Dissertations / Theses on the topic 'Quenc'
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Chiletti, Maxime. "Pertes par couplages dans les câbles en conduit supraconducteurs des réacteurs à fusion thermonucléaire : modélisation théorique et investigations expérimentales." Electronic Thesis or Diss., Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0552.
The objective of the present work is to generalize a purely analytical model used to assess the magnetization of a superconducting cable. These cables are assembled twisting several superconducting strands together in stages, making the electromagnetic description harder to handle due to this complex geometry. Starting from an already existing CEA model limited to the description of two consecutive stages, we strengthen its analytical basis in order to build a fully generalized model capable to represent complex cables with any number of stages. This new model, called N-stage COLISEUM, is confronted to experimental coupling losses measurements conducted on several cable samples in the JOSEFA facility, showing a fair agreement. The quality of the predictions from the N-stage COLISEUM is verified and also compared to an heuristic CEA model (MPAS), already established, opening the path for possible evolutions of both models and for stability applications
Vorster, Willem Johannes Jacobus. "Spray quench processing." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531785.
Fontecchio, Marco. "Quench probe and quench factor analysis of aluminum alloys in distilled water." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0429102-153911.
Coatanea-gouachet, Marc. "Quench detection and behaviour in case of quench in the ITER magnet systems." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4739/document.
The quench of one of the ITER magnet system is an irreversible transition from superconducting to normal resistive state, of a conductor. This normal zone propagates along the cable in conduit conductor dissipating a large power. The detection has to be fast enough to dump out the magnetic energy and avoid irreversible damage of the systems. The primary quench detection in ITER is based on voltage detection which is the most rapid detection. The very magnetically disturbed environment during the plasma scenario, makes the voltage detection particularly difficult, inducing large inductive components in the coils and voltage compensations have to be designed to discriminate the resistive voltage associated with the quench. A conceptual design of the quench detection based on voltage measurements is proposed for the three majors magnet systems of ITER. For this, a clear methodology was developed. It includes the classical hot spot criterion, the quench propagation study using the commercial code Gandalf and the careful estimation of the inductive disturbances by developing the TrapsAV code.Specific solutions have been proposed for the compensation in the three ITER magnet systems and for the quench detection parameters which are the voltage threshold (in the range of 0.1 V- 0.55 V) and the holding time (in the range of 1 -1.4 s). The selected values, in particular the holding time, are sufficiently high to ensure the reliability of the system and avoid fast safety discharges not induced by a quench which is a classical problem
Peixoto, Luísa Helena Figueiredo. "LLamando los colores/Pecón Quena." reponame:Repositório Institucional da UFSC, 2017. https://repositorio.ufsc.br/xmlui/handle/123456789/180911.
Made available in DSpace on 2017-11-14T03:24:04Z (GMT). No. of bitstreams: 1 349147.pdf: 3838509 bytes, checksum: 45a83519e4630f48469ce1dbb63b6dbc (MD5) Previous issue date: 2017
Este trabalho trata da produção da artista plástica Lastenia Canayo. A obra dessa artista faz parte de um circuito artístico emergente na Amazônia peruana, caracterizado por produzirem imagens relacionadas ao universo das plantas con poder. A artista se destaca nisto, a meu ver, pela escolha de suportes variados e pelo tema de seu trabalho que se destaca como processo de individuação criativa ao criar o mundo dos "donos" por meio da arte. As noções de "donos" são conhecidas por distintos nomes por cada sociedade amazônica, cada qual informado etnograficamente, e compreendido segundo as relações de controle e proteção que estabelecem com o coletivo com o qual interagem. Ela reinsere, assim, por meio de sua produção iconográfica, os diversos entes, tais como plantas, animais, pessoas, espíritos e coisas na sociabilidade de domínio e maestria Shipibo-Konibo.
Abstract : This present paper deals with the production of the plastic artist Lastenia Canayo. The work of this artist is part of an emerging artistic circuit in the Peruvian Amazon, characterized by producing images related to the universe of plants with power. The artist stands out in this, in my opinion, for the choice of varied supports and the subject of her work that highlights as a process of individualization by creating the world of 'owners' through art. The notions of ?owners? are known by different names by each Amazonian society, each one ethnographically informed and understood according to control and protection relations which they set with the group with which they interact. It insert as well, through its iconographic production, the various beings, such as plants, animals, people, spirits, and things in the sociability of Shipibo-Konibo domain and Mastery.
