Download or read book Background Pressure Effects on Internal and Near field Ion Velocity Distribution of the BHT 600 Hall Thruster Preprint written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented is a study of the effects of chamber background pressure on the ion axial velocity distribution within the discharge chamber and in the near-field of the Busek BHT-HD-600 xenon Hall effect thruster. Ion velocity distributions were measured along the acceleration channel centerline using laser-induced fluorescence of the 5d[4](sub 7/2)-6p[3](sub 5/2) xenon ion excited state transition. Measurements were taken at the lowest possible chamber background pressure and a pressure that was a factor of two higher. In addition to varying the background pressure, the magnetic field of the discharge chamber was switched between two configurations. The radial magnetic was set to a low and high strength case, which produced two different anode current oscillatory regimes. Ion axial velocity distribution function peaks were used to approximate ion energy and axial electric field strength to compare the acceleration profiles of the tested thruster operating conditions. Increasing background pressure shifted the ion acceleration region upstream in the discharge chamber. The width of the velocity distributions correlated strongly to the radial magnetic field strength. The high magnetic field case data showed narrower peaks.
Download or read book Performance Evaluation of the SPT 140 written by and published by . This book was released on 1997 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Materials Characterization written by Norbert G. H. Meyendorf and published by Springer Science & Business Media. This book was released on 2013-11-21 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an emphasis on aircraft materials, this book describes techniques for the material characterization to detect and quantify degradation processes such as corrosion and fatigue. It introduces readers to these techniques based on x-ray, ultrasonic, optical and thermal principles and demonstrates the potential of the techniques for a wide variety of applications concerning aircraft materials, especially aluminum and titanium alloys. The advantages and disadvantages of various techniques are evaluated.
Download or read book Automated Rendezvous and Docking of Spacecraft written by Wigbert Fehse and published by Cambridge University Press. This book was released on 2003-11-13 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: The definitive reference for space engineers on rendezvous and docking/berthing (RVD/B) related issues, this book answers key questions such as: How does the docking vehicle accurately approach the target spacecraft? What technology is needed aboard the spacecraft to perform automatic rendezvous and docking, and what systems are required by ground control to supervise this process? How can the proper functioning of all rendezvous-related equipment, systems and operations be verified before launch? The book provides an overview of the major issues governing approach and mating strategies, and system concepts for rendezvous and docking/berthing. These issues are described and explained such that aerospace engineers, students and even newcomers to the field can acquire a basic understanding of RVD/B. The author would like to extend his thanks to Dr Shufan Wu, GNC specialist and translator of the book's Chinese edition, for his help in the compilation of these important errata.
Download or read book Laser Spectroscopy written by Wolfgang Demtröder and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impact of lasers on spectroscopy can hardly be overestimated. Lasers re present intense light sources with spectral energy densities which may exceed those of i ncoheren t sources by severa 1 orders of magnitude. Furthermore be cause of their extremely small bandwidth, single-mode lasers allow a spectral resolution which far exceeds that of conventional spectrometers. Many experi ments which could not be done before the application of lasers because of lack of intensity or insufficient resol ution are readily performed wi th lasers. Now several thousands of laser lines are known which span the whole spec tral range from the vacuum-ultraviolet to the far-infrared region. Of parti cular interest are the continuously tunable lasers which may in many cases replace wavelength-selecting elements, such as spectrometers or interferome ters. In combination with optical frequency mixing, techniques such conti nuously tunable monochromatic coherent light sources are available at nearly any desired wavelength above 100 nm.
Download or read book Photoabsorption Photoionization and Photoelectron Spectroscopy written by Joseph Berkowitz and published by Academic Press. This book was released on 2012-12-02 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoabsorption, Photoionization, and Photoelectron Spectroscopy explores photoabsorption processes involving individual, isolated molecules in the wavelength or photon energy range from the ionization thresholds of molecules (usually in the vacuum ultraviolet region) through the soft and hard X-ray region and beyond the ""K edge."" The interaction between electromagnetic radiation and isolated molecules based on photoabsorption, photoionization, and photoelectron spectroscopy studies is described, along with the techniques for measurement of total and partial cross sections. This book is comprised of eight chapters and examines the decomposition of molecules and molecular ions as well as mildly excited (valence shell excitation) and highly excited (inner shell excitation) molecules. After providing a general theoretical background, it discusses certain classes of atoms and molecules and considers electromagnetic interactions with gases. The following chapters focus on photoabsorption below the first ionization limit; quasi-discrete states above the first ionization potential; and the ionization continuum. Total photoabsorption and photoionization cross sections for selected molecules are also considered, and the angular distribution of photoelectrons is analyzed. The various measurement techniques are described in the last chapter. This monograph will be of interest to radiation chemists, radiation physicists, photochemists, mass spectrometrists, and perhaps radiation biologists.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Maintaining U S Leadership in Aeronautics written by National Research Council and published by National Academies Press. This book was released on 1998-10-07 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the completion of the National Research Council (NRC) report, Maintaining U.S. Leadership in Aeronautics: Scenario-Based Strategic Planning for NASA's Aeronautics Enterprise (1997), the National Aeronautics and Space Administration (NASA) Office of Aeronautics and Space Transportation Technology requested that the NRC remain involved in its strategic planning process by conducting a study to identify a short list of revolutionary or breakthrough technologies that could be critical to the 20 to 25 year future of aeronautics and space transportation. These technologies were to address the areas of need and opportunity identified in the above mentioned NRC report, which have been characterized by NASA's 10 goals (see Box ES-1) in "Aeronautics & Space Transportation Technology: Three Pillars for Success" (NASA, 1997). The present study would also examine the 10 goals to determine if they are likely to be achievable, either through evolutionary steps in technology or through the identification and application of breakthrough ideas, concepts, and technologies.
