e dagli approcci chimici, fisici e biotecnologici adottati durante i processi di produzione. Poiché un gran numero di microrganismi sono coinvolti, la maggior parte dei prodotti dovrebbe essere considerata come matrici complesse in cui ogni componente microbico ha un ruolo preciso e si evolve in risposta ai cambiamenti dell'intero sistema. Inoltre, la comprensione delle dinamiche microbiche coinvolte nella produzione alimentare è utile per migliorare i processi industriali e il prodotto stesso. L'analisi del microbiota alimentare è fondamentale per migliorare i processi di biotrasformazione, come la vinificazione. Da tempo l’industria del vino ha coltivato selettivamente cultivar di vite che mostrano tratti diversi (dimensioni, colore, sapore dell'uva) e piccole variazioni nella composizione del suolo, nell'irrigazione e del clima sono da tempo associate a cambiamenti in questi tratti. La flora microbica che coesiste con la pianta può essere uno dei fattori chiave che influenzano queste peculiarità. Le tecnologie High Throughput Sequencing (HTS) sono al giorno d'oggi uno strumento emergente e ampiamente adottato per la caratterizzazione microbica, anche nelle matrici alimentari. Per chiarire il contributo del microbioma della vite durante le fasi di fermentazione, ho utilizzato un approccio basato sull'HTS per identificare le comunità di batteri e funghi associate a bacche e mosti della cultivar Cannonau, provenienti da quattro vigneti di diverse regioni della Sardegna. Il Cannonau è la più importante cultivar di vite della Sardegna (Italia), dove la maggior parte dei vigneti non subisce senza trattamenti fitochimici. Le analisi bioinformatiche hanno suggerito che i microbiomi delle bacche raccolte condividevano una composizione batterica caratterizzata da Enterobacteriales, Pseudomonadales, Bacillales e Rhodospirillales. Tuttavia, ogni area sembra arricchire i microbiomi delle bacche con tratti microbici peculiari. Ad esempio, le bacche appartenenti ai vigneti biodinamici di Mamoiada erano ricche di batteri Bacillales tipici del letame. Durante la vinificazione, eseguita nella stessa cantina in condizioni controllate e senza l'utilizzo di starter, oltre il 50% dei gruppi batterici di bacche raggiungeva i mosti e ogni località aveva la propria firma microbica. Questo suggerisce che il microbioma delle bacche potrebbe essere influenzato dalle condizioni pedoclimatiche e antropologiche e che i microrganismi dei frutti persistono durante la fermentazione. Una delle principali domande aperte sul microbioma dell'uva riguarda il ruolo attivo delle cultivar di vite nella conformazione della comunità microbica. Per studiare la relazione tra genotipo vegetale, microbioma e contributo delle condizioni ambientali e pedoclimatiche del campo, ho pianificato attività di campionamento nel bacino del Mediterraneo per raccogliere 3 diverse varietà di vite Sauvignon Blanc, Syrha, Cabernet Sauvignon e campioni di suolo provenienti da tre diverse aree geografiche Pavia (Nord Italia), San Michele all'Adige (Nord Italia, vicino alle Alpi) e Logroño (Spagna). L'analisi HTS dei campioni raccolti ha permesso di caratterizzare i profili batterici e la correlazione tra pianta, microbioma di frutta e ambiente. Questo rappresenta un primo passo verso la comprensione del ruolo del terroir e del genotipo delle piante nell’influenzare il microbioma e la qualità del frutto della vite e dei prodotti correlati. Nel complesso, tale lavoro dimostra che le caratteristiche biogeografiche dei microrganismi del campo possono determinare nelle coltivazioni delle proprietà di tipo regionale. Così come il microbioma umano sta cambiando il volto della medicina, allo stesso modo, i futuri sforzi di ricerca dovrebbero essere sempre più focalizzati sull'analisi delle comunità microbiche coltivate e ambientali per cambiare il volto dell'agricoltura.
Food safety and quality depend on raw material characteristics and on the chemical, physical and biotechnological approaches adopted during manufacturing and transformation processes. Since a huge number of microorganisms are involved in food production, most products should be considered as complex matrices where any microbial component has a precise role and evolves in response to changes in physical and chemical features of the whole system. So, understanding the dynamics of microbial community involved in a food supply chain is useful to reduce food spoilage outbreaks, enhance industrial processes and extend product’s shelf-life. The analysis of food microbiota is also pivotal to improve biotransformation processes, like winemaking. From time immemorial, the wine industry has been selectively growing grapevine cultivars showing different traits (e.g., grape size, color and flavor), and small variations in soil composition, irrigation and climate, have long been associated with shifts in these traits. The microbial flora coexisting with the plant may be one of the key factors influencing these traits. Despite long-time difficulties in analyzing single bacterial strains, the High Throughput Sequencing technologies (HTS) are nowadays an emerging and widely adopted tool for microbial characterization, even in food matrices. To clarify the contribution of the microbiome of grape during wine fermentation steps, I used an HTS-based approach to identify bacteria and fungi communities associated to berries and musts of Cannonau cultivar from four vineyards belonging to different regions in Sardinia. Cannonau is the most important grapevine cultivar of Sardinia (Italy), where most vineyards are cultivated without phytochemical treatments. Bioinformatics analyses suggested that microbiome colonizing berries collected at the four different localities shared a core composition characterized by Enterobacteriales, Pseudomonadales, Bacillales, and Rhodospirillales. However, any area seems to enrich berries microbiome with peculiar microbial traits. For example, berries belonging to the biodynamic vineyards of Mamoiada were rich in Bacillales bacteria typical of manure. During vinification processes, performed at the same wine cellar under controlled conditions and without using any yeast starter, more than 50% of bacteria groups of berries reached musts, and each locality had its own private bacteria signature. This work suggests that natural berries microbiome could be influenced by pedoclimatic and anthropological conditions (e.g., farming management), and that fruits’ microorganisms persist during the fermentation process. One of the main open questions about grape microbiome, regards the active role of grapevine cultivars in modelling microbial community. To investigate the relationship between plant genotype, its microbiome and the contribution of field environmental and pedoclimatic conditions, I planned sampling activities in the Mediterranean basin to collect 3 different grapevine cultivars Sauvignon Blanc, Syrha, Cabernet Sauvignon and soil samples from 3 different geographical area Pavia (Northern Italy), San Michele all’Adige (Northern Italy, close to the Alps) and Logroño (Spain). The HTS analysis of collected samples allowed to characterize bacterial profiles and the correlation between plant, fruit microbiome and the environment. This is a first step towards the understanding of the role of terroir and plant genotype in shaping the microbiome and quality of grapevine fruit and related products (i.e., must and wine). On the whole, such work provides clear evidence that the biogeographic characteristics of field’s microorganisms may lead to regional properties associated to valuable crops. Human microbiome is changing the face of medicine. Similarly, future research efforts should be more and more focused on the analysis of crop and environmental microbial communities to change the face of conventional agriculture.
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31

