Download or read book Experimental Studies of Metallic Hydrogen at Very High Pressures written by and published by . This book was released on 1996 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic hydrogen, because of its small mass and large recombination energy, is theoretically the most promising of all chemical propellants. Currently the best existing chemical propellant is the molecular hydrogen-oxygen fuel. Even in the liquid form, because of its low density, these fuels require large storage tanks, which add to the weight of a vehicle. Thus metallic hydrogen has two important advantages: it has a large specific impulse and its density will be more than an order of magnitude larger than that of ambient liquid hydrogen. Together these factors provide enormous advantages in rocket propulsion and are the reason for investigating the feasibility of producing metallic hydrogen in the laboratory. It is now known that to produce the atomic metallic phase by the brute force method of compression of molecular hydrogen, pressures in the range of 2-5 megabars are required. Achieving pressures in the 1- to 2-megabar range, under careful laboratory conditions using diamond anvils, is now fairly routine. With some care, higher pressures have been achieved. jg p7.
Download or read book Experimental Attempt to Metallize Hydrogen at Very High Pressures written by and published by . This book was released on 1992 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic hydrogen is potential candidate as a high energy density material. The possibility of metallizing hydrogen by submitting it to very high pressures has been experimentally investigated. Great advances have been made in this study. Pressures as high as 2.3 megabar on hydrogen have been obtained in diamond anvil cells (DACs). Several new phase transitions have been observed in the megabar pressure region. One of these, called the hydrogen-A (H-A) phase is believed to be the metallic molecular phase of hydrogen. However, current limitations on the optical techniques available to diamond anvil cell research have prevented direct determination of the conductive state and techniques for the direct measurement of the dc electrical conductivity are still under development. Band structure calculations have shown that metallization may be profoundly affected by molecular orientational order. Other observed phase transitions are believed to be associated with orientational order and fundamental changes in the molecular symmetry at high densities. A pulsed NMR system for studying very small samples of hydrogen has been constructed and will be useful in analyzing the nature of high density hydrogen. Metallic hydrogen, high pressure.
Download or read book High Pressure Multi Mbar Conductivity Experiments on Hydrogen written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-dense hydrogen has long been the subject of intense experimental and theoretical research due to the fascinating physics which arises from this supposedly simple system. The properties of ultra-dense hydrogen also have important implications for planetary physics, since the interiors of the giant planets Jupiter and Saturn are believed to consist of cores of dense, metallic hydrogen. Finally, ultra-dense hydrogen is of direct programmatic interest, and multiple-shock compression experiments on hydrogen to the metallic state have stimulated the accelerated development of new hydrogen equation-of-state (EOS) models used for ICF and other applications. The focus of our research has often been described as the ''Holy Grail'' of high-pressure physics research: The metallization of solid hydrogen. Metallic hydrogen has long been considered to be the prototypical system for the study of insulator-to-metal (I-M) transitions. Although metallic hydrogen (Z=1) may superficially appear to be a very simple material, it is in fact an extremely challenging system for theoretical analysis due to the presence of large zero-point atomic motions and the complete absence of any core electrons. Thus, solid metallic hydrogen promises to be a fascinating material. Among its predicted properties is the possibility of being a high temperature superconductor with a critical temperature T{sub c} of the order of (almost equal to) 100K [1]. The successful metallization of solid hydrogen would be a groundbreaking scientific discovery and open up new frontiers in science and possibly technology as well.
Download or read book Metallic Hydrogen Research written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical studies predict that molecular hydrogen can be converted to the metallic phase at very high density and pressure. These conditions were achieved by subjecting liquid hydrogen to isentropic compression in a magnetic-flux compression device. Hydrogen became electrically conducting at a density of about 1.06 g/cm3 and a calculated pressure of about 2 Mbar. In the experimental device, a cylindrical liner, on implosion by high explosive, compresses a magnetic flux which in turn isentropically compresses a hydrogen sample; coaxial conical anvils prevent escape of the sample during compression. One anvil contains a coaxial cable that uses alumina ceramic as an insulator; this probe allows continuous measurement of the electrical conductivity of the hydrogen. A flash x-ray radiograph exposed during the experiment records the location of the sample-tube boundaries and permits calculation of the sample density. The theoretical underpinnings of the metallic transition of hydrogen are briefly summarized, and the experimental apparatus and technique, analytical methods, and results are described. 9 figures.
Download or read book Molecular and Metallic Hydrogen written by Marvin Ross and published by . This book was released on 1977 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a comprehensive review and analysis of the published data on metallic hydrogen and a summary of the properties of molecular hydrogen that are required to determine the molecular-to-metallic hydrogen transition pressure. The best available effective interaction potential is utilized in calculating the equation of state for solid molecular hydrogen. The equation of state of metallic hydrogen is determined by four different methods and the possible range of molecular-to-metallic hydrogen is largely responsible for the wide discrepancy in calculations of the transition pressure. Metastability of metallic hydrogen is discussed and the experimental high- pressure research pertinent to the determination of molecular-to-metallic hydrogen transition pressure is reviewed.
