Download or read book Advances in Pulsed Zero Field NMR written by Tobias Fredrik Sjolander and published by . This book was released on 2017 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear Magnetic Resonance (NMR) is ubiquitous as a tool for investigating the structure of both molecules and materials. In most cases the best results are obtained by placing the sample under study in the largest possible magnetic field, since this maximizes both the sensitivity and the resolution of the experiment. This fact underlies the momentous engineering effor that has gone into developing ever larger super-conducting magnets for use in NMR experiments. However, there are many applications of NMR where the sheer size, not to mention cost, of a high-field instrument can not be accommodated. Therefore there has been a sustained research effort aimed at developing small mobile NMR systems that are not based on super-conducting magnets. NMR performed in zero-field, using magnetic shielding to screen out the ambient field of the earth, and detected using vapor-cell magnetometers, is one such approach. In zero-field NMR the signal originates entirely in the spin-spin coupling part of the Hamiltonian and chemically informative spectra are obtained even in the absence of chemical-shifts. The very large absolute field homogeneity obtainable at zero-field ensures that the spectral resolution is even better than in high-field spectrometers. Perhaps even more interestingly, the different geometry that results from not having a preferred axis imposed on the system enables experiments that are not possible in the presence of magnetic fields. Examples include the ability to distinguish enantiomers based on the phase of an NMR signal. This work extends directly detected zero-field NMR beyond pulse-acquire type experiments. New methods for spin control and excitation, as well as two-dimensional spectroscopy and various decoupling techniques are introduced and demonstrated experimentally. For completeness this dissertation also contains a review of zero-field J-spectroscopy, as well as a detailed guide to the relevant instrumentation. It is my hope that the techniques presented herein will find use in future NMR experiments performed in the regime of zero and ultralow field, whether the application is portable chemical analysis, fundamental physics, or anything in between.
Download or read book Advances in Magnetic Resonance written by Warren S. Warren and published by Academic Press. This book was released on 2012-12-02 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Magnetic Resonance: The Waugh Symposium, Volume 14 is a collection of manuscripts presented at the 1989 symposium on "High Resolution NMR in Solids, held at the Massachusetts Institute of Technology. The contributors provide 20- to 30-page articles consistent with AMR's traditional emphasis on quantitative analysis of NMR techniques. Organized into 13 chapters, this book discusses the principles triple-quantum filtered two-dimensional exchange spectroscopy and its application in the measurement of cross correlation between pairs of dipole-dipole interactions. It then describes alternative ways of using fictitious spin in pulsed nuclear quadrupole resonance or NMR. General topics on the application of optical spectroscopy; the saturation of spin-spin energy by slow continuous bulk rotation; the frequency-switched Lee-Goldburg pulse cycle; and high-resolution proton NMR in solid systems are also explored. A chapter examines an entirely different view of spin dynamics in the presence of radio-frequency fields. This book also deals with the theoretical background and application of solid-state and zero-field NMR spectroscopies to structure determination. Lastly, the utilization of the Floquet formalism in the design of broadband propagators in two-level systems and the two classes of novel NMR phenomena related to the symmetrization postulate are discussed. Analytical and quantum chemists, physicists, biochemists, and materials science researchers will find this book invaluable.
Download or read book Advances in Zero Field Nuclear Magnetic Resonance Spectroscopy written by Thomas Theis and published by . This book was released on 2012 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of the last century, Nuclear magnetic resonance (NMR) has become a powerful and ubiquitous analytical tool for the determination of molecular identity, structure, and function. Traditionally, the great analytical power of NMR comes at the cost of mobility and large expenses for cryogenic cooling. This thesis presents how zero-field NMR detected with an atomic magnetometer is emerging as a new, potentially portable and cost-effective modality of NMR with the ability of providing information-rich and high-resolution spectra. A detailed description of the zero-field NMR spectrometer and its operation is provided. The thesis details how the acquired zero-field NMR spectra result from the electron mediated scalar interaction (J-coupling) of nuclear spins in an analyte. Simple rules of addition of angular momenta are introduced for the prediction of the observed spectral lines overcoming the need for numerical simulations and enabling unambiguous assignment of peaks to different molecules. Additional information can be obtained in the near zero field regime, where the Zeeman interaction can be treated as a perturbation to the J-coupling. The presence of small magnetic fields results in splitting of the zero-field NMR lines, imparting additional information to the pure zero-field spectra. In addition to the utilization of the atomic magnetometers for enhanced sensitivity, hyperpolarization schemes can be implemented. This thesis shows that chemically specific zero-field NMR spectra can be recorded using hydrogenative and non-hydrogenative parahydrogen induced polarization (PHIP, NH-PHIP), enabling high-resolution NMR. The increased sensitivity enables detection of compounds with 13C or 15N in natural abundance. Since PHIP and NH-PHIP operate in situ, and eliminate the need for a prepolarizing magnet, they broaden the analytical capabilities of zero-field NMR. Lastly, this thesis gives insight into the PHIP and NH-PHIP mechanism by developing an appropriate theoretical framework.