Ercolano, Giorgio. "Superior pinning properties in nano-engineered YBa2Cu3O7-δ". Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/240614.

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Large electrical current transport in the absence of energy losses is thekey factor in commercial applications of high temperature superconductors. This thesis demonstrates an easy and inexpensive bottom-uptechnique to produce self assembled nanorods, segmented nanorodsas well as nanoparticles in YBa2Cu3O7-δ thin films grown by pulsedlaser deposition. The structural and morphological characteristic ofthe pinning landscapes produced are investigated and correlated totheir effects on the superconducting properties of the thin films. In particular two pinning landscapes are investigated: Ba2YNbO6nanorods are grown in YBa2Cu3O7-δ thin films using a Ba2YNbO6doped YBa2Cu3O7-δ pulsed laser deposition targets andBa2(Y/Gd)(Nb/Ta)O6 segmented nanorods together with (Y/Gd)2O3nanoparticles are grown in (Y/Gd)Ba2Cu3O7-δ thin films using aBa2YNbO6 + Gd3TaO7 doped YBa2Cu3O7-δ pulsed laser depositiontargets. The Ba2YNbO6 + YBa2Cu3O7-δ is deeply characterised and the effectsof the deposition parameters are analysed. Ba2YNbO6 is demonstratedto be an interesting novel pinning addition capable to increasethe critical current and to reduce the YBa2Cu3O7-δ critical currentsangular dependencies anisotropy. The Ba2YNbO6 + Gd3TaO7 + YBa2Cu3O7-δ is found to produce anew complex pinning landscape extremely effective. At high fieldsthe synergetic combination of the different defects typology is shownto generate an interesting new feature in the critical current angulardependencies. Chapter 1 is an introduction to superconductivity, the fundamentals ofthe field are briefly presented. In chapter 2 the discussion in focused onpinning in high temperature superconductors. Cuprates and in particularYBa2Cu3O7-δ are presented. The pinning phenomenon andthe practical pinning engineering in thin films is also discussed in thischapter. Chapter 3 describes the thin films preparation methods andthe characterisation techniques used in the research work. Chapter 4and 5 are focused on the Ba2YNbO6 doped YBa2Cu3O7-δ thin films. Chapter 4 is an introduction to Ba2YNbO6 doped YBa2Cu3O7-δ, thepreliminary results obtained on Ba2YNbO6 doped YBa2Cu3O7-δ thin films are shown in this chapter. The crystalline structure, the morphologyand the superconducting properties of thin films depositedadopting different deposition parameters are analysed and discussedin chapter 5. In chapter 6 the new complex pinning landscape ofBa2(Y/Gd)(Nb/Ta)O6 and (Y/Gd)2O3 in (Y/Gd)Ba2Cu3O7-δ is presented. Concluding remarks on the research described in the workends the thesis in a brief final chapter 7.
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32

Seng, Chor Chow. "A business case analysis of the Hard Target Void Sensing Fuze (HTVSF) Joint Capability Technology Demonstration (JCTD)." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Dec/08Dec%5FSeng.pdf.

