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Sample records for non-destructive magic angle

  1. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  2. New magic angle bumps and magic translation bumps

    SciTech Connect

    Seeman, J.

    1983-10-28

    SLC beams of opposite charge can be transversely deflected in the same direction by RF fields in the accelerating cavities caused by girder tilts, coupler-asymmetries, or manufacturing errors. A symmetric deflection can be corrected by a magic angle bump if the deflection is located adjacent to one of the linac quadrupoles. However, if the deflection is located between quadrupoles, two magic angle bumps or a magic angle bump and a magic translation bump are needed for the correction. Several examples of translation bumps are included. A new magic angle bump is also presented which is longitudinally compressed and has significantly reduced particle excursions. Finally, if new correctors are added midway along the girders so that the number of correctors are doubled, then the longitudinal extent and the maximum particle excursion of these new magic bumps can be further reduced.

  3. Non-destructive microwave evaluation of TBC delamination induced by acute angle laser drilling

    NASA Astrophysics Data System (ADS)

    Sezer, H. K.; Li, Lin; Wu, Z.; Anderson, B.; Williams, P.

    2007-01-01

    Laser drilling has been applied to the production of cooling holes of various size and angles in the modern aerospace gas turbine components such as turbine blades, nozzle guide vanes, combustion chambers and afterburner. These parts are usually made of heat resistant nickel superalloys. The superalloy substrate is coated with yttria-stabilized zirconia thermal barrier coatings (TBCs) to protect them from reaching excessive temperatures in hot engine environments. Drilling the parts at acute angles to the surface is complicated because (i) multiple layers are being drilled through, (ii) the melt ejection and heat flow patterns around the hole are non-symmetrical and (iii) the drilling distance is greater than when drilling normal to the surface. In a previous investigation by the authors, delamination of TBC was addressed as a main problem of angled drilling and mechanisms involved were discussed. Characterization of delamination cracks was normally performed via metallographic techniques. It involves sectioning the samples using an abrasive cutting machine, grinding with successively finer silicon carbide paper up to the centre of the hole and polishing to allow optical microscopic analysis of the cracks. However, clamping and sectioning process of thermal-spray-coated workpieces can introduce cracks in brittle coatings due to the drag of the cut-off wheels. Hence, it is not possible to decide if the delamination is caused as a result of post-process sectioning or laser drilling. In this paper, a microwave non-destructive testing (NDT) technique is employed to evaluate the integrity of TBC after acute angle laser drilling. An Agilent 8510 XF network analyser operating over the frequency range of 45 MHz to 110 GHz was used to measure the amplitude and phase variations of scattered waves. The results significantly indicated the existence of delamination of 1-1.5 mm long at the TBC/substrate interface on the leading edge part of an acute-angled hole laser drilled

  4. MAGIC SHIMMING: gradient shimming with magic angle sample spinning.

    PubMed

    Nishiyama, Yusuke; Tsutsumi, Yu; Utsumi, Hiroaki

    2012-03-01

    A simple method to automatically shim NMR samples spinning at the magic angle is introduced based on the gradient shimming approach. The field inhomogeneity along the spinning axis is measured and automatically corrected. The combination of a normal magic angle spinning (MAS) probe, a conventional homospoil gradient, and a set of properly chosen standard room-temperature shims are used to perform the gradient shimming of samples spinning at the magic angle. The resulting (13)C NMR adamantane linewidth is less than 1 Hz (0.0078 ppm at 11.7 T). PMID:22370722

  5. MAGIC SHIMMING: Gradient shimming with magic angle sample spinning

    NASA Astrophysics Data System (ADS)

    Nishiyama, Yusuke; Tsutsumi, Yu; Utsumi, Hiroaki

    2012-03-01

    A simple method to automatically shim NMR samples spinning at the magic angle is introduced based on the gradient shimming approach. The field inhomogeneity along the spinning axis is measured and automatically corrected. The combination of a normal magic angle spinning (MAS) probe, a conventional homospoil gradient, and a set of properly chosen standard room-temperature shims are used to perform the gradient shimming of samples spinning at the magic angle. The resulting 13C NMR adamantane linewidth is less than 1 Hz (0.0078 ppm at 11.7 T).

  6. The magic angle: a solved mystery.

    PubMed

    Jouffrey, B; Schattschneider, P; Hébert, C

    2004-12-01

    We resolve the long-standing mysterious discrepancy between the experimental magic angle in EELS--approximately 2theta(E)--and the quantum mechanical prediction of approximately 4theta(E). A relativistic approach surpassing the usually applied kinematic correction yields a magic angle close to the experimental value. The reason is that the relativistic correction of the inelastic scattering cross section in anisotropic systems is significantly higher than in isotropic ones. PMID:15556701

  7. Magic Angle Spinning NMR of Viruses

    PubMed Central

    Quinn, Caitlin; Lu, Manman; Suiter, Christopher L.; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-01-01

    Viruses, relatively simple pathogens, are able to replicate in many living organisms and to adapt to various environments. Conventional atomic-resolution structural biology techniques, X-ray crystallography and solution NMR spectroscopy provided abundant information on the structures of individual proteins and nucleic acids comprising viruses; however, viral assemblies are not amenable to analysis by these techniques because of their large size, insolubility, and inherent lack of long-range order. In this article, we review the recent advances in magic angle spinning NMR spectroscopy that enabled atomic-resolution analysis of structure and dynamics of large viral systems and give examples of several exciting case studies. PMID:25919197

  8. Broadband "Infinite-Speed" Magic-Angle Spinning NMR Spectroscopy

    SciTech Connect

    Hu, Yan-Yan; Levin, E.M; Schmidt-Rohr, Klaus

    2009-06-02

    High-resolution magic-angle spinning NMR of high-Z spin- 1/2 nuclei such as {sup 125}Te, {sup 207}Pb, {sup 119}Sn, {sup 113}Cd, and {sup 195}Pt is often hampered by large (>1000 ppm) chemical-shift anisotropies, which result in strong spinning sidebands that can obscure the centerbands of interest. In various tellurides with applications as thermoelectrics and as phase-change materials for data storage, even 22-kHz magic-angle spinning cannot resolve the center- and sidebands broadened by chemical-shift dispersion, which precludes peak identification or quantification. For sideband suppression over the necessary wide spectral range (up to 200 kHz), radio frequency pulse sequences with few, short pulses are required. We have identified Gan's two-dimensional magic-angle-turning (MAT) experiment with five 90{sup o} pulses as a promising broadband technique for obtaining spectra without sidebands. We have adapted it to broad spectra and fast magic-angle spinning by accounting for long pulses (comparable to the dwell time in t{sub 1}) and short rotation periods. Spectral distortions are small and residual sidebands negligible even for spectra with signals covering a range of 1.5 {gamma}B{sub 1}, due to a favorable disposition of the narrow ranges containing the signals of interest in the spectral plane. The method is demonstrated on various technologically interesting tellurides with spectra spanning up to 170 kHz, at 22 kHz MAS.

  9. Magic-angle-spinning NMR studies of zeolite SAPO-5

    NASA Astrophysics Data System (ADS)

    Freude, D.; Ernst, H.; Hunger, M.; Pfeifer, H.; Jahn, E.

    1988-01-01

    SAPO-5 was synthesized using triethylamine as template. Magic-angle-spinning (MAS) NMR of 1H, 27Al, 29Si and 31P was used to study the silicon incorporation into the framework and the nature of the Brønsted sites. 1H MAS NMR shows two types of bridging hydroxyl groups. 29Si MAS NMR indicates that silicon substitutes mostly for phosphorus and that there is a small amount of crystalline SiO 2 in the zeolite powder.

  10. NMR in rotating magnetic fields: Magic angle field spinning

    SciTech Connect

    Sakellariou, D.; Meriles, C.; Martin, R.; Pines, A.

    2004-09-10

    Magic angle sample spinning has been one of the cornerstones in high-resolution solid state NMR. Spinning frequencies nowadays have increased by at least one order of magnitude over the ones used in the first experiments and the technique has gained tremendous popularity. It is currently a routine procedure in solid-state NMR, high-resolution liquid-state NMR and solid-state MRI. The technique enhances the spectral resolution by averaging away rank 2 anisotropic spin interactions thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings. Andrew proposed that it should be possible to induce similar effects in a static sample if the direction of the magnetic field is varied, e.g., magic-angle rotation of the B0 field (B0-MAS) and this has been recently demonstrated using electromagnetic field rotation. Here we discuss on the possibilities to perform field rotation using alternative hardware, together with spectroscopic methods to recover isotropic resolution even in cases where the field is not rotating at the magic angle. Extension to higher magnetic fields would be beneficial in situations where the physical manipulation of the sample is inconvenient or impossible. Such situations occur often in materials or biomedical samples where ''ex-situ'' NMR spectroscopy and imaging analysis is needed.

  11. HYDROGEN AND DEUTERIUM NMR OF SOLIDS BY MAGIC ANGLE SPINNING

    SciTech Connect

    Eckman, R.R.

    1982-10-01

    The nuclear magnetic resonance of solids has long been characterized by very large spectral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. For example, the homonuclear dipolar broadening, HD, for hydrogen is usually several tens of kilohertz. For deuterium, HD is relatively small; however, the quadrupole interaction causes a broadening which can be hundreds of kilohertz in polycrystalline or amorphous solids. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, {beta}{sub m} = Arccos(3{sup -1/2}), with respect to the direction of the external magnetic field. Two approaches have been developed for each nucleus. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of {beta}. A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H{sub D} was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal

  12. Methods for magnetic resonance analysis using magic angle technique

    DOEpatents

    Hu, Jian Zhi; Wind, Robert A.; Minard, Kevin R.; Majors, Paul D.

    2011-11-22

    Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

  13. High-resolution NMR of anisotropic samples with spinning away from the magic angle

    SciTech Connect

    Sakellariou, Dimitris; Meriles, Carlos A.; Martin, Rachel W.; Pines, Alexander

    2003-03-31

    High-resolution NMR of samples in the solid state is typically performed under mechanical sample spinning around an axis that makes an angle, called the magic angle, of 54.7 degrees with the static magnetic field. There are many cases in which geometrical and engineering constraints prevent spinning at this specific angle. Implementations of in-situ and ex-situ magic angle field spinning might be extremely demanding because of the power requirements or an inconvenient sample size or geometry. Here we present a methodology based on switched angle spinning between two angles, none of which is the magic angle, which provide both isotropic and anisotropic information. Using this method, named Projected Magic Angle Spinning, we were able to obtain resolved isotropic chemical shifts in spinning samples where the broadening is mostly inhomogeneous.

  14. Ultrashort TE T1ρ magic angle imaging.

    PubMed

    Du, Jiang; Statum, Sheronda; Znamirowski, Richard; Bydder, Graeme M; Chung, Christine B

    2013-03-01

    An ultrashort TE T(1)ρ sequence was used to measure T(1) ρ of the goat posterior cruciate ligament (n = 1) and human Achilles tendon specimens (n = 6) at a series of angles relative to the B(0) field and spin-lock field strengths to investigate the contribution of dipole-dipole interaction to T(1)ρ relaxation. Preliminary results showed a significant magic angle effect. T(1)ρ of the posterior cruciate ligament increased from 6.9 ± 1.3 ms at 0° to 36 ± 5 ms at 55° and then gradually reduced to 12 ± 3 ms at 90°. Mean T(1)ρ of the Achilles tendon increased from 5.5 ± 2.2 ms at 0° to 40 ± 5 ms at 55°. T(1)ρ dispersion study showed a significant T(1)ρ increase from 2.3 ± 0.9 ms to 11 ± 3 ms at 0° as the spin-lock field strength increased from 150 Hz to 1 kHz, and from 30 ± 3 ms to 42 ± 4 ms at 55° as the spin-lock field strength increased from 100 to 500 Hz. These results suggest that dipolar interaction is the dominant T(1)ρ relaxation mechanism in tendons and ligaments. PMID:22539354

  15. High-pressure magic angle spinning nuclear magnetic resonance

    SciTech Connect

    Hoyt, David W.; Turcu, Romulus V. F.; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. Finally, as an application example, in situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

  16. High-pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Hoyt, David W; Turcu, Romulus V F; Sears, Jesse A; Rosso, Kevin M; Burton, Sarah D; Felmy, Andrew R; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ(13)C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg(2)SiO(4)) reacted with supercritical CO(2) and H(2)O at 150 bar and 50°C are reported, with relevance to geological sequestration of carbon dioxide. PMID:21862372

  17. High-pressure magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Hoyt, David W.; Turcu, Romulus V. F.; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg 2SiO 4) reacted with supercritical CO 2 and H 2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

  18. Solid effect in magic angle spinning dynamic nuclear polarization

    NASA Astrophysics Data System (ADS)

    Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.

    2012-08-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an ω _0 ^{ - 2} field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ɛ = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of 1H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear 1H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements to address the unfavorable field dependence of the solid effect.

  19. Solid effect in magic angle spinning dynamic nuclear polarization

    PubMed Central

    Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.

    2012-01-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}\\omega _0 ^{ - 2}\\end{equation*} \\end{document}ω0−2 field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ɛ = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of 1H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear 1H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements

  20. Solid effect in magic angle spinning dynamic nuclear polarization.

    PubMed

    Corzilius, Björn; Smith, Albert A; Griffin, Robert G

    2012-08-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an ω(0)(-2) field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ε = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of (1)H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear (1)H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements to address the unfavorable field dependence of the solid effect. PMID:22894339

  1. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    SciTech Connect

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  2. Direct determination of phosphate sugars in biological material by (1)H high-resolution magic-angle-spinning NMR spectroscopy.

    PubMed

    Diserens, Gaëlle; Vermathen, Martina; Gjuroski, Ilche; Eggimann, Sandra; Precht, Christina; Boesch, Chris; Vermathen, Peter

    2016-08-01

    The study aim was to unambiguously assign nucleotide sugars, mainly UDP-X that are known to be important in glycosylation processes as sugar donors, and glucose-phosphates that are important intermediate metabolites for storage and transfer of energy directly in spectra of intact cells, as well as in skeletal muscle biopsies by (1)H high-resolution magic-angle-spinning (HR-MAS) NMR. The results demonstrate that sugar phosphates can be determined quickly and non-destructively in cells and biopsies by HR-MAS, which may prove valuable considering the importance of phosphate sugars in cell metabolism for nucleic acid synthesis. As proof of principle, an example of phosphate-sugar reaction and degradation kinetics after unfreezing the sample is shown for a cardiac muscle, suggesting the possibility to follow by HR-MAS NMR some metabolic pathways. Graphical abstract Glucose-phosphate sugars (Glc-1P and Glc-6P) detected in muscle by 1H HR-MAS NMR. PMID:27271261

  3. Theoretical aspects of Magic Angle Spinning - Dynamic Nuclear Polarization

    NASA Astrophysics Data System (ADS)

    Mentink-Vigier, Frederic; Akbey, Ümit; Oschkinat, Hartmut; Vega, Shimon; Feintuch, Akiva

    2015-09-01

    Magic Angle Spinning (MAS) combined with Dynamic Nuclear Polarization (DNP) has been proven in recent years to be a very powerful method for increasing solid-state NMR signals. Since the advent of biradicals such as TOTAPOL to increase the nuclear polarization new classes of radicals, with larger molecular weight and/or different spin properties have been developed. These have led to unprecedented signal gain, with varying results for different experimental parameters, in particular the microwave irradiation strength, the static field, and the spinning frequency. Recently it has been demonstrated that sample spinning imposes DNP enhancement processes that differ from the active DNP mechanism in static samples as upon sample spinning the DNP enhancements are the results of energy level anticrossings occurring periodically during each rotor cycle. In this work we present experimental results with regards to the MAS frequency dependence of the DNP enhancement profiles of four nitroxide-based radicals at two different sets of temperature, 110 and 160 K. In fact, different magnitudes of reduction in enhancement are observed with increasing spinning frequency. Our simulation code for calculating MAS-DNP powder enhancements of small model spin systems has been improved to extend our studies of the influence of the interaction and relaxation parameters on powder enhancements. To achieve a better understanding we simulated the spin dynamics of a single three-spin system {ea -eb - n } during its steady state rotor periods and used the Landau-Zener formula to characterize the influence of the different anti-crossings on the polarizations of the system and their necessary action for reaching steady state conditions together with spin relaxation processes. Based on these model calculations we demonstrate that the maximum steady state nuclear polarization cannot become larger than the maximum polarization difference between the two electrons during the steady state rotor cycle

  4. Hall Plateaus at magic angles in ultraquantum Bismuth

    NASA Astrophysics Data System (ADS)

    Benoît, Fauqué.

    2009-03-01

    The behaviour of a three-dimensional electron gas in the presence of a magnetic field strong enough to put all carriers in the first Landau level (i.e. beyond the quantum limit) is a longstanding question of theoretical condensed matter physics [1]. This issue has been recently explored by two high-field experiments on elemental semi-metal Bismuth. In a first study of transport coefficients (which are dominated by hole-like carriers), the Nernst coefficient presented three unexpected maxima that are concomitant with quasi-plateaux in the Hall coefficient [2]. In a second series of experiments, torque magnetometry (which mainly probes the three Dirac valley electron pockets) detected a field-induced phase transition [3]. The full understanding of the electron and hole behaviours above the quantum limit of pure Bi is therefore still under debate. In this talk, we will present our measurement of the Hall resistivity and torque magnetometry with magnetic field up to 31 T and rotating in the trigonal-bisectrix plane [4]. The Hall response is dominated by the hole pockets according to its sign as well as the period and the angular dependence of its quantum oscillations. In the vicinity of the quantum limit, it presents additional anomalies which are the fingerprints of the electron pockets. We found that for particular orientations of the magnetic field (namely ``magic angles''), the Hall response becomes field-independent within the experimental resolution around 20T. This drastic dependence of the plateaux on the field orientation provides strong constraints for theoretical scenarios. [4pt] [1] Bertrand I. Halperin, Japanese Journal of Applied Physics, 26, Supplement 26-3 (1987).[0pt] [2] Kamran Behnia, Luis Balicas, Yakov Kopelevich, Science, 317, 1729 (2008).[0pt] [3] Lu Li, J. G. Checkelsky, Y. S. Hor, C. Uher, A. F. Hebard, R. J. Cava, and N. P. Ong , Science, 321, 5888 (2008).[0pt] [4] Benoît Fauqu'e, Luis Balicas, Ilya Sheikin, Jean Paul Issi and Kamran Behnia

  5. Theoretical aspects of Magic Angle Spinning - Dynamic Nuclear Polarization.

    PubMed

    Mentink-Vigier, Frederic; Akbey, Ümit; Oschkinat, Hartmut; Vega, Shimon; Feintuch, Akiva

    2015-09-01

    Magic Angle Spinning (MAS) combined with Dynamic Nuclear Polarization (DNP) has been proven in recent years to be a very powerful method for increasing solid-state NMR signals. Since the advent of biradicals such as TOTAPOL to increase the nuclear polarization new classes of radicals, with larger molecular weight and/or different spin properties have been developed. These have led to unprecedented signal gain, with varying results for different experimental parameters, in particular the microwave irradiation strength, the static field, and the spinning frequency. Recently it has been demonstrated that sample spinning imposes DNP enhancement processes that differ from the active DNP mechanism in static samples as upon sample spinning the DNP enhancements are the results of energy level anticrossings occurring periodically during each rotor cycle. In this work we present experimental results with regards to the MAS frequency dependence of the DNP enhancement profiles of four nitroxide-based radicals at two different sets of temperature, 110 and 160K. In fact, different magnitudes of reduction in enhancement are observed with increasing spinning frequency. Our simulation code for calculating MAS-DNP powder enhancements of small model spin systems has been improved to extend our studies of the influence of the interaction and relaxation parameters on powder enhancements. To achieve a better understanding we simulated the spin dynamics of a single three-spin system {ea-eb-n} during its steady state rotor periods and used the Landau-Zener formula to characterize the influence of the different anti-crossings on the polarizations of the system and their necessary action for reaching steady state conditions together with spin relaxation processes. Based on these model calculations we demonstrate that the maximum steady state nuclear polarization cannot become larger than the maximum polarization difference between the two electrons during the steady state rotor cycle. This

  6. NON-DESTRUCTIVE BEAM MEASUREMENTS.

    SciTech Connect

    BAI,M.

    2004-07-05

    In high energy accelerators, especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is an ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with a Schottky detector, phase advance measurements as well as nonlinear resonance measurements with the ac dipoles in the Brookhaven RHIC.

  7. Slow Magic Angle Sample Spinning: A Non- or Minimally Invasive Method for High- Resolution 1H Nuclear Magnetic Resonance (NMR) Metabolic Profiling

    SciTech Connect

    Hu, Jian Z.

    2011-05-01

    High resolution 1H magic angle spinning nuclear magnetic resonance (NMR), using a sample spinning rate of several kHz or more (i.e., high resolution-magic angle spinning (hr-MAS)), is a well established method for metabolic profiling in intact tissues without the need for sample extraction. The only shortcoming with hr-MAS is that it is invasive and is thus unusable for non-destructive detections. Recently, a method called slow-MAS, using the concept of two dimensional NMR spectroscopy, has emerged as an alternative method for non- or minimal invasive metabolomics in intact tissues, including live animals, due to the slow or ultra-slow-sample spinning used. Although slow-MAS is a powerful method, its applications are hindered by experimental challenges. Correctly designing the experiment and choosing the appropriate slow-MAS method both require a fundamental understanding of the operation principles, in particular the details of line narrowing due to the presence of molecular diffusion. However, these fundamental principles have not yet been fully disclosed in previous publications. The goal of this chapter is to provide an in depth evaluation of the principles associated with slow-MAS techniques by emphasizing the challenges associated with a phantom sample consisting of glass beads and H2O, where an unusually large magnetic susceptibility field gradient is obtained.

  8. An efficient amplification pulse sequence for measuring chemical shift anisotropy under fast magic-angle spinning.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2011-12-01

    A two-dimensional experiment for measuring chemical shift anisotropy (CSA) under fast magic-angle spinning (MAS) is presented. The chemical shift anisotropy evolution is amplified by a sequence of π-pulses that repetitively interrupt MAS averaging. The amplification generates spinning sideband manifolds in the indirect dimension separated by the isotropic shift along the direct dimension. The basic unit of the pulse sequence is designed based on the magic-angle turning experiment and can be concatenated for larger amplification factors. PMID:21962909

  9. Simple cylindrical magic-angle spinner for NMR studies in electromagnets

    NASA Astrophysics Data System (ADS)

    Mai, Michael T.; Ribeiro, Anthony; Jardetzky, Oleg

    A novel cylindrical magic-angle spinner for use in electromagnet systems is described. It features radial and thrust air bearings and easily constructed rotors of relatively large sample volume (˜0.7 cm 3) assembled into a removable spinner/coil Teflon housing. The design allows stable spinning speeds in the range 0.3 to 2.4 kHz with excellent rotor-to-rotor magic-angle resettabilities. High resolution, solid-state NMR studies are illustrated with 13C NMR spectra for crystalline adamantane and a macromolecule, lysozyme.

  10. Towards monomaterial p-n junctions: Single-step fabrication of tin oxide films and their non-destructive characterisation by angle-dependent X-ray photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Krzywiecki, Maciej; Sarfraz, Adnan; Erbe, Andreas

    2015-12-01

    The application of a non-destructive method for characterization of electronic structure of an ultra-thin SnO1angle dependent XPS, we quantified stoichiometry changes inside the SnO1

  11. True Pathologic Abnormality versus Artifact Foot Position and Magic Angle Artifact in the Peroneal Tendons with 3T Imaging.

    PubMed

    Horn, Deena B; Meyers, Steven; Astor, William

    2015-09-01

    Magnetic resonance imaging is a commonly ordered examination by many foot and ankle surgeons for ankle pain and suspected peroneal tendon pathologic abnormalities. Magic angle artifact is one of the complexities associated with this imaging modality. Magic angle refers to the increased signal on magnetic resonance images associated with the highly organized collagen fibers in tendons and ligaments when they are orientated at a 55° angle to the main magnetic field. We present several examples from a clinical practice setting using 3T imaging illustrating a substantial reduction in magic angle artifact of the peroneal tendon in the prone plantarflexed position compared with the standard neutral (right angle) position. PMID:26429616

  12. Sealed magic angle spinning nuclear magnetic resonance probe and process for spectroscopy of hazardous samples

    DOEpatents

    Cho, Herman M.; Washton, Nancy M.; Mueller, Karl T.; Sears, Jr., Jesse A.; Townsend, Mark R.; Ewing, James R.

    2016-06-14

    A magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) probe is described that includes double containment enclosures configured to seal and contain hazardous samples for analysis. The probe is of a modular design that ensures containment of hazardous samples during sample analysis while preserving spin speeds for superior NMR performance and convenience of operation.

  13. Devices and process for high-pressure magic angle spinning nuclear magnetic resonance

    DOEpatents

    Hoyt, David W; Sears, Jr., Jesse A; Turcu, Romulus V.F.; Rosso, Kevin M; Hu, Jian Zhi

    2014-04-08

    A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

  14. Hydrogen and deuterium NMR of solids by magic-angle spinning

    SciTech Connect

    Eckman, R.R.

    1982-10-01

    The nuclear magnetic resonance of solids has long been characterized by very large specral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, ..beta../sub m/ = Arccos (3/sup -1/2/), with respect to the direction of the external magnetic field. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of ..beta... A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H/sub D/ was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal motion. In the general case of large H/sub D/, isotropic spectra were obtained by dilution of /sup 1/H with /sup 2/H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids.