Download or read book V 22 Osprey Tilt Rotor Aircraft written by Ronald O'Rourke and published by DIANE Publishing. This book was released on 2009-11 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The V-22 Osprey is a tilt-rotor aircraft that takes off and lands vertically like a helicopter and flies forward like an airplane. DoD plans call for procuring a total of 458 V-22s. Contents of this report: (1) Intro.; (2) The V-22 In Brief; Intended Missions; Key Contractors; Total and Annual Procurement Quantities; Multiyear Procurement for FY2008-FY2012; Est. Total Program Cost; Prior-Year Funding; FY2010 Funding Request; Request for MV-22s; Request for CV-22s; Program History in Brief; Deployment to Iraq; Anticipated 2009 Deployment to Afghanistan; Foreign Military Sales; (3) Aircraft Reliability and Maintainability; Other Potential Issues; (4) Legislative Activity in 2009; May 21, 2009, Hearing on V-22 Program. Illustrations.
Download or read book Future Spacecraft Propulsion Systems written by Paul A. Czysz and published by Springer Science & Business Media. This book was released on 2006-09-19 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: An understandable perspective on the types of space propulsion systems necessary to enable low-cost space flights to Earth orbit and to the Moon and the future developments necessary for exploration of the solar system and beyond to the stars.
Download or read book The Reaction Wheel Pendulum written by Daniel J. Block and published by Morgan & Claypool Publishers. This book was released on 2007-12-01 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, to the nonlinear control problem of swingup control. We also discuss hybrid and switching control, which is useful for switching between the swingup and balance controllers. We also discuss important practical issues such as friction modeling and friction compensation, quantization of sensor signals, and saturation. This monograph can be used as a supplement for courses in feedback control at the undergraduate level, courses in mechatronics, or courses in linear and nonlinear state space control at the graduate level. It can also be used as a laboratory manual and as a reference for research in nonlinear control.
Download or read book Electric Propulsion Development written by Ernst Stuhlinger and published by Elsevier. This book was released on 1963-01-01 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress in Astronautics and Aeronautics, Volume 9: Electric Propulsion Development covers the proceedings of the Second Electric Propulsion Conference of the American Rocker Society, held in Berkeley, California on March 14-16, 1962. The conference focuses on the existing problems in electric propulsion and their possible solutions. This book is organized into four sections encompassing 35 chapters. The first section deals with the thermodynamics of arcs; the problems of heat and momentum transfer; the chemical processes within arcs; the arc system materials; and the arc jet design problems. The second section considers the problems of ion systems, the various ion sources, and the neutralization of ion beams. This section also looks into the basic ionization processes, the production and charging of heavy particles, the corrosive properties of cesium, and the ion-optical designs. The third section describes various plasma systems, including helical transmission lines, pulsed pinch accelerators, coaxial systems, and j x B accelerators. The theoretical analyses of these systems are briefly examined. The fourth section includes papers on flight testing of electric propulsion models, on vertical rocket probes, and on satellites, This section also discusses some advanced concepts in electric propulsion, such as air scooping during ascent through the atmosphere, systems design and optimization, and planetary and interplanetary missions. This book is of great value to physicists, space engineers and designers, as well as researchers in the fields of astronautics and aeronautics.
Download or read book Thin Films Photovoltaics written by Beddiaf Zaidi and published by BoD – Books on Demand. This book was released on 2022-02-23 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film photovoltaic-based solar modules produce power at a low cost per watt. They are ideal candidates for large-scale solar farms as well as building-integrated photovoltaic applications. They can generate consistent power, not only at elevated temperatures but also on cloudy, overcast days and at low sun angles.Thin film photovoltaics are second-generation solar cells produced by depositing one or more thin layers, or thin films, of photosensitive material on a suitable substrate such as glass, polymer, or metal. Thin film solar cells are based on various materials such as cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin film silicon (a-Si, TF-Si) are commercially used in several conventional and advanced technologies.
Download or read book Control of a Human powered Helicopter in Hover written by Joseph J. Totah and published by . This book was released on 1988 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Transonic Aerodynamics written by David Nixon and published by . This book was released on 1989 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume complements Transonic aerodynamics (v.81 in the series) which is concerned with steady flow. This is the only book to address the subject of unsteady transonic aerodynamics, a field much different from steady aerodynamics. The most pronounced difference is the complex shock wave motions
Download or read book NASA SP written by and published by . This book was released on 1962 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