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Thesis (M.S. in Operations Research)--Naval Postgraduate School, December 2008.
Thesis Advisor(s): Nussbaum, Daniel. "December 2008." Description based on title screen as viewed on January 29, 2009. Includes bibliographical references (p. 49-51). Also available in print.
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33

Wolfbrandt, Anna. "AC losses in HTS as a function of magnetic fields with arbitrary directions." Doctoral thesis, KTH, Electrical Systems, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-35.

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Although a superconductor has zero resistivity when carrying a direct current, losses do occur when it is exposed to an alternating magnetic field and/or is carrying an alternating current. The magnitude of these so-called AC losses depends on the operating temperature, the amplitude and the direction of the magnetic field, the transport current, and the frequency. Therefore, the use of high-temperature superconductors, HTSs, in electric power components such as cables, transformers or reactors, requires knowledge of the AC losses.

This thesis deals with the development of AC loss models for HTSs, mainly for Bi-2223 tapes. In particular, the orientation of the applied magnetic field is taken into account in the modelling. The basis for the models is the results of experimental investigations.

The basic concepts of HTSs with special emphasis on the modelling of AC losses are presented. These can be broken down into several components. Their sources and natures are described. One of the components is the hysteretic loss and it is the dominating loss in AC applications at power frequencies. Therefore, the other loss components are neglected in the modelling.

Models are presented and the associated parameters are investigated with respect to their dependence of the magnetic field as well as the temperature. The AC losses for parallel and perpendicular magnetic field with respect to the wide side of the tape are calculated numerically. Moreover, a semi-empirical model for intermediate angels of the applied magnetic field is proposed. The comparisons show good agreement with experimental results.

Keywords: High-temperature superconductors, AC loss modelling, hysteresis, E-J characteristic.

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34

Hayakawa, N., S. Noguchi, C. Kurupakorn, H. Kojima, F. Endo, N. Hirano, S. Nagaya, and H. Okubo. "Electrical and thermal characteristics of Bi2212/Ag HTS coils for conduction-cooled SMES." Institute of Physics, 2006. http://hdl.handle.net/2237/9148.

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35

Schaffer, Michelle Lee. "Assay development for the directed evolution of NRPS - HTS and phage display technology." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614093.

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36

Bellin, Boris. "Contributions à l'étude des bobinages supraconducteurs : le projet DGA du SMES HTS impulsionnel." Grenoble INPG, 2006. https://tel.archives-ouvertes.fr/tel-00178786.

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Dans le contexte d'un contrat de la Délégation Générale pour l'Armement (DGA) avec la société Nexans, le CRTBT-CNRS a développé un SMES (Superconducting Magnetic Energy Storage). Un SMES est un bobinage supraconducteur qui permet de stocker l'énergie électrique sous forme magnétique. Le bobinage utilise des rubans PIT Bi-2212 fonctionnant à 20 K pour stocker une énergie de 800 kJ. La cryogénie est réalisée avec des drains thermiques en cuivre qui relient les cryoréfrigérateurs et le bobinage. L'interface HT (Haute Tension) entre les drains et le bobinage a une tenue diélectrique de 5 kV et permet de refroidir efficacement le bobinage. Le procédé de co étamage des rubans supraconducteurs développés par Nexans permet d'adapter la géométrie du conducteur à sa situation dans le bobinage. Les essais des dix premières galettes bobinées a validé la cryogénie développée. Enfin l'étude d'extrapolation présente un SMES de 20 MJ
Ln the context of a contra et of the DGA (Délégation Générale pour l'Armement) with the Nexans company, the CRTBT-CNRS developed a SMES (Superconducting Magnetic Energy Storage). A SMES is a superconductive winding which stores the electric energy in magnetic form. Winding uses PIT Bi-2212 tapes at 20 K to store an energy of 800 kJ. Cryogenies is carried out with thermal copper drains that connect the cryocoolers and winding. HT (High VOltage) interface between the drains and winding has a dielectric strength of 5 kV and cools the winding effectively. The soldering process of the superconductive tapes developed by Nexans makes it possible to adapt the geometry of the conductor to its situation in winding. The tests of the first ten pancakes validate developed cryogenies. Finally the study of extrapolation presents a SMES of 20 MJ
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37

Casali, Marco <1984&gt. "Experimental Analysis and Numerical Simulation of Quench in Superconducting HTS Tapes and Coils." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6242/1/Experimental_Analysis_and_Numerical_Simulation_of_Quench_in_Superconducting_HTS_Tapes_and_Coils.pdf.