Download or read book Pulsed Zero Field NMR of Solids and Liquid Crystals written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes the development and applications to solids and liquid crystals of zero field nuclear magnetic resonance (NMR) experiments with pulsed dc magnetic fields. Zero field NMR experiments are one approach for obtaining high resolution spectra of amorphous and polycrystalline materials which normally (in high field) display broad featureless spectra. The behavior of the spin system can be coherently manipulated and probed in zero field with dc magnetic field pulses which are employed in a similar manner to radiofrequency pulses in high field NMR experiments. Nematic phases of liquid crystalline systems are studied in order to observe the effects of the removal of an applied magnetic field on sample alignment and molecular order parameters. In nematic phases with positive and negative magnetic susceptibility anisotropies, a comparison between the forms of the spin interactions in high and low fields is made. High resolution zero field NMR spectra of unaligned smectic samples are also obtained and reflect the symmetry of the liquid crystalline environment. These experiments are a sensitive measure of the motionally induced asymmetry in biaxial phases. Homonuclear and heteronuclear solute spin systems are compared in the nematic and smectic phases. Nonaxially symmetric dipolar couplings are reported for several systems. The effects of residual fields in the presence of a non-zero asymmetry parameter are discussed theoretically and presented experimentally. Computer programs for simulations of these and other experimental results are also reported. 179 refs., 75 figs.
Download or read book Optical Magnetometry written by Dmitry Budker and published by Cambridge University Press. This book was released on 2013-03-07 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive coverage of the principles, technology and diverse applications of optical magnetometry for graduate students and researchers in atomic physics.
Download or read book Pulsed Zero Field NMR of Solids and Liquid Crystals written by Ann Montgomery Thayer and published by . This book was released on 1987 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NMR Basic Principles and Progress NMR Grundlagen und Fortschritte written by P. Diehl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Contents o. Kanert and M. Mehring Static Quadrupole Effects in Disordered Cubic Solids 1 F. Noack Nuclear Magnetic Relaxation Spectroscopy 83 Static Quadrupole Effects in Disordered Cubic Solids O. KANERT and M. MEHRING Physikalisches Institut der Universitat MUnster, BRD Contents I. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 II. Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Zero Field Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. High Field Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Transformation of the Electric Field Gradient Tensor . . . . . . . . . . 7 III. The Influence of the Quadrupole Perturbation on the NMR Signal . 8 1. General Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 a) The Free Induction Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 b) The Wide-Line Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 c) The Spin Echo Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :. .
Download or read book Advances in Magnetic Resonance written by John S. Waugh and published by Academic Press. This book was released on 2013-10-22 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Magnetic Resonance, Volume 8 describes the magnetic resonance in spin polarization and saturation transfer. This book discusses the theory of chemically induced dynamic spin polarization; basic results for the radical-pair mechanism; and optical spin polarization in molecular crystals. The theory of optical electronic polarization (OEP); NMR in flowing systems; and applications of NMR in a flowing liquid are also elaborated. This text likewise covers the saturation transfer spectroscopy; studies of spin labels in the intermediate and fast motion regions; and spin-density matrix and the Harniltonian. This publication is beneficial to physical chemistry students and individuals researching on spin polarization.
Download or read book Advances in Magnetic and Optical Resonance written by Warren S. Warren and published by Academic Press. This book was released on 2013-10-22 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Magnetic and Optical Resonance, Volume 17 reviews different developing branches of coherent spectroscopy, focusing on the incoherent radiation pulses in optics and magnetic resonance. This book is divided into two chapters. Chapter 1 summarizes the uses and occasional advantages of incoherent radiation pulses in optics and magnetic resonance. The second chapter reviews theoretical developments in zero-field NMR and ESR spectroscopies. Other topics include the nonlinear incoherent spectroscopy; stochastic nonlinear susceptibilities; nonlinear interferometer for magnetic resonance; and nonlinear interference and optics. The zero-field spin dynamics and relaxation and ZF line shapes in the presence of molecular reorientations are also covered. This publication is a good reference for students and researchers interested in coherent spectroscopy.
