New Signal Processing Techniques in NMR Spectroscopy

New Signal Processing Techniques in NMR Spectroscopy PDF Author: Michael Langton De Warrenne Waller
Publisher:
ISBN:
Category :
Languages : en
Pages : 478

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New Signal Processing Techniques in NMR Spectroscopy

New Signal Processing Techniques in NMR Spectroscopy PDF Author: Michael Langton De Warrenne Waller
Publisher:
ISBN:
Category :
Languages : en
Pages : 478

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Signal Treatment and Signal Analysis in NMR

Signal Treatment and Signal Analysis in NMR PDF Author: D.N. Rutledge
Publisher: Elsevier
ISBN: 0080541208
Category : Science
Languages : en
Pages : 567

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Book Description
Signal analysis and signal treatment are integral parts of all types of Nuclear Magnetic Resonance. In the last ten years, much has been achieved in the development of dimensional spectra. At the same time new NMR techniques such as NMR Imaging and multidimensional spectroscopy have appeared, requiring entirely new methods of signal analysis. Up until now, most NMR texts and reference books limited their presentation of signal processing to a short introduction to the principles of the Fourier Transform, signal convolution, apodisation and noise reduction. To understand the mathematics of the newer signal processing techniques, it was necessary to go back to the primary references in NMR, chemometrics and mathematics journals. The objective of this book is to fill this void by presenting, in a single volume, both the theory and applications of most of these new techniques to Time-Domain, Frequency-Domain and Space-Domain NMR signals. Details are provided on many of the algorithms used and a companion CD-ROM is also included which contains some of the computer programs, either as source code or in executable form. Although it is aimed primarily at NMR users in the medical, industrial and academic fields, it should also interest chemometricians and programmers working with other techniques.

Development of New Signal Processing and Mixture Separation Techniques for Nuclear Magnetic Resonance Spectroscopy Applications

Development of New Signal Processing and Mixture Separation Techniques for Nuclear Magnetic Resonance Spectroscopy Applications PDF Author: Hasan Celik
Publisher:
ISBN: 9781267079671
Category :
Languages : en
Pages : 158

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Book Description
Although originally designed to treat neither spectroscopic nor multidimensional data, FDM was adapted to process NMR spectra of both large and small molecules in liquids in 1D, 2D, 3D, and 4D spectra, with the multidimensional cases requiring important modifications. FDM outperforms the discrete Fourier Transform (DFT) whenever sensitivity is good, the spectrum is sufficiently sparse, the spectral peaks are sharp and Lorentzian, and the extent of the measured time-domain data is short, so that the FT spectrum exhibits line shapes that are distorted only by the time-frequency uncertainty principle. A further study of FDM to perturbations under non-ideal conditions lead to further improvements and finally a multi-dimensional, phase-sensitive, hybrid FDM (HFDM) algorithm that is introduced for the first time. HFDM can enhance the resolution of peaks distorted by time-frequency uncertainty, while still producing a spectrum in which all the original imperfections are present, such that a true noise floor prevents inadvertent contouring of features that look like resonances but that would in fact be buried in noise in any decent spectral estimate. This opens the door to the application of HFDM on NMR data sets with more reliability. Mixture separation is another important area of NMR research and will be the focus of the third chapter. Separating a mixture of signals into its source components is an engaging but challenging problem relevant to research in a wide variety of fields from neurology and medical signal processing to speech recognition systems. The vast majority of NMR spectroscopic data is taken on isolated, purified compounds; yet mixtures are clearly important to tackle. The pharmaceutical industry is a key example of a field that would benefit tremendously from more robust NMR mixture separation techniques. Structural information about promising candidates from the drug design process must be extracted from samples that also contain the target molecule, side products, and impurities. NMR can identify individual samples with respect to their unique fingerprint spectra; however, it has been traditionally poor at handling mixtures. Diffusion ordered spectroscopy (DOSY) has been one of the few NMR techniques that can be used for mixture separation. It uses translational diffusion to effect a partial separation and can be quite powerful when the individual compounds have a distinguishable difference in their diffusion constants. However, the separation problem becomes more difficult when the component molecules have similar chemical functional group and overlap in their NMR spectra. Blind Source Separation (BSS) is a technique that can be used to extract an individual NMR subspectrum from spectra of a number of different mixtures; and--if the molecules do not interact strongly--these individual subspectra adhere closely to those of the corresponding pure compounds under the same conditions. Furthermore, the "mixture spectra" need not be different physical samples: any method that can modify the intensities of all the peaks from a given molecule, in concert, is applicable. Previously a mixture of two components was successfully separated. Recent efforts have uncovered a flaw in the original BSS algorithm that causes behaves erratically for samples with three or more components. This complication will be described in detail, and a newly developed approach-- dubbed "BISI" for Blind Iterative Source Identification--will be introduced that overcomes those previously unforeseen problems.