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The quench characteristics of second generation (2 G) YBCO Coated Conductor (CC) tapes are of fundamental importance for the design and safe operation of superconducting cables and magnets based on this material. Their ability to transport high current densities at high temperature, up to 77 K, and at very high fields, over 20 T, together with the increasing knowledge in their manufacturing, which is reducing their cost, are pushing the use of this innovative material in numerous system applications, from high field magnets for research to motors and generators as well as for cables. The aim of this Ph. D. thesis is the experimental analysis and numerical simulations of quench in superconducting HTS tapes and coils. A measurements facility for the characterization of superconducting tapes and coils was designed, assembled and tested. The facility consist of a cryostat, a cryocooler, a vacuum system, resistive and superconducting current leads and signal feedthrough. Moreover, the data acquisition system and the software for critical current and quench measurements were developed. A 2D model was developed using the finite element code COMSOL Multiphysics R . The problem of modeling the high aspect ratio of the tape is tackled by multiplying the tape thickness by a constant factor, compensating the heat and electrical balance equations by introducing a material anisotropy. The model was then validated both with the results of a 1D quench model based on a non-linear electric circuit coupled to a thermal model of the tape, to literature measurements and to critical current and quench measurements made in the cryogenic facility. Finally the model was extended to the study of coils and windings with the definition of the tape and stack homogenized properties. The procedure allows the definition of a multi-scale hierarchical model, able to simulate the windings with different degrees of detail.
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38

Casali, Marco <1984&gt. "Experimental Analysis and Numerical Simulation of Quench in Superconducting HTS Tapes and Coils." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6242/.

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Анотація:
The quench characteristics of second generation (2 G) YBCO Coated Conductor (CC) tapes are of fundamental importance for the design and safe operation of superconducting cables and magnets based on this material. Their ability to transport high current densities at high temperature, up to 77 K, and at very high fields, over 20 T, together with the increasing knowledge in their manufacturing, which is reducing their cost, are pushing the use of this innovative material in numerous system applications, from high field magnets for research to motors and generators as well as for cables. The aim of this Ph. D. thesis is the experimental analysis and numerical simulations of quench in superconducting HTS tapes and coils. A measurements facility for the characterization of superconducting tapes and coils was designed, assembled and tested. The facility consist of a cryostat, a cryocooler, a vacuum system, resistive and superconducting current leads and signal feedthrough. Moreover, the data acquisition system and the software for critical current and quench measurements were developed. A 2D model was developed using the finite element code COMSOL Multiphysics R . The problem of modeling the high aspect ratio of the tape is tackled by multiplying the tape thickness by a constant factor, compensating the heat and electrical balance equations by introducing a material anisotropy. The model was then validated both with the results of a 1D quench model based on a non-linear electric circuit coupled to a thermal model of the tape, to literature measurements and to critical current and quench measurements made in the cryogenic facility. Finally the model was extended to the study of coils and windings with the definition of the tape and stack homogenized properties. The procedure allows the definition of a multi-scale hierarchical model, able to simulate the windings with different degrees of detail.
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39

Pallarès, Albanell Joan 1988. "Evaluation of non-coding RNAs in Parkinson's disease." Doctoral thesis, Universitat Pompeu Fabra, 2017. http://hdl.handle.net/10803/664379.

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Анотація:
Parkinson’s disease (PD) is the commonest movement disorder and a devastating neurodegenerative condition. Although PD motor symptoms arise from the progressive loss of dopaminergic neurons on the Substantia Nigra, this disease also affects other brain areas. This thesis explores the intersection between deregulated non-coding RNAs (ncRNAs), key gene expression regulators, and PD. We do so investigating different ncRNAs species: small non-coding RNAs (sncRNAs) and long non-coding RNAs (lncRNAs). Our results suggest that ncRNA deregulation is a specific process, presenting selective temporal and spatial deregulation patterns. We show that Oxidative Stress (OS), a key PD component, modifies the expression levels of ncRNAs. Besides, we performed two High-Throughput Functional Screenings that identified sncRNAs important for neuronal maintenance and response to OS. Finally, we used an engineered CRISPR-Cas9 tool in cell culture to overexpress the endogenous lncRNA LINC01007, which is a putative master gene expression regulator.
La malaltia de Parkinson (MP) és l’afecció del moviment més comú i una malaltia neurodegenerativa devastadora. Tot i que els símptomes motors de la MP són deguts a la pèrdua progressiva de neurones dopaminèrgiques a la Substància Negra, aquesta malaltia també afecta altres àrees del cervell. Aquesta tesi explora la intersecció entre la desregulació d’ARNs no codificants (ARNnc), reguladors clau de l’expressió gènica, i la MP. Això ho fem investigant diverses espècies d’ARNnc: ARN no codificants petits (ARNncp) i ARN no codificants llargs (ARNncl). Els nostres resultats suggereixen que la desregulació d’ARNnc és un procés específic, presentant uns patrons de desregulació temporal i espacial selectius. Mostrem que l’Estrès Oxidatiu (EO), un component clau de la MP, modifica els nivells d’expressió d’ARNncs. A més, em dut a terme dos Cribratges Funcionals d’Alt Rendiment que han identificat ARNncp importants per al manteniment neuronal i la resposta a EO. Finalment, en cultius cel·lulars, em emprat una eina CRISPR-Cas9 modificada per a sobreexpressar l’ARNncl endogen LINC01007, que és un putatiu regulador transcripcional mestre.
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40

Santos, de Medeiros Ana. "Chemical Genetic Studies of Chemical Modulators of Mammalian Adenylyl Cyclases and Phosphodiesterases Expressed in Fission Yeast." Thesis, Boston College, 2016. http://hdl.handle.net/2345/bc-ir:106850.