  15. Complete protocol for slow-spinning high-resolution magic-angle spinning NMR analysis of fragile tissues.

    PubMed

    André, Marion; Dumez, Jean-Nicolas; Rezig, Lamya; Shintu, Laetitia; Piotto, Martial; Caldarelli, Stefano

    2014-11-01

    High-resolution magic-angle spinning (HR-MAS) nuclear magnetic resonance (NMR) is an essential tool to characterize a variety of semisolid systems, including biological tissues, with virtually no sample preparation. The "non-destructive" nature of NMR is typically compromised, however, by the extreme centrifugal forces experienced under conventional HR-MAS frequencies of several kilohertz. These features limit the usefulness of current HR-MAS approaches for fragile samples. Here, we introduce a full protocol for acquiring high-quality HR-MAS NMR spectra of biological tissues at low spinning rates (down to a few hundred hertz). The protocol first consists of a carefully designed sample preparation, which yields spectra without significant spinning sidebands at low spinning frequency for several types of sample holders, including the standard disposable inserts classically used in HR-MAS NMR-based metabolomics. Suppression of broad spectral features is then achieved using a modified version of the recently introduced PROJECT experiment with added water suppression and rotor synchronization, which deposits limited power in the sample and which can be suitably rotor-synchronized at low spinning rates. The performance of the slow HR-MAS NMR procedure is demonstrated on conventional (liver tissue) and very delicate (fish eggs) samples, for which the slow-spinning conditions are shown to preserve the structural integrity and to minimize intercompartmental leaks of metabolites. Taken together, these results expand the applicability and reliability of HR-MAS NMR spectroscopy. These results have been obtained at 400 and 600 MHz and suggest that high-quality slow HR-MAS spectra can be expected at higher magnetic fields using the described protocol. PMID:25286333

  16. Non-Destructive Testing Scanner

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Bio-Imaging Research's technology that originated in an aerospace program has come full circle with a new aerospace adaptation called the Advanced Computed Tomography Inspection System, or ACTIS. The medical version of CT scans the human body for tumors or other abnormalities, the ACTIS system finds imperfections in aerospace structures and components, such as castings, assemblies, rocket motors and nozzles. ACTIS is described by its developer as the most versatile CT scanner available for non-destructive testing applications. ACTIS is a variable geometry system. ACTIS source and detectors can be moved closer together or farther apart to optimize the geometry for different sizes of test objects. The combination of variable geometry, three sources, and focusing detectors makes ACTIS cost effective for a broad range of applications. System can scan anything from very small turbine blades to large rocket assemblies.

  17. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2004-12-28

    A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

  18. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2003-12-30

    A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

  19. Towards monomaterial p-n junctions: Single-step fabrication of tin oxide films and their non-destructive characterisation by angle-dependent X-ray photoelectron spectroscopy

    SciTech Connect

    Krzywiecki, Maciej; Sarfraz, Adnan; Erbe, Andreas

    2015-12-07

    The application of a non-destructive method for characterization of electronic structure of an ultra-thin SnO{sub 1angle dependent XPS, we quantified stoichiometry changes inside the SnO{sub 1

  20. Discrete magic angle turning system, apparatus, and process for in situ magnetic resonance spectroscopy and imaging

    DOEpatents

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Wind, Robert A.

    2009-05-19

    Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.

  1. A sensitive, high resolution magic angle turning experiment for measuring chemical shift tensor principal values

    NASA Astrophysics Data System (ADS)

    Alderman, D. W.

    1998-12-01

    A sensitive, high-resolution 'FIREMAT' two-dimensional (2D) magic-angle-turning experiment is described that measures chemical shift tensor principal values in powdered solids. The spectra display spinning-sideband patterns separated by their isotropic shifts. The new method's sensitivity and high resolution in the isotropic-shift dimension result from combining the 5pi magic-angle-turning pulse sequence, an extension of the pseudo-2D sideband-suppression data rearrangement, and the TIGER protocol for processing 2D data. TPPM decoupling is used to enhance resolution. The method requires precise synchronization of the pulses and sampling to the rotor position. It is shown that the technique obtains 35 natural-abundance 13C tensors from erythromycin in 19 hours, and high quality naturalabundance 15N tensors from eight sites in potassium penicillin V in three days on a 400MHz spectrometer.

  2. Excitation of multiple quantum transitions under magic angle spinning conditions: Adamantane

    NASA Astrophysics Data System (ADS)

    Meier, B. H.; Earl, William L.

    1986-11-01

    A pulse sequence designed for the excitation of multiple quantum transitions in magic angle spinning solid state NMR spectroscopy is presented. It is shown that under the action of the standard time-reversal pulse sequence, the change in the sign of the dipole coupling (which is used to generate the multiple quantum coherences) upon rotation causes the multiple quantum intensity to vanish after each rotor period. This effect is demonstrated both in calculations and in experimental 1H spectra of adamantane. A modification of the time-reversal pulse sequence, which involves switching the phase of the rf pulses every half-rotor period causes the spin part of the Hamiltonian to switch sign in synchrony with the modulation of the spacial part. This allows the creation of multiple quantum coherences in solids with magic angle spinning. The effectiveness of this pulse sequence is demonstrated through calculations and experiments.

  3. Excitation of multiple quantum transitions under magic angle spinning conditions: Adamantane

    SciTech Connect

    Meier, B.H.; Earl, W.L.

    1986-11-01

    A pulse sequence designed for the excitation of multiple quantum transitions in magic angle spinning solid state NMR spectroscopy is presented. It is shown that under the action of the standard time-reversal pulse sequence, the change in the sign of the dipole coupling (which is used to generate the multiple quantum coherences) upon rotation causes the multiple quantum intensity to vanish after each rotor period. This effect is demonstrated both in calculations and in experimental /sup 1/H spectra of adamantane. A modification of the time-reversal pulse sequence, which involves switching the phase of the rf pulses every half-rotor period causes the spin part of the Hamiltonian to switch sign in synchrony with the modulation of the spacial part. This allows the creation of multiple quantum coherences in solids with magic angle spinning. The effectiveness of this pulse sequence is demonstrated through calculations and experiments.

  4. Spin-locking and cross-polarization under magic-angle spinning of uniformly labeled solids.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2015-07-01

    Spin-locking and cross-polarization under magic-angle spinning are investigated for uniformly (13)C and (15)N labeled solids. In particular, the interferences from chemical shift anisotropy, and (1)H heteronuclear and (13)C homonuclear dipolar couplings are identified. The physical origin of these interferences provides guidelines for selecting the best (13)C and (15)N polarization transfer rf fields. Optimal settings for both the zero- and double-quantum cross-polarization transfer mechanisms are recommended. PMID:25965280

  5. NMR high-resolution magic angle spinning rotor design for quantification of metabolic concentrations

    NASA Astrophysics Data System (ADS)

    Holly, R.; Damyanovich, A.; Peemoeller, H.

    2006-05-01

    A new high-resolution magic angle spinning nuclear magnetic resonance technique is presented to obtain absolute metabolite concentrations of solutions. The magnetic resonance spectrum of the sample under investigation and an internal reference are acquired simultaneously, ensuring both spectra are obtained under the same experimental conditions. The robustness of the technique is demonstrated using a solution of creatine, and it is shown that the technique can obtain solution concentrations to within 7% or better.

  6. Spin-locking and cross-polarization under magic-angle spinning of uniformly labeled solids

    NASA Astrophysics Data System (ADS)

    Hung, Ivan; Gan, Zhehong

    2015-07-01

    Spin-locking and cross-polarization under magic-angle spinning are investigated for uniformly 13C and 15N labeled solids. In particular, the interferences from chemical shift anisotropy, and 1H heteronuclear and 13C homonuclear dipolar couplings are identified. The physical origin of these interferences provides guidelines for selecting the best 13C and 15N polarization transfer rf fields. Optimal settings for both the zero- and double-quantum cross-polarization transfer mechanisms are recommended.

  7. Solid-state proton multiple-quantum NMR spectroscopy with fast magic angle spinning

    NASA Astrophysics Data System (ADS)

    Geen, Helen; Titman, Jeremy J.; Gottwald, Johannes; Spiess, Hans W.

    1994-09-01

    The feasibility of multiple-quantum NMR spectroscopy with high resolution for protons in solids is explored. A new multiple-quantum excitation sequence suitable for use with fast magic angle spinning is described, and its performance is compared to that of both static and slow-spinning multiple-quantum methods. Modified sequences with scale the rate of development of the multiple-quantum coherences are also demonstrated, and two-dimensional double-quantum spectra of adamantane and polycarbonate are presented.

  8. Microfabricated inserts for magic angle coil spinning (MACS) wireless NMR spectroscopy.

    PubMed

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the "magic angle" of 54.74° with respect to the direction of the magnetic field (magic angle spinning - MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  9. Magic-Angle-Spinning NMR Magnet Development: Field Analysis and Prototypes

    PubMed Central

    Voccio, John; Hahn, Seungyong; Park, Dong Keun; Ling, Jiayin; Kim, Youngjae; Bascuñán, Juan; Iwasa, Yukikazu

    2013-01-01

    We are currently working on a program to complete a 1.5 T/75 mm RT bore magic-angle-spinning nuclear magnetic resonance magnet. The magic-angle-spinning magnet comprises a z-axis 0.866-T solenoid and an x-axis 1.225-T dipole, each to be wound with NbTi wire and operated at 4.2 K in persistent mode. A combination of the fields creates a 1.5-T field pointed at 54.74 degrees (magic angle) from the rotation (z) axis. In the first year of this 3-year program, we have completed magnetic analysis and design of both coils. Also, using a winding machine of our own design and fabrication, we have wound several prototype dipole coils with NbTi wire. As part of this development, we have repeatedly made successful persistent NbTi-NbTi joints with this multifilamentary NbTi wire. PMID:24058275

  10. An isotropic chemical shift-chemical shift anisotropic correlation experiment using discrete magic angle turning.

    PubMed

    Hu, Jian Zhi; Sears, Jesse A; Kwak, Ja Hun; Hoyt, David W; Wang, Yong; Peden, Charles H F

    2009-05-01

    An isotropic-anisotropic shift 2D correlation spectroscopy is introduced that combines the advantages of both magic angle turning (MAT) and magic angle hopping (MAH) technologies. In this new approach, denoted DMAT for "discrete magic angle turning", the sample rotates clockwise followed by an anticlockwise rotation of exactly the same amount with each rotation less or equal than 360 degrees but greater than 240 degrees , with the rotation speed being constant only for times related to the evolution dimension. This back and forth rotation is repeated and synchronized with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. For any spin-interaction of rank-2 such as chemical shift anisotropy, isotropic magnetic susceptibility interaction, and residual homo-nuclear dipolar interaction in biological fluid samples, the projection along the isotropic dimension is a high resolution spectrum. Since a less than 360 degrees sample rotation is involved, the design potentially allows for in situ control over physical parameters such as pressure, flow conditions, feed compositions, and temperature so that true in situ NMR investigations can be carried out. PMID:19246221

  11. Magic angle and height quantization in nanofacets on SiC(0001) surfaces

    SciTech Connect

    Sawada, Keisuke; Iwata, Jun-Ichi; Oshiyama, Atsushi

    2014-02-03

    We report on the density-functional calculations that provide microscopic mechanism of the facet formation on the SiC (0001) surface. We first identify atom-scale structures of single-, double-, and quad-bilayer steps and find that the single-bilayer (SB) step has the lowest formation energy. We then find that the SB steps are bunched to form a nanofacet with a particular angle relative to the (0001) plane (magic facet angle) and with a discretized height along the (0001) direction (height quantization). We also clarify a microscopic reason for the self-organization of the nanofacet observed experimentally.

  12. Microfabricated Inserts for Magic Angle Coil Spinning (MACS) Wireless NMR Spectroscopy

    PubMed Central

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G.; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the “magic angle” of 54.74° with respect to the direction of the magnetic field (magic angle spinning – MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  13. Non-destructive identification of twisted light.

    PubMed

    Li, Pengyun; Wang, Bo; Song, Xinbing; Zhang, Xiangdong

    2016-04-01

    The non-destructive identification of the orbital angular momentum (OAM) is essential to various applications in the optical information processing. Here, we propose and demonstrate experimentally an efficient method to identify non-destructively the OAM by using a modified Mach-Zehnder interferometer. Our schemes are applicable not only to the case with integer charges, but also to optical vortices with noninteger charges. Our Letter presents the first experimental demonstration of the non-destructive identification of twisted light with integer or noninteger topological charges, which has potential applications in the OAM-based data transmission for optical communications. PMID:27192290

  14. Measurement of nuclear magnetic dipole—dipole couplings in magic angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Tycko, Robert; Dabbagh, Gary

    1990-10-01

    We describe a method for measuring nuclear magnetic dipole—dipole couplings in NMR spectra of solids undergoing rapid magic angle spinning (MAS). We show in theory, simulations, and experiments that the couplings, which are averaged out by MAS alone, can be recovered by applying simple resonant radiofrequency pulse sequences in synchrony with the sample rotation. Experimental 13C dipolar powder pattern spectra of polycrystalline ( 13CH 3) 2C(OH)SO 3Na obtained in a two-dimensional experiment based on this method are presented. The method provides a means of determining internuclear distances in polycrystalline and noncrystalline solids while retaining the high resolution and sensitivity afforded by MAS.

  15. The use of variable temperature and magic-angle sample spinning in studies of fulvic acids

    USGS Publications Warehouse

    Earl, W.L.; Wershaw, R. L.; Thorn, K.A.

    1987-01-01

    Intensity distortions and poor signal to noise in the cross-polarization magic-angle sample spinning NMR of fulvic acids were investigated and attributed to molecular mobility in these ostensibly "solid" materials. We have shown that inefficiencies in cross polarization can be overcome by lowering the sample temperature to about -60??C. These difficulties can be generalized to many other synthetic and natural products. The use of variable temperature and cross-polarization intensity as a function of contact time can yield valuable qualitative information which can aid in the characterization of many materials. ?? 1987.

  16. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Rosay, Melanie; Blank, Monica; Engelke, Frank

    2016-03-01

    Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100 K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered.

  17. Tethered or adsorbed supported lipid bilayers in nanotubes characterized by deuterium magic angle spinning NMR spectroscopy.

    PubMed

    Wattraint, Olivier; Warschawski, Dror E; Sarazin, Catherine

    2005-04-12

    2H solid-state NMR experiments were performed under magic angle spinning on lipid bilayers oriented into nanotubes arrays, as a new method to assess the geometrical arrangement of the lipids. Orientational information is obtained from the intensities of the spinning sidebands. The lipid bilayers are formed by fusion of small unilamellar vesicles of DMPC-d54 inside a nanoporous anodic aluminum oxide, either by direct adsorption on the support or by tethering through a streptavidin/biotin linker. The results support that the quality of the lipid bilayers alignment is clearly in favor of the tethering rather than an adsorbed strategy. PMID:15807556

  18. On the magic-angle turning and phase-adjusted spinning sidebands experiments.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2010-05-01

    The underlying relation between the magic-angle turning (MAT) and phase-adjusted spinning sidebands (PASS) experiments is examined. The MAT experiment satisfies the PASS conditions for separating spinning sidebands with a non-constant total evolution time and only requires linear t(1) increments of up to one rotor period. The time-domain data of the two experiments are related by a shearing transformation. A combination of the linear evolution-time increments of MAT and simple data processing of PASS are particularly attractive for the implementation of MAT for measuring chemical shift anisotropy. PMID:20202873

  19. High-resolution magic-angle-spinning NMR spectroscopy of intact tissue.

    PubMed

    Giskeødegård, Guro F; Cao, Maria D; Bathen, Tone F

    2015-01-01

    High-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy is a nondestructive technique that is used to obtain the metabolite profile of a tissue sample. This method requires minimal sample preparation. However, it is important to handle the sample with care and keep it frozen during preparation to minimize degradation. Here, we describe a typical protocol for HR-MAS analysis of intact tissue. We also include examples of typical pulse sequence programs and quantification methods that are used today. PMID:25677145

  20. High resolution 11B NMR of magnesium diboride using cryogenic magic angle spinning

    NASA Astrophysics Data System (ADS)

    Beckett, Peter; Denning, Mark S.; Heinmaa, Ivo; Dimri, Mukesh C.; Young, Edward A.; Stern, Raivo; Carravetta, Marina

    2012-09-01

    Static and magic-angle spinning 11B nuclear magnetic resonance (NMR) data at 4.7 T and 8.5 T have been obtained under cryogenic conditions on a diluted sample of magnesium diboride powder in the normal and superconducting state. The data provide accurate information on the magnetic shift and longitudinal relaxation time down to a temperature of 8 K, with a resolution improvement over the entire temperature range. The onset of superconductivity is unaffected by the sample rotation, as revealed by a steep variation of the magnetic shift just below the critical temperature.

  1. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    DOEpatents

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  2. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR.

    PubMed

    Rosay, Melanie; Blank, Monica; Engelke, Frank

    2016-03-01

    Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered. PMID:26920834

  3. In vivo high-resolution magic angle spinning magnetic resonance spectroscopy of Drosophila melanogaster at 14.1 T shows trauma in aging and in innate immune-deficiency is linked to reduced insulin signaling

    PubMed Central

    RIGHI, VALERIA; APIDIANAKIS, YIORGOS; MINTZOPOULOS, DIONYSSIOS; ASTRAKAS, LOUKAS; RAHME, LAURENCE G.; TZIKA, A. ARIA

    2010-01-01

    In vivo magnetic resonance spectroscopy (MRS), a non-destructive biochemical tool for investigating live organisms, has yet to be used in the fruit fly Drosophila melanogaster, a useful model organism for investigating genetics and physiology. We developed and implemented a high-resolution magic-angle-spinning (HRMAS) MRS method to investigate live Drosophila at 14.1 T. We demonstrated, for the first time, the feasibility of using HRMAS MRS for molecular characterization of Drosophila with a conventional MR spectrometer equipped with an HRMAS probe. We showed that the metabolic HRMAS MRS profiles of injured, aged wild-type (wt) flies and of immune deficient (imd) flies were more similar to chico flies mutated at the chico gene in the insulin signaling pathway, which is analogous to insulin receptor substrate 1–4 (IRS1–4) in mammals and less to those of adipokinetic hormone receptor (akhr) mutant flies, which have an obese phenotype. We thus provide evidence for the hypothesis that trauma in aging and in innate immune-deficiency is linked to insulin signaling. This link may explain the mitochondrial dysfunction that accompanies insulin resistance and muscle wasting that occurs in trauma, aging and immune system deficiencies, leading to higher susceptibility to infection. Our approach advances the development of novel in vivo non-destructive research approaches in Drosophila, suggests biomarkers for investigation of biomedical paradigms, and thus may contribute to novel therapeutic development. PMID:20596596

  4. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle

    NASA Astrophysics Data System (ADS)

    Perras, Frédéric A.; Kobayashi, Takeshi; Pruski, Marek

    2016-03-01

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI-MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP-MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that the largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. The STRAFI-MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP-MAS NMR.

  5. MATPASS/CPMG: a sensitivity enhanced magic-angle spinning sideband separation experiment for disordered solids.

    PubMed

    Hung, Ivan; Edwards, Trenton; Sen, Sabyasachi; Gan, Zhehong

    2012-08-01

    A Carr-Purcell Meiboom-Gill (CPMG) sensitivity-enhanced spinning sideband separation experiment is presented. The experiment combines the idea of magic-angle turning and phase-adjusted sideband separation (MATPASS), allowing for isotropic/anisotropic chemical shift separation of disordered solids with line widths far greater than the magic-angle spinning frequency. The use of CPMG enhances the sensitivity of the wide-line spectra by an order of magnitude via multiple-echo acquisition. The MATPASS/CPMG protocol involves acquisition of time-domain data using a MAT/CPMG pulse sequence followed by f(1) shearing during data processing to arrive at the PASS representation. Such a protocol has √2 higher sensitivity than the conventional PASS method because all CPMG echo signals are used for the final PASS spectrum. Application of this method is demonstrated using a GeSe₄ glass sample with both ⁷⁷Se isotropic line widths and chemical shift anisotropy that far exceed the spinning frequency. The sideband separation allows for the measurement of chemical shift anisotropy of the disordered solids. PMID:22750637

  6. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle.

    PubMed

    Perras, Frédéric A; Kobayashi, Takeshi; Pruski, Marek

    2016-03-01

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI-MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP-MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that the largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. The STRAFI-MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP-MAS NMR. PMID:26920838

  7. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle

    DOE PAGESBeta

    Perras, Frederic A.; Kobayashi, Takeshi; Pruski, Marek

    2016-02-23

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI–MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP–MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that themore » largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. Furthermore, the STRAFI–MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP–MAS NMR.« less

  8. Advanced slow-magic angle spinning probe for magnetic resonance imaging and spectroscopy

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi; Minard, Kevin R.; Rommereim, Donald N.

    2006-01-24

    The present invention relates to a probe and processes useful for magnetic resonance imaging and spectroscopy instruments. More particularly, the invention relates to a MR probe and processes for obtaining resolution enhancements of fluid objects, including live specimens, using an ultra-slow (magic angle) spinning (MAS) of the specimen combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. Proton NMR spectra were measured of the torso and the top part of the belly of a female BALBc mouse in a 2T field, while spinning the animal at a speed of 1.5 Hz. Results show that even in this relatively low field with PHORMAT, an isotropic spectrum is obtained with line widths that are a factor 4.6 smaller than those obtained in a stationary mouse. Resolution of 1H NMR metabolite spectra are thus significantly enhanced. Results indicate that PHORMAT has the potential to significantly increase the utility of 1H NMR spectroscopy for in vivo biochemical, biomedical and/or medical applications involving large-sized biological objects such as mice, rats and even humans within a hospital setting. For small-sized objects, including biological objects, such as excised tissues, organs, live bacterial cells, and biofilms, use of PASS at a spinning rate of 30 Hz and above is preferred.

  9. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2003-11-25

    A method of performing a magnetic resonance analysis of a biological object that includes placing the biological object in a main magnetic field and in a radio frequency field, the main magnetic field having a static field direction; rotating the biological object at a rotational frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. According to another embodiment, the radio frequency is pulsed to provide a sequence capable of producing a spectrum that is substantially free of spinning sideband peaks.

  10. High Resolution 1H NMR Spectroscopy in Rat Liver Using Magic Angle Turning at a 1 Hz Spinning Rate

    SciTech Connect

    Hu, Jian Zhi ); Rommereim, Donald N. ); Wind, Robert A. )

    2001-12-01

    It is demonstrated that a high resolution 1H NMR spectrum of excised rat liver can be obtained using the technique of magic angle turning at a sample spinning rate of 1 Hz. A variant of the phase-corrected magic angle turning (PHORMAT) pulse sequence that includes a water suppression segment was developed for the investigation. The spectral resolution achieved with PHORMAT is approaching that obtained from a standard magic angle spinning experiment at a spinning rate of several kHz. With such ultra-slow spinning, tissue and cell damage associated with the standard MAS experiment is minimized or eliminated. The technique is potentially useful for obtaining high-resolution 1H spectra in live animals.

  11. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning

    SciTech Connect

    Mance, Deni; Baldus, Marc; Gast, Peter; Huber, Martina; Ivanov, Konstantin L.

    2015-06-21

    We develop a theoretical description of Dynamic Nuclear Polarization (DNP) in solids under Magic Angle Spinning (MAS) to describe the magnetic field dependence of the DNP effect. The treatment is based on an efficient scheme for numerical solution of the Liouville-von Neumann equation, which explicitly takes into account the variation of magnetic interactions during the sample spinning. The dependence of the cross-effect MAS-DNP on various parameters, such as the hyperfine interaction, electron-electron dipolar interaction, microwave field strength, and electron spin relaxation rates, is analyzed. Electron spin relaxation rates are determined by electron paramagnetic resonance measurements, and calculations are compared to experimental data. Our results suggest that the observed nuclear magnetic resonance signal enhancements provided by MAS-DNP can be explained by discriminating between “bulk” and “core” nuclei and by taking into account the slow DNP build-up rate for the bulk nuclei.

  12. Non-Fermi-liquid magic angle effects in high magnetic fields

    NASA Astrophysics Data System (ADS)

    Lebed, A. G.

    2016-07-01

    We investigate a theoretical problem of electron-electron interactions in an inclined magnetic field in a quasi-one-dimensional (Q1D) conductor. We show that they result in strong non-Fermi-liquid corrections to a specific heat, provided that the direction of the magnetic field is far from the so-called Lebed's magic angles (LMAs). If magnetic field is directed close to one of the LMAs, the specific heat corrections become small and the Fermi-liquid picture restores. As a result, we predict Fermi-liquid-non-Fermi-liquid angular crossovers in the vicinities of the LMA directions of the field. We suggest to perform the corresponding experiment in the Q1D conductor (Per) 2Au (mnt) 2 under pressure in magnetic fields of the order of H ≃25 T .

  13. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning

    NASA Astrophysics Data System (ADS)

    Mance, Deni; Gast, Peter; Huber, Martina; Baldus, Marc; Ivanov, Konstantin L.