Ducatel, Estelle. "Composting of ethane pyrolysis quench sludge." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0017/MQ48061.pdf.
Zajc, David. "Experimental study of a quench process." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176232474.
Lilley, I. "Quench correction in liquid scintillation counting." Thesis, Nottingham Trent University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376969.
Huang, Taotao. "Quench modelling of high temperature superconductor." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/65717/.
Lu, Yuan. "Heat Transfer, Hardenability and Steel Phase Transformations during Gas Quenching." Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-dissertations/399.
Lee, Kyoungjin. "Electrical properties of quench-condensed thin film." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1596.
Lu, Yuan. "A Study on Gas Quench Steel Hardenability." Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-theses/125.
Bottura, L. "The numerical solution of 'quench' in superconducting magnets." Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636123.
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.
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.
Ang, Ing Chea. "Stability and quench protection of high-temperature superconductors." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/35665.
Includes bibliographical references (leaves 83-84).
In the design and operation of a superconducting magnet, stability and protection are two key issues that determine the magnet's reliability and safe operation. Although the high-temperature superconductor (HTS) is considered much more stable than the low-temperature superconductor (LTS), it is susceptible to damage caused primarily by three events that can occur in large-scale "real" devices: 1) overheating; 2) high voltage; and, 3) overstressing. In this thesis, we have investigated the first two issues as well acoustic emission (AE) technique as a possible mean for an early detection of a quench. For most of the experimental work reported here, we used "pancake" coils wound with coated YBCO conductor, the HTS of choice by those currently developing HTS-based electric power devices, though, YBCO itself to date is still in the development phase. For protection against overheating, an HTS magnet assembled with pancake coils may be made self-protecting through speedy 2-D or even 3-D normal zone propagation (NZP) within its winding, aided by good thermally-diffusive turn-to-turn spacers.
(cont.) We have found experimentally that good thermal diffusivity alone, however, does not guarantee fast 2-D NZP: thermal contact resistance between winding layers plays a crucial role in NZP in the transverse direction. For high internal voltage, a small test "magnet" consisting of two pancake coils was studied to investigate the internal voltage distributions within the magnet when one of the pancakes was driven normal with a heater. Measured voltage distributions were compared with those of simulation. Finally, to complement standard resistive voltage technique, an acoustic emission (AE) technique was investigated for detection of a quench at an instance earlier than that possible with a resistive voltage technique. With improved understanding of these issues, we should be able to develop protection techniques that ensure reliable and safe operation of HTS devices.
by Ing Chea Ang.
S.M.
Robert-Demolaize, Guillaume. "Design and performance optimization of the LHC collimation system." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10215.
The Large Hadron Collider (LHC) of CERN is a circular machine using superconducting magnets to achieve the large bending fields required to run two proton beams up to a 7 TeV energy. The maximum foreseen luminosity is set to L = 1034 cm2s-1. Halo particles that drifted away from the core of the beam must be removed for superconducting quenches to be avoided. This is achieved with a multi-stage cleaning system using two-sided collimators located at adequate positions in the machine. Due to the high luminosity value, the required inefficiency of the LHC collimation regions must be much lower than any other machine, around 0. 00002 % in the top energy case. Detailed simulations ofrealistic operational conditions were performed to address the sensitivity ofthe cleaning system. Bearn 10ss maps show the distribution oflocal proton losses around the machine to the 10 cm level. The level of performance ofthe LHC collimation system is given in the ideal machine case and for a realistic scenario of orbit perturbation : the machine can only be run with respectively 43 % (ideal case) and 27 % (error model) of the nominal machine intensity. A list of characteristic loss locations is also given to help monitor beam losses at optimal locations regarding machine protection issues. A prototype collimator was tested in real LHC-like beam conditions. The control of the collimator gap was achieved down to the 50 μm 1evel, and interesting results on the actual beam physics with collimation were also obtained. The robustness of the graphite collimator jaws was also tested and results were compared with simulation programs to validate aIl previous estimates on energy deposition studies
Mahar, Scott B. "Spontaneous brillouin scattering quench diagnostics for large superconducting magnets." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/53258.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 243-250).