Download or read book High Pressure and Low Temperature Physics written by J.A. Woollam and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: High pressure science is a rapidly growing diverse fi. e1d. The high pressure technique has become a powerful tool for both the study and preparation of materials. In spi. te of the many high pressure conferences held in recent years, I felt that there was a need for scientists within a well-defined area (not bound merely by the common experimental technique) to meet in an atmosphere conducive to frank exchange and close interaction. In this spirit, the Cleveland State University hosted such a conference from July 20 to 22, 1977, in which the physics of solids under high pressures and at low tempera tures was specifically examined. Both the original and review papers presented at the conference and the candid discussions following their presentations appear in this volume. They clearly cover a rather complete spectrum of current research in the physics of solids at high pressures and low temperatures. I wish to thank the National Aeronautics and Space Administra tion, the Office of Naval Research and the National Science Founda tion for their financial support of the conference. In addition, I wish especially to thank Steinar Huang for his unceasing assistance in arranging this conference. I also wish to thank him and Francis Stephenson for their assistance in preparing this book. C. W. Chu, Chairman, International Conference on High Pressure and Low Temperature Physics v Contents HYDROGEN AND METAL-HYDRIDES (Chairman: I. Spain) PROSPECTS FOR METALLIC HYDROGEN 1 A. L.
Download or read book Hydrogen in Steel written by Michael Smialowski and published by Elsevier. This book was released on 2014-05-09 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen in Steel: Effect of Hydrogen on Iron and Steel During Production, Fabrication, and Use focuses on the effect of hydrogen on iron and steel during production, fabrication, and use. Topics covered range from the solubility of hydrogen in iron and ferrous alloys to the diffusion and permeation of hydrogen through iron and steel. Electrochemical problems related to the ability of iron to absorb hydrogen from aqueous solutions are also considered. Comprised of 19 chapters, this book begins with a detailed treatment of the nature and properties of metal-hydrogen systems, paying particular attention to the behavior of hydrogen in the bulk of the metal phase and the mechanism of reactions between metals and hydrogen or hydrogen-producing compounds. The reader is then introduced to the solubility of hydrogen in iron and ferrous alloys as well as the nature of the final product of the hydrogen-iron interaction. Subsequent chapters deal with dimensional changes and stresses produced in steel by cathodically evolved hydrogen; the effects of hydrogen on the physical, mechanical, and chemical properties of iron and steel; influence of welding on hydrogen; and sulfide corrosion cracking of steel. The effects of pickling on steel are also examined, along with the blistering and embrittlement caused by hydrogen on the base metal during electroplating. This book will be of value to students and practitioners in the field of physical chemistry.
Download or read book Hydrogen Storage Materials written by R. G. Barnes and published by . This book was released on 1988 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ames Laboratory, Iowa, USA
Download or read book Hydrogen Materials Science and Chemistry of Metal Hydrides written by Michael D. Hampton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: In September, 1999, with the generous support of NATO, scientists from 18 different nations gathered in Katsiveli, Yalta, Ukraine at the NATO Advanced Research Workshop on Hydrogen Materials Science and Chemistry of Metal Hydrides to present their research and to discuss world energy problems and possible solutions, interactions of hydrogen with materials, the role of hydrogen in materials science, and the chemistry of metal hydrides. High level and highly professional presentations were accompanied by a great deal of discussion and debate of the issues from both fundamental and global perspectives. The result was a large number of new collaborations, new directions, and better understanding of energy and materials issues. The research presented at this meeting can be found in this volume. These papers range from global perspectives such as the new vision of energy and how hydrogen fits into that future, to reviews such as a look at nickel hydride over the last 40 years, to very specific current research. A large number of papers are included on hydrogen and materials. These papers include articles on properties such as superconductivity, diffusion EMF, magnetic properties, physico chemical properties, phase composition, and permeability as a result of the interaction with or incorporation of hydrogen. Also included are papers discussing the use of hydrogen as a processing or alloying agent. The use of hydrogen in the synthesis of battery electrode materials, composite materials, and alloys is also presented.