    2015-06-01

    We develop a theoretical description of Dynamic Nuclear Polarization (DNP) in solids under Magic Angle Spinning (MAS) to describe the magnetic field dependence of the DNP effect. The treatment is based on an efficient scheme for numerical solution of the Liouville-von Neumann equation, which explicitly takes into account the variation of magnetic interactions during the sample spinning. The dependence of the cross-effect MAS-DNP on various parameters, such as the hyperfine interaction, electron-electron dipolar interaction, microwave field strength, and electron spin relaxation rates, is analyzed. Electron spin relaxation rates are determined by electron paramagnetic resonance measurements, and calculations are compared to experimental data. Our results suggest that the observed nuclear magnetic resonance signal enhancements provided by MAS-DNP can be explained by discriminating between "bulk" and "core" nuclei and by taking into account the slow DNP build-up rate for the bulk nuclei.

  14. Efficient dipolar double quantum filtering under magic angle spinning without a 1H decoupling field

    NASA Astrophysics Data System (ADS)

    Courtney, Joseph M.; Rienstra, Chad M.

    2016-08-01

    We present a systematic study of dipolar double quantum (DQ) filtering in 13C-labeled organic solids over a range of magic-angle spinning rates, using the SPC-n recoupling sequence element with a range of n symmetry values from 3 to 11. We find that efficient recoupling can be achieved for values n ⩾ 7, provided that the 13C nutation frequency is on the order of 100 kHz or greater. The decoupling-field dependence was investigated and explicit heteronuclear decoupling interference conditions identified. The major determinant of DQ filtering efficiency is the decoupling interference between 13C and 1H fields. For 13C nutation frequencies greater than 75 kHz, optimal performance is observed without an applied 1H field. At spinning rates exceeding 20 kHz, symmetry conditions as low as n = 3 were found to perform adequately.

  15. Magic-angle spinning NMR of intact bacteriophages: Insights into the capsid, DNA and their interface

    NASA Astrophysics Data System (ADS)

    Abramov, Gili; Morag, Omry; Goldbourt, Amir

    2015-04-01

    Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses.

  16. Primary processes in isolated Photosystem II reaction centres probed by magic angle transient absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Klug, David R.; Rech, Thomas; Melissa Joseph, D.; Barber, James; Durrant, James R.; Porter, George

    1995-05-01

    There is currently some disagreement regarding the dominant time constant for formation of the radical pair state P680 +Ph - in isolated photosystem two reaction centres. It has recently been suggested that this disagreement may originate, at least in part, from different polarisations of the pump and probe beams used in optical experiments. In this paper, we present data collected using a magic angle configuration of the pump and probe polarisations. We find that these data support our previous interpretation of data collected using a parallel polarisation configuration. Moreover, we present further evidence to support our conclusion that formation of the P680 +Ph - state primarily occurs with a 21 ps time constant when P680 is directly excited. A 3 ps component is also observed; this component is not associated with a large proportion of the radical pair formation. We discuss our data and interpretation in comparison with those of other groups.

  17. Rapid proton-detected NMR assignment for proteins with fast magic angle spinning.

    PubMed

    Barbet-Massin, Emeline; Pell, Andrew J; Retel, Joren S; Andreas, Loren B; Jaudzems, Kristaps; Franks, W Trent; Nieuwkoop, Andrew J; Hiller, Matthias; Higman, Victoria; Guerry, Paul; Bertarello, Andrea; Knight, Michael J; Felletti, Michele; Le Marchand, Tanguy; Kotelovica, Svetlana; Akopjana, Inara; Tars, Kaspars; Stoppini, Monica; Bellotti, Vittorio; Bolognesi, Martino; Ricagno, Stefano; Chou, James J; Griffin, Robert G; Oschkinat, Hartmut; Lesage, Anne; Emsley, Lyndon; Herrmann, Torsten; Pintacuda, Guido

    2014-09-01

    Using a set of six (1)H-detected triple-resonance NMR experiments, we establish a method for sequence-specific backbone resonance assignment of magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of 5-30 kDa proteins. The approach relies on perdeuteration, amide (2)H/(1)H exchange, high magnetic fields, and high-spinning frequencies (ωr/2π ≥ 60 kHz) and yields high-quality NMR data, enabling the use of automated analysis. The method is validated with five examples of proteins in different condensed states, including two microcrystalline proteins, a sedimented virus capsid, and two membrane-embedded systems. In comparison to contemporary (13)C/(15)N-based methods, this approach facilitates and accelerates the MAS NMR assignment process, shortening the spectral acquisition times and enabling the use of unsupervised state-of-the-art computational data analysis protocols originally developed for solution NMR. PMID:25102442

  18. Magic-angle spinning NMR of intact bacteriophages: insights into the capsid, DNA and their interface.

    PubMed

    Abramov, Gili; Morag, Omry; Goldbourt, Amir

    2015-04-01

    Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses. PMID:25797007

  19. Magic-angle-spinning NMR studies of acid sites in zeolite H-ZSM-5

    SciTech Connect

    Brunner, E.; Ernst, H.; Freude, D.; Froehlich, T.; Hunger, M.; Pfeifer, H. )

    1991-01-01

    {sup 1}H, {sup 13}C, {sup 27}Al, and {sup 29}Si magic-angle-spinning (MAS) NMR was used to elucidate the nature of the catalytic activity of zeolite H-ZSM-5. {sup 1}H MAS NMR of sealed samples after mild hydrothermal dealumination shows that the enhanced activity for n-hexane cracking is not due to an enhanced Bronstead acidity. The concentrations of the various OH groups and aluminous species suggest that the reason for the enhanced catalytic activity is the interaction of the n-hexane molecule with a bridging hydroxyl group and with extra-framework aluminium species, which give rise to the enhanced activity, cannot be easily removed from their positions, and are therefore immobilized by the zeolitic framework.

  20. Forensic examination of electrical tapes using high resolution magic angle spinning ¹H NMR spectroscopy.

    PubMed

    Schoenberger, Torsten; Simmross, Ulrich; Poppe, Christian

    2016-01-01

    The application of high resolution magic angle spinning (HR-MAS) (1)H NMR spectroscopy is ideally suited for the differentiation of plastics. In addition to the actual material composition, the different types of polymer architectures and tacticity provide characteristic signals in the fingerprint of the (1)H NMR spectra. The method facilitates forensic comparison, as even small amounts of insoluble but swellable plastic particles are utilized. The performance of HR-MAS NMR can be verified against other methods that were recently addressed in various articles about forensic tape comparison. In this study samples of the 90 electrical tapes already referenced by the FBI laboratory were used. The discrimination power of HR-MAS is demonstrated by the fact that more tape groups can be distinguished by NMR spectroscopy than by using the combined evaluation of several commonly used analytical techniques. An additional advantage of this robust and quick method is the very simple sample preparation. PMID:26558760

  1. Efficient dipolar double quantum filtering under magic angle spinning without a (1)H decoupling field.

    PubMed

    Courtney, Joseph M; Rienstra, Chad M

    2016-08-01

    We present a systematic study of dipolar double quantum (DQ) filtering in (13)C-labeled organic solids over a range of magic-angle spinning rates, using the SPC-n recoupling sequence element with a range of n symmetry values from 3 to 11. We find that efficient recoupling can be achieved for values n⩾7, provided that the (13)C nutation frequency is on the order of 100kHz or greater. The decoupling-field dependence was investigated and explicit heteronuclear decoupling interference conditions identified. The major determinant of DQ filtering efficiency is the decoupling interference between (13)C and (1)H fields. For (13)C nutation frequencies greater than 75kHz, optimal performance is observed without an applied (1)H field. At spinning rates exceeding 20kHz, symmetry conditions as low as n=3 were found to perform adequately. PMID:27314744

  2. Magic angle spinning solid-state NMR experiments for structural characterization of proteins.

    PubMed

    Shi, Lichi; Ladizhansky, Vladimir

    2012-01-01

    Solid-state nuclear magnetic resonance (SSNMR) has become a prominent method in biology and is suitable for the characterization of insoluble proteins and protein aggregates such as amyloid fibrils, membrane-lipid complexes, and precipitated proteins. Often, the initial and the most critical step is to obtain spectroscopic assignments, that is, to determine chemical shifts of individual atoms. The procedures for SSNMR spectroscopic assignments are now well established for small microcrystalline proteins, where high signal-to-noise can be obtained. The sensitivity of the experiments and spectral resolution decrease with the increasing molecular weight, which makes setting SSNMR experiments in large proteins a much more challenging and demanding procedure. Here, we describe the protocol for the most common set of 3D magic angle spinning (MAS) SSNMR experiments. While the procedures described in the text are well known to SSNMR practitioners, we hope they will be of interest to scientists interested in extending their repertoire of biophysical techniques. PMID:22760319

  3. Pulsed field gradient magic angle spinning NMR self-diffusion measurements in liquids.

    PubMed

    Viel, Stéphane; Ziarelli, Fabio; Pagès, Guilhem; Carrara, Caroline; Caldarelli, Stefano

    2008-01-01

    Several investigations have recently reported the combined use of pulsed field gradient (PFG) with magic angle spinning (MAS) for the analysis of molecular mobility in heterogeneous materials. In contrast, little attention has been devoted so far to delimiting the role of the extra force field induced by sample rotation on the significance and reliability of self-diffusivity measurements. The main purpose of this work is to examine this phenomenon by focusing on pure liquids for which its impact is expected to be largest. Specifically, we show that self-diffusion coefficients can be accurately determined by PFG MAS NMR diffusion measurements in liquids, provided that specific experimental conditions are met. First, the methodology to estimate the gradient uniformity and to properly calibrate its absolute strength is briefly reviewed and applied on a MAS probe equipped with a gradient coil aligned along the rotor spinning axis, the so-called 'magic angle gradient' coil. Second, the influence of MAS on the outcome of PFG MAS diffusion measurements in liquids is investigated for two distinct typical rotors of different active volumes, 12 and 50 microL. While the latter rotor led to totally unreliable results, especially for low viscosity compounds, the former allowed for the determination of accurate self-diffusion coefficients both for fast and slowly diffusing species. Potential implications of this work are the possibility to measure accurate self-diffusion coefficients of sample-limited mixtures or to avoid radiation damping interferences in NMR diffusion measurements. Overall, the outlined methodology should be of interest to anyone who strives to improve the reliability of MAS diffusion studies, both in homogeneous and heterogeneous media. PMID:18006344

  4. Method for non-destructive testing

    DOEpatents

    Akers, Douglas W.

    2011-08-30

    Non-destructive testing method may include providing a source material that emits positrons in response to bombardment of the source material with photons. The source material is exposed to photons. The source material is positioned adjacent the specimen, the specimen being exposed to at least some of the positrons emitted by the source material. Annihilation gamma rays emitted by the specimen are detected.

  5. Magic Angle Spinning NMR Spectroscopy: A Versatile Technique for Structural and Dynamic Analysis of Solid-Phase Systems

    PubMed Central

    Polenova, Tatyana; Gupta, Rupal; Goldbourt, Amir

    2016-01-01

    Magic Angle Spinning (MAS) NMR spectroscopy is a powerful method for analysis of a broad range of systems, including inorganic materials, pharmaceuticals, and biomacromolecules. The recent developments in MAS NMR instrumentation and methodologies opened new vistas to atomic-level characterization of a plethora of chemical environments previously inaccessible to analysis, with unprecedented sensitivity and resolution. PMID:25794311

  6. Magic-angle sample spinning electron paramagnetic resonance--instrumentation, performance, and limitations.

    PubMed

    Hessinger, D; Bauer, C; Hubrich, M; Jeschke, G; Spiess, H W

    2000-12-01

    An electron paramagnetic resonance (EPR) setup for line narrowing experiments with fast sample spinning at variable angles between the rotation axis and the static magnetic field is described and applied in the magic-angle sample spinning (MAS) EPR experiment at X-band frequencies (9.5 GHz). Sample spinning speeds up to 17 kHz at temperatures down to 200 K can be achieved with rotors of 4-mm outer and 2.5-mm inner diameter without severe losses in microwave amplitude compared to standard pulse EPR probeheads. A phase cycle is introduced that provides pure absorption MAS EPR spectra and allows one to distinguish between positive and negative frequency offsets (pseudo-quadrature detection). Possible broadening mechanisms in MAS EPR spectra are discussed. It is demonstrated both by theory and by experiment that the MAS EPR experiment requires excitation bandwidths that are comparable to the total spectral width, since otherwise destructive interference between contributions of spins with similar resonance offsets suppresses the signal. Experimental observations on the E(1) center in gamma-irradiated silica glass and on the SO(-)(3) radical in gamma-irradiated sulfamic acid are reported. PMID:11097812

  7. Hybrid holographic non-destructive test system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  8. Recoupling of chemical shift anisotropy by R-symmetry sequences in magic angle spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Hou, Guangjin; Byeon, In-Ja L.; Ahn, Jinwoo; Gronenborn, Angela M.; Polenova, Tatyana

    2012-10-01

    13C and 15N chemical shift (CS) interaction is a sensitive probe of structure and dynamics in a wide variety of biological and inorganic systems, and in the recent years several magic angle spinning NMR approaches have emerged for residue-specific measurements of chemical shift anisotropy (CSA) tensors in uniformly and sparsely enriched proteins. All of the currently existing methods are applicable to slow and moderate magic angle spinning (MAS) regime, i.e., MAS frequencies below 20 kHz. With the advent of fast and ultrafast MAS probes capable of spinning frequencies of 40-100 kHz, and with the superior resolution and sensitivity attained at such high frequencies, development of CSA recoupling techniques working under such conditions is necessary. In this work, we present a family of R-symmetry based pulse sequences for recoupling of 13C/15N CSA interactions that work well in both natural abundance and isotopically enriched systems. We demonstrate that efficient recoupling of either first-rank (σ1) or second-rank (σ2) spatial components of CSA interaction is attained with appropriately chosen γ-encoded RNnv symmetry sequences. The advantage of these γ-encoded RNnv-symmetry based CSA (RNCSA) recoupling schemes is that they are suitable for CSA recoupling under a wide range of MAS frequencies, including fast MAS regime. Comprehensive analysis of the recoupling properties of these RNnv symmetry sequences reveals that the σ1-CSA recoupling symmetry sequences exhibit large scaling factors; however, the partial homonuclear dipolar Hamiltonian components are symmetry allowed, which makes this family of sequences suitable for CSA measurements in systems with weak homonuclear dipolar interactions. On the other hand, the γ-encoded symmetry sequences for σ2-CSA recoupling have smaller scaling factors but they efficiently suppress the homonuclear dipole-dipole interactions. Therefore, the latter family of sequences is applicable for measurements of CSA parameters in

  9. Structure of a protein determined by solid-state magic-angle-spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Castellani, Federica; van Rossum, Barth; Diehl, Annette; Schubert, Mario; Rehbein, Kristina; Oschkinat, Hartmut

    2002-11-01

    The determination of a representative set of protein structures is a chief aim in structural genomics. Solid-state NMR may have a crucial role in structural investigations of those proteins that do not easily form crystals or are not accessible to solution NMR, such as amyloid systems or membrane proteins. Here we present a protein structure determined by solid-state magic-angle-spinning (MAS) NMR. Almost complete 13C and 15N resonance assignments for a micro-crystalline preparation of the α-spectrin Src-homology 3 (SH3) domain formed the basis for the extraction of a set of distance restraints. These restraints were derived from proton-driven spin diffusion (PDSD) spectra of biosynthetically site-directed, labelled samples obtained from bacteria grown using [1,3-13C]glycerol or [2-13C]glycerol as carbon sources. This allowed the observation of long-range distance correlations up to ~7Å. The calculated global fold of the α-spectrin SH3 domain is based on 286 inter-residue 13C-13C and six 15N-15N restraints, all self-consistently obtained by solid-state MAS NMR. This MAS NMR procedure should be widely applicable to small membrane proteins that can be expressed in bacteria.

  10. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Shmyreva, Anna A.; Safdari, Majid; Furó, István; Dvinskikh, Sergey V.

    2016-06-01

    Orders of magnitude decrease of 207Pb and 199Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time.

  11. Structure of fully protonated proteins by proton-detected magic-angle spinning NMR.

    PubMed

    Andreas, Loren B; Jaudzems, Kristaps; Stanek, Jan; Lalli, Daniela; Bertarello, Andrea; Le Marchand, Tanguy; Cala-De Paepe, Diane; Kotelovica, Svetlana; Akopjana, Inara; Knott, Benno; Wegner, Sebastian; Engelke, Frank; Lesage, Anne; Emsley, Lyndon; Tars, Kaspars; Herrmann, Torsten; Pintacuda, Guido

    2016-08-16

    Protein structure determination by proton-detected magic-angle spinning (MAS) NMR has focused on highly deuterated samples, in which only a small number of protons are introduced and observation of signals from side chains is extremely limited. Here, we show in two fully protonated proteins that, at 100-kHz MAS and above, spectral resolution is high enough to detect resolved correlations from amide and side-chain protons of all residue types, and to reliably measure a dense network of (1)H-(1)H proximities that define a protein structure. The high data quality allowed the correct identification of internuclear distance restraints encoded in 3D spectra with automated data analysis, resulting in accurate, unbiased, and fast structure determination. Additionally, we find that narrower proton resonance lines, longer coherence lifetimes, and improved magnetization transfer offset the reduced sample size at 100-kHz spinning and above. Less than 2 weeks of experiment time and a single 0.5-mg sample was sufficient for the acquisition of all data necessary for backbone and side-chain resonance assignment and unsupervised structure determination. We expect the technique to pave the way for atomic-resolution structure analysis applicable to a wide range of proteins. PMID:27489348

  12. A LOW-E MAGIC ANGLE SPINNING PROBE FOR BIOLOGICAL SOLID STATE NMR AT 750 MHz

    PubMed Central

    McNeill, Seth A.; Gor’kov, Peter L.; Shetty, Kiran; Brey, William W.; Long, Joanna R.

    2009-01-01

    Crossed-coil NMR probes are a useful tool for reducing sample heating for biological solid state NMR. In a crossed-coil probe, the higher frequency 1H field, which is the primary source of sample heating in conventional probes, is produced by a separate low-inductance resonator. Because a smaller driving voltage is required, the electric field across the sample and the resultant heating is reduced. In this work we describe the development of a magic angle spinning (MAS) solid state NMR probe utilizing a dual resonator. This dual resonator approach, referred to as “Low-E,” was originally developed to reduce heating in samples of mechanically aligned membranes. The study of inherently dilute systems, such as proteins in lipid bilayers, via MAS techniques requires large sample volumes at high field to obtain spectra with adequate signal-to-noise ratio under physiologically relevant conditions. With the Low-E approach, we are able to obtain homogeneous and sufficiently strong radiofrequency fields for both 1H and 13C frequencies in a 4 mm probe with a 1H frequency of 750 MHz. The performance of the probe using windowless dipolar recoupling sequences is demonstrated on model compounds as well as membrane embedded peptides. PMID:19138870

  13. Alignment of high resolution magic angle spinning magnetic resonance spectra using warping methods.

    PubMed

    Giskeødegård, Guro F; Bloemberg, Tom G; Postma, Geert; Sitter, Beathe; Tessem, May-Britt; Gribbestad, Ingrid S; Bathen, Tone F; Buydens, Lutgarde M C

    2010-12-17

    The peaks of magnetic resonance (MR) spectra can be shifted due to variations in physiological and experimental conditions, and correcting for misaligned peaks is an important part of data processing prior to multivariate analysis. In this paper, five warping algorithms (icoshift, COW, fastpa, VPdtw and PTW) are compared for their feasibility in aligning spectral peaks in three sets of high resolution magic angle spinning (HR-MAS) MR spectra with different degrees of misalignments, and their merits are discussed. In addition, extraction of information that might be present in the shifts is examined, both for simulated data and the real MR spectra. The generic evaluation methodology employs a number of frequently used quality criteria for evaluation of the alignments, together with PLS-DA to assess the influence of alignment on the classification outcome. Peak alignment greatly improved the internal similarity of the data sets. Especially icoshift and COW seem suitable for aligning HR-MAS MR spectra, possibly because they perform alignment segment-wise. The choice of reference spectrum can influence the alignment result, and it is advisable to test several references. Information from the peak shifts was extracted, and in one case cancer samples were successfully discriminated from normal tissue based on shift information only. Based on these findings, general recommendations for alignment of HR-MAS MRS data are presented. Where possible, observations are generalized to other data types (e.g. chromatographic data). PMID:21094376

  14. Quantitative neuropathology by high resolution magic angle spinning proton magnetic resonance spectroscopy

    PubMed Central

    Cheng, L. L.; Ma, M. J.; Becerra, L.; Ptak, T.; Tracey, I.; Lackner, A.; González, R. G.

    1997-01-01

    We describe a method that directly relates tissue neuropathological analysis to medical imaging. Presently, only indirect and often tenuous relationships are made between imaging (such as MRI or x-ray computed tomography) and neuropathology. We present a biochemistry-based, quantitative neuropathological method that can help to precisely quantify information provided by in vivo proton magnetic resonance spectroscopy (1HMRS), an emerging medical imaging technique. This method, high resolution magic angle spinning (HRMAS) 1HMRS, is rapid and requires only small amounts of unprocessed samples. Unlike chemical extraction or other forms of tissue processing, this method analyzes tissue directly, thus minimizing artifacts. We demonstrate the utility of this method by assessing neuronal damage using multiple tissue samples from differently affected brain regions in a case of Pick disease, a human neurodegenerative disorder. Among different regions, we found an excellent correlation between neuronal loss shown by traditional neurohistopathology and decrease of the neuronal marker N-acetylaspartate measured by HRMAS 1HMRS. This result demonstrates for the first time, to our knowledge, a direct, quantitative link between a decrease in N-acetylaspartate and neuronal loss in a human neurodegenerative disease. As a quantitative method, HRMAS 1HMRS has potential applications in experimental and clinical neuropathologic investigations. It should also provide a rational basis for the interpretation of in vivo 1HMRS studies of human neurological disorders. PMID:9177231

  15. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning.

    PubMed

    Shmyreva, Anna A; Safdari, Majid; Furó, István; Dvinskikh, Sergey V

    2016-06-14

    Orders of magnitude decrease of (207)Pb and (199)Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time. PMID:27306000

  16. High-resolution magic angle spinning 1H MRS in prostate cancer.

    PubMed

    Decelle, Emily A; Cheng, Leo L

    2014-01-01

    Prostate cancer (PCa) is the most frequently diagnosed malignancy in men worldwide, largely as a result of the increased use of the annual serum prostate-specific antigen (PSA) screening test for detection. PSA screening has saved lives, but it has also resulted in the overtreatment of many patients with PCa because of a limited ability to accurately localize and characterize PCa lesions through imaging. High-resolution magic angle spinning (HRMAS) (1)H MRS has proven to be a strong potential clinical tool for PCa diagnosis and prognosis. The HRMAS technique allows valuable metabolic information to be obtained from ex vivo intact tissue samples and also enables the performance of histopathology on the same tissue specimens. Studies have found that the quantification of individual metabolite levels and metabolite ratios, as well as metabolomic profiles, shows strong potential to improve accuracy in PCa detection, diagnosis and monitoring. Ex vivo HRMAS is also a valuable tool for the interpretation of in vivo results, including the localization of tumors, and thus has the potential to improve in vivo diagnostic tests used in the clinic. Here, we primarily review publications of HRMAS (1)H MRS and its use for the study of intact human prostate tissue. PMID:23529951

  17. Magic-angle spinning solid-state multinuclear NMR on low-field instrumentation

    NASA Astrophysics Data System (ADS)

    Sørensen, Morten K.; Bakharev, Oleg; Jensen, Ole; Jakobsen, Hans J.; Skibsted, Jørgen; Nielsen, Niels Chr.

    2014-01-01

    Mobile and cost-effective NMR spectroscopy exploiting low-field permanent magnets is a field of tremendous development with obvious applications for arrayed large scale analysis, field work, and industrial screening. So far such demonstrations have concentrated on relaxation measurements and lately high-resolution liquid-state NMR applications. With high-resolution solid-state NMR spectroscopy being increasingly important in a broad variety of applications, we here introduce low-field magic-angle spinning (MAS) solid-state multinuclear NMR based on a commercial ACT 0.45 T 62 mm bore Halbach magnet along with a homebuilt FPGA digital NMR console, amplifiers, and a modified standard 45 mm wide MAS probe for 7 mm rotors. To illustrate the performance of the instrument and address cases where the low magnetic field may offer complementarity to high-field NMR experiments, we demonstrate applications for 23Na MAS NMR with enhanced second-order quadrupolar coupling effects and 31P MAS NMR where reduced influence from chemical shift anisotropy at low field may facilitate determination of heteronuclear dipole-dipole couplings.

  18. A unified heteronuclear decoupling strategy for magic-angle-spinning solid-state NMR spectroscopy

    SciTech Connect

    Equbal, Asif; Bjerring, Morten; Nielsen, Niels Chr. E-mail: ncn@inano.au.dk; Madhu, P. K. E-mail: ncn@inano.au.dk

    2015-05-14

    A unified strategy of two-pulse based heteronuclear decoupling for solid-state magic-angle spinning nuclear magnetic resonance is presented. The analysis presented here shows that different decoupling sequences like two-pulse phase-modulation (TPPM), X-inverse-X (XiX), and finite pulse refocused continuous wave (rCW{sup A}) are basically specific solutions of a more generalized decoupling scheme which incorporates the concept of time-modulation along with phase-modulation. A plethora of other good decoupling conditions apart from the standard, TPPM, XiX, and rCW{sup A} decoupling conditions are available from the unified decoupling approach. The importance of combined time- and phase-modulation in order to achieve the best decoupling conditions is delineated. The consequences of different indirect dipolar interactions arising from cross terms comprising of heteronuclear and homonuclear dipolar coupling terms and also those between heteronuclear dipolar coupling and chemical-shift anisotropy terms are presented in order to unfold the effects of anisotropic interactions under different decoupling conditions. Extensive numerical simulation results are corroborated with experiments on standard amino acids.