Large superconducting magnets used in fusion reactors, as well as other applications, need a diagnostic that can non-invasively measure the temperature and strain throughout the magnet in real-time. A new fiber optic sensor has been developed for these long-length superconducting magnets that simultaneously measures the temperature and strain based on spontaneous Brillouin scattering in an optical fiber. Using an extremely narrow (200 Hz) linewidth Brillouin laser with very low noise as a frequency shifted local oscillator, the frequency shift of spontaneous Brillouin scattered light was measured using heterodyne detection. A pulsed laser was used to probe the fiber using Optical Time Domain Reflectometry (OTDR) to define the spatial resolution. The spontaneous Brillouin frequency shift and linewidth as a function of temperature agree well with previous literature of stimulated Brillouin data from room temperature down to 4 K. Analyzing the frequency spectrum of the scattered light after an FFT gives the Brillouin frequency shift, linewidth. and intensity. For the first time, these parameters as a function of strain have been calibrated down to 4 K. Measuring these three parameters allow for simultaneously determining the temperature and strain in real-time throughout a fiber with a spatial resolution on the order of several meters. The accuracy of the temperature and strain measurements vary over temperature-strain space, but an accuracy of better than + 2 K and ± 100 Pe are possible throughout most of the calibrated temperature-strain space (4-298 K and 0-3500 p/g). In the area of interest for low-temperature superconducting magnets (4-25 K), the temperature accuracy is better than + 1 degree.
(cont.) This temperature accuracy, along with the sub-second measurement time, allows this system to be used not only as a quench detection system, but also as a quench propagation diagnostic. The sensing fiber can also simultaneously provide the first ever spatially resolved strain measurement in an operating magnet.
by Scott Brian Mahar.
Ph.D.
Donati, Laurent. "Experimental investigation of Zn vapour oxidation in a quench apparatus." Zürich : ETH, Eidgenössische Technische Hochschule Zürich, Institut für Ergenietechnik, 2006. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=280.
Malcomson, Matthew. "Momentum evolution numerics of an impurity in a quantum quench." Thesis, Lancaster University, 2016. http://eprints.lancs.ac.uk/78429/.
Ziraldo, Simone. "Thermalization and relaxation after a quantum quench in disordered Hamiltonians." Doctoral thesis, SISSA, 2013. http://hdl.handle.net/20.500.11767/4817.
Qu, Hao. "Advanced High Strength Steel Through Paraequilibrium Carbon Partitioning and Austenite Stabilization." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1283353953.
Chigusa, S., N. Hayakawa, and H. Okubo. "Quench-induced dynamic breakdown strength of liquid helium for superconducting coils." IEEE, 2000. http://hdl.handle.net/2237/6763.
Shajii, A. (Ali). "Theory and modelling of quench in cable-in-conduit superconducting magnets." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11987.
Östlund, Rickard. "Microstructure based modelling of ductile fracture in quench-hardenable boron steel." Doctoral thesis, Luleå tekniska universitet, Material- och solidmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26413.
Godkänd; 2015; 20150219 (ricost); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Rickard Östlund Ämne: Hållfasthetslära /Solid Mechanics Avhandling: Microstructure Based Modelling of Ductile Fracture in Quench-Hardenable Boron Steel Opponent: Professor Michael Worswick, Dept of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada Ordförande: Professor Mats Oldenburg, Avd för Material- och solidmekanik, Institutionen för Teknikvetenskap och matematik, Luleå tekniska universitet, Luleå. Tid: Fredag 17 april kl 10.00 Plats: E231, Luleå tekniska universitet
ISLAM, MD SHAHRUL. "Can Asymmetry Quench Self-Heating in MOS High Electron Mobility Transistors?" OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2736.
Poole, Charles Randall. "QUENCH PROTECTION STUDIES OF MAGNESIUM DIBORIDE SUPERCONDUCTING MAGNETS FOR MRI APPLICATIONS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1523017967730333.
