Download or read book Etude de l usinage des mat riaux performants et surveillance de l usinage written by François Girardin and published by . This book was released on 2010 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: A l'heure de la banalisation de l'usinage à grande vitesse et de la surenchère dans les systèmes de surveillance, cette thèse aborde le problème de la bande passante pour l'analyse de l'effort de coupe en fraisage, et développe une nouvelle approche pour l'observation et la surveillance du fraisage. Les dynamomètres à quartz piézoélectriques sont largement utilisés dans le cadre des laboratoires pour qualifier et observer l'usinage. En revanche, leur bande passante est limitée pour l'observation du fraisage, en particulier pour l'usinage à grande vitesse et l'usinage de finition. Le travail développé dans cette thèse démontre toutefois que la table dynamométrique délivre une information qualitative à haute fréquence, même après ses premiers modes de résonance, et permet de détecter des phénomènes fondamentaux dans la compréhension de l'usinage, tels que les fréquences de segmentation du copeau. Une analyse fine de la réponse fréquentielle du dynamomètre sert de base à une correction dans le domaine fréquentiel permettant de doubler la bande passante. Les équipes de recherche sur les machines tournantes ont développé dernièrement des techniques de surveillance de la vitesse angulaire instantanée pour détecter des défauts sur des dents d'engrenage. La transposition de ces méthodes dans le domaine de l'usinage, combinée avec une technique d'échantillonnage originale du signal du codeur de broche, a démontré un potentiel d'observation très prometteur. La vitesse angulaire instantanée de la broche s'est révélée être un très bon signal pour surveiller les opérations de fraisage. Les variations locales de cette vitesse générées par les passages des différentes dents de l'outil associées à un modèle dynamique de la broche en rotation ont permis de reconstruire une image très fidèle du couple d'usinage. De plus, l'évolution de ces variations de vitesse a été démontrée comme étant une excellente indication pour l'état de l'outil, débouchant sur le suivi de l'usure et la détection de la rupture des différentes dents de l'outil. Ce travail ouvre également de nombreuses perspectives pour l'observation et la surveillance de l'usinage, allant d'une meilleure intégration du codeur sur la broche à la détection des modes propres de la broche et la surveillance des vibrations auto-régénérées en usinage.
Download or read book Adhesion Between Polymers and Concrete Adh sion Entre Polym res Et B ton written by H. R. Sasse and published by Springer. This book was released on 1986 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preface Adhesion is a phenomenon architects and civil engineers are not very familiar with. In other disciplines knowledge about surface properties and the background of bonding energies is also far from satisfactory; nevertheless there are many important· applications in concrete engineering, where adhesion is necessary for success and durability. These include: - coating and painting - repair of concrete surfaces - bonding of fresh to old concrete - crack injection - glueing of precast elements - glueing of steel to concrete, etc. In 1981 RILEM established the technical committee 52-RAC 'Resin Adherence to Concrete'. The main aims of the committee's work were - to collect research results and practical experiences - to initiate and coordinate research programs - to develop, on a scientific base, test methods for field and for laboratory purposes. One of the results of the committee's work is a state-of-the-art report, which will be presented orally as a General Report at the International Symposium ISAP '86, and will be printed either in the RILEM journal Materials and Structures or separately. Several test recommendations have been elaborated and will be prepared as drafts for the participants ofISAP '86. These are: - direct tensile test - pull-off test - direct shear test - slant shear test - four-point bending test - dynamic loading test - thermal compatibility test (two versions) - injectibility test.
Download or read book Dictionary of Building and Civil Engineering written by Don Montague and published by Taylor & Francis. This book was released on 1996 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dual-language dictionary lists over 20,000 specialist terms in both French and English, covering architecture, building, engineering and property terms. It meets the needs of all building professionals working on projects overseas. It has been comprehensively researched and compiled to provide an invaluable reference source in an increasingly European marketplace.
Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.
Download or read book Satellite Situation Report written by Goddard Space Flight Center. Office of Public Affairs and published by . This book was released on 1977 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uranium Ore Processing written by and published by . This book was released on 2006 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book L Esprit de L Escalier written by Dominique / D. Bonten / and published by CreateSpace. This book was released on 2014-01 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'esprit de L'escalier is a French term for when you think of what you should have said after it is too late. This is a collection of poetry; These are things you wish you said.
Download or read book Low Frequency Scattering written by George Dassios and published by Oxford University Press. This book was released on 2000 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scattering theory deals with the interactions of waves with obstacles in their path, and low frequency scattering occurs when the obstacles involved are very small. This book gives an overview of the subject for graduates and researchers, for the first time unifying the theories covering acoustic, electromagnetic and elastic waves.