  19. Magnetization transfer magic-angle-spinning z-spectroscopy of excised tissues

    NASA Astrophysics Data System (ADS)

    Avni, Reut; Mangoubi, Oren; Bhattacharyya, Rangeet; Degani, Hadassa; Frydman, Lucio

    2009-07-01

    NMR experiments devised to aid in analyses of tissues include magnetization transfer (MT), which can highlight the signals of biological macromolecules through cross-relaxation and/or chemical exchange processes with the bulk 1H water resonance, and high-resolution magic-angle-spinning (HRMAS) methods, akin to those used in solid-state NMR to introduce additional spectral resolution via the averaging of spin anisotropies. This paper explores the result of combining these methodologies, and reports on MT "z-spectroscopy" between water and cell components in excised tissues under a variety of HRMAS conditions. Main features arising from the resulting 1H "MTMAS" experiments include strong spinning sideband manifolds centered at the liquid water shift, high-resolution isotropic features coinciding with aliphatic and amide proton resonances, and a second sideband manifold arising as spinning speeds are increased. Interpretations are given for the origin of these various features, including simulations shedding further light onto the nature of MT NMR signals observed for tissue samples. Concurrently, histological examinations are reported validating the limits of HRMAS NMR procedures to the analysis of tissue samples preserved in a number of different ways.

  20. Dynamic nuclear polarization at 40 kHz magic angle spinning.

    PubMed

    Chaudhari, Sachin R; Berruyer, Pierrick; Gajan, David; Reiter, Christian; Engelke, Frank; Silverio, Daniel L; Copéret, Christophe; Lelli, Moreno; Lesage, Anne; Emsley, Lyndon

    2016-04-21

    DNP-enhanced solid-state NMR spectroscopy under magic angle spinning (MAS) is rapidly developing into a powerful analytical tool to investigate the structure of a wide range of solid materials, because it provides unsurpassed sensitivity gains. Most developments and applications of DNP MAS NMR were so far reported at moderate spinning frequencies (up to 14 kHz using 3.2 mm rotors). Here, using a 1.3 mm MAS DNP probe operating at 18.8 T and ∼100 K, we show that signal amplification factors can be increased by up to a factor two when using smaller volume rotors as compared to 3.2 mm rotors, and report enhancements of around 60 over a range of sample spinning rates from 10 to 40 kHz. Spinning at 40 kHz is also shown to increase (29)Si coherence lifetimes by a factor three as compared to 10 kHz, substantially increasing sensitivity in CPMG type experiments. The contribution of quenching effects to the overall sensitivity gain at very fast MAS is evaluated, and applications are reported on a functionalised mesostructured organic-inorganic material. PMID:27035630

  1. Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

    PubMed Central

    Barnes, Alexander B.; Mak-Jurkauskas, Melody L.; Matsuki, Yoh; Bajaj, Vikram S.; van der Wel, Patrick C. A.; DeRocher, Ronald; Bryant, Jeffrey; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Lugtenburg, Johan; Herzfeld, Judith; Griffin, Robert G.

    2009-01-01

    We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here — which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole — circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100 K which shows 30 Hz linewidths. PMID:19356957

  2. High-resolution magic-angle spinning (13)C spectroscopy of brain tissue at natural abundance.

    PubMed

    Yang, Yongxia; Chen, Lei; Gao, Hongchang; Zeng, Danlin; Yue, Yong; Liu, Maili; Lei, Hao; Deng, Feng; Ye, Chaohui

    2006-03-01

    High-resolution magic-angle spinning (MAS) (1)H and (13)C magnetic resonance spectroscopy (MRS) has recently been applied to study the metabolism in intact biological tissue samples. Because of the low natural abundance and the low gyromagnetic ratio of the (13)C nuclei, signal enhancement techniques such as cross-polarization (CP) and distortionless enhancement by polarization transfer (DEPT) are often employed in MAS (13)C MRS to improve the detection sensitivity. In this study, several sensitivity enhancement techniques commonly used in liquid- and solid-state NMR, including CP, DEPT and nuclear Overhauser enhancement (NOE), were combined with MAS to acquire high-resolution (13)C spectra on intact rat brain tissue at natural abundance, and were compared for their performances. The results showed that different signal enhancement techniques are sensitive to different classes of molecules/metabolites, depending on their molecular weights and mobility. DEPT was found to enhance the signals of low-molecular weight metabolites exclusively, while the signals of lipids, which often are associated with membranes and have relatively lower mobility, were highly sensitive to CP enhancement. PMID:16477685

  3. Frequency-stepped acquisition in nuclear magnetic resonance spectroscopy under magic angle spinning

    NASA Astrophysics Data System (ADS)

    Pell, Andrew J.; Clément, Raphaële J.; Grey, Clare P.; Emsley, Lyndon; Pintacuda, Guido

    2013-03-01

    The nuclear magnetic resonance of paramagnetic solids is usually characterized by the presence of large chemical shifts and shift anisotropies due to hyperfine interactions. Frequently the resulting spectra cover a frequency range of several megahertz, which is greater than the bandwidth of commercially available radio-frequency (RF) probes, making it impossible to acquire the whole spectrum in a single experiment. In these cases it common to record a series of spectra, in which the probe is tuned to a different frequency for each, and then sum the results to give the "true" spectrum. While this method is very widely used on static samples, the application of frequency stepping under magic-angle spinning (MAS) is less common, owing to the increased complexity of the spin dynamics when describing the interplay of the RF irradiation with the mechanical rotation of the shift tensor. In this paper, we present a theoretical description, based on the jolting frame formalism of Caravatti et al. [J. Magn. Reson. 55, 88 (1983), 10.1016/0022-2364(83)90279-2], for describing the spin dynamics of a powder sample under MAS when subjected to a selective pulse of low RF-field amplitude. The formalism is used to describe the frequency stepping method under MAS, and under what circumstances the true spectrum is reproduced. We also present an experimental validation of the methodology under ultra-fast MAS with the paramagnetic materials LiMnPO4 and TbCsDPA.

  4. Deuterium magic angle spinning studies of substrates bound to cytochrome P450.

    PubMed

    Lee, H; Ortiz de Montellano, P R; McDermott, A E

    1999-08-17

    We report solid-state deuterium magic angle spinning NMR spectra of perdeuterated adamantane bound to the active site of microcrystalline cytochrome P450cam (CP450cam) in its resting state. CP450cam contains a high-spin ferric (Fe3+) heme in the resting state; the isotropic shift was displaced from the diamagnetic value and varied with temperature consistent with Curie-law dependence. A nondeuterated competitive tighter binding ligand, camphor, was used to displace the adamantane-bound species. This addition resulted in the disappearance of the hyperfine-shifted signal associated with a perdeuterated adamantane bound to CP450cam, while signals presumably associated with adamantane bound to other cavities persisted. We simulated the deuterium spinning side-band intensities for the enzyme-bound species using dipolar hyperfine coupling as the only anisotropic interaction; the deuterium quadrupolar interaction was apparently averaged due to a fast high-symmetry motion. These data provide direct support for previous proposals that substrates are conformationally mobile on the time scale of enzymatic turnover. The simulations suggested that the adamantane binds with an average metal-deuterium distance of 6.2 (+/-0.2) A, corresponding to a dipolar coupling constant of 6.5 (+/-0.5) kHz. PMID:10451377

  5. Molecular dynamics in paramagnetic materials as studied by magic-angle spinning 2H NMR spectra.

    PubMed

    Mizuno, Motohiro; Suzuki, You; Endo, Kazunaka; Murakami, Miwa; Tansho, Masataka; Shimizu, Tadashi

    2007-12-20

    A magic-angle spinning (MAS) 2H NMR experiment was applied to study the molecular motion in paramagnetic compounds. The temperature dependences of 2H MAS NMR spectra were measured for paramagnetic [M(H2O)6][SiF6] (M=Ni2+, Mn2+, Co2+) and diamagnetic [Zn(H2O)6][SiF6]. The paramagnetic compounds exhibited an asymmetric line shape in 2H MAS NMR spectra because of the electron-nuclear dipolar coupling. The drastic changes in the shape of spinning sideband patterns and in the line width of spinning sidebands due to the 180 degrees flip of water molecules and the reorientation of [M(H2O)6]2+ about its C3 axis were observed. In the paramagnetic compounds, paramagnetic spin-spin relaxation and anisotropic g-factor result in additional linebroadening of each of the spinning sidebands. The spectral simulation of MAS 2H NMR, including the effects of paramagnetic shift and anisotropic spin-spin relaxation due to electron-nuclear dipolar coupling and anisotropic g-factor, was performed for several molecular motions. Information about molecular motions in the dynamic range of 10(2) s(-1)

  6. Double-quantum homonuclear rotary resonance: Efficient dipolar recovery in magic-angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Nielsen, N. C.; Bildsøe, H.; Jakobsen, H. J.; Levitt, M. H.

    1994-08-01

    We describe an efficient method for the recovery of homonuclear dipole-dipole interactions in magic-angle spinning NMR. Double-quantum homonuclear rotary resonance (2Q-HORROR) is established by fulfilling the condition ωr=2ω1, where ωr is the sample rotation frequency and ω1 is the nutation frequency around an applied resonant radio frequency (rf) field. This resonance can be used for double-quantum filtering and measurement of homonuclear dipolar interactions in the presence of magic-angle spinning. The spin dynamics depend only weakly on crystallite orientation allowing good performance for powder samples. Chemical shift effects are suppressed to zeroth order. The method is demonstrated for singly and doubly 13C labeled L-alanine.

  7. Rotary resonance recoupling of 13C- 1H dipolar interactions in magic angle spinning 13C NMR of dynamic solids

    NASA Astrophysics Data System (ADS)

    Kitchin, Simon J.; Harris, Kenneth D. M.; Aliev, Abil E.; Apperley, David C.

    2000-06-01

    Rotary resonance recoupling of heteronuclear 13C- 1H dipolar interactions in magic angle spinning solid state 13C NMR spectra (recorded under conditions of 1H decoupling at frequency ν1 and magic angle spinning at frequency νr) has been studied for three examples of molecular solids (adamantane, ferrocene and hexamethylbenzene) in which substantial molecular motion is known to occur. It is shown that when rotary resonance conditions are satisfied (i.e. ν1/νr= n, for n=1 or 2), the recoupling can lead to motionally averaged Pake-like powder patterns from which information on 13C- 1H internuclear distances and/or molecular motion can be derived.

  8. Development of a magic-angle spinning nuclear magnetic resonance probe with a cryogenic detection system for sensitivity enhancement

    NASA Astrophysics Data System (ADS)

    Mizuno, Takashi; Hioka, Katsuya; Fujioka, Koji; Takegoshi, K.

    2008-04-01

    A novel nuclear magnetic resonance (NMR) probe for high-resolution solid-state NMR has been developed. In this probe, temperature of the detection coil is kept at cryogenic temperature (˜12K) for sensitivity enhancement, which is achieved not only by suppression of thermal noise but also by increment of a Q factor of the coil. A marked feature of this probe is that a sample rotating at magic angle is thermally isolated from the cryogenic system in order to realize high-resolution solid-state NMR measurement at various sample temperatures. We call this system as cryocoil magic-angle spinning (cryocoil MAS). H1 MAS NMR with the coil temperature of ˜20K was successfully observed for solid adamantane rotating at room temperature, and signal-to-noise increment due to this cryocoil approach was confirmed.

  9. High Resolution Structural Characterization of Aβ42 Amyloid Fibrils by Magic Angle Spinning NMR

    PubMed Central

    2015-01-01

    The presence of amyloid plaques composed of amyloid beta (Aβ) fibrils is a hallmark of Alzheimer’s disease (AD). The Aβ peptide is present as several length variants with two common alloforms consisting of 40 and 42 amino acids, denoted Aβ1–40 and Aβ1–42, respectively. While there have been numerous reports that structurally characterize fibrils of Aβ1–40, very little is known about the structure of amyloid fibrils of Aβ1–42, which are considered the more toxic alloform involved in AD. We have prepared isotopically 13C/15N labeled AβM01–42 fibrils in vitro from recombinant protein and examined their 13C–13C and 13C–15N magic angle spinning (MAS) NMR spectra. In contrast to several other studies of Aβ fibrils, we observe spectra with excellent resolution and a single set of chemical shifts, suggesting the presence of a single fibril morphology. We report the initial structural characterization of AβM01–42 fibrils utilizing 13C and 15N shift assignments of 38 of the 43 residues, including the backbone and side chains, obtained through a series of cross-polarization based 2D and 3D 13C–13C, 13C–15N MAS NMR experiments for rigid residues along with J-based 2D TOBSY experiments for dynamic residues. We find that the first ∼5 residues are dynamic and most efficiently detected in a J-based TOBSY spectrum. In contrast, residues 16–42 are easily observed in cross-polarization experiments and most likely form the amyloid core. Calculation of ψ and φ dihedral angles from the chemical shift assignments indicate that 4 β-strands are present in the fibril’s secondary structure. PMID:26001057

  10. High resolution structural characterization of Aβ42 amyloid fibrils by magic angle spinning NMR.

    PubMed

    Colvin, Michael T; Silvers, Robert; Frohm, Birgitta; Su, Yongchao; Linse, Sara; Griffin, Robert G

    2015-06-17

    The presence of amyloid plaques composed of amyloid beta (Aβ) fibrils is a hallmark of Alzheimer's disease (AD). The Aβ peptide is present as several length variants with two common alloforms consisting of 40 and 42 amino acids, denoted Aβ1-40 and Aβ1-42, respectively. While there have been numerous reports that structurally characterize fibrils of Aβ1-40, very little is known about the structure of amyloid fibrils of Aβ1-42, which are considered the more toxic alloform involved in AD. We have prepared isotopically (13)C/(15)N labeled AβM01-42 fibrils in vitro from recombinant protein and examined their (13)C-(13)C and (13)C-(15)N magic angle spinning (MAS) NMR spectra. In contrast to several other studies of Aβ fibrils, we observe spectra with excellent resolution and a single set of chemical shifts, suggesting the presence of a single fibril morphology. We report the initial structural characterization of AβM01-42 fibrils utilizing (13)C and (15)N shift assignments of 38 of the 43 residues, including the backbone and side chains, obtained through a series of cross-polarization based 2D and 3D (13)C-(13)C, (13)C-(15)N MAS NMR experiments for rigid residues along with J-based 2D TOBSY experiments for dynamic residues. We find that the first ∼5 residues are dynamic and most efficiently detected in a J-based TOBSY spectrum. In contrast, residues 16-42 are easily observed in cross-polarization experiments and most likely form the amyloid core. Calculation of ψ and φ dihedral angles from the chemical shift assignments indicate that 4 β-strands are present in the fibril's secondary structure. PMID:26001057

  11. FIRST 100 T NON-DESTRUCTIVE MAGNET

    SciTech Connect

    J. R. SIMS; ET AL

    1999-10-01

    The first 100 T non-destructive (100 T ND) magnet and power supplies as currently designed are described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field Laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND magnet will provide a 100 T pulsed field of 5 ms duration (above 90% of full field) in a 15 mm diameter bore once per hour. Magnet operation will be non-destructive. The magnet will consist of a controlled power outer coil set which produces a 47 T platform field in a 225 mm diameter bore. Located within the outer coil set will be a 220 mm outer diameter capacitor powered insert coil. Using inertial energy storage a synchronous motor/generator will provide ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters will energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. The insert will then be energized to produce the balance of the 100 T peak field using a 2.3 MJ, 18 kV (charged to 15 kV), 14.4 mF capacitor bank controlled with solid-state switches. The magnet will be the first of its kind and the first non-destructive, reusable 100 T pulsed magnet. The operation of the magnet will be described along with special features of its design and construction.

  12. High zenith angle observations of PKS 2155-304 with the MAGIC-I telescope

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; Antoranz, P.; Asensio, M.; Backes, M.; Barres de Almeida, U.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Borla Tridon, D.; Braun, I.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Cea del Pozo, E.; De Lotto, B.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Eisenacher, D.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; Gozzini, S. R.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Jogler, T.; Kellermann, H.; Klepser, S.; Krähenbühl, T.; Krause, J.; Kushida, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López, R.; López-Oramas, A.; Lorenz, E.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moldón, J.; Moralejo, A.; Munar-Adrover, P.; Niedzwiecki, A.; Nieto, D.; Nilsson, K.; Nowak, N.; Orito, R.; Paiano, S.; Paneque, D.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puerto Gimenez, I.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamatescu, V.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Sun, S.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Tibolla, O.; Torres, D. F.; Treves, A.; Uellenbeck, M.; Vankov, H.; Vogler, P.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.

    2012-08-01

    Context. The high frequency peaked BL Lac PKS 2155-304 with a redshift of z = 0.116 was discovered in 1997 in the very high energy (VHE, E > 100 GeV) γ-ray range by the University of Durham Mark VI γ-ray Cherenkov telescope in Australia with a flux corresponding to 20% of the Crab Nebula flux. It was later observed and detected with high significance by the southern Cherenkov observatory H.E.S.S. establishing this source as the best studied southern TeV blazar. Detection from the northern hemisphere is difficult due to challenging observation conditions under large zenith angles. In July 2006, the H.E.S.S. collaboration reported an extraordinary outburst of VHE γ-emission. During the outburst, the VHE γ-ray emission was found to be variable on the time scales of minutes and with a mean flux of ~7 times the flux observed from the Crab Nebula. Follow-up observations with the MAGIC-I standalone Cherenkov telescope were triggered by this extraordinary outburst and PKS 2155-304 was observed between 28 July to 2 August 2006 for 15 h at large zenith angles. Aims: We studied the behavior of the source after its extraordinary flare. Furthermore, we developed an analysis method in order to analyze these data taken under large zenith angles. Methods: Here we present an enhanced analysis method for data taken at high zenith angles. We developed improved methods for event selection that led to a better background suppression. Results: The quality of the results presented here is superior to the results presented previously for this data set: detection of the source on a higher significance level and a lower analysis threshold. The averaged energy spectrum we derived has a spectral index of (-3.5 ± 0.2) above 400 GeV, which is in good agreement with the spectral shape measured by H.E.S.S. during the major flare on MJD 53 944. Furthermore, we present the spectral energy distribution modeling of PKS 2155-304. With our observations we increased the duty cycle of the source

  13. Complementary Electromagnetic Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tian, Gui Yun; Wilson, John; Morozov, Maxim

    2011-06-01

    The use of non-destructive evaluation (NDE) for defect detection and failure prediction in structures and specimens is widespread in energy industries, aimed at ageing power plants and pipelines, material degradation, fatigue and radiation damage, etc. At present there are no suitable electromagnetic NDE methods for the measurement and characterization of material degradation, in irradiated samples in particular, which is very important and timely for the nuclear power industry in the UK. This paper reports recent developments in the field of electromagnetic (EM) NDE at Newcastle University, including pulsed eddy current (PEC), pulsed magnetic flux leakage (PMFL), magnetic Barkhausen emission (MBE) and magneto-acoustic emission (MAE). As different EM methods have different strengths, an integrative EM framework is introduced. Case studies through the second round robin tests organized by the Universal Network for Magnetic Non-Destructive Evaluation (UNMNDE), representing eighteen leading research groups worldwide in the area of electromagnetic NDE, are reported. Twelve samples with different ageing times and rolling reduction ratios were tested using different magnetic methods among the UNMNDE members. Based on the studies, the complementary characteristics of electromagnetic techniques for NDE are discussed.

  14. Microwave field distribution in a magic angle spinning dynamic nuclear polarization NMR probe.

    PubMed

    Nanni, Emilio A; Barnes, Alexander B; Matsuki, Yoh; Woskov, Paul P; Corzilius, Björn; Griffin, Robert G; Temkin, Richard J

    2011-05-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B(1S)) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4mm diameter sapphire rotor containing the sample. The predicted average B(1S) field is 13μT/W(1/2), where S denotes the electron spin. For a routinely achievable input power of 5W the corresponding value is γ(S)B(1S)=0.84MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement (ϵ) vs. ω(1S)/(2π) for a sample of (13)C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment. PMID:21382733

  15. Spinning-sideband patterns in multiple-quantum magic-angle spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Friedrich, Ulli

    1998-12-01

    Recent interest has focused on solid-state NMR experiments which excite multiple-quantum (MQ) coherences in the presence of magic-angle spinning (MAS). Such experiments have been applied to both dipolar-coupled spin Ι = 1/2 and half-integer quadrupolar systems. A feature common to both cases is the observation of interesting spinning sideband patterns in the indirect (MQ) dimension. In this paper, the origin of these patterns is reviewed in terms of two distinct mechanisms: first, rotor encoding of the dipolar or quadrupolar interaction caused by the change in the Hamiltonian active during the MQ reconversion period relative to the excitation period (reconversion rotor encoding, RRE); and, second, rotor modulation of the interaction during the evolution of the MQ coherences in the t1 dimension (evolution rotor modulation, ERM). Only the first mechanism is present for total spin coherences, while for lower-order MQ coherences both mechanisms contribute to the pattern. For dipolar and quadrupolar model systems, i.e., the three protons of a methyl group and quadrupolar nuclei with spin Ι = 3/2 and Ι = 5/2 and axially symmetric first-order quadrupolar interactions, analytical expressions are derived for all orders of MQ MAS signals. Simulations based on these analytical expressions and numerical density matrix simulations are compared with experimental spectra. Additional perturbing influences, such as the heteronuclear dipolar coupling between a quadrupolar and a spin Ι = 1/2 nucleus, are taken into account. The effect of dipolar couplings on a quadrupolar MQ spectrum is found to be enhanced by the order of the observed MQ coherence.

  16. Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance

    SciTech Connect

    Turcu, Romulus V.F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 deg C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  17. Rotor design for high pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Turcu, Romulus V F; Hoyt, David W; Rosso, Kevin M; Sears, Jesse A; Loring, John S; Felmy, Andrew R; Hu, Jian Zhi

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low (1)H and (13)C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe(2+))(3)Si(2)O(5)(OH)(4)), in contact with liquid water in water-saturated supercritical CO(2) (scCO(2)) at 150 bar and 50°C. This mineral is relevant to the deep geologic disposal of CO(2), but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields. PMID:23220181

  18. Rotor design for high pressure magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Turcu, Romulus V. F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Zhi

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 °C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  19. Microwave field distribution in a magic angle spinning dynamic nuclear polarization NMR probe

    NASA Astrophysics Data System (ADS)

    Nanni, Emilio A.; Barnes, Alexander B.; Matsuki, Yoh; Woskov, Paul P.; Corzilius, Björn; Griffin, Robert G.; Temkin, Richard J.

    2011-05-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B 1 S) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4 mm diameter sapphire rotor containing the sample. The predicted average B 1 S field is 13 μT/W 1/2, where S denotes the electron spin. For a routinely achievable input power of 5 W the corresponding value is γSB 1 S = 0.84 MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement ( ɛ) vs. ω1 S/(2 π) for a sample of 13C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment.

  20. Tailored low-power cross-polarization under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Demers, Jean-Philippe; Vijayan, Vinesh; Becker, Stefan; Lange, Adam

    2010-08-01

    High static magnetic fields and very fast magic-angle spinning (MAS) promise to improve resolution and sensitivity of solid-state NMR experiments. The fast MAS regime has permitted the development of low-power cross-polarization schemes, such as second-order cross-polarization (SOCP), which prevent heat deposition in the sample. Those schemes are however limited in bandwidth, as weak radio-frequency (RF) fields only cover a small chemical shift range for rare nuclei (e.g. 13C). Another consideration is that the efficiency of cross-polarization is very sensitive to magnetization decay that occurs during the spin-lock pulse on the abundant nuclei (e.g. 1H). Having characterized this decay in glutamine at 60 kHz MAS, we propose two complementary strategies to tailor cross-polarization to desired spectral regions at low RF power. In the case of multiple sites with small chemical shift dispersion, a larger bandwidth for SOCP is obtained by slightly increasing the RF power while avoiding recoupling conditions that lead to fast spin-lock decay. In the case of two spectral regions with large chemical shift offset, an extension of the existing low-power schemes, called MOD-CP, is introduced. It consists of a spin-lock on 1H and an amplitude-modulated spin-lock on the rare nucleus. The range of excited chemical shifts is assessed by experimental excitation profiles and numerical simulation of an I 2S spin system. All SOCP-based schemes exhibit higher sensitivity than high-power CP schemes, as demonstrated on solid (glutamine) and semi-solid (hydrated, micro-crystalline ubiquitin) samples.