Signal Processing for Magnetic Resonance Imaging and Spectroscopy

Signal Processing for Magnetic Resonance Imaging and Spectroscopy PDF Author: Hong Yan
Publisher: CRC Press
ISBN: 9780203908785
Category : Technology & Engineering
Languages : en
Pages : 676

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Book Description
This reference/text contains the latest signal processing techniques in magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for more efficient clinical diagnoses-providing ready-to-use algorithms for image segmentation and analysis, reconstruction and visualization, and removal of distortions and artifacts for increased detec

Signal Processing and Analysis Techniques for Nuclear Quadrupole Resonance Spectroscopy

Signal Processing and Analysis Techniques for Nuclear Quadrupole Resonance Spectroscopy PDF Author: Cristian Monea
Publisher: Springer Nature
ISBN: 3030878619
Category : Technology & Engineering
Languages : en
Pages : 190

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Book Description
This book is about improving prohibited substances detection using the nuclear quadrupole resonance (NQR) technique at security checkpoints. The book proposes multiple signal processing and analysis techniques for improving detection of dangerous or contraband substances, such as explosives, narcotics, or toxic substances. Also, several hardware solutions are described and implemented in a custom-designed NQR spectrometer. A new approach to NQR signal detection is introduced using artificial intelligence/deep learning techniques. The book will be useful for for researchers and practitioners in the areas of electrical engineering, signal processing and analysis, applied spectroscopy, as well as for security or laboratory equipment manufacturers.

New Methods for the Acquisition and Processing of Solid-State NMR Spectra

New Methods for the Acquisition and Processing of Solid-State NMR Spectra PDF Author: Adam Robert Altenhof
Publisher:
ISBN:
Category : Chemistry, Physical and theoretical
Languages : en
Pages : 0

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Book Description
Solid-state nuclear magnetic resonance (SSNMR) is a powerful tool for the study of chemical structure and dynamics. The interactions that manifest in NMR spectra are anisotropic (id est, orientation dependent) in origin, often resulting in inhomogeneous broadening that can yield spectra exceeding circa 250 kHz in breadth; such spectra are often referred to as ultra-wideline (UW) NMR spectra. In many cases, UWNMR spectra cannot be acquired using conventional methods and rectangular radiofrequency (RF) pulses - rather, specialized pulses and techniques must be implemented. Furthermore, the large suite of high-resolution methods based on magic-angle spinning (MAS) are generally unsuitable for the acquisition of UWNMR spectra. Frequency-swept (FS) pulses are amplitude- and phase-modulated pulses that can irradiate NMR frequencies over large bandwidths. One of these is the wideband uniform-rate smooth-truncation (WURST) pulse, which features a linear effective frequency sweep. WURST pulses are used in the WURST-Carr-Purcell/Meiboom-Gill (WURST-CPMG) and broadband adiabatic inversion-cross polarization (BRAIN-CP) pulse sequences, which have been shown to be effective for the acquisition of UWNMR spectra of stationary (static) samples. These sequences have limitations, and to date, their capabilities have not been fully explored, nor have they been described from a theoretical point of view in a comprehensive manner.Signal processing is an integral component of pulsed-Fourier transform NMR spectroscopy, and comprises many protocols for enhancing spectral sensitivity and resolution. There has been much interest in advanced spectral processing methods such as alternate basis transformations (id est, besides Fourier encoding), statistical analyses (e.g., singular value decomposition, SVD, and principal component analysis, PCA), numerical regression (e.g., non-negative least squares), and the use of deep learning and neural networks. Such methodologies are now routinely implemented in imaging and multidimensional solution NMR, but are seldom explored in SSNMR. This thesis describes the development of new methods for the acquisition and advanced processing of conventional, wideline, and UW SSNMR spectra, including: (i) the design of new pulses and pulse sequences with optimal control theory (OCT); (ii) the modification of existing pulse sequences for UWNMR under MAS conditions; (iii) achieving signal enhancements with CPMG pulse sequences via the suppression of weak homonuclear dipolar coupling interactions under static and MAS conditions; (iv) the application of the BRAIN-CP pulse sequence to integer-spin nuclei, along with a thorough theoretical treatment; (v) rapid and robust measurements of longitudinal relaxation time constants (T1) and T1 anisotropies from UWNMR spectra under static conditions; (vi) the development and application of advanced processing methods for resolving UWNMR relaxation data with inverse Laplace transforms; and (vii) the development of a Python library for denoising 1D and 2D NMR spectra with SVD, PCA, and wavelet transforms. It is hoped that these methods will open up the Periodic Table of elements to increasingly routine exploration by SSNMR spectroscopy, aiding researchers in chemistry, biochemistry, materials science, and physics with advanced molecular-level characterization of their materials.