Mohamed, Mohamed Saad Kamel. "An investigation of hot forming quench process for AA6082 aluminium alloys." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6147.
Patki, Rahul P. "Quench Crystallization of Linear Polyethylene: Crystallization Kinetics, Morphology and Structure Investigation." Cincinnati, Ohio : University of Cincinnati, 2008. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1227282696.
Merchant, Lynne M. "Variation of the superconductor order parameter in quench-condensed granular films /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9984298.
Menegoz, Giuseppe. "Prethermalization after a sudden quench in a weakly interacting Bose system." Doctoral thesis, SISSA, 2014. http://hdl.handle.net/20.500.11767/3872.
Huang, Yawei. "Etude et modélisation des phénomènes thermohydrauliques résultant du quench d'un aimant supraconducteur refroidi en hélium supercritique." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS230/document.
During the last decades, the quench phenomenon has been one of the most important issues addressed in the superconducting magnets designs. Indeed, the quench transition of a magnet from its superconducting state to its normal state induces a large deposition of the Joule effect energy leading to an abrupt temperature increase in the conductor as well as a large pressure rise in the helium coolant. Any excess of these two parameters can cause an irreversible damage either to the magnet or to the cryogenic system. In order to achieve a better understanding of the quench behavior of the TF coils in the superconducting Tokamak JT-60SA, we carried out both experimental and numerical studies of the thermohydraulic phenomena taking place during the quench of a superconducting magnet manufactured with Cable-In-Conduit Conductor and cooled in forced flow with supercritical helium. In this framework, all the 18 JT-60SA TF coils were tested in a single coil configuration at their nominal operating conditions of current and temperature (25.7kA and 5K). A progressive temperature increase has been applied to the helium inlet up to the quench temperature, followed by a current fast discharge as soon as the quench is detected to protect the magnet. The experimental analyses of these tests allowed first to identify several very different dynamic phases in the overall quench propagation time. Then, the physical phenomena driving each one of these phases have been studied and the most predominant ones have been highlighted such as the external heat loads, the strands magnetic performances, the conductive and convective heat transfers between conductors and helium or even the helium expulsion and reverse flow. Based on these experimental analyses, a single pancake numerical model has been developed in the THEA code in order to analyze one physical phenomenon at a time without building a too complex global model of the entire magnet. This single pancake model has been validated on the quench experiments data and has been successfully applied to make further more detailed analyses of the physical phenomena as well as the dynamic phases identified during the TF coils quench propagation. This numerical model even allowed identifying some driving physical phenomena that could not be studied in the experimental analysis, such as the impact of the testing conditions instabilities on the quench dynamics. The very good results of this model and its coherence with physical experimental analyses makes it a very interesting step towards the full modelling of the entire JT-60SA TF coil and the study of its quench behavior in real Tokamak and not test facility conditions
Hayakawa, N., F. Iwahana, S. Chigusa, and H. Okubo. "Highly time-resolved measurement of quench inception and propagation in ac superconducting wires." IEEE, 2000. http://hdl.handle.net/2237/6752.
Monteiro, Barbara Vanessa de Brito. "An?lise da resposta Th17 em l?quen plano oral." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17122.