  1. Correlating high-resolution magic angle spinning NMR spectroscopy and gene analysis in osteoarthritic cartilage.

    PubMed

    Tufts, Lauren; Shet Vishnudas, Keerthi; Fu, Eunice; Kurhanewicz, John; Ries, Michael; Alliston, Tamara; Li, Xiaojuan

    2015-05-01

    Osteoarthritis (OA) is a common multifactorial and heterogeneous degenerative joint disease, and biochemical changes in cartilage matrix occur during the early stages of OA before morphological changes occur. Thus, it is desired to measure regional biochemical changes in the joint. High-resolution magic angle spinning (HRMAS) NMR spectroscopy is a powerful method of observing cartilaginous biochemical changes ex vivo, including the concentrations of alanine and N-acetyl, which are markers of collagen and total proteoglycan content, respectively. Previous studies have observed significant changes in chondrocyte metabolism of OA cartilage via the altered gene expression profiles of ACAN, COL2A1 and MMP13, which encode aggrecan, type II collagen and matrix metalloproteinase 13 (a protein crucial in the degradation of type II collagen), respectively. Employing HRMAS, this study aimed to elucidate potential relationships between N-acetyl and/or alanine and ACAN, COL2A1 and/or MMP13 expression profiles in OA cartilage. Thirty samples from the condyles of five subjects undergoing total knee arthroplasty to treat OA were collected. HRMAS spectra were obtained at 11.7 T for each sample. RNA was subsequently extracted to determine gene expression profiles. A significant negative correlation between N-acetyl metabolite and ACAN gene expression levels was observed; this provides further evidence of N-acetyl as a biomarker of cartilage degeneration. The alanine doublet was distinguished in the spectra of 15 of the 30 specimens of this study. Alanine can only be detected with HRMAS NMR spectroscopy when the collagen framework has been degraded such that alanine is sufficiently mobile to form a distinguished peak in the spectrum. Thus, HRMAS NMR spectroscopy may provide unique localized measurements of collagenous degeneration in OA cartilage. The identification of imaging markers that could provide a link between OA pathology and chondrocyte metabolism will facilitate the

  2. Nuclear depolarization and absolute sensitivity in magic-angle spinning cross effect dynamic nuclear polarization.

    PubMed

    Mentink-Vigier, Frédéric; Paul, Subhradip; Lee, Daniel; Feintuch, Akiva; Hediger, Sabine; Vega, Shimon; De Paëpe, Gaël

    2015-09-14

    Over the last two decades solid state Nuclear Magnetic Resonance has witnessed a breakthrough in increasing the nuclear polarization, and thus experimental sensitivity, with the advent of Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). To enhance the nuclear polarization of protons, exogenous nitroxide biradicals such as TOTAPOL or AMUPOL are routinely used. Their efficiency is usually assessed as the ratio between the NMR signal intensity in the presence and the absence of microwave irradiation εon/off. While TOTAPOL delivers an enhancement εon/off of about 60 on a model sample, the more recent AMUPOL is more efficient: >200 at 100 K. Such a comparison is valid as long as the signal measured in the absence of microwaves is merely the Boltzmann polarization and is not affected by the spinning of the sample. However, recent MAS-DNP studies at 25 K by Thurber and Tycko (2014) have demonstrated that the presence of nitroxide biradicals combined with sample spinning can lead to a depolarized nuclear state, below the Boltzmann polarization. In this work we demonstrate that TOTAPOL and AMUPOL both lead to observable depolarization at ≈110 K, and that the magnitude of this depolarization is radical dependent. Compared to the static sample, TOTAPOL and AMUPOL lead, respectively, to nuclear polarization losses of up to 20% and 60% at a 10 kHz MAS frequency, while Trityl OX63 does not depolarize at all. This experimental work is analyzed using a theoretical model that explains how the depolarization process works under MAS and gives new insights into the DNP mechanism and into the spin parameters, which are relevant for the efficiency of a biradical. In light of these results, the outstanding performance of AMUPOL must be revised and we propose a new method to assess the polarization gain for future radicals. PMID:26235749

  3. Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR

    PubMed Central

    Bayro, Marvin J.; Debelouchina, Galia T.; Eddy, Matthew T.; Birkett, Neil R.; MacPhee, Catherine E.; Rosay, Melanie; Maas, Werner E.; Dobson, Christopher M.

    2011-01-01

    We describe magic-angle spinning NMR experiments designed to elucidate the interstrand architecture of amyloid fibrils. Three methods are introduced for this purpose, two being based on the analysis of long-range 13C-13C correlation spectra and a third based on the identification of intermolecular interactions in 13C-15N spectra. We show, in studies of fibrils formed by the 86-residue SH3 domain of PI3 kinase (PI3-SH3), that efficient 13C-13C correlation spectra display a resonance degeneracy that establishes a parallel, in-register alignment of the proteins in the amyloid fibrils. In addition, this degeneracy can be circumvented to yield direct intermolecular constraints. The 13C-13C experiments are corroborated by 15N-13C correlation spectrum obtained from a mixed [15N,12C]/[14N,13C] sample which directly quantifies interstrand distances. Furthermore, when the spectra are recorded with signal enhancement provided by dynamic nuclear polarization (DNP) at 100 K, we demonstrate a dramatic increase (from 23 to 52) in the number of intermolecular 15N-13C constraints present in the spectra. The increase in the information content is due to the enhanced signal intensities and to the fact that dynamic processes, leading to spectral intensity losses, are quenched at low temperatures. Thus, acquisition of low temperature spectra addresses a problem that is frequently encountered in MAS spectra of proteins. In total the experiments provide 111 intermolecular 13C-13C and 15N-13C constraints that establish that the PI3-SH3 protein strands are aligned in a parallel, in-register arrangement within the amyloid fibril. PMID:21774549

  4. Microwave Field Distribution in a Magic Angle Spinning Dynamic Nuclear Polarization NMR Probe

    PubMed Central

    Nanni, Emilio A.; Barnes, Alexander B.; Matsuki, Yoh; Woskov, Paul P.; Corzilius, Björn; Griffin, Robert G.; Temkin, Richard J.

    2011-01-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B1S) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4 mm diameter sapphire rotor containing the sample. The predicted average B1S field is 13µT/W1/2, where S denotes the electron spin. For a routinely achievable input power of 5 W the corresponding value is γ SB1S = 0.84 MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement (ε) vs. ω1S/(2π) for a sample of 13C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment. PMID:21382733

  5. Non-destructive testing method and apparatus

    DOEpatents

    Akers, Douglas W.

    2011-10-04

    Non-destructive testing apparatus may comprise a photon source and a source material that emits positrons in response to bombardment of the source material with photons. The source material is positionable adjacent the photon source and a specimen so that when the source material is positioned adjacent the photon source it is exposed to photons produced thereby. When the source material is positioned adjacent the specimen, the specimen is exposed to at least some of the positrons emitted by the source material. A detector system positioned adjacent the specimen detects annihilation gamma rays emitted by the specimen. Another embodiment comprises a neutron source and a source material that emits positrons in response to neutron bombardment.

  6. Non-destructive evaluation of composites

    NASA Technical Reports Server (NTRS)

    Chu, Tsuchin Philip

    1996-01-01

    The composite materials have been used in aerospace industries for quite some time. Several non-destructive evaluation (NDE) methods have been developed to inspect composites in order to detect flaws, matrix cracking, and delamination. These methods include ultrasonics, acoustic emission, shearography, thermography, X-ray, and digital image correlation. The NDE Branch of Marshall Space Flight Center has recently acquired a thermal imaging NDE system. The same system has been used at NASA Langley Research Center for detecting disbonds. In order to compare different NDE methods, three carbon/carbon composite panels were used for experiment using ultrasonic C-scan, shearography, and thermography methods. These panels have teflon inserts to simulate the delamination between plies in a composite panel. All three methods have successfully located the insert. The experiment and results are presented in the following sections.

  7. NON-DESTRUCTIVE FLAW DETECTION APPARATUS

    DOEpatents

    Stateman, M.J.; Holloway, H.R.

    1957-12-17

    An apparatus is described for the non-destructive detection of flaws in electrical conducting articles. The particular feature of the detection apparatus is that a flaw in the front or back of the test article will not be masked by signals caused by the passage of the end and front of the article through the detection apparatus. The present invention alleviates the above problem by mounting detection coils on directly opposite sides of the test passageway so that the axes of the pickup coils are perpendicular to the axis of an energizing coil through which the article is passed. A flaw in the article will cause a change in the voltage induced in one pickup coil, but passage of the end or front of the article will not produce unequal signals. The signals are compared in appropriate electrical circuitry to actuate a recorder only when unequal signals are present, indicating the presence of a flaw.

  8. Solid-state {sup 17}O magic-angle and dynamic-angle spinning NMR study of the SiO{sub 2} polymorph coesite

    SciTech Connect

    Grandinetti, P.J.; Baltisberger, J.H.; Farnan, I.; Stebbins, J.F.; Werner, U.; Pines, A. |

    1995-08-10

    Five distinctly resolved {sup 17}O solid-state NMR resonances in room temperature coesite, an SiO{sub 2} polymorph, have been observed and assigned using dynamic angle spinning (DAS) at 11.7 T along with magic angle spinning (MAS) spectra at 9.4 and 11.7 T. The {sup 17}O quadrupolar parameters for each of the five oxygen environments in coesite are correlated with the Si-O-Si bridging bond angles determined by diffraction experiments. The sign of e{sup 2}-qQ/h along with the orientation of the electric field gradient for oxygen in the Si-O-Si linkage were determined from a Townes-Dailey analysis of the data. 41 refs., 7 figs., 5 tabs.

  9. Characterization of lithium coordination sites with magic-angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Haimovich, A.; Goldbourt, A.

    2015-05-01

    Lithium, in the form of lithium carbonate, is one of the most common drugs for bipolar disorder. Lithium is also considered to have an effect on many other cellular processes hence it possesses additional therapeutic as well as side effects. In order to quantitatively characterize the binding mode of lithium, it is required to identify the interacting species and measure their distances from the metal center. Here we use magic-angle spinning (MAS) solid-state NMR to study the binding site of lithium in complex with glycine and water (LiGlyW). Such a compound is a good enzyme mimetic since lithium is four-coordinated to one water molecule and three carboxylic groups. Distance measurements to carbons are performed using a 2D transferred echo double resonance (TEDOR) MAS solid-state NMR experiment, and water binding is probed by heteronuclear high-resolution proton-lithium and proton-carbon correlation (wPMLG-HETCOR) experiments. Both HETCOR experiments separate the main complex from impurities and non-specifically bound lithium species, demonstrating the sensitivity of the method to probe the species in the binding site. Optimizations of the TEDOR pulse scheme in the case of a quadrupolar nucleus with a small quadrupole coupling constant show that it is most efficient when pulses are positioned on the spin-1/2 (carbon-13) nucleus. Since the intensity of the TEDOR signal is not normalized, careful data analysis that considers both intensity and dipolar oscillations has to be performed. Nevertheless we show that accurate distances can be extracted for both carbons of the bound glycine and that these distances are consistent with the X-ray data and with lithium in a tetrahedral environment. The lithium environment in the complex is very similar to the binding site in inositol monophosphatase, an enzyme associated with bipolar disorder and the putative target for lithium therapy. A 2D TEDOR experiment applied to the bacterial SuhB gene product of this enzyme was designed

  10. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    SciTech Connect

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  11. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    DOEpatents

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  12. Method of non-destructively inspecting a curved wall portion

    DOEpatents

    Fong, James T.

    1996-01-01

    A method of non-destructively inspecting a curved wall portion of a large and thick walled vessel for a defect by computed tomography is provided. A collimated source of radiation is placed adjacent one side of the wall portion and an array of detectors for the radiation is placed on the other side adjacent the source. The radiation from the source passing through the wall portion is then detected with the detectors over a limited angle, dependent upon the curvature of the wall of the vessel, to obtain a dataset. The source and array are then coordinately moved relative to the wall portion in steps and a further dataset is obtained at each step. The plurality of datasets obtained over the limited angle is then processed to produce a tomogram of the wall portion to determine the presence of a defect therein. In a preferred embodiment, the curved wall portion has a center of curvature so that the source and the array are positioned at each step along a respective arc curved about the center. If desired, the detector array and source can be reoriented relative to a new wall portion and an inspection of the new wall portion can be easily obtained. Further, the source and detector array can be indexed in a direction perpendicular to a plane including the limited angle in a plurality of steps so that by repeating the detecting and moving steps at each index step, a three dimensional image can be created of the wall portion.

  13. Lipid bilayer preparations of membrane proteins for oriented and magic-angle spinning solid-state NMR samples

    PubMed Central

    Das, Nabanita; Murray, Dylan T; Cross, Timothy A

    2014-01-01

    Solid-state NMR spectroscopy has been used successfully for characterizing the structure and dynamics of membrane proteins as well as their interactions with other proteins in lipid bilayers. such an environment is often necessary for achieving native-like structures. sample preparation is the key to this success. Here we present a detailed description of a robust protocol that results in high-quality membrane protein samples for both magic-angle spinning and oriented-sample solid-state NMR. the procedure is demonstrated using two proteins: CrgA (two transmembrane helices) and rv1861 (three transmembrane helices), both from Mycobacterium tuberculosis. the success of this procedure relies on two points. First, for samples for both types of NMR experiment, the reconstitution of the protein from a detergent environment to an environment in which it is incorporated into liposomes results in ‘complete’ removal of detergent. second, for the oriented samples, proper dehydration followed by rehydration of the proteoliposomes is essential. By using this protocol, proteoliposome samples for magic-angle spinning NMR and uniformly aligned samples (orientational mosaicity of <1°) for oriented-sample NMR can be obtained within 10 d. PMID:24157546

  14. Cryogenic Storage Tank Non-Destructive Evaluation

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2010-01-01

    This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

  15. Non destructive testing of soft body armor

    NASA Astrophysics Data System (ADS)

    Bhise, Karan

    Pristine bullet proof vests are extremely effective at halting pre-determined projectile threats and have saved over 3000 lives. However, the effectiveness of these vests to halt a bullet is seen to decrease over time.Owing to the importance of bullet proof vests over a period of time, tests to determine their effectiveness have been carried out on every batch of vests at the time of inception and at certain time intervals by shooting a bullet through them. A few vests from every batch are picked up and shot at to check for bullet penetration during this process while these results are extrapolated onto the other vests from the batch.One of the main issues with this method is the fact that testing a few jackets among a large set of jackets does not guarantee the safety of every jacket in the entire batch.Further the jackets that are shot-at have the possibility of undergoing substantial damage during the process thus compromising its safety rendering them unsafe for future use.As the vest penetration phenomenon is extremely complex too, there arose a need for a better testing procedure that could not only help ensure more safety, but also save time and money.The new testing procedure proposed a non-destructive evaluation of the jackets that would solve the issues previous faced in testing the vests. This would lead to the building of a portable set up which could be carried to any location to test jackets in a matter of minutes thus saving time and money.

  16. Floquet-Magnus expansion for general N-coupled spins systems in magic-angle spinning nuclear magnetic resonance spectra

    NASA Astrophysics Data System (ADS)

    Mananga, Eugene Stephane; Charpentier, Thibault

    2015-04-01

    In this paper we present a theoretical perturbative approach for describing the NMR spectrum of strongly dipolar-coupled spin systems under fast magic-angle spinning. Our treatment is based on two approaches: the Floquet approach and the Floquet-Magnus expansion. The Floquet approach is well known in the NMR community as a perturbative approach to get analytical approximations. Numerical procedures are based on step-by-step numerical integration of the corresponding differential equations. The Floquet-Magnus expansion is a perturbative approach of the Floquet theory. Furthermore, we address the " γ -encoding" effect using the Floquet-Magnus expansion approach. We show that the average over " γ " angle can be performed for any Hamiltonian with γ symmetry.

  17. Magic-angle-spinning NMR of the drug resistant S31N M2 proton transporter from influenza A.

    PubMed

    Andreas, Loren B; Eddy, Matthew T; Chou, James J; Griffin, Robert G

    2012-05-01

    We report chemical shift assignments of the drug-resistant S31N mutant of M2(18-60) determined using 3D magic-angle-spinning (MAS) NMR spectra acquired with a (15)N-(13)C ZF-TEDOR transfer followed by (13)C-(13)C mixing by RFDR. The MAS spectra reveal two sets of resonances, indicating that the tetramer assembles as a dimer of dimers, similar to the wild-type channel. Helicies from the two sets of chemical shifts are shown to be in close proximity at residue H37, and the assignments reveal a difference in the helix torsion angles, as predicted by TALOS+, for the key resistance residue N31. In contrast to wild-type M2(18-60), chemical shift changes are minimal upon addition of the inhibitor rimantadine, suggesting that the drug does not bind to S31N M2. PMID:22480220

  18. NON-DESTRUCTIVE SOIL CARBON ANALYZER.

    SciTech Connect

    Wielopolski, Lucian; Hendrey, G.; Orion, I.; Prior, S.; Rogers, H.; Runion, B.; Torbert, A.

    2004-02-01

    This report describes the feasibility, calibration, and safety considerations of a non-destructive, in situ, quantitative, volumetric soil carbon analytical method based on inelastic neutron scattering (INS). The method can quantify values as low as 0.018 gC/cc, or about 1.2% carbon by weight with high precision under the instrument's configuration and operating conditions reported here. INS is safe and easy to use, residual soil activation declines to background values in under an hour, and no radiological requirements are needed for transporting the instrument. The labor required to obtain soil-carbon data is about 10-fold less than with other methods, and the instrument offers a nearly instantaneous rate of output of carbon-content values. Furthermore, it has the potential to quantify other elements, particularly nitrogen. New instrumentation was developed in response to a research solicitation from the U.S. Department of Energy (DOE LAB 00-09 Carbon Sequestration Research Program) supporting the Terrestrial Carbon Processes (TCP) program of the Office of Science, Biological and Environmental Research (BER). The solicitation called for developing and demonstrating novel techniques for quantitatively measuring changes in soil carbon. The report includes raw data and analyses of a set of proof-of-concept, double-blind studies to evaluate the INS approach in the first phase of developing the instrument. Managing soils so that they sequester massive amounts of carbon was suggested as a means to mitigate the atmospheric buildup of anthropogenic CO{sub 2}. Quantifying changes in the soils' carbon stocks will be essential to evaluating such schemes and documenting their performance. Current methods for quantifying carbon in soil by excavation and core sampling are invasive, slow, labor-intensive and locally destroy the system being observed. Newly emerging technologies, such as Laser Induced Breakdown Spectroscopy and Near-Infrared Spectroscopy, offer soil

  19. SCAM-STMAS: satellite-transition MAS NMR of quadrupolar nuclei with self-compensation for magic-angle misset

    NASA Astrophysics Data System (ADS)

    Ashbrook, Sharon E.; Wimperis, Stephen

    2003-06-01

    Several methods are available for the acquisition of high-resolution solid-state NMR spectra of quadrupolar nuclei with half-integer spin quantum number. Satellite-transition MAS (STMAS) offers an approach that employs only conventional MAS hardware and can yield substantial signal enhancements over the widely used multiple-quantum MAS (MQMAS) experiment. However, the presence of the first-order quadrupolar interaction in the satellite transitions imposes the requirement of a high degree of accuracy in the setting of the magic angle on the NMR probehead. The first-order quadrupolar interaction is only fully removed if the sample spinning angle, χ, equals cos-1(1/ 3) exactly and rotor synchronization is performed. The required level of accuracy is difficult to achieve experimentally, particularly when the quadrupolar interaction is large. If the magic angle is not set correctly, the first-order splitting is reintroduced and the spectral resolution is severely compromised. Recently, we have demonstrated a novel STMAS method (SCAM-STMAS) that is self-compensated for angle missets of up to ±1° via coherence transfer between the two different satellite transitions ST +( mI=+3/2↔+1/2) and ST -( mI=-1/2↔-3/2) midway through the t1 period. In this work we describe in more detail the implementation of SCAM-STMAS and demonstrate its wider utility through 23Na ( I=3/2), 87Rb ( I=3/2), 27Al ( I=5/2), and 59Co ( I=7/2) NMR. We discuss linewidths in SCAM-STMAS and the limits over which angle-misset compensation is achieved and we demonstrate that SCAM-STMAS is more tolerant of temporary spinning rate fluctuations than STMAS, resulting in less " t1 noise" in the two-dimensional spectrum. In addition, alternative correlation experiments, for example involving the use of double-quantum coherences, that similarly display self-compensation for angle misset are investigated. The use of SCAM-STMAS is also considered in systems where other high-order interactions, such as third

  20. Indirectly detected chemical shift correlation NMR spectroscopy in solids under fast magic angle spinning

    SciTech Connect

    Mao, Kanmi

    2011-01-01

    The development of fast magic angle spinning (MAS) opened up an opportunity for the indirect detection of insensitive low-γ nuclei (e.g., 13C and 15N) via the sensitive high-{gamma} nuclei (e.g., 1H and 19F) in solid-state NMR, with advanced sensitivity and resolution. In this thesis, new methodology utilizing fast MAS is presented, including through-bond indirectly detected heteronuclear correlation (HETCOR) spectroscopy, which is assisted by multiple RF pulse sequences for 1H-1H homonuclear decoupling. Also presented is a simple new strategy for optimization of 1H-1H homonuclear decoupling. As applications, various classes of materials, such as catalytic nanoscale materials, biomolecules, and organic complexes, are studied by combining indirect detection and other one-dimensional (1D) and two-dimensional (2D) NMR techniques. Indirectly detected through-bond HETCOR spectroscopy utilizing refocused INEPT (INEPTR) mixing was developed under fast MAS (Chapter 2). The time performance of this approach in 1H detected 2D 1H{l_brace}13C{r_brace} spectra was significantly improved, by a factor of almost 10, compared to the traditional 13C detected experiments, as demonstrated by measuring naturally abundant organic-inorganic mesoporous hybrid materials. The through-bond scheme was demonstrated as a new analytical tool, which provides complementary structural information in solid-state systems in addition to through-space correlation. To further benefit the sensitivity of the INEPT transfer in rigid solids, the combined rotation and multiple-pulse spectroscopy (CRAMPS) was implemented for homonuclear 1H decoupling under fast MAS (Chapter 3). Several decoupling schemes (PMLG5m$\\bar{x}$, PMLG5mm$\\bar{x}$x and SAM3) were analyzed to maximize the performance of through-bond transfer based

  1. Molecular orientational dynamics in solid C70: Investigation by one- and two-dimensional magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Tycko, R.; Dabbagh, G.; Vaughan, G. B. M.; Heiney, P. A.; Strongin, R. M.; Cichy, M. A.; Smith, A. B., III

    1993-11-01

    We present the results of 13C nuclear magnetic resonance (NMR) measurements that probe molecular orientational dynamics in solid C70 in the temperature range 223-343 K. Orientational dynamics affect the NMR line shapes and spin-lattice relaxation rates by modulating the 13C chemical shift anisotropy (CSA). Motionally averaged CSA line shapes, determined from both one-dimensional and two-dimensional magic angle spinning NMR spectra, and relaxation rates are determined for each of the five inequivalent carbon sites in the C70 molecule. Comparisons of the results for the five sites provide evidence for rapid uniaxial molecular reorientation in the monoclinic (T≤280 K) and rhombohedral (280≤T≤330 K) phases and rapid isotropic reorientation in the face-centered cubic (T≥330 K) phase. The orientational correlation time is roughly 2 ns at 250 K and of the order of 5 ps at 340 K.

  2. Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI.

    PubMed

    Sakellariou, Dimitris; Hugon, Cédric; Guiga, Angelo; Aubert, Guy; Cazaux, Sandrine; Hardy, Philippe

    2010-12-01

    We introduce a cylindrical permanent magnet design that generates a homogeneous and strong magnetic field having an arbitrary inclination with respect to the axis of the cylinder. The analytical theory of 3 D magnetostatics has been applied to this problem, and a hybrid magnet structure has been designed. This structure contains two magnets producing a longitudinal and transverse component for the magnetic field, whose amplitudes and homogeneities can be fully controlled by design. A simple prototype has been constructed using inexpensive small cube magnets, and its magnetic field has been mapped using Hall and NMR probe sensors. This magnet can, in principle, be used for magic angle field spinning NMR and MRI experiments allowing for metabolic chemical shift profiling in small living animals. PMID:20891027

  3. Biochemical classification of kidney carcinoma biopsy samples using magic-angle-spinning 1H nuclear magnetic resonance spectroscopy.