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Thesis advisor: Charles Hoffman
Cyclic adenosine monophosphate (cAMP) and the second messengers that modulate several biological processes are regulated by adenylyl cyclase (AC) and cyclic nucleotide phosphodiesterases (PDEs). ACs and PDEs are comprised of superfamilies of enzymes that are viewed as druggable targets due to their many distinct biological roles and tissue-specific distribution. As such, small molecule regulators of ACs and PDEs are important as chemical probes to study the roles of individual ACs or PDEs and as potential therapeutics. In the past, our lab has expressed 15 mammalian PDE genes in S. pombe, replacing the endogenous Cgs2 PDE. High throughput screens for PDE inhibitors identified novel compounds that show relevant biological activity in mammalian cell culture assays. The aim of this thesis is to develop tools to understand the mechanism of interaction between key regulators of the cAMP pathway and small molecules. The current study is comprised of two parts. In the first part of this thesis, I developed a genetic screen that detected alleles whose proteins remain active in the presence of BC54 and was to confirm the effect of the PDE4BT407A mutation using cell-based assays and in vitro enzyme assays. In the second part of this thesis, I developed and carried out HTSs using a PKA-repressed GFP reporter that can identify compounds that reduce PKA activity, which would include PDE activators and AC or GNAS1 inhibitors. To date, I have identified three AC inhibitors that appear to act on several of the ten different mammalian ACs. To our knowledge, this is the first time a large HTS has identified AC inhibitors, where inhibition was assessed inside the cells. The findings in this thesis will be useful in the design of more effective PDE inhibitors and in the development of novel chemical probes for studying cAMP signaling in mammalian cells
Thesis (PhD) — Boston College, 2016
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
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41

Matsumura, T., H. Shimizu, and Y. Yokomizu. "Design guideline of flux-lock type HTS fault current limiter for power system application." IEEE, 2001. http://hdl.handle.net/2237/6783.

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42

CONSTANTE, Caroline Santos. "Prevalência de sintomas urinários em indivíduos portadores do Vírus Linfotrópico de Células T Humanas do tipo 1 (HTVL-1)." Universidade Federal do Pará, 2014. http://repositorio.ufpa.br/jspui/handle/2011/9190.