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Th17 cells have been strongly associated with the pathogenesis of several autoimmune and inflammatory diseases. IL-17 and IL-23 are important cytokines associated with this lineage. The aim of this study was to analyze, through immunohistochemical methods, the immunoexpression of IL-17 and IL-23 in the inflammatory infiltrate of oral lichen planus (OLP) lesion compared to that of inflammatory fibrous hyperplasia (IFH) and between clinical forms reticular and erosive of OLP. The sample included 41 cases of OLP, of which 23 were reticular and 18 erosive and 10 cases of IFH. The results were subjected to nonparametric statistical tests with a 5% significance level. In OLP lesions histomorphological analysis, the most common findings were: hyperparakeratinization, specimens with atrophic epithelium in erosive clinical form (p = 0.011), epithelial projections in most of reticular type of lesions, in addition Civatte bodies were identified in most samples of both clinical forms. For immunohistochemistry analysis, five fields with strong immunoreactivity for IL-17 and IL-23 were photomicrographed at 400x magnification, images were transferred to a computer where with ImageJ software?, lymphocytes that exhibited cytoplasmic immunostaining for these cytokines were counted. A mean was established after for each case. There was no statistically significant difference in the number of imunopositive lymphocytes for IL-17 and IL-23 among the group of OLP and IFH group, however a larger amount of lymphocytes imunopositive for IL-17 was found in the LPO group (p = 0.079) and significantly higher amounts of those lymphocytes were found in the erosive OLP when compared to the group of reticular OLP and IFH (p = 0.019). Furthermore, a marker epithelial immunopositivity for IL-17 was observed in OLP group. Although the results of this study do not permit the forceful assertion about the participation of Th17 lineage in OLP lesions, the findings of immunopositive lymphocytes counting for IL-17 and IL-23, which are potent proinflammatory cytokines, together with the the marked epithelial immunopositivity found for IL-17 in this study, suggest a possible role of this lineage in the pathogenesis of this disorder
As c?lulas Th17 t?m sido fortemente associadas com a patogenia de diversas doen?as autoimunes e inflamat?rias. A IL-17 e a IL-23 s?o importantes citocinas associadas com esta linhagem. O objetivo do presente trabalho foi analisar, atrav?s de m?todos imunohistoqu?micos, a imunoexpress?o da IL-17 e da IL-23 no infiltrado inflamat?rio das les?es de l?quen plano oral (LPO) comparando ao da hiperplasia fibrosa inflamat?ria (HFI) e entre as formas cl?nicas reticular e erosiva do LPO com o intuito de esclarecer se a linhagem Th17 participa da patog?nese do LPO. Na amostra foram inclu?dos 41 casos de LPO, dos quais 23 eram reticulares e 18 erosivos, al?m de 10 casos de HFI. Os resultados foram submetidos a testes estat?sticos n?o param?tricos com n?vel de signific?ncia de 5%. Na an?lise histomorfol?gica das les?es de LPO, observou-se predom?nio de: les?es hiperparaceratinizadas, esp?cimes com epit?lio atr?fico na forma cl?nica erosiva (p=0,011), proje??es epiteliais nas les?es do tipo reticular, al?m de corpos de Civatte identificados na maior parte da amostra de ambas as formas cl?nicas. Para o estudo imuno-histoqu?mico, cinco campos com forte imunorreatividade para a IL-17 e para a IL-23 foram fotomicrografados sob o aumento de 400x, as fotos foram transferidas para um computador onde com o aux?lio do software ImageJ?, realizou-se a contagem dos linf?citos que exibiram imunomarca??o citoplasm?tica para estas citocinas. Posteriormente, foi estabelecida uma m?dia para cada caso. N?o foram observadas diferen?as estatisticamente significativas na quantidade de linf?citos imunopositivos para a IL-17 e para a IL-23 entre o grupo do LPO e da HFI, no entanto uma maior quantidade desses linf?citos para a IL-17 foi encontrada no grupo do LPO (p=0,079) e uma quantidade significativamente maior de linf?citos imunopositivos para a IL- 23 foi encontrada entre o grupo do LPO erosivo e da HFI (p=0,019). Al?m disto, foi observada uma marcante imunopositividade epitelial para a IL-17 no grupo do LPO. Ainda que os resultados do presente estudo n?o permitam a afirma??o contundente da participa??o da linhagem Th17 nas les?es de LPO, os achados da contagem dos linf?citos imunopositivos para a IL-17 e para a IL-23, que s?o potentes citocinas pr?-inflamat?rias, somados ? marcante imunopositividade epitelial encontrada para a IL-17 neste estudo, sugerem uma poss?vel participa??o desta linhagem na patog?nese desta desordem
Angelelli, Mario. "Bethe Ansatz techniques for quasilocal charges in quench problems of integrable models." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17960/.
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.
Kato, T., H. Shimizu, Y. J. Tang, N. Hayakawa, Y. Yokomizu, and T. Matsumura. "Quench current level-time characteristics of AC insulated multi-strand superconducting cables." IEEE, 1997. http://hdl.handle.net/2237/6805.
