Download or read book M thodes avanc es de traitement du signal pour la d tection de d fauts lectriques et m caniques dans les machines induction written by Shahin Hedayati Kia and published by . This book was released on 2009 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monitoring and diagnosis of the electrical and mechanical faults in railway traction systems have been studied in this dissertation. The railway traction system works in complex condition in which traditional techniques of signal processing cannot be used intensively. Initially, different methods such as non-parametric, parametric and subspace techniques have been examined and finally a method based on MUSIC (MUltiple SIgnal Classification) has been proposed to improve diagnosis of broken bar fault in induction machine, by detecting a large number of frequencies in a given bandwidth. This method is called zoom-MUSIC. The broken bar fault diagnosis in induction machines needs the speed information in order to localize the side-band frequencies around the fundamental in the stator current spectrum. The accurate slip estimation needs also advance signal processing. This fact has been used to define a new technique of broken bar fault detection based on discrete wavelet transform without slip estimation. The non-invasive techniques for mechanical system monitoring are interesting alternatives leading to low cost diagnosis systems. In this way, a theoretical framework has been proposed to show all the effects of a gearbox-based mechanical system torsional vibration on mechanical torque and then on the stator current of the driving machine. This study has been carried out with a basic modeling approach based on the realistic dynamic behavior of a healthy gearbox to show the influence of transmission error, eccentricities of pinion/wheel and teeth contact stiffness variation in the electromagnetic torque and the stator current signatures. In order to test the effectiveness of proposed methods under healthy and faulty mechanical conditions, a unique reduced-scale set-up based on a real railway traction system has been realized and instrumented. The diagnostic methods validated in this reduced-scale, will be in the near future implemented in a scale 1 industrial experimental set-up

Download or read book Contribution au d veloppement de m thodes de d tection des d fauts lectriques dans les machines induction doublement aliment es pour a rog n rateurs written by Amine Yazidi and published by . This book was released on 2006 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les parcs de production de l’énergie éolienne ont connu un grand développement ces dernières années grâce à la libéralisation du marché de l’électricité et au développement de la production décentralisée de l’énergie. Ces parcs sont constitués d’un ensemble d’aérogénérateurs qui utilisent généralement la machine à induction fonctionnement à vitesse variable pour la génération d’énergie. Ce type de technologie est le plus utilisé actuellement car il présente un grand intérêt en terme de puissance. Néanmoins, ces aérogénérateurs sont en quotidiennement exposés à des pannes de type électrique, mécanique ou électronique qui entraînent l’arrêt immédiat de la production électrique et engendrent par conséquent des pertes considérables. Il faut donc détecter ces défauts au stade de la fabrication et assurer une surveillance continue pour éviter les arrêts de courtes, moyennes ou longues durées de manière à ce que la production d’énergie soit la plus économique possible en minimisant les impacts sur l’environnement et en assurant la sécurité des personnes. Ce travail a été réalisé dans le cadre du C.N.R.T (Centre National de Recherche Technologique) Futurelec 2« Machines et réseaux électriques du futur » et s’inscrit dans le cadre des études menées au sein du CREA(Centre de Robotique, d’Electrotechnique et d’Automatique) à Amiens pour le développement des nouvelles méthodes numériques expérimentales de diagnostic et de surveillance de la machine à induction à partir decapteurs non invasifs. Il s’agit de développer des méthodes basées sur l’étude spectrale des courants et du flux de dispersion de la machine à induction utilisée dans les aérogénérateurs pour détecter un défaut ou une panne électrique dans la partie rotorique ou statorique.Une étude théorique et expérimentale a été élaborée pour la détection de défaut de barres cassées dans unrotor à cage et de court-circuit entre spires statoriques dans une machine à induction. Cette étude a pu être exploitée aussi pour les machines à induction à rotor bobiné alimentées directement par le réseau ou doublement alimentées via un convertisseur de type « back-to-back ». L’approche consiste à chercher dans le spectre du signal mesuré, en l’occurrence le flux de dispersion, des signatures préalablement calculées. Celles-ci informentsur la présence ou non d’un défaut dans une machine à induction en fonctionnement. Les résultats expérimentauxont conforté et validé l’étude théorique et les résultats de simulations.

Download or read book AGARD Conference Proceedings written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantum Mechanics Volume 3 written by Claude Cohen-Tannoudji and published by John Wiley & Sons. This book was released on 2019-12-16 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.

Download or read book Advances in Rotorcraft Technology written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Flight Vehicle Integration Panel. Symposium and published by . This book was released on 1997 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Routledge International Handbook of Ignorance Studies written by Matthias Gross and published by Routledge. This book was released on 2015-05-15 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once treated as the absence of knowledge, ignorance today has become a highly influential topic in its own right, commanding growing attention across the natural and social sciences where a wide range of scholars have begun to explore the social life and political issues involved in the distribution and strategic use of not knowing. The field is growing fast and this handbook reflects this interdisciplinary field of study by drawing contributions from economics, sociology, history, philosophy, cultural studies, anthropology, feminist studies, and related fields in order to serve as a seminal guide to the political, legal and social uses of ignorance in social and political life. Chapter 33 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license available here: https://tandfbis.s3-us-west-2.amazonaws.com/rt-files/docs/Open+Access+Chapters/9780415718967_oachapter33.pdf