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Анотація:
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) infecta cerca de 20 milhões de pessoas em todo mundo. Ele está associado principalmente à leucemia/linfoma de células T do adulto (LLTA) e à doença neurológica paraparesia espástica tropical/mielopatia associada ao HTLV (PET/MAH). A PET/MAH provoca alterações motoras, fraqueza, rigidez nos membros inferiores, disfunções erétil e urinária. Alguns estudos demonstram que existe uma tendência de pacientes portadores de HTLV-1 apresentarem algum sintoma urinário não apenas em indivíduos com PET/MAH, mas também em indivíduos considerados como portadores assintomáticos, destacando a importância de estudos que abordem o universo dos sintomas urinários em indivíduos portadores de HTLV-1 a fim de aprofundar o conhecimento científico da evolução clínica dos indivíduos infectados pelo vírus, favorecer diagnósticos e intervenções mais precoces e melhorar a qualidade de vida e a saúde dos portadores de HTLV-1. A presente pesquisa teve por objetivo principal verificar a prevalência de sintomas urinários entre indivíduos portadores de HTLV-1 e, como objetivos específicos, descrever as características sócio-demográficas; identificar os sintomas urinários mais frequentes; verificar a associação da presença de sintomas urinários aos achados clínico-neurológicos e analisar o impacto na qualidade de vida dos sintomas urinários em indivíduos portadores de HTLV-1. Foi realizado um estudo transversal envolvendo 45 indivíduos portadores de HTLV-1 atendidos no ambulatório do NMT⁄UFPA, por meio de avaliação clínico-neurológica, avaliação quanto à presença de sintomas urinários e avaliação do impacto dos sintomas urinários sobre a qualidade de vida com a aplicação do King´s Health Questionnaire. A amostra apresentou média de 48,82 anos de idade, sendo a maioria assintomática (64,44%); do gênero feminino (64,44%); casada (64,44%), com ensino fundamental (53,33%); sem conhecimento do seu modo de infecção (53,33%). A prevalência de sintomas urinários foi de 73,33% sendo 69% entre portadores de HTVL-1 assintomáticos e 81,3% entre indivíduos com PET⁄MAH. Os sintomas urinários mais frequentes foram a noctúria (71,11%); urge-incontinência (44,44%) e urgência urinária (42,22%). Não houve associação entre os achados clínico-neurológicos e a presença de sintomas urinários e, a avaliação da qualidade de vida mostrou impacto negativo em sete dos nove domínios abordados pelo questionário. Foi encontrada alta prevalência de sintomas urinários em indivíduos portadores de HLTV-1, não somente em indivíduos com PET⁄MAH, mas também em portadores considerados assintomáticos. Sugere-a realização de novos estudos com amostras maiores e com exames de diagnóstico mais precisos para esclarecer melhor o surgimento desses sintomas entre os portadores assintomáticos do HTLV-1 e sua relação com o agravamento da mielopatia.
The human T-cells lymphotropic virus type 1 (HTLV-I) infects approximately 20 million people worldwide. It is mainly associated with adult T-cell leukemia/lymphoma (ATLL) and a neurological disease HLTV associated myelopathy/ tropical spastic paraparesis (HAM/TSP). The HAM/TSP causes motor abnormalities, weakness, increased tone in the lower limbs, urinary and erectile dysfunction. Studies show that there is a tendency of patients with HTLV-I to have some urinary symptoms. These symptoms persist not only in individuals with HAM/TSP, but also in individuals considered as asymptomatic carriers. This highlights the importance of studies that address the multitude of urinary symptoms in individuals with HTLV-I in order to deepen the scientific knowledge of the clinical progression of HTLV-I infected individuals, facilitate diagnosis, allow for earlier interventions and improve the quality of life and health of patients with HTLV-I. This research was aimed to determine the prevalence of urinary symptoms among individuals with HTLV-I with the specific objectives to describe the socio-demographic characteristics; identify the most frequent urinary symptoms reported; verify the association of the presence of urinary symptoms to neurological findings and analyze the impact on quality of life of urinary symptoms in individuals with HTLV-I. The study involved cross-sectional analysis involving 45 individuals with HTLV-I through the outpatient clinic at the NMT/UFPA. Through clinical neurological evaluation, the presence of urinary symptoms and impact assessment of urinary symptoms on quality of life by carriers HTLV-I was assessed applying the King's Health Questionnaire. The sample have had an average of 48.82 years of age, most were asymptomatic (64,44%), female (64,44%), married (64,44%), with primary education (53,33%) and without knowledge of its mode of infection (53,33%). The prevalence of urinary symptoms was 73,33% being 69% among patients with asymptomatic HTVL-I and 81,3% among individuals with HAM/TSP. The most common urinary symptoms were nocturia (71.11%), urinary urgency with incontinence (44.44%) and urinary urgency (42.22%). There was no association between neurological findings and the presence of urinary symptoms and the assessment of quality of life showed negative impact on seven of the nine areas covered by the questionnaire. High prevalence of urinary symptoms was found in individuals with HTLV-I, not only in individuals with HAM/TSP, but also in patients considered asymptomatic carriers. It is suggested that further studies with larger sample sizes and more accurate diagnostic tests to clarify development of these symptoms among asymptomatic carriers and its relationship with the worsening of myelopathy.
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43

Frugier, François. "Pathogenèse du syndrome sec associé à l'infection par le virus HTVL-I : recherche de variants, modèle d'étude in vitro." Poitiers, 2001. http://www.theses.fr/2001POIT2285.

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44

Xu, Lin. "Novel G2 cell cycle checkpoint inhibitors and antimitotic agents isolated through two new HTS bioassays." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61207.pdf.

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45

Le, Maguer Sébastien. "Évaluation expérimentale d'un système statistique de synthèse de la parole, HTS, pour la langue française." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00934060.

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Анотація:
Les travaux présentés dans cette thèse se situent dans le cadre de la synthèse de la parole à partir du texte et, plus précisément, dans le cadre de la synthèse paramétrique utilisant des règles statistiques. Nous nous intéressons à l'influence des descripteurs linguistiques utilisés pour caractériser un signal de parole sur la modélisation effectuée dans le système de synthèse statistique HTS. Pour cela, deux méthodologies d'évaluation objective sont présentées. La première repose sur une modélisation de l'espace acoustique, généré par HTS par des mélanges gaussiens (GMM). En utilisant ensuite un ensemble de signaux de parole de référence, il est possible de comparer les GMM entre eux et ainsi les espaces acoustiques générés par les différentes configurations de HTS. La seconde méthodologie proposée repose sur le calcul de distances entre trames acoustiques appariées pour pouvoir évaluer la modélisation effectuée par HTS de manière plus locale. Cette seconde méthodologie permet de compléter les diverses analyses en contrôlant notamment les ensembles de données générées et évaluées. Les résultats obtenus selon ces deux méthodologies, et confirmés par des évaluations subjectives, indiquent que l'utilisation d'un ensemble complexe de descripteurs linguistiques n'aboutit pas nécessairement à une meilleure modélisation et peut s'avérer contre-productif sur la qualité du signal de synthèse produit.
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46

Caetano, Leonardo Martins. "Materiais supercondutores HTS para arranjos de antenas e aplica??o de PBG para micro-ondas." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15238.