NMR Data Processing

NMR Data Processing PDF Author: Jeffrey C. Hoch
Publisher: Wiley-Liss
ISBN: 9780471039006
Category : Science
Languages : en
Pages : 230

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Book Description
NMR DATA PROCESSING Jeffrey C. Hoch and Alan S. Stern Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful nondestructive technique for exploring the structure of matter. In recent years, NMR instrumentation has become increasingly sophisticated, and the software used to acquire and process NMR data continues to expand in scope and complexity. This software has always been difficult to understand, and, until now, it seemed likely to remain that way. NMR Data Processing examines and explains the techniques used to process, present, and analyze NMR data. It provides a complete account of the fundamentals of spectrum analysis and establishes a framework for applying those fundamentals to real NMR data. It also details, in clear and concise language, the basic principles underlying the complex software needed to analyze the data. Two chapters are devoted to the fundamentals and applications of discrete Fourier transform (DFT) in NMR, which was crucial to the development of modern NMR spectroscopy. A large part of the book focuses on increasingly important non-DFT methods, which obtain higher sensitivity and resolution. Other topics covered include: * Data formats * Processing for multidimensional experiments * Parametric modeling of NMR signals * Standard techniques-apodization, zero-filling, the Hilbert transform * Artifacts-aliasing, leakage, solvent signals * Advanced processing techniques-LP, MaxEnt, Bayesian analysis Jeffrey C. Hoch and Alan S. Stern conclude their in-depth look at this rapidly growing field by exploring methods for analyzing processed data, including visualization, quantification, and error analysis. Readers are provided with a solid foundation for developing new methods of their own. NMR Data Processing is an important tool for students learning basic principles for the first time, technicians troubleshooting data processing problems, and professional researchers developing new techniques. It will help all NMR users acquire a true grasp of the methods behind the process, avoid the pitfalls of misapplication and misinterpretation, and exploit the full power of NMR software.

Signal Processing for NMR Spectroscopy

Signal Processing for NMR Spectroscopy PDF Author: Yan Zhu
Publisher:
ISBN:
Category : Nuclear magnetic resonance spectroscopy
Languages : en
Pages : 262

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Analysis of NMR Spectra Using Digital Signal Processing Techniques

Analysis of NMR Spectra Using Digital Signal Processing Techniques PDF Author: Jason Aaron Gearheart
Publisher:
ISBN:
Category :
Languages : en
Pages : 45

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Book Description
Since its development, nuclear magnetic resonance (NMR) has become one of the primary methods of chemists for structure elucidation, which is the determination of a compound's molecular structure. Current software packages enable scientists to visualize the raw data produced by the spectrometer so that they can manually determine a compound's component parts. This is accomplished by manually comparing the spectrum of the mixture with various reference materials believed to be present.

Digital Signal Processing Techniques for an NMR Receiver

Digital Signal Processing Techniques for an NMR Receiver PDF Author: Michael Charles Anas
Publisher:
ISBN:
Category : Nuclear magnetic resonance
Languages : en
Pages :

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