Download or read book Earth as an Evolving Planetary System written by Kent C. Condie and published by Academic Press. This book was released on 2011-08-22 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth as an Evolving Planetary System, Second Edition, explores key topics and questions relating to the evolution of the Earth's crust and mantle over the last four billion years. This updated edition features exciting new information on Earth and planetary evolution and examines how all subsystems in our planet—crust, mantle, core, atmosphere, oceans and life—have worked together and changed over time. It synthesizes data from the fields of oceanography, geophysics, planetology, and geochemistry to address Earth's evolution. This volume consists of 10 chapters, including two new ones that deal with the Supercontinent Cycle and on Great Events in Earth history. There are also new and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes. In addition, the book now includes new tomographic data tracking plume tails into the deep mantle. This book is intended for advanced undergraduate and graduate students in Earth, Atmospheric, and Planetary Sciences, with a basic knowledge of geology, biology, chemistry, and physics. It also may serve as a reference tool for structural geologists and professionals in related disciplines who want to look at the Earth in a broader perspective. - Kent Condie's corresponding interactive CD, Plate Tectonics and How the Earth Works, can be purchased from Tasa Graphic Arts here: http://www.tasagraphicarts.com/progptearth.html - Two new chapters on the Supercontinent Cycle and on Great Events in Earth history - New and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes - Also new in this Second Edition: the lower mantle and the role of the post-perovskite transition, the role of water in the mantle, new tomographic data tracking plume tails into the deep mantle, Euxinia in Proterozoic oceans, The Hadean, A crustal age gap at 2.4-2.2 Ga, and continental growth
Download or read book The Metal Hydrogen System written by Yuh Fukai and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: I think it is expedient here to clearly specify the readership for whom this book is intended. Some readers might infer from the title that this is a data book convenient for occasional reference purposes. Most of the data on the bulk properties and a comprehensive list of publications are indeed compiled here, will be found useful as they are. The primary purpose of the book is, however, and rather to provide a coherent and consistent description of the basic bulk properties of the metal-hydrogen system, ranging from macroscopic properties such as solubilities and phase diagrams to microscopic properties such as atomistic states and diffusion. The emphasis has been placed on the physics of how these properties actually come about. This structure of the book is considered to be useful, and even necessary, not only for physicists but also for researchers interested in the materials-science aspects of the system. Who could have anticipated that the solubility of hydrogen in iron reaches a level as high as [H]/[Fe] ~ 1 under a hydrogen pressure of 10 GPa; who could have anticip ated that the diffusivity of hydrogen in metals increases at low temperatures; who could unravel the mechanism of "cold" fusion (if this indeed exists), without a basic understanding of the metal-hydrogen system? Obviously, these prob lems are not only of academic interest but also have profound technical implications.
Download or read book Hydrogen in Metals Application oriented properties written by G. Alefeld and published by . This book was released on 1978 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Metal Hydrogen System written by Yuh Fukai and published by Springer Science & Business Media. This book was released on 2006-02-02 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal hydrides are of inestimable importance for the future of hydrogen energy. This unique monograph presents a clear and comprehensive description of the bulk properties of the metal-hydrogen system. The statistical thermodynamics is treated over a very wide range of pressure, temperature and composition. Another prominent feature of the book is its elucidation of the quantum mechanical behavior of interstitial hydrogen atoms, including their states and motion. The important topic of hydrogen interaction with lattice defects and its materials-science implications are also discussed thoroughly. This second edition has been substantially revised and updated.
Download or read book Hydrogen in Metal Systems II written by F. A. Lewis and published by . This book was released on 2000 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the behaviour of hydrogen in metals is one of the most pressing research tasks in the physical sciences. The embrittling effect of hydrogen in mild steel was recognised from the very beginnings of the Industrial Revolution, and its effects still plague modern alloys during either fabrication or use. At the same time, the tendency of certain alloys to form stable hydrides in a reversible manner holds out the promise of the safe storage of hydrogen in vehicles and therefore the prospect of non-polluting transport and a true 'hydrogen economy'. Researchers in this field will therefore welcome the publication of this 2-volume set, Hydrogen Metal Systems I & II, which presents comprehensive information and critical data concerning ionic and metallic hydrides; all conveniently based upon a periodic-table layout.
Download or read book Experiments with Phase Transitions at Very High Pressure written by Ian L. Spain and published by . This book was released on 1983 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal water Reactions written by Sydney C. Furman and published by . This book was released on 1959 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Abcs Of High pressure Science written by Sergei M Stishov and published by World Scientific. This book was released on 2021-04-20 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the famous High-Pressure scientist of the Russian Academy of Sciences, The ABCs of High-Pressure Science contains brief information explaining the terms and concepts adopted by professionals involved in research in the field of high pressure, be it physics, geology, chemistry, or technology. The book also includes brief biographical essays describing activities of the outstanding scientists who largely determined the current state of high-pressure science. The book is organized in the form of short chapters or notes in alphabetical order, so a search of the necessary information is not difficult. The ABCs is intended for young scientists, graduate students, and students; nevertheless, well-established scientists can also find useful information here. Finally, The ABCs of High-Pressure Science is not a reference book and is designed to ensure that the reader can easily find the needed information from the Internet.