Download or read book Protected Area Management written by Barbara Sladonja and published by BoD – Books on Demand. This book was released on 2012-08-08 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Protected areas are at the base of the most national and international conservation strategies. Due to the many unpredictable elements in ecology matters, each protected area requires a case-specific set of guidelines but a common issue is how to cope with human interaction. The management of protected areas is replete with challenges and the only way to gain understanding and achieve greater management possibilities is to exchange experiences and knowledge. Environmental managers are aware of that and together with scientists are looking for more modern and better solutions, both with respect to natural resources and human interactions in many issues regarding nature protection. This publication presents reviews and research results on protected areas management, as well as 12 case studies derived from around the world with the aim of improving management effectiveness of the protected areas.
Download or read book The Evolution of Technology written by George Basalla and published by Cambridge University Press. This book was released on 1989-02-24 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an evolutionary theory of technological change based upon recent scholarship in the history of technology and upon relevant material drawn from economic history and anthropology. It challenges the popular notion that technology advances by the efforts of a few heroic individuals who produce a series of revolutionary inventions owing little or nothing to the technological past. Therefore, the book's argument is shaped by analogies taken selectively from the theory of organic evolution, and not from the theory and practice of political revolution. Three themes appear, and reappear with variations, throughout the study. The first is diversity: an acknowledgment of the vast numbers of different kinds of made things (artifacts) that have long been available to humanity; the second is necessity: the belief that humans are driven to invent new artifacts in order to meet basic biological requirements such as food, shelter, and defense; and the third is technological evolution: an organic analogy that explains both the emergence of novel artifacts and their subsequent selection by society for incorporation into its material life without invoking either biological necessity or technological progress. Although the book is not intended to provide a strict chronological account of the development of technology, historical examples - including many of the major achievements of Western technology: the waterwheel, the printing press, the steam engine, automobiles and trucks, and the transistor - are used extensively to support its theoretical framework. The Evolution of Techology will be of interest to all readers seeking to learn how and why technology changes, including both students and specialists in the history of technology and science.
Download or read book Technology in Western Civilization Technology in the twentieth century written by Melvin Kranzberg and published by Oxford University Press, USA. This book was released on 1967 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and well-planned account of the history of technology in Western civilization from pre-historic man to the present age of the computer.
Download or read book Advanced Micro Mesoporous Materials written by K. Hadjiivanov and published by Heron Press. This book was released on 2008-10-31 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Encyclopaedia of the History of Technology written by Ian McNeil and published by . This book was released on 1996 with total page 1062 pages. Available in PDF, EPUB and Kindle. Book excerpt: Available for the first time in paperback, this volume includes twenty-two chapters by international experts covering the entire history of technology from humankind's earliest use of stone tools to the exploration of space. Written clearly and without unnecessary jargon, each chapter traces the development of its subject from earliest times to the present day, stressing the social context and its place in scientific thought. * Usefully drawn with over 150 tables, drawings and photographs * Two comprehensive indexes of names and subjects * Essential reading for teachers and students in the History and Philosophy of Science and Technology, Industrial History and Archaeology.
Download or read book Mechanical Vibration written by William John Palm and published by . This book was released on 2007 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model, analyze, and solve vibration problems, using modern computer tools. Featuring clear explanations, worked examples, applications, and modern computer tools, William Palm's Mechanical Vibration provides a firm foundation in vibratory systems. You'll learn how to apply knowledge of mathematics and science to model and analyze systems ranging from a single degree of freedom to complex systems with two and more degrees of freedom. Separate MATLAB sections at the end of most chapters show how to use the most recent features of this standard engineering tool, in the context of solving vibration problems. The text introduces Simulink where solutions may be difficult to program in MATLAB, such as modeling Coulomb friction effects and simulating systems that contain non-linearities. Ample problems throughout the text provide opportunities to practice identifying, formulating, and solving vibration problems. KEY FEATURES Strong pedagogical approach, including chapter objectives and summaries Extensive worked examples illustrating applications Numerous realistic homework problems Up-to-date MATLAB coverage The first vibration textbook to cover Simulink Self-contained introduction to MATLAB in Appendix A Special section dealing with active vibration control in sports equipment Special sections devoted to obtaining parameter values from experimental data
Download or read book Targeting for Strategic Deterrence written by Desmond Ball and published by . This book was released on 1983 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amerikanske synspunkter, som de har udviklet sig, vedrørende anvendelsen af atomvåben.