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Анотація:
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Atualmente as antenas de microfita lineares e planares t?m despertado interesses devido as suas caracter?sticas e vantagens que oferecem quando comparadas com os demais tipos de antenas. Na ?rea de comunica??es sem fio ? necessidade de antenas desse tipo, tem se tornado cada vez mais utilizada devido ao intenso desenvolvimento, que necessita de antenas que operem em multifrequ?ncias e em banda larga. As antenas de microfita apresentam largura de banda estreita devido ?s perdas no diel?trico geradas pela irradia??o. Outra limita??o ? a degrada??o do diagrama de irradia??o devido ? gera??o de ondas de superf?cie no substrato. Outras t?cnicas est?o sendo desenvolvidas para minimizar esta limita??o de banda, como ? o caso do estudo de materiais do tipo PBG Photonic Band Gap, para compor o material diel?trico. Este trabalho tem como objetivo principal o estudo dos arranjos de antenas de microfita com patch retangular supercondutor. ? apresentado um estudo das principais teorias que explicam o fen?meno microsc?pico e macrosc?pico da supercondutividade. As teorias BCS, equa??es de London e modelo dos Dois Fluidos, s?o as teorias usadas nas aplica??es dos supercondutores, nas antenas e arranjos de antenas de microfita. Os arranjos de fase s?o analisados em configura??es lineares e planares. S?o obtidos os fatores de arranjos para estas configura??es, e os crit?rios da fase e do espa?amento entre os elementos que comp?em os arranjos, ao qual ser?o examinados, com o objetivo de minimizar as perdas no material, comparados com condutores normais. A antena com patch retangular, constitu?da de material supercondutor, com a temperatura cr?tica a 160K tem a f?rmula qu?mica ? SnBaCaCuOy. A an?lise ? feita atrav?s do m?todo din?mico da Linha de Transmiss?o Transversa (LTT), desenvolvido por H.C.C.Fernandes, no dom?nio da transformada de Fourier (FTD). O m?todo LTT ? um m?todo de onda completa, que tem como regra a obten??o dos campos eletromagn?ticos em termos dos componentes transversais ? estrutura. A inclus?o do patch supercondutor ? feita utilizando-se a condi??o de contorno complexa resistiva, usando-se a imped?ncia do supercondutor na fun??o Did?tica de Green, da estrutura. A efici?ncia dessas t?cnicas ser? investigada atrav?s de simula??es realizadas pelo Ansoft HFSS, utilizado na an?lise precisa do comportamento eletromagn?tico dos respectivos arranjos de antenas linear e planar, atrav?s do m?todo dos elementos finitos (FEM). S?o obtidos resultados da frequ?ncia de resson?ncia em fun??o dos par?metros da antena, utilizando material supercondutor, diagramas de radia??o no Plano-E e no Plano-H, para os arranjos de fase de antenas nas configura??es lineares e planares, bem como os seus respectivos ganhos
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47

Wang, Yuanyuan (Marcia). "Statistical Methods for High Throughput Screening Drug Discovery Data." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/1204.

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Анотація:
High Throughput Screening (HTS) is used in drug discovery to screen large numbers of compounds against a biological target. Data on activity against the target are collected for a representative sample of compounds selected from a large library. The goal of drug discovery is to relate the activity of a compound to its chemical structure, which is quantified by various explanatory variables, and hence to identify further active compounds. Often, this application has a very unbalanced class distribution, with a rare active class.

Classification methods are commonly proposed as solutions to this problem. However, regarding drug discovery, researchers are more interested in ranking compounds by predicted activity than in the classification itself. This feature makes my approach distinct from common classification techniques.

In this thesis, two AIDS data sets from the National Cancer Institute (NCI) are mainly used. Local methods, namely K-nearest neighbours (KNN) and classification and regression trees (CART), perform very well on these data in comparison with linear/logistic regression, neural networks, and Multivariate Adaptive Regression Splines (MARS) models, which assume more smoothness. One reason for the superiority of local methods is the local behaviour of the data. Indeed, I argue that conventional classification criteria such as misclassification rate or deviance tend to select too small a tree or too large a value of k (the number of nearest neighbours). A more local model (bigger tree or smaller k) gives a better performance in terms of drug discovery.

Because off-the-shelf KNN works relatively well, this thesis takes this promising method and makes several novel modifications, which further improve its performance. The choice of k is optimized for each test point to be predicted. The empirically observed superiority of allowing k to vary is investigated. The nature of the problem, ranking of objects rather than estimating the probability of activity, enables the k-varying algorithm to stand out. Similarly, KNN combined with a kernel weight function (weighted KNN) is proposed and demonstrated to be superior to the regular KNN method.

High dimensionality of the explanatory variables is known to cause problems for KNN and many other classifiers. I propose a novel method (subset KNN) of averaging across multiple classifiers based on building classifiers on subspaces (subsets of variables). It improves the performance of KNN for HTS data. When applied to CART, it also performs as well as or even better than the popular methods of bagging and boosting. Part of this improvement is due to the discovery that classifiers based on irrelevant subspaces (unimportant explanatory variables) do little damage when averaged with good classifiers based on relevant subspaces (important variables). This result is particular to the ranking of objects rather than estimating the probability of activity. A theoretical justification is proposed. The thesis also suggests diagnostics for identifying important subsets of variables and hence further reducing the impact of the curse of dimensionality.