Szwangruber, Piotr [Verfasser], Oliver [Akademischer Betreuer] Boine-Frankenheim, and Rüdiger [Akademischer Betreuer] Schmidt. "Quench Study for FAIR Magnets / Piotr Szwangruber ; Oliver Boine-Frankenheim, Rüdiger Schmidt." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1152007122/34.
Catalão, Ricardo Jorge Carreira Ferreira de Castelo. "Desenvolvimento de um sistema de detecção de quench baseado em campo magnético." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10234.
A eficiência energética tem vindo a assumir importância vital na sociedade actual, sendo por isso essencial criar estratégias que visem melhorar o aproveitamento que é feito dos recursos energéticos existentes. A utilização dos materiais supercondutores de alta temperatura no âmbito da optimização do armazenamento de energia é uma das opções interessantes a ter em conta para um desenvolvimento sustentável e de longo prazo. Assegurar a estabilidade térmica e eléctrica deste tipo de materiais é assim indispensável para maximizar a eficiência das aplicações que dependem da sua fiabilidade. Neste contexto os sistemas de detecção de quench assumem particular relevância. Este tipo de sistemas tem como principal objectivo evitar a perda da supercondutividade do material, através de uma rápida e eficaz detecção do fenómeno de quench. Neste trabalho é apresentado um método de detecção de quench para fitas supercondutoras de Bi-2223, vulgarmente denominadas por fitas de primeira geração, baseado na leitura de campos de indução magnética. Com esta dissertação pretende-se projectar e simular o sistema de detecção em causa recorrendo à ferramenta de elementos finitos Flux2D e implementar esse mesmo sistema, visando demonstrar a eficiência desta técnica para suprimir algumas das dificuldades inerentes a outros métodos de detecção, já amplamente estudados.
Xu, Yan 1963 Jan 31. "Effect of quench rate on the coercivity of Nd-Fe-B permanent magnets." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55669.
Tavora, Marco. "Prethermalization, universal scaling at macroscopic short times, and thermalization following a quantum quench." Thesis, New York University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3716614.
The study of the quantum dynamics of many-particle systems has recently become the subject of intensive research, stimulated in part by enormous progress in experimental techniques, particularly the manipulation of ultracold atomic gases, which allow high tunability of artificial systems with decoherence and dissipation strongly suppressed. One of the simplest protocols for out of equilibrium dynamics is a quantum quench where the time-scale associated with an external variation is much smaller than the typical relaxation time of the system. Here we first study in detail the dynamics after a quantum quench in the one-dimensional sine-Gordon model in the phase where the boson spectrum remains gapless. We construct a Dyson equation to leading order in the cosine potential and show that the resulting quantum kinetic equation is atypical in that it involves multi-particle scattering processes. We also show that using an effective action, which generates the Dyson equation by a variational principle, the conserved stress-momentum tensor can be constructed. We solve the dynamics numerically by making a quasi-classical approximation that makes the quantum kinetic equation local in time while retaining the multi-particle nature of the scattering processes. At long times the system is found to thermalize, with a thermalization time that depends in a non-monotonic way on the amount of energy injected into the system by the quench. This non-monotonic behavior arises due to the competing effect of an increase of phase space for scattering on the one hand, and an enhancement of the orthogonality catastrophe on the other hand as the quench amplitude is increased. The approach to equilibrium is found to be purely exponential for large quench amplitudes but more complex for smaller ones. In the following chapter, the dynamics of interacting bosons in one dimension after a sudden switching on of a weak disordered potential is investigated. We find that on time scales before quasiparticles scatter, which correspond to the prethermalization regime, the dephasing from random elastic forward scattering causes the correlations to decay exponentially fast, while the system remains far from thermal equilibrium. For longer times however, the combined effect of disorder and interactions gives rise to inelastic scattering which eventually leads to thermalization. A novel quantum kinetic equation taking into account both disorder and interactions is employed to study the dynamics. It is found that thermalization becomes most effective close to the superfluid-Bose glass critical point where nonlinearities become increasingly important. The thermalization times obtained numerically are found to agree well with analytic estimates. In the last chapter we investigate the dynamics of a scalar field theory in spatial dimension d=4 after a quench close to a critical point, using renormalization-group methods. We show that after the system is quenched, but before eventually thermalizing due to dissipative effects, it approaches a different, thermal-like regime associated with a fixed-point describing a dynamical scaling behaviour. Within this regime the time dependence of the dynamical correlations is characterized by a novel short-time universal exponent.