    PubMed

    Moka, D; Vorreuther, R; Schicha, H; Spraul, M; Humpfer, E; Lipinski, M; Foxall, P J; Nicholson, J K; Lindon, J C

    1998-05-01

    High resolution 1H nuclear magnetic resonance (NMR) spectra using spinning at the magic angle (1H MAS NMR) have been obtained on intact normal and pathological kidney tissue samples from patients undergoing surgery for renal cell carcinoma (RCC). The spectra were measured on ca. 80 mg samples and provided high resolution 1H NMR spectra in which effects of dipolar couplings, chemical shift anisotropy and magnetic susceptibility differences are minimised thus yielding high spectral resolution. Conventional one-dimensional and spin-echo spectra and two-dimensional J-resolved, TOCSY and 1H-13C HMQC spectra were also measured on selected samples and these allowed the assignment of resonances of endogenous substances comprising both cytosolic and membrane components. The tumour tissues were characterised principally by an increased lipid content. These are the first reported results on human tumour tissues using this technique and the approach offers potential for the rapid classification of different types of tumour tissue. PMID:9608434

  4. Two-dimensional (13)C-(13)C correlation spectroscopy with magic angle spinning and dynamic nuclear polarization.

    PubMed

    Rosay, Melanie; Weis, Volker; Kreischer, Kenneth E; Temkin, Richard J; Griffin, Robert G

    2002-04-01

    The sensitivity of solid-state NMR experiments can be enhanced with dynamic nuclear polarization (DNP), a technique that transfers the high Boltzmann polarization of unpaired electrons to nuclei. Signal enhancements of up to 23 have been obtained for magic angle spinning (MAS) experiments at 5 T and 85-90 K using a custom-designed high-power gyrotron. The extended stability of MAS/DNP experiments at low temperature is demonstrated with (1)H-driven (13)C spin-diffusion experiments on the amino acid proline. These (13)C-(13)C chemical shift correlation spectra are the first two-dimensional MAS/DNP experiments performed at high field (>1.4 T). PMID:11916398

  5. Nondestructive high-resolution solid-state NMR of rotating thin films at the magic-angle.

    PubMed

    Inukai, Munehiro; Noda, Yasuto; Takeda, Kazuyuki

    2011-12-01

    We present a new approach to nondestructive magic-angle spinning (MAS) nuclear magnetic resonance (NMR) for thin films. In this scheme, the sample put on the top of a rotor is spun using the conventional MAS system, and the NMR signals are detected with an additional coil. Stable spinning of disk-shaped samples with diameters of 7 mm and 12 mm at 14.2 and 7 kHz are feasible. We present 7Li MAS NMR experiments of a thin-film sample of LiCoO2 with a thickness of 200 nm. Taking advantage of the nondestructive feature of the experiment, we also demonstrate ex situ experiments, by tracing conformation change upon annealing for various durations. This approach opens the door for in situ MAS NMR of thin-film devices as well. PMID:21958755

  6. Magic angle spinning NMR investigation of influenza A M2(18-60): support for an allosteric mechanism of inhibition.

    PubMed

    Andreas, Loren B; Eddy, Matthew T; Pielak, Rafal M; Chou, James; Griffin, Robert G

    2010-08-18

    The tetrameric M2 proton channel from influenza A virus conducts protons at low pH and is inhibited by aminoadamantyl drugs such as amantadine and rimantadine (Rmt). We report magic angle spinning NMR spectra of POPC and DPhPC membrane-embedded M2(18-60), both apo and in the presence of Rmt. Similar line widths in the spectra of apo and bound M2 indicate that Rmt does not have a significant impact on the dynamics or conformational heterogeneity of this construct. Substantial chemical shift changes for many residues in the transmembrane region support an allosteric mechanism of inhibition. An Rmt titration supports a binding stoichiometry of >1 Rmt molecule per channel and shows that nonspecific binding or changes in membrane composition are unlikely sources of the chemical shift changes. In addition, doubling of spectral lines in all of the observed samples provides evidence that the channel assembles with twofold symmetry. PMID:20698642

  7. Nondestructive high-resolution solid-state NMR of rotating thin films at the magic-angle

    NASA Astrophysics Data System (ADS)

    Inukai, Munehiro; Noda, Yasuto; Takeda, Kazuyuki

    2011-12-01

    We present a new approach to nondestructive magic-angle spinning (MAS) nuclear magnetic resonance (NMR) for thin films. In this scheme, the sample put on the top of a rotor is spun using the conventional MAS system, and the NMR signals are detected with an additional coil. Stable spinning of disk-shaped samples with diameters of 7 mm and 12 mm at 14.2 and 7 kHz are feasible. We present 7Li MAS NMR experiments of a thin-film sample of LiCoO 2 with a thickness of 200 nm. Taking advantage of the nondestructive feature of the experiment, we also demonstrate ex situ experiments, by tracing conformation change upon annealing for various durations. This approach opens the door for in situ MAS NMR of thin-film devices as well.

  8. Experimental study of resolution of proton chemical shifts in solids: Combined multiple pulse NMR and magic-angle spinning

    SciTech Connect

    Ryan, L.M.; Taylor, R.E.; Paff, A.J.; Gerstein, B.C.

    1980-01-01

    High-resolution nuclear magnetic resonance spectra of protons in rigid, randomly oriented solids have been measured using combined homonuclear dipolar decoupling (via multiple pulse techniques) and attenuation of chemical shift anisotropies (via magic-angle sample spinning). Under those conditions, isotropic proton chemical shifts were recorded for a variety of chemical species, with individual linewidths varying from about 55 to 110 Hz (1--2 ppm). Residual line broadening was due predominately to (i) magnetic-field instability and inhomogeneity, (ii) unresolved proton--proton spin couplings, (iii) chemical shift dispersion, (iv) residual dipolar broadening, and (v) lifetime broadening under the multiple pulse sequences used. The magnitudes of those effects and the current limits of resolution for this experiment in our spectrometer have been investigated. The compounds studied included organic solids (4, 4'-dimethylbenzophenone, 2, 6-dimethylbenzoic acid, and aspirin), polymers (polystyrene and polymethylmethacrylate), and the vitrain portion of a bituminous coal.

  9. Non-Destructive Classification Approaches for Equilibrated Ordinary Chondrites

    NASA Astrophysics Data System (ADS)

    Righter, K.; Harrington, R.; Schroeder, C.; Morris, R. V.

    2013-09-01

    In order to compare a few non-destructive classification techniques with the standard approaches, we have characterized a group of chondrites from the Larkman Nunatak region using magnetic susceptibility and Mössbauer spectroscopy.

  10. NON-DESTRUCTIVE TESTING METHODS FOR GEOTHERMAL PIPING.

    SciTech Connect

    BERNDT,M.L.

    2001-03-23

    Non-destructive testing is a key component of optimized plant inspection and maintenance programs. Risk based inspection, condition based maintenance and reliability centered maintenance systems all require detection, location and sizing of defects or flaws by non-destructive methods. Internal damage of geothermal piping by corrosion and erosion-corrosion is an ongoing problem requiring inspection and subsequent maintenance decisions to ensure safe and reliable performance. Conventional manual ultrasonic testing to determine remaining wall thickness has major limitations, particularly when damage is of a random and localized nature. Therefore, it is necessary to explore alternative non-destructive methods that offer potential benefits in terms of accurate quantification of size, shape and location of damage, probability of detection, ability to use on-line over long ranges, and economics. A review of non-destructive methods and their applicability to geothermal piping was performed. Based on this, ongoing research will concentrate on long range guided wave and dynamic methods.

  11. Non-destructive testing and fracture mechanics: A short discussion

    NASA Astrophysics Data System (ADS)

    Zerbst, Uwe; Heckel, Thomas; Carboni, Michele

    2016-02-01

    A short discussion is provided on the relationship between non-destructive testing and fracture mechanics. The basic tasks behind this are to guarantee the safety of a component at a potential hazard loading event, to specify inspection intervals or, alternatively, of demands on non-destructive testing for a fixed inspection regime, to plan accompanying actions for cases of temporary continued operation of structures in which cracks have been detected, and, finally, fatigue strength considerations which take into account initial defects.

  12. Resonance Assignments and Secondary Structure Analysis of Dynein Light Chain 8 by Magic-angle Spinning NMR Spectroscopy

    SciTech Connect

    Sun, Shangjin; Butterworth, Andrew H.; Paramasivam, Sivakumar; Yan, Si; Lightcap, Christine M.; Williams, John C.; Polenova, Tatyana E.

    2011-08-04

    Dynein light chain LC8 is the smallest subunit of the dynein motor complex and has been shown to play important roles in both dynein-dependent and dynein-independent physiological functions via its interaction with a number of its binding partners. It has also been linked to pathogenesis including roles in viral infections and tumorigenesis. Structural information for LC8-target proteins is critical to understanding the underlying function of LC8 in these complexes. However, some LC8-target interactions are not amenable to structural characterization by conventional structural biology techniques owing to their large size, low solubility, and crystallization difficulties. Here, we report magic-angle spinning (MAS) NMR studies of the homodimeric apo-LC8 protein as a first effort in addressing more complex, multi-partner, LC8-based protein assemblies. We have established site-specific backbone and side-chain resonance assignments for the majority of the residues of LC8, and show TALOS+-predicted torsion angles ø and ψ in close agreement with most residues in the published LC8 crystal structure. Data obtained through these studies will provide the first step toward using MAS NMR to examine the LC8 structure, which will eventually be used to investigate protein–protein interactions in larger systems that cannot be determined by conventional structural studies.

  13. Closed-cycle cold helium magic-angle spinning for sensitivity-enhanced multi-dimensional solid-state NMR

    NASA Astrophysics Data System (ADS)

    Matsuki, Yoh; Nakamura, Shinji; Fukui, Shigeo; Suematsu, Hiroto; Fujiwara, Toshimichi

    2015-10-01

    Magic-angle spinning (MAS) NMR is a powerful tool for studying molecular structure and dynamics, but suffers from its low sensitivity. Here, we developed a novel helium-cooling MAS NMR probe system adopting a closed-loop gas recirculation mechanism. In addition to the sensitivity gain due to low temperature, the present system has enabled highly stable MAS (vR = 4-12 kHz) at cryogenic temperatures (T = 35-120 K) for over a week without consuming helium at a cost for electricity of 16 kW/h. High-resolution 1D and 2D data were recorded for a crystalline tri-peptide sample at T = 40 K and B0 = 16.4 T, where an order of magnitude of sensitivity gain was demonstrated versus room temperature measurement. The low-cost and long-term stable MAS strongly promotes broader application of the brute-force sensitivity-enhanced multi-dimensional MAS NMR, as well as dynamic nuclear polarization (DNP)-enhanced NMR in a temperature range lower than 100 K.

  14. Low-temperature dynamic nuclear polarization with helium-cooled samples and nitrogen-driven magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Thurber, Kent; Tycko, Robert

    2016-03-01

    We describe novel instrumentation for low-temperature solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS), focusing on aspects of this instrumentation that have not been described in detail in previous publications. We characterize the performance of an extended interaction oscillator (EIO) microwave source, operating near 264 GHz with 1.5 W output power, which we use in conjunction with a quasi-optical microwave polarizing system and a MAS NMR probe that employs liquid helium for sample cooling and nitrogen gas for sample spinning. Enhancement factors for cross-polarized 13C NMR signals in the 100-200 range are demonstrated with DNP at 25 K. The dependences of signal amplitudes on sample temperature, as well as microwave power, polarization, and frequency, are presented. We show that sample temperatures below 30 K can be achieved with helium consumption rates below 1.3 l/h. To illustrate potential applications of this instrumentation in structural studies of biochemical systems, we compare results from low-temperature DNP experiments on a calmodulin-binding peptide in its free and bound states.

  15. (1)H and (13)C magic-angle spinning nuclear magnetic resonance studies of the chicken eggshell.

    PubMed

    Pisklak, Dariusz Maciej; Szeleszczuk, Lukasz; Wawer, Iwona

    2012-12-19

    The chicken eggshell, a product of biomineralization, contains inorganic and organic substances whose content changes during the incubation process. Bloch-decay (BD) (1)H, (13)C, and cross-polarization (CP) (13)C nuclear magnetic resonance (NMR) spectra of chicken eggshells were acquired under magic-angle spinning (MAS). Variable contact time (13)C CP MAS NMR experiments revealed the signals of carbonyl groups from organic and inorganic compounds. In the (13)C BD NMR spectra, a single peak at 168.1 ppm was detected, whereas in the (1)H BD spectra, the signals from water and the bicarbonate ion were assigned. A simultaneous decrease of the water signal in the (1)H MAS NMR spectra and an increase of the carbonate ion signal in the (13)C CP MAS NMR spectra of eggshells collected during the incubation period indicate the substitution of calcium ions by hydrogen ions in the calcium carbonate crystalline phase during the incubation of an egg. PMID:23157303

  16. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy

    PubMed Central

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS 1H NMR spectroscopy. HR-MAS 1H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values < 0.05 were considered statistically significant. Univariate analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS 1H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  17. Evaluation of Cancer Metabolomics Using ex vivo High Resolution Magic Angle Spinning (HRMAS) Magnetic Resonance Spectroscopy (MRS)

    PubMed Central

    Fuss, Taylor L.; Cheng, Leo L.

    2016-01-01

    According to World Health Organization (WHO) estimates, cancer is responsible for more deaths than all coronary heart disease or stroke worldwide, serving as a major public health threat around the world. High resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS) has demonstrated its usefulness in the identification of cancer metabolic markers with the potential to improve diagnosis and prognosis for the oncology clinic, due partially to its ability to preserve tissue architecture for subsequent histological and molecular pathology analysis. Capable of the quantification of individual metabolites, ratios of metabolites, and entire metabolomic profiles, HRMAS MRS is one of the major techniques now used in cancer metabolomic research. This article reviews and discusses literature reports of HRMAS MRS studies of cancer metabolomics published between 2010 and 2015 according to anatomical origins, including brain, breast, prostate, lung, gastrointestinal, and neuroendocrine cancers. These studies focused on improving diagnosis and understanding patient prognostication, monitoring treatment effects, as well as correlating with the use of in vivo MRS in cancer clinics. PMID:27011205

  18. Variable temperature system using vortex tube cooling and fiber optic temperature measurement for low temperature magic angle spinning NMR.

    PubMed

    Martin, Rachel W; Zilm, Kurt W

    2004-06-01

    We describe the construction and operation of a variable temperature (VT) system for a high field fast magic angle spinning (MAS) probe. The probe is used in NMR investigations of biological macromolecules, where stable setting and continuous measurement of the temperature over periods of several days are required in order to prevent sample overheating and degradation. The VT system described is used at and below room temperature. A vortex tube is used to provide cooling in the temperature range of -20 to 20 degrees C, while a liquid nitrogen-cooled heat exchanger is used below -20 degrees C. Using this arrangement, the lowest temperature that is practically achievable is -140 degrees C. Measurement of the air temperature near the spinning rotor is accomplished using a fiber optic thermometer that utilizes the temperature dependence of the absorption edge of GaAs. The absorption edge of GaAs also has a magnetic field dependence that we have measured and corrected for. This dependence was calibrated at several field strengths using the well-known temperature dependence of the (1)H chemical shift difference of the protons in methanol. PMID:15140428

  19. Low-temperature dynamic nuclear polarization with helium-cooled samples and nitrogen-driven magic-angle spinning.

    PubMed

    Thurber, Kent; Tycko, Robert

    2016-03-01

    We describe novel instrumentation for low-temperature solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS), focusing on aspects of this instrumentation that have not been described in detail in previous publications. We characterize the performance of an extended interaction oscillator (EIO) microwave source, operating near 264 GHz with 1.5 W output power, which we use in conjunction with a quasi-optical microwave polarizing system and a MAS NMR probe that employs liquid helium for sample cooling and nitrogen gas for sample spinning. Enhancement factors for cross-polarized (13)C NMR signals in the 100-200 range are demonstrated with DNP at 25K. The dependences of signal amplitudes on sample temperature, as well as microwave power, polarization, and frequency, are presented. We show that sample temperatures below 30K can be achieved with helium consumption rates below 1.3 l/h. To illustrate potential applications of this instrumentation in structural studies of biochemical systems, we compare results from low-temperature DNP experiments on a calmodulin-binding peptide in its free and bound states. PMID:26920835

  20. Closed-cycle cold helium magic-angle spinning for sensitivity-enhanced multi-dimensional solid-state NMR.

    PubMed

    Matsuki, Yoh; Nakamura, Shinji; Fukui, Shigeo; Suematsu, Hiroto; Fujiwara, Toshimichi

    2015-10-01

    Magic-angle spinning (MAS) NMR is a powerful tool for studying molecular structure and dynamics, but suffers from its low sensitivity. Here, we developed a novel helium-cooling MAS NMR probe system adopting a closed-loop gas recirculation mechanism. In addition to the sensitivity gain due to low temperature, the present system has enabled highly stable MAS (vR=4-12 kHz) at cryogenic temperatures (T=35-120 K) for over a week without consuming helium at a cost for electricity of 16 kW/h. High-resolution 1D and 2D data were recorded for a crystalline tri-peptide sample at T=40 K and B0=16.4 T, where an order of magnitude of sensitivity gain was demonstrated versus room temperature measurement. The low-cost and long-term stable MAS strongly promotes broader application of the brute-force sensitivity-enhanced multi-dimensional MAS NMR, as well as dynamic nuclear polarization (DNP)-enhanced NMR in a temperature range lower than 100 K. PMID:26302269

  1. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    PubMed Central

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2012-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20–25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier (Thurber et al., J. Magn. Reson. 2008) [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids. PMID:23238592

  2. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    NASA Astrophysics Data System (ADS)

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2013-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20-25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids.

  3. Concentration Profiling in Rat Tissue by High-Resolution Magic-Angle Spinning NMR Spectroscopy: Investigation of a Model Drug

    PubMed Central

    Lucas, Laura H.; Wilson, Sarah F.; Lunte, Craig E.; Larive, Cynthia K.

    2008-01-01

    The utility of high-resolution magic-angle spinning (HR-MAS) NMR for studying drug delivery in whole tissues was explored by dosing female Sprague–Dawley rats with topical or injectable benzoic acid (BA). In principle, HR-MAS NMR permits the detection of both intra- and extracellular compounds. This is an advantage over the previous detection of topically applied BA using microdialysis coupled to HPLC/UV as microdialysis samples only the extracellular space. Skin and muscle samples were analyzed by 1H HR-MAS NMR, and BA levels were determined using an external standard solution added to the sample rotor. One to two percent of the BA topical dose was detected in the muscle, showing that BA penetrated through the dermal and subcutaneous layers. Since BA was not detected in the muscle in the microdialysis studies, the NMR spectra revealed the intracellular localization of BA. The amount of BA detected in muscle after subcutaneous injection correlated with the distance from the dosing site. Overall, the results suggest that HR-MAS NMR can distinguish differences in the local concentration of BA varying with tissue type, dosage method, and tissue proximity to the dosing site. The results illustrate the potential of this technique for quantitative analysis of drug delivery and distribution and the challenges to be addressed as the method is refined. PMID:15859619

  4. Satellite transitions acquired in real time by magic angle spinning (STARTMAS): ``Ultrafast'' high-resolution MAS NMR spectroscopy of spin I =3/2 nuclei

    NASA Astrophysics Data System (ADS)

    Thrippleton, Michael J.; Ball, Thomas J.; Wimperis, Stephen

    2008-01-01

    The satellite transitions acquired in real time by magic angle spinning (STARTMAS) NMR experiment combines a train of pulses with sample rotation at the magic angle to refocus the first- and second-order quadrupolar broadening of spin I =3/2 nuclei in a series of echoes, while allowing the isotropic chemical and quadrupolar shifts to evolve. The result is real-time isotropic NMR spectra at high spinning rates using conventional MAS equipment. In this paper we describe in detail how STARTMAS data can be acquired and processed with ease on commercial equipment. We also discuss the advantages and limitations of the approach and illustrate the discussion with numerical simulations and experimental data from four different powdered solids.

  5. Order-selective multiple-quantum excitation in magic-angle spinning NMR: creating triple-quantum coherences with a trilinear Hamiltonian

    NASA Astrophysics Data System (ADS)

    Edén, Mattias

    2002-12-01

    Order-selective multiple-quantum excitation in magic-angle spinning nuclear magnetic resonance is explored using a class of symmetry-based pulse sequences, denoted S Mχ. Simple rules are presented that aid the design of S Mχ schemes with certain desirable effective Hamiltonians. They are applied to construct sequences generating trilinear effective dipolar Hamiltonians, suitable for efficient excitation of triple-quantum coherences in rotating solids. The new sequences are investigated numerically and demonstrated by 1H experiments on adamantane.

  6. Non-destructive methods for food texture assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food texture is important to the successful marketing and profitability of food products. Non-destructive sensing would allow food producers and processors to inspect, sort, grade, or track individual product items, so that they can deliver consistent, superior food products to the marketplace. Over...

  7. Automated Non-Destructive Testing Array Evaluation System

    SciTech Connect

    Wei, T; Zavaljevski, N; Bakhtiari, S; Miron, A; Kupperman, D

    2004-12-24

    Automated Non-Destructive Testing Array Evaluation System (ANTARES) sofeware alogrithms were developed for use on X-probe(tm) data. Data used for algorithm development and preliminary perfomance determination was obtained for USNRC mock-up at Argone and data from EPRI.

  8. 19F Magic angle spinning NMR reporter molecules: empirical measures of surface shielding, polarisability and H-bonding.

    PubMed

    Budarin, Vitaliy L; Clark, James H; Deswarte, Fabien E I; Mueller, Karl T; Tavener, Stewart J

    2007-06-14

    Magic Angle Spinning (MAS) (19)F NMR spectra have been obtained and chemical shifts measured for 37 molecules in the gas phase and adsorbed on the surfaces of six common materials: octadecyl- and octyl-functionalised chromatography silicas, Kieselgel 100 silica, Brockmann neutral alumina, Norit activated charcoal and 3-(1-piperidino)propyl functionalised silica. From these six surfaces, octadecyl-silica is selected as a non-polar reference to which the others are compared. The change in chemical shift of a fluorine nucleus within a molecule on adsorption to a surface from the gas phase, Deltadelta(gas)(surface), is described by the empirical relationship: Deltadelta(gas)(surface) = delta(s) + (alpha(s)+pi(s))/alpha(r) (Deltadelta(gas)(reference) - delta(r)) + delta(HBA) + delta(HBD), where delta(s) and delta(r) are constants that describe the chemical shift induced by the electromagnetic field of the surface under investigation and reference surface, alpha(s) and alpha(r) are the relative surface polarisability for the surface and reference, pi(s) is an additional contribution to the surface polarisabilities due to its ability to interact with aromatic molecules, and delta(HBA) and delta(HBD) are measurements of the hydrogen acceptor and donor properties of the surface. These empirical parameters are measured for the surfaces under study. Silica and alumina are found to undergo specific interactions with aromatic reporter molecules and both accept and donate H-bonds. Activated charcoal was found to have an extreme effect on shielding but no specific interactions with the adsorbed molecules. 3-(1-Piperidino)propyl functionalised silica exhibits H-bond acceptor ability, but does not donate H-bonds. PMID:17487325

  9. Intratumoral Agreement of High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopic Profiles in the Metabolic Characterization of Breast Cancer

    PubMed Central

    Park, Vivian Youngjean; Yoon, Dahye; Koo, Ja Seung; Kim, Eun-Kyung; Kim, Seung Il; Choi, Ji Soo; Park, Seho; Park, Hyung Seok; Kim, Suhkmann; Kim, Min Jung

    2016-01-01

    Abstract High-resolution magic angle spinning (HR-MAS) magnetic resonance (MR) spectroscopy data may serve as a biomarker for breast cancer, with only a small volume of tissue sample required for assessment. However, previous studies utilized only a single tissue sample from each patient. The aim of this study was to investigate whether intratumoral location and biospecimen type affected the metabolic characterization of breast cancer assessed by HR-MAS MR spectroscopy This prospective study was approved by the institutional review board and informed consent was obtained. Preoperative core-needle biopsies (CNBs), central, and peripheral surgical tumor specimens were prospectively collected under ultrasound (US) guidance in 31 patients with invasive breast cancer. Specimens were assessed with HR-MAS MR spectroscopy. The reliability of metabolite concentrations was evaluated and multivariate analysis was performed according to intratumoral location and biospecimen type. There was a moderate or higher agreement between the relative concentrations of 94.3% (33 of 35) of metabolites in the center and periphery, 80.0% (28 of 35) of metabolites in the CNB and central surgical specimens, and 82.9% (29 of 35) of metabolites between all 3 specimen types. However, there was no significant agreement between the concentrations of phosphocholine (PC) and phosphoethanolamine (PE) in the center and periphery. The concentrations of several metabolites (adipate, arginine, fumarate, glutamate, PC, and PE) had no significant agreement between the CNB and central surgical specimens. In conclusion, most HR-MAS MR spectroscopic data do not differ based on intratumoral location or biospecimen type. However, some metabolites may be affected by specimen-related variables, and caution is recommended in decision-making based solely on metabolite concentrations, particularly PC and PE. Further validation through future studies is needed for the clinical implementation of these biomarkers based

  10. The mobility of chondroitin sulfate in articular and artificial cartilage characterized by 13C magic-angle spinning NMR spectroscopy.

    PubMed

    Scheidt, Holger A; Schibur, Stephanie; Magalhães, Alvicler; de Azevedo, Eduardo R; Bonagamba, Tito J; Pascui, Ovidiu; Schulz, Ronny; Reichert, Detlef; Huster, Daniel

    2010-06-01

    We have studied the molecular dynamics of one of the major macromolecules in articular cartilage, chondroitin sulfate. Applying (13)C high-resolution magic-angle spinning NMR techniques, the NMR signals of all rigid macromolecules in cartilage can be suppressed, allowing the exclusive detection of the highly mobile chondroitin sulfate. The technique is also used to detect the chondroitin sulfate in artificial tissue-engineered cartilage. The tissue-engineered material that is based on matrix producing chondrocytes cultured in a collagen gel should provide properties as close as possible to those of the natural cartilage. Nuclear relaxation times of the chondroitin sulfate were determined for both tissues. Although T(1) relaxation times are rather similar, the T(2) relaxation in tissue-engineered cartilage is significantly shorter. This suggests that the motions of chondroitin sulfate in natural and artificial cartilage are different. The nuclear relaxation times of chondroitin sulfate in natural and tissue-engineered cartilage were modeled using a broad distribution function for the motional correlation times. Although the description of the microscopic molecular dynamics of the chondroitin sulfate in natural and artificial cartilage required the identical broad distribution functions for the correlation times of motion, significant differences in the correlation times of motion that are extracted from the model indicate that the artificial tissue does not fully meet the standards of the natural ideal. This could also be confirmed by macroscopic biomechanical elasticity measurements. Nevertheless, these results suggest that NMR is a useful tool for the investigation of the quality of artificially engineered tissue. PMID:20091673

  11. Mineral Carbonation in Wet Supercritical CO2: An in situ High-Pressure Magic Angle Spinning Nuclear Magnetic Resonance Study

    NASA Astrophysics Data System (ADS)

    Turcu, R. V.; Hoyt, D. H.; Sears, J. A.; Rosso, K. M.; Felmy, A. R.; Hu, J. Z.