In order to have a broader evaluation of these methods, subset KNN and weighted KNN are applied to three other data sets: the NCI AIDS data with Constitutional descriptors, Mutagenicity data with BCUT descriptors and Mutagenicity data with Constitutional descriptors. The k-varying algorithm as a method for unbalanced data is also applied to NCI AIDS data with Constitutional descriptors. As a baseline, the performance of KNN on such data sets is reported. Although different methods are best for the different data sets, some of the proposed methods are always amongst the best.

Finally, methods are described for estimating activity rates and error rates in HTS data. By combining auxiliary information about repeat tests of the same compound, likelihood methods can extract interesting information about the magnitudes of the measurement errors made in the assay process. These estimates can be used to assess model performance, which sheds new light on how various models handle the large random or systematic assay errors often present in HTS data.
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48

Xu, Yongli. "High Jc Epitaxial YBa2Cu3O7-δ Films Through a Non-Fluorine Approach for Coated Conductor Applications". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1075992286.

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49

AGOSTINETTO, GIULIA. "Data-driven approaches for biodiversity exploration via DNA metabarcoding data analysis." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/365346.

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Анотація:
Gli approcci metagenomici hanno cambiato il modo di studiare la biologia e la biodiversità in diversi campi. In particolare, il progresso tecnologico ci consente di determinare la composizione tassonomica dei campioni e di studiare la biodiversità in ambienti molto diversi. Al giorno d'oggi, il DNA metabarcoding è una procedura standard, applicata in un'ampia gamma di settori, dalla salute umana all'ecologia, alle applicazioni industriali. Negli ultimi anni, il DNA metabarcoding applicato al 16S rRNA è stato ampiamente utilizzato per studiare la comunità batterica, portando ad analisi di routine che hanno creato enormi quantità di dati, consentendo ai ricercatori di sviluppare strategie data-driven per rispondere a domande biologiche complesse. Inoltre, il DNA metabarcoding può essere utilizzato anche per studiare Piante, Animali o Funghi, grazie allo sviluppo di diversi marcatori molecolari. In entrambi i casi, considerando l'enorme quantità di dati prodotti dai ricercatori e disponibili nelle banche dati, una prospettiva di ‘data mining’ nella gestione e nell'esplorazione dei dati di DNA metabarcoding potrebbe essere utile per identificare nuovi pattern ed estrarre maggiori informazioni dai dati. Nella mia tesi di dottorato, mi sono focalizzata su una prospettiva incentrata sui dati di DNA metabarcoding, toccando quattro punti principali che possono potenziare e migliorare le strategie attuali: i) considerare le informazioni molecolari ottenute dal sequenziamento high-throughput del DNA (HTS) e disponibili in archivi pubblici, ii ) migliorare la fase di assegnazione della tassonomia, iii) studiare nuovi metodi per la ricostruzione di pattern di biodiversità e iv) utilizzare dati già prodotti come risorsa preziosa per la ricerca. Questi quattro punti possono migliorare a diversi livelli le potenzialità delle applicazioni di tecniche fondate sul DNA metabarcoding, aprendo la strada a procedure di standardizzazione per marcatori meno diffusi e all'integrazione di nuove strategie di data mining e riutilizzo di dati di DNA metabarcoding.
Metagenomic approaches have changed the way to study biology and biodiversity in several fields. In particular, technology advancement enables us to determine taxa composition and to study complex biodiversity patterns in very different environments. Nowadays, DNA metabarcoding is a standard procedure, applied on a wide range of fields, from human health to ecology, to industry applications. In the last few years, 16S rRNA metabarcoding was widely used to study the bacterial community, leading to routine analysis which created huge amounts of data, bringing researchers to develop data mining strategies in order to answer complex biological questions. On the other hand, DNA metabarcoding can be applied also to study Plants, Animals or Fungi, as very different molecular markers have been identified. In both cases, considering the huge amount of data produced by researchers and available in repositories, a data-driven perspective in managing and exploring DNA metabarcoding data could be useful to collect hidden information and potentially determine undiscovered aspects. In this PhD dissertation, I focused the attention on a data-centered perspective of DNA metabarcoding data, touching four main points that can enhance and ameliorate the current strategies: i) consider the molecular information obtained from high-throughput DNA sequencing (HTS) and available in public repositories, ii) enhance taxonomy assignment step, iii) investigate new methods for pattern reconstruction and iv) use data as a valuable resource for research. These four steps can enhance at different levels the potentials of DNA metabarcoding applications, paving the way for standardization procedures for uncommon markers and the integration of new data mining and data reuse strategies of metabarcoding data.
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50

Wong, Yum-wing. "Design and implementation of high temperature superconducting (HTS) tape RF coil and cryostat for MRI applications." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37109984.

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