Download or read book Experimental Pulse NMR written by Eiichi Fukushima and published by Addison Wesley Publishing Company. This book was released on 1981-01-21 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is about pulse nuclear magnetic resonance (NMR), with its techniques, the information to be obtained, and practical advice on performing experiments. The emphasis is on the motivation and ph"
Download or read book High resolution NMR Techniques in Organic Chemistry written by T. Claridge and published by Elsevier. This book was released on 1999-12-24 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the initial observation of proton magnetic resonance in water and in paraffin, the discipline of nuclear magnetic resonance has seen unparalleled growth as an analytical method. Modern NMR spectroscopy is a highly developed, yet still evolving, subject which finds application in chemistry, biology, medicine, materials science and geology. In this book, emphasis is on the more recently developed methods of solution-state NMR applicable to chemical research, which are chosen for their wide applicability and robustness. These have, in many cases, already become established techniques in NMR laboratories, in both academic and industrial establishments. A considerable amount of information and guidance is given on the implementation and execution of the techniques described in this book.
Download or read book Quantum Magnetic Resonance Imaging Diagnostics of Human Brain Disorders written by Madan M Kaila and published by Elsevier. This book was released on 2010-06-21 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a medical imaging technique used to visualize detailed internal structure of the body. This book discusses the recent developments in the field of MRI and its application to the diagnosis of human brain disorders. In addition, it reviews the newly emerging concepts and technology, based on the multi-coherence imaging (MQCI). It explains how computer packages can be used to generate images in diseased states and compare them to in vivo results. This will help improve the diagnosis of brain disorders based on the real-time events happening on atomic and molecular quantum levels. This is important since quantum-based MRI would enable clinicians to detect brain tumors at the very early stages. - Uses practical examples to explain the techniques - making it easier to understand the concepts - Uses diagrams to explain the physics behind the technique - avoiding the use of complicated mathematical formulae
Download or read book Lectures on Pulsed NMR written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 55 figs.
Download or read book Compact NMR written by Bernhard Blümich and published by Walter de Gruyter. This book was released on 2014-01-31 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this book is to provide an introduction to the practical use of mobile NMR at a level as basic as the operation of a smart phone. Each description follows the same didactic pattern: introduction, basic theory, pulse sequences and parameters, beginners-level measurements, advanced-level measurements, and data processing. Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue depicting the brain function and the beating heart. In both applications large super-conducting magnets are employed which magnetize atomic nuclei of an object positioned inside the magnet. Their circulating motion is interrogated by radio-frequency waves. Depending on the operating mode, the frequency spectrum provides the chemist with molecular information, the medical doctor with anatomic images, while the materials scientist is interested in NMR relaxation parameters, which scale with material properties and determine the contrast in magnetic resonance images. Recent advances in magnet technology led to a variety of small permanent magnets, by which NMR spectra, images, and relaxation parameters can be measured with mobile and low-cost instruments.
Download or read book Experiments in Modern Physics written by Adrian Constantin Melissinos and published by . This book was released on 1966 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present text is an outgrowth of such a laboratory course given by the author at the University of Rochester between 1959 and 1963. It consisted of a one-year course with two 3-hour meetings in the laboratory and two 1-hour lecture meetings weekly; the students had access to the laboratory at all
Download or read book Advances in Low field NMR Relaxometry written by Denis Jaschtschuk and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pulse and Fourier Transform NMR written by Thomas Clark Farrar and published by Academic Press. This book was released on 1971-08-28 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulse and Fourier Transform NMR: Introduction to Theory and Methods presents the different types of pulse experiments that are commonly used and provides the theoretical background necessary for understanding these techniques. This book evaluates the practical application of pulse methods and the necessary instrumentation. Organized into seven chapters, this book begins with an overview of the NMR fundamentals and the basic pulse methods. This text then summarizes the important features of pulse spectrometers. Other chapters consider the rationale, the advantages, and the limitations of Fourier transform NMR methods. This book discusses as well how the idea of the rotating frame can be utilized to understand certain experiments that extend the range of application of pulse methods. The final chapter deals with a few significant special uses of pulse techniques. This book is a valuable resource for chemists and readers who are familiar with high resolution NMR but with no background in pulse methods.