    2011-12-01

    Understanding the mechanisms and kinetics of mineral carbonation reactions relevant to sequestering carbon dioxide as a supercritical fluid (scCO2) in geologic formations is crucial for accurately predicting long-term storage risks. In situ probes that provide molecular-level information at geologically relevant temperatures and pressures are highly desirable and challenging to develop. Magic angle spinning nuclear magnetic resonance (MAS NMR) is a powerful tool for obtaining detailed molecular structure and dynamics information of a system regardless whether the system is in a solid, a liquid, a gaseous, a supercritical state, or a mixture thereof. However, MAS NMR under scCO2 conditions has never been realized due to the tremendous technical difficulties of achieving and maintaining high pressure within a fast spinning MAS sample rotor. In this work, we report development of a unique high pressure MAS NMR capability capable of handling fluid pressure exceeding 170 bars and temperatures up to 80°C, and its application to mineral carbonation in scCO2 under geologically relevant temperatures and pressures. Mineral carbonation reactions of the magnesium silicate mineral forsterite and the magnesium hydroxide brucite reacted with scCO2 (up to 170 bar) and containing variable content of H2O (at, below, and above saturation in scCO2) were investigated at 50 to 70°C. In situ 13C MAS NMR spectra show peaks corresponding to the reactants, intermediates, and the magnesium carbonation products in a single spectrum. For example, Figure 1 shows the reaction dynamics, i.e., the formation and conversion of reaction intermediates, i.e., HCO3- and nesquehonite, to magnesite as a function of time at 70°C. This capability offers a significant advantage over traditional ex situ 13C MAS experiments on similar systems, where, for example, CO2 and HCO3- are not directly observable.

  12. Magic-angle-spinning NMR on solid biological systems. Analysis Of the origin of the spectral linewidths

    NASA Astrophysics Data System (ADS)

    Hemminga, M. A.; de Jager, P. A.; Krüse, J.; Lamerichs, R. M. J. N.

    Magic-angle-spinning (MAS) high-power 1H-decoupled 13C and 31P NMR has been applied to solid biological materials to obtain information about the mechanisms that determine the spectral linewidths. The line broadening in MAS 31P NMR spectra of solid tobacco mosaic virus (TMV) has been investigated by selective saturation and T2 measurements. About 90 Hz stems from homogeneous effects, whereas the inhomogeneous contribution is approximately 100 Hz. The inhomogeneous line broadening is assigned to macroscopic inhomogeneities in the sample and not to variations in the nucleotide bases along the RNA strand in TMV. It is concluded that sample preparation is of vital importance for obtaining well-resolved spectra. Under optimal preparation techniques the isotropic values of the chemical shift of the different 31P sites have been determined to obtain information about the secondary structure of the viral RNA. The chemical shift anisotropy has been determined from the relative intensities of the spinning side bands in the spectra. The chemical shift information is used to make a tentative assignment of the resonance in terms of the three structurally distinguishable phosphate groups in TMV. The origin of the linewidths in MAS NMR has been examined further by 13C NMR of approximately 10% 13C-enriched coat protein of cowpea chlorotic mottle virus, using selective excitation and saturation techniques, as well as measurements of the relaxation times T1 γ and T2. The CO resonance in the spectrum is composed of an inhomogeneous and homogeneous part with a total linewidth of 700 Hz. The homogeneous linewidth, contributing with 200 Hz, is found to arise from slow molecular motions in the solid on a millisecond timescale.

  13. Metabolic profiling of a Schistosoma mansoni infection in mouse tissues using magic angle spinning-nuclear magnetic resonance spectroscopy.

    PubMed

    Li, Jia V; Holmes, Elaine; Saric, Jasmina; Keiser, Jennifer; Dirnhofer, Stephan; Utzinger, Jürg; Wang, Yulan

    2009-04-01

    In order to enhance our understanding of physiological and pathological consequences of a patent Schistosoma mansoni infection in the mouse, we examined the metabolic responses of different tissue samples recovered from the host animal using a metabolic profiling strategy. Ten female NMRI mice were infected with approximately 80 S. mansoni cercariae each, and 10 uninfected age- and sex-matched animals served as controls. At day 74 post infection (p.i.), mice were killed and jejunum, ileum, colon, liver, spleen and kidney samples were removed. We employed (1)H magic angle spinning-nuclear magnetic resonance spectroscopy to generate tissue-specific metabolic profiles. The spectral data were analyzed using multivariate modelling methods including an orthogonal signal corrected-projection to latent structure analysis and hierarchical principal component analysis to assess the differences and/or similarities in metabolic responses between infected and non-infected control mice. Most tissues obtained from S. mansoni-infected mice were characterized by high levels of amino acids, such as leucine, isoleucine, lysine, glutamine and asparagine. High levels of membrane phospholipid metabolites, including glycerophosphoryl choline and phosphoryl choline were found in the ileum, colon, liver and spleen of infected mice. Additionally, low levels of energy-related metabolites, including lipids, glucose and glycogen were observed in ileum, spleen and liver samples of infected mice. Energy-related metabolites in the jejunum, liver and renal medulla were found to be positively correlated with S. mansoni worm burden upon dissection. These findings show that a patent S. mansoni infection causes clear disruption of metabolism in a range of tissues at a molecular level, which can be interpreted in relation to the previously reported signature in a biofluid (i.e. urine), giving further evidence of the global effect of the infection. PMID:19068218

  14. Distortional binding of transition state analogs to human purine nucleoside phosphorylase probed by magic angle spinning solid-state NMR.

    PubMed

    Vetticatt, Mathew J; Itin, Boris; Evans, Gary B; Schramm, Vern L

    2013-10-01

    Transition state analogs mimic the geometry and electronics of the transition state of enzymatic reactions. These molecules bind to the active site of the enzyme much tighter than substrate and are powerful noncovalent inhibitors. Immucillin-H (ImmH) and 4'-deaza-1'-aza-2'-deoxy-9-methylene Immucillin-H (DADMe-ImmH) are picomolar inhibitors of human purine nucleoside phosphorylase (hPNP). Although both molecules are electronically similar to the oxocarbenium-like dissociative hPNP transition state, DADMe-ImmH is more potent than ImmH. DADMe-ImmH captures more of the transition state binding energy by virtue of being a closer geometric match to the hPNP transition state than ImmH. A consequence of these similarities is that the active site of hPNP exerts greater distortional forces on ImmH than on DADMe-ImmH to "achieve" the hPNP transition state geometry. By using magic angle spinning solid-state NMR to investigate stable isotope-labeled ImmH and DADMe-ImmH, we have explored the difference in distortional binding of these two inhibitors to hPNP. High-precision determinations of internuclear distances from NMR recoupling techniques, rotational echo double resonance, and rotational resonance, have provided unprecedented atomistic insight into the geometric changes that occur upon binding of transition state analogs. We conclude that hPNP stabilizes conformations of these chemically distinct analogs having distances between the cation and leaving groups resembling those of the known transition state. PMID:24043827

  15. Live-cell high resolution magic angle spinning magnetic resonance spectroscopy for in vivo analysis of Pseudomonas aeruginosa metabolomics.

    PubMed

    Righi, Valeria; Constantinou, Caterina; Kesarwani, Meenu; Rahme, Laurence G; Tzika, Aria A

    2013-09-01

    Pseudomonas aeruginosa (PA) is a pathogenic gram-negative bacterium that is widespread in nature, inhabiting soil, water, plants and animals. PA is a prevalent cause of deleterious human infections, particularly in patients whose host defense mechanisms have been compromised. Metabolomics is an important tool used to study host-pathogen interactions and to identify novel therapeutic targets and corresponding compounds. The aim of the present study was to report the metabolic profile of live PA bacteria using in vivo high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance spectroscopy (NMR), in combination with 1- and 2-dimensional HRMAS NMR. This methodology provides a new and powerful technique to rapidly interrogate the metabolome of intact bacterial cells and has several advantages over traditional techniques that identify metabolome components from disrupted cells. Furthermore, application of multidimensional HRMAS NMR, in combination with the novel technique total through-Bond correlation Spectroscopy (TOBSY), is a promising approach that may be used to obtain in vivo metabolomics information from intact live bacterial cells and can mediate such analyses in a short period of time. Moreover, HRMAS (1)H NMR enables the investigation of the associations between metabolites and cell processes. In the present study, we detected and quantified several informative metabolic molecules in live PA cells, including N-acetyl, betaine, citrulline, alanine and glycine, which are important in peptidoglycan synthesis. The results provided a complete metabolic profile of PA for future studies of PA clinical isolates and mutants. In addition, this in vivo NMR biomedical approach might have clinical utility and should prove useful in gene function validation, the study of pathogenetic mechanisms, the classification of microbial strains into functional/clinical groups, the testing of anti-bacterial agents and the determination of metabolic profiles of bacterial

  16. Characterization of metabolites in infiltrating gliomas using ex vivo ¹H high-resolution magic angle spinning spectroscopy.

    PubMed

    Elkhaled, Adam; Jalbert, Llewellyn; Constantin, Alexandra; Yoshihara, Hikari A I; Phillips, Joanna J; Molinaro, Annette M; Chang, Susan M; Nelson, Sarah J

    2014-05-01

    Gliomas are routinely graded according to histopathological criteria established by the World Health Organization. Although this classification can be used to understand some of the variance in the clinical outcome of patients, there is still substantial heterogeneity within and between lesions of the same grade. This study evaluated image-guided tissue samples acquired from a large cohort of patients presenting with either new or recurrent gliomas of grades II-IV using ex vivo proton high-resolution magic angle spinning spectroscopy. The quantification of metabolite levels revealed several discrete profiles associated with primary glioma subtypes, as well as secondary subtypes that had undergone transformation to a higher grade at the time of recurrence. Statistical modeling further demonstrated that these metabolomic profiles could be differentially classified with respect to pathological grading and inter-grade conversions. Importantly, the myo-inositol to total choline index allowed for a separation of recurrent low-grade gliomas on different pathological trajectories, the heightened ratio of phosphocholine to glycerophosphocholine uniformly characterized several forms of glioblastoma multiforme, and the onco-metabolite D-2-hydroxyglutarate was shown to help distinguish secondary from primary grade IV glioma, as well as grade II and III from grade IV glioma. These data provide evidence that metabolite levels are of interest in the assessment of both intra-grade and intra-lesional malignancy. Such information could be used to enhance the diagnostic specificity of in vivo spectroscopy and to aid in the selection of the most appropriate therapy for individual patients. PMID:24596146

  17. Application of High-Resolution Magic-Angle Spinning NMR Spectroscopy to Define the Cell Uptake of MRI Contrast Agents

    NASA Astrophysics Data System (ADS)

    Calabi, Luisella; Alfieri, Goffredo; Biondi, Luca; De Miranda, Mario; Paleari, Lino; Ghelli, Stefano

    2002-06-01

    A new method, based on proton high-resolution magic-angle spinning ( 1H HR-MAS) NMR spectroscopy, has been employed to study the cell uptake of magnetic resonance imaging contrast agents (MRI-CAs). The method was tested on human red blood cells (HRBC) and white blood cells (HWBC) by using three gadolinium complexes, widely used in diagnostics, Gd-BOPTA, Gd-DTPA, and Gd-DOTA, and the analogous complexes obtained by replacing Gd(III) with Dy(III), Nd(III), and Tb(III) (i.e., complexes isostructural to the ones of gadolinium but acting as shift agents). The method is based on the evaluation of the magnetic effects, line broadening, or induced lanthanide shift (LIS) caused by these complexes on NMR signals of intra- and extracellular water. Since magnetic effects are directly linked to permeability, this method is direct. In all the tests, these magnetic effects were detected for the extracellular water signal only, providing a direct proof that these complexes are not able to cross the cell membrane. Line broadening effects (i.e., the use of gadolinium complexes) only allow qualitative evaluations. On the contrary, LIS effects can be measured with high precision and they can be related to the concentration of the paramagnetic species in the cellular compartments. This is possible because the HR-MAS technique provides the complete elimination of bulk magnetic susceptibility (BMS) shift and the differentiation of extra- and intracellular water signals. Thus with this method, the rapid quantification of the MRI-CA amount inside and outside the cells is actually feasible.

  18. Magic-Angle Spinning Solid-State NMR Spectroscopy of Nanodisc– Embedded Human CYP3A4†

    PubMed Central

    Kijac, Aleksandra; Li, Ying; Sligar, Stephen G.; Rienstra, Chad M.

    2008-01-01

    Cytochrome P450 (CYP) 3A4 contributes to the metabolism of approximately 50% of commercial drugs by oxidizing a large number of structurally diverse substrates. Like other endoplasmic reticulum-localized P450s, CYP3A4 contains a membrane-anchoring N-terminal helix and a significant number of hydrophobic domains, important for the interaction between CYP3A4 and the membrane. Although the membrane affects specificity of CYP3A4 ligand binding, the structural details of the interaction have not been revealed so far because x-ray crystallography studies are available only for the soluble domain of CYP3A4. Here we report sample preparation and initial magic-angle spinning (MAS) solid-state NMR (SSNMR) of CYP3A4 (Δ3−12) embedded in a nanoscale membrane bilayer, or Nanodisc. The growth protocol yields ∼2.5 mg of the enzymatically active, uniformly 13C, 15N-enriched CYP3A4 from a liter of growth medium. Polyethylene glycol 3350-precipitated CYP3A4 in Nanodiscs yields spectra of high resolution and sensitivity, consistent with a folded, homogeneous protein. CYP3A4 in Nanodiscs remains enzymatically active throughout the precipitation protocol as monitored by bromocriptine binding. The 13C line widths measured from 13C-13C 2D chemical shift correlation spectra are ∼0.5 ppm. The secondary structure distribution within several amino acid types determined from 13C chemical shifts is consistent with the ligand-free x-ray structures. These results demonstrate that MAS SSNMR can be performed on Nanodisc-embedded membrane proteins in a folded, active state. The combination of SSNMR and Nanodisc methodologies opens up new possibilities for obtaining structural information on CYP3A4 and other integral membrane proteins with full retention of functionality. PMID:17985934

  19. High-resolution paramagnetically enhanced solid-state NMR spectroscopy of membrane proteins at fast magic angle spinning.

    PubMed

    Ward, Meaghan E; Wang, Shenlin; Krishnamurthy, Sridevi; Hutchins, Howard; Fey, Michael; Brown, Leonid S; Ladizhansky, Vladimir

    2014-01-01

    Magic angle spinning nuclear magnetic resonance (MAS NMR) is well suited for the study of membrane proteins in membrane mimetic and native membrane environments. These experiments often suffer from low sensitivity, due in part to the long recycle delays required for magnetization and probe recovery, as well as detection of low gamma nuclei. In ultrafast MAS experiments sensitivity can be enhanced through the use of low power sequences combined with paramagnetically enhanced relaxation times to reduce recycle delays, as well as proton detected experiments. In this work we investigate the sensitivity of (13)C and (1)H detected experiments applied to 27 kDa membrane proteins reconstituted in lipids and packed in small 1.3 mm MAS NMR rotors. We demonstrate that spin diffusion is sufficient to uniformly distribute paramagnetic relaxation enhancement provided by either covalently bound or dissolved CuEDTA over 7TM alpha helical membrane proteins. Using paramagnetic enhancement and low power decoupling in carbon detected experiments we can recycle experiments ~13 times faster than under traditional conditions. However, due to the small sample volume the overall sensitivity per unit time is still lower than that seen in the 3.2 mm probe. Proton detected experiments, however, showed increased efficiency and it was found that the 1.3 mm probe could achieve sensitivity comparable to that of the 3.2 mm in a given amount of time. This is an attractive prospect for samples of limited quantity, as this allows for a reduction in the amount of protein that needs to be produced without the necessity for increased experimental time. PMID:24338448

  20. Powder-XRD and (14) N magic angle-spinning solid-state NMR spectroscopy of some metal nitrides.

    PubMed

    Kempgens, Pierre; Britton, Jonathan

    2016-05-01

    Some metal nitrides (TiN, ZrN, InN, GaN, Ca3 N2 , Mg3 N2 , and Ge3 N4 ) have been studied by powder X-ray diffraction (XRD) and (14) N magic angle-spinning (MAS) solid-state NMR spectroscopy. For Ca3 N2 , Mg3 N2 , and Ge3 N4 , no (14) N NMR signal was observed. Low speed (νr  = 2 kHz for TiN, ZrN, and GaN; νr  = 1 kHz for InN) and 'high speed' (νr  = 15 kHz for TiN; νr  = 5 kHz for ZrN; νr  = 10 kHz for InN and GaN) MAS NMR experiments were performed. For TiN, ZrN, InN, and GaN, powder-XRD was used to identify the phases present in each sample. The number of peaks observed for each sample in their (14) N MAS solid-state NMR spectrum matches perfectly well with the number of nitrogen-containing phases identified by powder-XRD. The (14) N MAS solid-state NMR spectra are symmetric and dominated by the quadrupolar interaction. The envelopes of the spinning sidebands manifold are Lorentzian, and it is concluded that there is a distribution of the quadrupolar coupling constants Qcc 's arising from structural defects in the compounds studied. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26687421

  1. Non-destructive examination system of vitreous body

    NASA Astrophysics Data System (ADS)

    Shibata, Takuma; Gong, Jin; Watanabe, Yosuke; Kabir, M. Hasnat; Masato, Makino; Furukawa, Hidemitsu; Nishitsuka, Koichi

    2014-04-01

    Eyeball plays a quite important role in acquiring the vision. Vitreous body occupies the largest part of the eyeball and consists of biological, elastic, transparent, gel materials. In the present medical examination, the non-destructive examination method of the vitreous body has not been well established. Here, we focus on an application of dynamic light scattering to this topic. We tried to apply our lab-made apparatus, scanning microscopic light scattering (SMILS), which was specially designed for observing the nanometer-scale network structure in gel materials. In order to examine the vitreous body using SMILS method, a commercial apparatus, nano Partica (Horiba Co. Ltd.) was also customized. We analyzed vitreous body using both the SMILS and the customized nano Partica. We successfully examined the vitreous bodies of healthy pigs in non-destructive way.

  2. Non-Destructive Techniques Based on Eddy Current Testing

    PubMed Central

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  3. Infrared Thermography for Temperature Measurement and Non-Destructive Testing

    PubMed Central

    Usamentiaga, Rubèn; Venegas, Pablo; Guerediaga, Jon; Vega, Laura; Molleda, Julio; Bulnes, Francisco G.

    2014-01-01

    The intensity of the infrared radiation emitted by objects is mainly a function of their temperature. In infrared thermography, this feature is used for multiple purposes: as a health indicator in medical applications, as a sign of malfunction in mechanical and electrical maintenance or as an indicator of heat loss in buildings. This paper presents a review of infrared thermography especially focused on two applications: temperature measurement and non-destructive testing, two of the main fields where infrared thermography-based sensors are used. A general introduction to infrared thermography and the common procedures for temperature measurement and non-destructive testing are presented. Furthermore, developments in these fields and recent advances are reviewed. PMID:25014096

  4. Non-destructive NIR FT Raman analysis of plants

    NASA Astrophysics Data System (ADS)

    Schrader, B.; Klump, H. H.; Schenzel, K.; Schulz, H.

    1999-10-01

    Non-destructive analyses of animal and plant cells and tissues by 'classical' Raman spectroscopy with excitation in the visible range have not been possible since the samples are destroyed photochemically or their fluorescence conceals the Raman spectra completely. When excited with the Nd:YAG laser line at 1064 nm fluorescence-free Raman spectra of animal or plant cells and tissues can be recorded without special preparation. In this paper we concentrate on plants and its constituents: essential oils, natural dyes, flavors, spices, alkaloids and fibers can be characterized. The spectra allow the observation of biochemical processes, to observe the distribution of natural products, application to taxonomy, optimizing plant breeding, the harvesting time and control of food—everything non-destructively in living plants!

  5. Non-destructive techniques based on eddy current testing.

    PubMed

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  6. Mathematical models applied in inductive non-destructive testing

    NASA Astrophysics Data System (ADS)

    Wac-Wlodarczyk, A.; Goleman, R.; Czerwinski, D.; Gizewski, T.

    Non-destructive testing are the wide group of investigative methods of non-homogenous material. Methods of computer tomography, ultrasonic, magnetic and inductive methods still developed are widely applied in industry. In apparatus used for non-destructive tests, the analysis of signals is made on the basis of complex system answers. The answer is linearized due to the model of research system. In this paper, the authors will discuss the applications of the mathematical models applied in investigations of inductive magnetic materials. The statistical models and other gathered in similarity classes will be taken into consideration. Investigation of mathematical models allows to choose the correct method, which in consequence leads to precise representation of the inner structure of examined object. Inductive research of conductive media, especially those with ferromagnetic properties, are run with high frequency magnetic field (eddy-currents method), which considerably decrease penetration depth.

  7. Non-destructive metallurgical analysis of astrolabes utilizing synchrotron radiation.

    SciTech Connect

    Newbury, B.; Stephenson, B.; Almer, J. D.; Notis, M.; Haeffner, D. R.; Slade Cargill, G., III

    2002-05-22

    From the experiments performed it is possible to determine a wide range of information about the metallurgy of the astrolabes studied. It was found that different brass alloys were used for components that were cast and those that were mechanically deformed. Chemical composition, forming history, and thickness measurements are all determined non-destructively, illustrating that this technique could be useful for many applications with metal artifact analysis where non-intrusive methods are required.

  8. Non-Destructive Testing for Control of Radioactive Waste Package

    NASA Astrophysics Data System (ADS)

    Plumeri, S.; Carrel, F.

    2015-10-01

    Characterization and control of radioactive waste packages are important issues in the management of a radioactive waste repository. Therefore, Andra performs quality control inspection on radwaste package before disposal to ensure the compliance of the radwast characteristics with Andra waste disposal specifications and to check the consistency between Andra measurements results and producer declared properties. Objectives of this quality control are: assessment and improvement of producer radwaste packages quality mastery, guarantee of the radwaste disposal safety, maintain of the public confidence. To control radiological characteristics of radwaste package, non-destructive passive methods (gamma spectrometry and neutrons counting) are commonly used. These passive methods may not be sufficient, for instance to control the mass of fissile material contained inside radwaste package. This is particularly true for large concrete hull of heterogeneous radwaste containing several actinides mixed with fission products like 137Cs. Non-destructive active methods, like measurement of photofission delayed neutrons, allow to quantify the global mass of actinides and is a promising method to quantify mass of fissile material. Andra has performed different non-destructive measurements on concrete intermediate-level short lived nuclear waste (ILW-SL) package to control its nuclear material content. These tests have allowed Andra to have a first evaluation of the performance of photofission delayed neutron measurement and to identify development needed to have a reliable method, especially for fissile material mass control in intermediate-level long lived waste package.

  9. Sensitivity and resolution enhanced solid-state NMR for paramagnetic systems and biomolecules under very fast magic angle spinning.

    PubMed

    Parthasarathy, Sudhakar; Nishiyama, Yusuke; Ishii, Yoshitaka

    2013-09-17

    Recent research in fast magic angle spinning (MAS) methods has drastically improved the resolution and sensitivity of NMR spectroscopy of biomolecules and materials in solids. In this Account, we summarize recent and ongoing developments in this area by presenting (13)C and (1)H solid-state NMR (SSNMR) studies on paramagnetic systems and biomolecules under fast MAS from our laboratories. First, we describe how very fast MAS (VFMAS) at the spinning speed of at least 20 kHz allows us to overcome major difficulties in (1)H and (13)C high-resolution SSNMR of paramagnetic systems. As a result, we can enhance both sensitivity and resolution by up to a few orders of magnitude. Using fast recycling (∼ms/scan) with short (1)H T1 values, we can perform (1)H SSNMR microanalysis of paramagnetic systems on the microgram scale with greatly improved sensitivity over that observed for diamagnetic systems. Second, we discuss how VFMAS at a spinning speed greater than ∼40 kHz can enhance the sensitivity and resolution of (13)C biomolecular SSNMR measurements. Low-power (1)H decoupling schemes under VFMAS offer excellent spectral resolution for (13)C SSNMR by nominal (1)H RF irradiation at ∼10 kHz. By combining the VFMAS approach with enhanced (1)H T1 relaxation by paramagnetic doping, we can achieve extremely fast recycling in modern biomolecular SSNMR experiments. Experiments with (13)C-labeled ubiquitin doped with 10 mM Cu-EDTA demonstrate how effectively this new approach, called paramagnetic assisted condensed data collection (PACC), enhances the sensitivity. Lastly, we examine (13)C SSNMR measurements for biomolecules under faster MAS at a higher field. Our preliminary (13)C SSNMR data of Aβ amyloid fibrils and GB1 microcrystals acquired at (1)H NMR frequencies of 750-800 MHz suggest that the combined use of the PACC approach and ultrahigh fields could allow for routine multidimensional SSNMR analyses of proteins at the 50-200 nmol level. Also, we briefly discuss the

  10. Spin dynamics in the modulation frame: application to homonuclear recoupling in magic angle spinning solid-state NMR.

