Mobile single-sided NMR

Progress in Nuclear Magnetic Resonance Spectroscopy (Impact Factor: 7.24). 05/2008; 52(4):197-269. DOI: 10.1016/j.pnmrs.2007.10.002

ABSTRACT The development of NMR instrumentation, methods, and applications of mobile NMR, with particular attention to single-sided NMR is discussed. Inside-out NMR is a form of single-sided or unilateral NMR, where an NMR sensor much smaller than the object is placed near the object to acquire signals from the object volume near the sensor. Mobile NMR holds great promise in a variety of fields, in particular in medicine, materials science, chemical engineering and space science. A very promising area of application of mobile NMR is process control by sensors installed in the production line. The development of NMR methods for mobile NMR is driven by two sources. One is the need for more information from, and better accuracy of, well-logging instruments. The other is scientific curiosity about doing NMR in low and inhomogeneous fields with inexpensive instrumentation and with it the drive for expanding the range of applications of NMR.

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    • "There are several factors responsible for that. Most importantly, the inhomogeneous B 0 and B 1 fields lead to a distribution of RF pulses across the sensitive volume [15] [29], producing multiple magnetization pathways and reducing the contribution of the ideal (90–180–180–. . .) pathway to the total NMR signal with every subsequent echo. "
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    ABSTRACT: An NMR signal from a sample in a constant stray field of a portable NMR sensor is sensitized to vibrations. The CPMG sequence is synchronized to vibrations so that the constant gradient becomes an “effective” square-wave gradient, leading to the vibration-induced phase accumulation. The integrating nature of the spot measurement, combined with the phase distribution due to a non-uniform gradient and/or a wave field, leads to a destructive interference, the drop in the signal intensity and changes in the echo train shape. Vibrations with amplitudes as small as 140 nm were reliably detected with the permanent gradient of 12.4 T/m. The signal intensity depends on the phase offset between the vibrations and the pulse sequence. This approach opens the way for performing elastometry and micro-rheology measurements with portable NMR devices beyond the walls of a laboratory. Even without synchronization, if a vibration frequency is comparable to 1/2TE of the CPMG sequence, the signal can be severely affected, making it important for potential industrial applications of stray-field NMR.
    Journal of Magnetic Resonance 10/2014; 248:1-7. DOI:10.1016/j.jmr.2014.09.003 · 2.51 Impact Factor
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    • "It should be noninvasive, portable, accept a variety of sample geometries, and probe both metal and non-metal containers. These features are provided by a unilateral NMR circuit, or single-sided coil, which is an NMR tank circuit with a planar inductor that can non-invasively probe a wide range of sample geometries [9]. Interfacing this coil with a light weight permanent magnet that produces a small static magnetic field ultimately leads to increased metal transparency. "
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    ABSTRACT: Nuclear magnetic resonance (NMR) spectroscopy is used to track factory relevant tomato paste spoilage. It was found that spoilage in tomato paste test samples leads to longer spin lattice relaxation times T1 using a conventional low magnetic field NMR system. The increase in T1 value for contaminated samples over a five day room temperature exposure period prompted the work to be extended to the study of industry standard, 1,000 L, non-ferrous, metal-lined totes. NMR signals and T1 values were recovered from a large format container with a single-sided NMR sensor. The results of this work suggest that a handheld NMR device can be used to study tomato paste spoilage in factory process environments.
    Sensors 03/2014; 14(3):4167-76. DOI:10.3390/s140304167 · 2.25 Impact Factor
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    • "As a versatile analytical technique, nuclear magnetic resonance (NMR) has been used not only in fundamental research in physics, chemistry and biology, but also for practical applications such as medical imaging and oil well logging [1]. However, the poor sensitivity of conventional inductive pick-up coils at low frequency hinders many possible applications, and hence most endeavors in enhancing sensitivity focus on high-field NMR. "
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    ABSTRACT: We present a Cs atomic magnetometer with a sensitivity of 150fT/Hz(1/2) operating near room temperature. The nuclear magnetic resonance (NMR) signal of 125μL tap water was detected at an ultralow magnetic field down to 47nT, with the signal-to-noise ratio (SNR) of the NMR signal approaching 50 after eight averages. Relaxivity experiments with a Gd(DTPA) contrast agent in zero field were performed, in order to show the magnetometer's ability to measure spin-lattice relaxation time with high accuracy. This demonstrates the feasibility of an ultralow field NMR spectrometer based on a Cs atomic magnetometer, which has a low working temperature, short data acquisition time and high sensitivity. This kind of NMR spectrometer has great potential in applications such as chemical analysis and magnetic relaxometry detection in ultralow or zero fields.
    Journal of Magnetic Resonance 10/2013; 237C:158-163. DOI:10.1016/j.jmr.2013.10.008 · 2.51 Impact Factor
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