Haid, Benjamin J. (Benjamin John Jerome) 1974. "Two-dimensional quench propagation model for a three-dimensional "high-temperature" superconducting coil." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9598.
Includes bibliographical references (leaves 89-90).
Quenching is a thermal failure mechanism encountered with superconducting magnets. When a section of conductor is driven normal by an external heat input, the magnet transport current flows through a resistance, causing joule dissipation. If heat is not conducted away from the normal region faster than it is dissipated, the normal region will grow and the temperature will increase indefinitely. Growth of the normal region is commonly refereed to as normal zone propagation(NZP). A reliable NZP model is necessary for designing protection systems because a quench may cause irreparable damage if a section of the winding is over-heated. This thesis develops a numerical NZP model for a three dimensional, dry-wound, BSSCO- 2223 superconducting magnet. The test magnet operates under quasi-adiabatic conditions at 20 K and above, in zero background field. It is contained in a stainless steel cryostat and cooled by a Daikin cryocooler. The NZP model is based on the two-dimensional transient heat diffusion equation. Quenches arc simulated by a numerical code using the finite-difference method. Agreement between voltage traces obtained in the test magnet during heater-induced quenching events and those computed by the numerical NZP model is reasonable. The model indicates that thermal contact resistance has a dominant effect on propagation in the azimuthal direction(across layers). The model is also used to simulate quenching in persistent-mode magnets similar in construction with the test magnet. Specifically studied were effects of magnet inductance, for a given set of operating current and temperature, on the maximum temperature reached in one full turn of the conductor located at the magnet outermost layer driven normal with a heater. The simulation demonstrates that there is an operating current limit for a given magnet inductance and operating temperature below which the magnet can be considered self-protecting. The simulation also demonstrates that shunted subdivision lowers the maximum temperature.
by Benjamin J. Haid.
S.M.
Casali, Marco <1984>. "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.
Casali, Marco <1984>. "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/.
Zanella, Jo?o Carlos. "A beleza quen?tica do crucificado na teologia de Bruno Forte." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2010. http://tede2.pucrs.br/tede2/handle/tede/5841.
A presente disserta??o aborda o tema da beleza da cruz, na teologia de Bruno Forte. Parte-se da tem?tica da beleza, desenvolvida ao longo da hist?ria da teologia e articulada por Forte em suas obras. Expressa como a beleza ? fr?gil e pode ser ofuscada pelo v?u da incompreens?o de qualquer ?poca. Assim, destacam-se os eventos da encarna??o e crucifica??o de Jesus, como manifesta??es da beleza divina, que se revelam na condi??o quen?tica, ou seja, no esvaziamento e na ren?ncia de sua natural grandeza. Beleza e cruz podem apontar um caminho de vida e de amor, capaz de salvar a cria??o e a pessoa humana. Dessa reflex?o emergem algumas pistas pastorais para o trabalho de evangeliza??o.
Piatkowski, Nicolas. "Zn-nanoparticle in-situ hydrolysis for hydrogen production in a high quench rate reactor." Zürich : Departement Maschinenbau und Verfahrenstechnik, Eidgenössische Technische Hochschule, 2007. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=312.
Shimizu, H., Y. Yokomizu, T. Matsushima, T. Kato, Y. J. Tang, T. Nagafusa, and N. Hashimoto. "Position of quench initiation in 6 kV-200 A class superconducting fault current limiter." IEEE, 1997. http://hdl.handle.net/2237/6806.
Shimizu, H., T. Shiroki, Y. Yokomizu, and T. Matsumura. "Dependence of quench current level of superconducting wire and cable on the winding tension." IEEE, 1999. http://hdl.handle.net/2237/6792.
Nowill, Courtney Ann. "Investigation of the quench and heating rate sensitivities of selected 7000 series aluminum alloys." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-081307-103919/.
Edwards, John Stephan. "'Jane the Quene': A new consideration of Lady Jane Grey, England's nine-days queen." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3256390.