Download or read book The London Underground and the public private partnership agreements written by Great Britain: Parliament: House of Commons: Transport Committee and published by The Stationery Office. This book was released on 2008-01-25 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report from the Transport Committee, examines London Underground and the Public-Private Partnership Agreements. The Government originally announced proposals for modernising the London Underground network system via Public-Private Partnership (PPP) agreements in 1998. Three contracts were drawn up with: (i) Tube Lines for the maintenance and renewal of the Jubilee, Piccadilly and Northern Lines; (ii) with Metronet Rail BVC for the maintenance and renewal of the Bakerloo, Central, Victoria & Waterloo & City Lines; (iii) with Metronet Rail SSL, responsible for the maintenance and renewal of the "sub-surface lines": the Circle, District, Hammersmith & City, Metropolitan & East London Lines. These PPP Agreements, 30 years in duration, were arrangements to maintain, renew and upgrade parts of London Underground by private sector infrastructure companies (Infracos), whilst London Underground is responsible for services to customers. The PPP Agreements also set out a performance-related incentive and penalty scheme to remunerate the Infracos for the improvements they make to the network. In May 2007, Metronet admitted an overspend of £1 billion and was refused access to loan facilities by the banks. It then made a reference to the PPP Arbiter, which in turn triggered an Extraordinary Review (which occurs when extra costs are incurred above the level allowed for the bid). Metronet put in a bid for £551m but the PPP Arbiter provisionally concluded that a sum of £121m was appropriate. Metronet subsequently went into administration on 18 July 2007. The report sets out a number of conclusions and recommendations, including: contracts that were supposed to deliver 35 station upgrades, in fact delivered only 14, 40% of the requirement; stations that were supposed to cost Metronet SSL £2m, cost £7.5m, with only 65% of schedule track renewal accomplished; the Committee criticises the consequences of the imposition of PPP on Transport for London, as a "lamentable state of affairs", with the future of most of London Underground's upgrade and maintenance work in doubt; the Committee states, that the Government should remember the failure of Metronet before it considers entering similar arrangements; that the Government should publish a candid analysis of the events preceding Metronet's collapse and its consequences; the Committee believe that the PPP model was flawed and probably inferior to traditional public-sector management; that the Government needs to prioritise transparency and clarity to taxpayers and ensure that any future contracts result in clear accountability.

Download or read book On Becoming a Rock Musician written by H. Stith Bennett and published by Columbia University Press. This book was released on 2017-05-30 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 1960s and 1970s, becoming a rock musician was fundamentally different than playing other kinds of music. It was a learned rather than a taught skill. In On Becoming a Rock Musician, sociologist H. Stith Bennett observes what makes someone a rock musician and what persuades others to take him seriously in this role. The book explores how bands form; the backstage and onstage reality of playing in a band; how bands promote themselves and interact with audiences and music professionals like DJs; and the role of performance.

Download or read book Music in Geriatric Care written by Ruth Bright and published by Angus & Robertson. This book was released on 1972 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sing a Song of Social Significance written by R. Serge Denisoff and published by Bowling Green, Ohio : Bowling Green State University Popular Press. This book was released on 1972 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unidentified written by Robert Salas and published by Career Press. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1969 the U.S. Air Force issued a statement that read' "No UFO reported, investigated and evaluated by the Air Force was ever an indication of threat to our national security." This statement is patently false. It has been proven untrue by the testimony of many military officers and airmen and documentation of incidents involving UFOs and nuclear weapons, testimonies of which the U.S. Air Force was fully aware. Unidentified details many of these testimonies, some for the first time. As partial justification for its position, the Air Force cites a University of Colorado study that was contracted and paid for by federal funds. Unidentified reveals how this study was actually just another part of the plan to cover up the reality of the UFO phenomenon. For the first time, Unidentified publishes evidence that the investigators for the Colorado study knew about the UFO-related missile shutdown incidents but did not investigate them or include them in their final report.

Download or read book Lost Secrets of the Sacred Ark written by Laurence Gardner and published by HarperCollins UK. This book was released on 2004 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Ark of the Covenant is the source of one of the deepest mysteries of the Western world. Laurence Gardner has accessed Rosicrucian archives to reveal where the Ark is, what it is and how this lost secret of the distant past has led to the phenomenal new science of space-time manipulation.

Download or read book UFOs are Real written by Clifford E. Stone and published by S.P.I. Books. This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Encounter with Tiber written by Buzz Aldrin and published by Open Road Media. This book was released on 2013-05-28 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Apollo 11 astronaut and the Nebula Award–nominated author of Directive 51 present a novel that “conveys the wonder and promise of space” (Publishers Weekly). Born the year of the Moon landing, Chris Terence spends his life fighting to return humanity to that pinnacle. An engineering student with dreams of spaceflight, he finds upon graduation that the United States no longer has need for astronauts. Years of bureaucratic meddling have reduced the space program to a shell of itself, and it will take the greatest scientific find in history to send humanity skyward once more. After years battling budget hawks, Chris finally gets his chance to walk on the Moon. While there, he finds evidence of an ancient alien civilization, the Tiberians, who visited Earth’s satellite eight thousand years before. Understanding what happened to those long-forgotten travelers will define the lives of Chris and his son, as they fight against all odds to unlock the secrets of the universe. “The collaboration of the first man to pilot a moon lander (Aldrin) with a major voice in contemporary science fiction (Barnes) has produced a fascinating chronicle of man’s first encounter with alien intelligence” (Booklist).