    PubMed

    De Paëpe, Gaël; Lewandowski, Józef R; Griffin, Robert G

    2008-03-28

    We introduce a family of solid-state NMR pulse sequences that generalizes the concept of second averaging in the modulation frame and therefore provides a new approach to perform magic angle spinning dipolar recoupling experiments. Here, we focus on two particular recoupling mechanisms-cosine modulated rotary resonance (CMpRR) and cosine modulated recoupling with isotropic chemical shift reintroduction (COMICS). The first technique, CMpRR, is based on a cosine modulation of the rf phase and yields broadband double-quantum (DQ) (13)C recoupling using >70 kHz omega(1,C)/2pi rf field for the spinning frequency omega(r)/2=10-30 kHz and (1)H Larmor frequency omega(0,H)/2pi up to 900 MHz. Importantly, for p>or=5, CMpRR recouples efficiently in the absence of (1)H decoupling. Extension to lower p values (3.5

  11. Non-destructive electrical characterization of controlled Waspaloy microstructures

    NASA Astrophysics Data System (ADS)

    G. Kelekanjeri, V. Siva Kumar

    In this research, controlled Waspaloy microstructures are produced with the objective of studying microstructural evolution in this alloy via non-destructive electrical measurements. Waspaloy is a precipitation-hardenable gamma-gamma' nickel-base superalloy that is used in turbine blade applications demanding superior strength retention capabilities at elevated temperatures. Overall, three different sets of microstructures were produced that varied systematically as a function of the matrix (gamma) grain size and gamma' precipitate size distribution or just the latter. Initial solutionizing treatments conducted at 1045°C, 1090°C and 1145°C resulted in average y grain size of 13, 52 and 89 mum respectively. A vacancy stabilization treatment at 1045°C followed the solutionizing treatments in Set I experiments, after which the specimens were aged at 800°C for durations ranging from 0.1 hrs to 100 hrs. In Sets 11 and III, the matrix grain size was kept unchanged by an initial solution-treatment at 1145°C. The stabilization treatment at 1045°C was only conducted in Set II after the solution-treatment. Aging experiments were then conducted at 700°C (or 725°C in Set III), 800°C and 875°C to study the growth kinetics of gamma' precipitate distribution. The specimens with controlled microstructures were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), x-ray diffraction (XRD), ultra small-angle x-ray scattering (USAXS) and dc four-point probe resistivity. The applicability of two and four-probe ac impedance techniques was also investigated. Characterization of heat-treated specimens. Solution-treated SEM microstructures showed the presence of polygonal etch-pit shapes, which was proposed to be due to the condensation of excess quenched-in vacancies along crystallographically soft-directions in the gamma phase. The etch-pits evolved upon subsequent aging into progressively irregular shapes, concurrent with gamma' growth inside

  12. Investigations and Non-destructive Testing in New Building Design

    NASA Astrophysics Data System (ADS)

    Klimenov, V.; Ovchinnikov, A.; Osipov, S.; Shtein, A.; Ustinov, A.; Danilson, A.

    2016-01-01

    Mechanical rebar couplers are preferable in the advanced building construction and structural design of antiseismic elements. The paper presents destructive inspection techniques used to investigate stress fields (tensile and compressive) and deformation curves for mechanical rebar splicing. The properties of mechanical rebar splicing are investigated by the non-destructive testing digital radiography. The behavior of real connections (column-to- column, beam-to-column) is studied under static and dynamic loads. Investigation results allow the elaboration of recommendations on their application in the universal prefabricated antiseismic structural system developed at Tomsk State University of Architecture and Building, Tomsk, Russia.

  13. Potential techniques for non-destructive evaluation of cable materials

    NASA Astrophysics Data System (ADS)

    Gillen, Kenneth T.; Clough, Roger L.; Mattson, Bengt; Stenberg, Bengt; Oestman, Erik

    This paper describes the connection between mechanical degradation of common cable materials, in radiation and elevated temperature environments, and density increases caused by the oxidation which leads to this degradation. Two techniques based on density changes are suggested as potential non-destructive evaluation (NDE) procedures which may be applicable to monitoring the mechanical condition of cable materials in power plant environments. The first technique is direct measurement of density changes, via a density gradient column, using small shavings removed from the surface of cable jackets at selected locations. The second technique is computed X-ray tomography, utilizing a portable scanning device.

  14. APPARATUS FOR NON-DESTRUCTIVE INSPECTION OF CANTILEVERED MEMBERS

    DOEpatents

    Taylor, E.R.; Mahoney, C.H.; Lay, C.R.

    1961-10-24

    An apparatus for non-destructive inspection of cantilevered members, such as compressor blades, is described. The member under inspection is vibrated with a regulated source of air under pressure. The amplitude of vibration of the member is maintained at its natural frequency. The frequency of vibration of the member is measured. An indication of an excessive decay or erratic shifting in the measured frequency above an allowable hysteretic decay is provided as an indication of a fault in the member. The member is vibrated for a selected test period. (AEC)

  15. Non-destructive characterization using pulsed fast-thermal neutrons

    NASA Astrophysics Data System (ADS)

    Womble, P. C.; Schultz, F. J.; Vourvopoulos, G.

    1995-05-01

    Explosives, illicit drugs, and other contraband materials contain various chemical elements in quantities and ratios that differentiate them from each other and from innocuous substances. Furthermore, the major chemical elements in coal can provide information about various parameters of importance to the coal industry. In both examples, the non-destructive identification of chemical elements can be performed using pulsed fast-thermal neutrons that, through nuclear reactions, excite the nuclei of the various elements. This technique is being currently developed for the dismantling of nuclear weapons classified as trainers, and for the on-line coal bulk analysis.

  16. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins.

    PubMed

    Sharma, Kshama; Madhu, Perunthiruthy K; Mote, Kaustubh R

    2016-08-01

    One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text]  can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping. PMID:27364976

  17. Unexpected effects of third-order cross-terms in heteronuclear spin systems under simultaneous radio-frequency irradiation and magic-angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Tatton, Andrew S.; Frantsuzov, Ilya; Brown, Steven P.; Hodgkinson, Paul

    2012-02-01

    We recently noted [R. K. Harris, P. Hodgkinson, V. Zorin, J.-N. Dumez, B. Elena, L. Emsley, E. Salager, and R. Stein, Magn. Reson. Chem. 48, S103 (2010), 10.1002/mrc.2636] anomalous shifts in apparent 1H chemical shifts in experiments using 1H homonuclear decoupling sequences to acquire high-resolution 1H NMR spectra for organic solids under magic-angle spinning (MAS). Analogous effects were also observed in numerical simulations of model 13C,1H spin systems under homonuclear decoupling and involving large 13C,1H dipolar couplings. While the heteronuclear coupling is generally assumed to be efficiently suppressed by sample spinning at the magic angle, we show that under conditions typically used in solid-state NMR, there is a significant third-order cross-term from this coupling under the conditions of simultaneous MAS and homonuclear decoupling for spins directly bonded to 1H. This term, which is of the order of 100 Hz under typical conditions, explains the anomalous behaviour observed on both 1H and 13C spins, including the fast dephasing observed in 13C{1H} heteronuclear spin-echo experiments under 1H homonuclear decoupling. Strategies for minimising the impact of this effect are also discussed.

  18. Slow magic-angle rotation 13C NMR studies of solid phosphonium iodides. The interplay of dipolar, shielding, and indirect coupling tensors

    NASA Astrophysics Data System (ADS)

    Harris, Robin K.; Packer, Kenneth J.; Thayer, Ann M.

    High-resolution 13C NMR spectra were recorded for solid [Me 2Ph 2P] +I - and [Me 3PhP] +I - using high-power decoupling, cross-polarization, and magic-angle rotation. Spectra of the ipso carbon, obtained with the nonquaternary suppression (dipolar dephasing) pulse sequence, show an unequal distribution intensity of spinning sidebands for the two peaks split by the isotropic coupling constant 1JPC. This effect is traced to the joint influence of (P, C) dipolar coupling and 13C shielding anisotropy. The existence of scalar coupling enables magic-angle rotation to distinguish the two subspectra which are present. Analysis of the sideband patterns yields values of the NMR parameters. Under certain assumptions, including that the axis of greatest shielding is perpendicular to the PC bond, it is shown that 1JPC is positive. In contrast to traditional methods of determining signs, this conclusion does not rely on knowledge of signs of other coupling constants.

  19. Non destructive testing of works of art by terahertz analysis

    NASA Astrophysics Data System (ADS)

    Bodnar, Jean-Luc; Metayer, Jean-Jacques; Mouhoubi, Kamel; Detalle, Vincent

    2013-11-01

    Improvements in technologies and the growing security needs in airport terminals lead to the development of non destructive testing devices using terahertz waves. Indeed, these waves have the advantage of being, on one hand, relatively penetrating. They also have the asset of not being ionizing. It is thus potentially an interesting contribution in the non destructive testing field. With the help of the VISIOM Company, the possibilities of this new industrial analysis method in assisting the restoration of works of art were then approached. The results obtained within this framework are presented here and compared with those obtained by infrared thermography. The results obtained show first that the THZ method, like the stimulated infrared thermography allows the detection of delamination located in murals paintings or in marquetries. They show then that the THZ method seems to allow detecting defects located relatively deeply (10 mm) and defects potentially concealed by other defects. It is an advantage compared to the stimulated infra-red thermography which does not make it possible to obtain these results. Furthermore, they show that the method does not seem sensitive to the various pigments constituting the pictorial layer, to the presence of a layer of "Japan paper" and to the presence of a layer of whitewash. It is not the case of the stimulated infrared thermography. It is another advantage of the THZ method. Finally, they show that the THZ method is limited in the detection of low-size defects. It is a disadvantage compared to the stimulated infrared thermography.

  20. Local defect resonance for sensitive non-destructive testing

    NASA Astrophysics Data System (ADS)

    Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

    2016-02-01

    Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

  1. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI.

    PubMed

    Yesinowski, James P; Ladouceur, Harold D; Purdy, Andrew P; Miller, Joel B

    2010-12-21

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves (63)Cu, (65)Cu, and (127)I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu(+)-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the (207)Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu(+) vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the (63)Cu and (127)I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for (63)Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by

  2. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI

    NASA Astrophysics Data System (ADS)

    Yesinowski, James P.; Ladouceur, Harold D.; Purdy, Andrew P.; Miller, Joel B.

    2010-12-01

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves 63Cu, 65Cu, and 127I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu+-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the 207Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu+ vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the 63Cu and 127I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for 63Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by rotating a

  3. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    SciTech Connect

    B.Mi; X. Zhao; R. Bayles

    2006-05-26

    Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

  4. Non-destructive Raman analyses - polyacetylenes in plants

    NASA Astrophysics Data System (ADS)

    Schrader, Bernhard; Schulz, Hartwig; Baranska, Malgorzata; Andreev, George N.; Lehner, Caroline; Sawatzki, Juergen

    2005-05-01

    Ferdinand Bohlmann has described the isolation, the identification and the structure elucidation of acetylene compounds in many plants, and confirmed it by its synthesis. We have recorded the Raman spectra of most of these plants non-destructively by FT-Raman spectroscopy using radiation at 1064 nm. We could not observe any interfering fluorescence. We found acetylene compounds in some plants, even distinct compounds with different concentration in various parts of it. The distribution of the different compounds over the plant can be observed and their changes during the ontogenesis can be followed by a FT-Raman mapping technique. Of special help is a library of Raman and IR spectra and the structure of the compounds, synthesized by Bohlmann. Thus, the Raman technique allows analyses in a very short time replacing the usual time-consuming separation procedures and avoiding artefacts during clean-up procedures.

  5. Electromagnetic non-destructive technique for duplex stainless steel characterization

    NASA Astrophysics Data System (ADS)

    Rocha, João Vicente; Camerini, Cesar; Pereira, Gabriela

    2016-02-01

    Duplex stainless steel (DSS) is a two-phase (ferrite and austenite) material, which exhibits an attractive combination of mechanical properties and high corrosion resistance, being commonly employed for equipment of petrochemical plants, refining units and oil & gas platforms. The best properties of DSS are achieved when the phases are in equal proportions. However, exposition to high temperatures (e.g. welding process) may entail undesired consequences, such as deleterious phases precipitation (e.g. sigma, chi) and different proportion of the original phases, impairing dramatically the mechanical and corrosion properties of the material. A detailed study of the magnetic behavior of DSS microstructure with different ferrite austenite ratios and deleterious phases content was accomplished. The non destructive method evaluates the electromagnetic properties changes in the material and is capable to identify the presence of deleterious phases into DSS microstructure.

  6. Non-destructive evaluation method employing dielectric electrostatic ultrasonic transducers

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    2003-01-01

    An acoustic nonlinearity parameter (.beta.) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members novelly employs a loosely mounted dielectric electrostatic ultrasonic transducer (DEUT) to receive and convert ultrasonic energy into an electrical signal which can be analyzed to determine the .beta. of the test material. The dielectric material is ferroelectric with a high dielectric constant .di-elect cons.. A computer-controlled measurement system coupled to the DEUT contains an excitation signal generator section and a measurement and analysis section. As a result, the DEUT measures the absolute particle displacement amplitudes in test material, leading to derivation of the nonlinearity parameter (.beta.) without the costly, low field reliability methods of the prior art.

  7. Non-Destructive Classification Approaches for Equilbrated Ordinary Chondrites

    NASA Technical Reports Server (NTRS)

    Righter, K.; Harrington, R.; Schroeder, C.; Morris, R. V.

    2013-01-01

    Classification of meteorites is most effectively carried out by petrographic and mineralogic studies of thin sections, but a rapid and accurate classification technique for the many samples collected in dense collection areas (hot and cold deserts) is of great interest. Oil immersion techniques have been used to classify a large proportion of the US Antarctic meteorite collections since the mid-1980s [1]. This approach has allowed rapid characterization of thousands of samples over time, but nonetheless utilizes a piece of the sample that has been ground to grains or a powder. In order to compare a few non-destructive techniques with the standard approaches, we have characterized a group of chondrites from the Larkman Nunatak region using magnetic susceptibility and Moessbauer spectroscopy.

  8. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    NASA Astrophysics Data System (ADS)

    Gajdacz, Miroslav; Pedersen, Poul L.; Mørch, Troels; Hilliard, Andrew J.; Arlt, Jan; Sherson, Jacob F.

    2013-08-01

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration, to demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. This demonstrates that the method is a useful tool for the characterization of static and dynamically changing properties of ultracold atomic clouds.

  9. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    NASA Astrophysics Data System (ADS)

    Gajdacz, Miroslav; Pedersen, Poul; Mørch, Troels; Hilliard, Andrew; Arlt, Jan; Sherson, Jacob

    2013-05-01

    We investigate non-destructive measurements of ultra-cold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. In particular, we pursue applications to dynamically controlled ultracold atoms. The dependence of the Faraday signal on laser detuning, atomic density and temperature is characterized in a detailed comparison with theory. In particular the destructivity per measurement is extremely low and we illustrate this by imaging the same cloud up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration. Adding dynamic changes to system parameters, we demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. The method can be implemented particularly easily in standard imaging systems by the insertion of an extra polarizing beam splitter. These results are steps towards quantum state engineering using feedback control of ultracold atoms.

  10. Non-destructive Faraday imaging of dynamically controlled ultracold atoms.

    PubMed

    Gajdacz, Miroslav; Pedersen, Poul L; Mørch, Troels; Hilliard, Andrew J; Arlt, Jan; Sherson, Jacob F

    2013-08-01

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration, to demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. This demonstrates that the method is a useful tool for the characterization of static and dynamically changing properties of ultracold atomic clouds. PMID:24007051

  11. EVALUATION OF TRANSPORTATION OPTIONS FOR INTERMEDIATE NON DESTRUCTIVE EXAMINATIONS

    SciTech Connect

    Case, Susan; Hoggard, Gary

    2014-07-01

    Idaho National Laboratory (INL) shipments of irradiated experiments from the Advanced Test Reactor (ATR) to the Hot Fuels Examination Facility (HFEF) have historically been accomplished using the General Electric Model 2000 (GE 2000) Type B shipping container. Battelle Energy Alliance (BEA) concerns regarding the future availability and leasing and handling costs associated with the GE 2000 cask have warranted an evaluation of alternative shipping options. One or more of these shipping options may be utilized to perform non destructive examinations (NDE) such as neutron radiography and precision gamma scans of irradiated experiments at HFEF and then return the experiments to ATR for further irradiation, hereafter referred to as “intermediate NDE.”

  12. Induction thermography for non-destructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Balaji, L.; Balasubramaniam, Krishnan; Krishnamurthy, C. V.

    2013-01-01

    Adhesive bonding is widely used in automotive industry in the recent times. One of the major problems with adhesive bonds is the lack of a suitable non-destructive evaluation technique for assessing bonding. In this paper, an experimental study was carried out to apply induction thermography technique to evaluate adhesively bonded steel plates. Samples were fabricated with artificial defects such as air gap, foreign material, and improper adhesive filling. Induction thermography technique was found to detect defects and foreign inclusions. The sample specimen was also inspected using standard techniques such as Ultrasonic testing and Radiography testing. Defect detecting capabilities of the three techniques are compared. Induction thermography heating was FE modelled in 3D using COMSOL 3.5a. The simulated Induction thermography model was compared and validated with experimental results.

  13. Crocus sativus Petals: Waste or Valuable Resource? The Answer of High-Resolution and High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

    PubMed

    Righi, Valeria; Parenti, Francesca; Tugnoli, Vitaliano; Schenetti, Luisa; Mucci, Adele

    2015-09-30

    Intact Crocus sativus petals were studied for the first time by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, revealing the presence of kinsenoside (2) and goodyeroside A (3), together with 3-hydroxy-γ-butyrolactone (4). These findings were confirmed by HR-NMR analysis of the ethanol extract of fresh petals and showed that, even though carried out rapidly, partial hydrolysis of glucopyranosyloxybutanolides occurs during extraction. On the other hand, kaempferol 3-O-sophoroside (1), which is "NMR-silent" in intact petals, is present in extracts. These results suggest to evaluate the utilization of saffron petals for phytopharmaceutical and nutraceutical purposes to exploit a waste product of massive production of commercial saffron and point to the application of HR-MAS NMR for monitoring bioactive compounds directly on intact petals, avoiding the extraction procedure and the consequent hydrolysis reaction. PMID:26367873

  14. Caught in the act: ATP hydrolysis of an ABC-multidrug transporter followed by real-time magic angle spinning NMR.

    PubMed

    Hellmich, Ute A; Haase, Winfried; Velamakanni, Saroj; van Veen, Hendrik W; Glaubitz, Clemens

    2008-10-15

    The ATP binding cassette (ABC) transporter LmrA from Lactococcus lactis transports cytotoxic molecules at the expense of ATP. Molecular and kinetic details of LmrA can be assessed by solid-state nuclear magnetic resonance (ssNMR), if functional reconstitution at a high protein-lipid ratio can be achieved and the kinetic rate constants are small enough. In order to follow ATP hydrolysis directly by 31P-magic angle spinning (MAS) nuclear magnetic resonance (NMR), we generated such conditions by reconstituting LmrA-dK388, a mutant with slower ATP turnover rate, at a protein-lipid ration of 1:150. By analysing time-resolved 31P spectra, protein activity has been directly assessed. These data demonstrate the general possibility to perform ssNMR studies on a fully active full length ABC transporter and also form the foundation for further kinetic studies on LmrA by NMR. PMID:18817774

  15. Recent developments in solid-state magic-angle spinning, nuclear magnetic resonance of fully and significantly isotopically labelled peptides and proteins.

    PubMed Central

    Straus, Suzana K

    2004-01-01

    In recent years, a large number of solid-state nuclear magnetic resonance (NMR) techniques have been developed and applied to the study of fully or significantly isotopically labelled ((13)C, (15)N or (13)C/(15)N) biomolecules. In the past few years, the first structures of (13)C/(15)N-labelled peptides, Gly-Ile and Met-Leu-Phe, and a protein, Src-homology 3 domain, were solved using magic-angle spinning NMR, without recourse to any structural information obtained from other methods. This progress has been made possible by the development of NMR experiments to assign solid-state spectra and experiments to extract distance and orientational information. Another key aspect to the success of solid-state NMR is the advances made in sample preparation. These improvements will be reviewed in this contribution. Future prospects for the application of solid-state NMR to interesting biological questions will also briefly be discussed. PMID:15306412

  16. {sup 129}Xe magic-angle spinning spectra of xenon in zeolite NaA direct observation of mixed clusters of co-adsorbed species.

    SciTech Connect

    Jameson, A. K.; Jameson, C. J.; de Dios, A. C.; Oldfield, E.; Gerald, R. E., II; Turner, G. L.; Chemical Engineering; Loyola Univ.; Univ. of Illinois at Chicago; Univ. of Illinois; Spectral Data Services, Inc.

    1995-01-01

    We present the first demonstration that the individual {sup 129}Xe resonances corresponding to Xe{sub n} (n = 1-8) clusters inside the {alpha}-cages of zeolite NaA can be narrowed under magic-angle spinning (MAS). Under these high-resolution conditions we also observe upon addition of Kr the individual peaks corresponding to mixed clusters, Xe{sub n}Kr{sub m}, inside the a-cages, which will allow the first direct determination of the distribution of co-adsorbates in a microporous solid. Under MAS the chemical shifts of the Xe{sub n} clusters are shown to be highly sensitive to 'disorder' in the zeolite and provides new, quantitative information about the presence of {alpha}-cages of several types.

  17. Two-Dimensional NMR Study of a Liquid-Crystal Solution under Magic-Angle Spinning. Conformation of Carboxylic Ionophore Lasalocid A Dissolved in a Lyotropic Liquid Crystal

    NASA Astrophysics Data System (ADS)

    Kimura, Atsuomi; Kano, Tetsushi; Fujiwara, Hideaki

    1996-07-01

    The conformation of a carboxylic ionophore, lasalocid A, has been determined in a lyotropic liquid crystal by means of magic-angle spinning (MAS) and two-dimensional NMR experiments. The information extracted from ROESY spectra measured under MAS was analyzed according to the distance-geometry algorithm. The liquid crystal used for the solvent is cesium perfluorooctanoate dissolved in D2O, and the resulting structure of lasalocid A is a cyclic one, indicating cation complexation within a hydrophobic region of the liquid crystal. In this way, the two-dimensional MAS NMR experiment is proved to be a useful technique in conformational studies of complex molecules dissolved in lyotropic liquid crystal which may be regarded as offering a membrane-like environment.

  18. In situ structural characterization of a recombinant protein in native Escherichia coli membranes with solid-state magic-angle-spinning NMR.

    PubMed

    Fu, Riqiang; Wang, Xingsheng; Li, Conggang; Santiago-Miranda, Adriana N; Pielak, Gary J; Tian, Fang

    2011-08-17

    The feasibility of using solid-state magic-angle-spinning NMR spectroscopy for in situ structural characterization of the LR11 (sorLA) transmembrane domain (TM) in native Escherichia coli membranes is presented. LR11 interacts with the human amyloid precursor protein (APP), a central player in the pathology of Alzheimer's disease. The background signals from E. coli lipids and membrane proteins had only minor effects on the LR11 TM resonances. Approximately 50% of the LR11 TM residues were assigned by using (13)C PARIS data. These assignments allowed comparisons of the secondary structure of the LR11 TM in native membrane environments and commonly used membrane mimics (e.g., micelles). In situ spectroscopy bypasses several obstacles in the preparation of membrane proteins for structural analysis and offers the opportunity to investigate how membrane heterogeneity, bilayer asymmetry, chemical gradients, and macromolecular crowding affect the protein structure. PMID:21774553

  19. Homonuclear dipolar recoupling under ultra-fast magic-angle spinning: probing 19F-19F proximities by solid-state NMR.

    PubMed

    Wang, Qiang; Hu, Bingwen; Lafon, Olivier; Trébosc, Julien; Deng, Feng; Amoureux, Jean-Paul

    2010-03-01

    We describe dipolar recoupling methods that accomplish, at high magic-angle spinning (MAS) frequencies, the excitation of double-quantum (DQ) coherences between spin-1/2 nuclei. We employ rotor-synchronized symmetry-based pulse sequences which are either gamma-encoded or non-gamma-encoded. The sensitivity and the robustness to both chemical-shift anisotropy and offset are examined. We also compare different techniques to avoid signal folding in the indirect dimension of two-dimensional double-quantum<-->single-quantum (DQ-SQ) spectra. This comprehensive analysis results in the identification of satisfactory conditions for dipolar (19)F-(19)F recoupling at high magnetic fields and high MAS frequencies. The utility of these recoupling methods is demonstrated with high-resolution DQ-SQ NMR spectra, which allow probing (19)F-(19)F proximities in powered fluoroaluminates. PMID:20044288

  20. An NMR thermometer for cryogenic magic-angle spinning NMR: The spin-lattice relaxation of 127I in cesium iodide

    NASA Astrophysics Data System (ADS)

    Sarkar, Riddhiman; Concistrè, Maria; Johannessen, Ole G.; Beckett, Peter; Denning, Mark; Carravetta, Marina; al-Mosawi, Maitham; Beduz, Carlo; Yang, Yifeng; Levitt, Malcolm H.

    2011-10-01

    The accurate temperature measurement of solid samples under magic-angle spinning (MAS) is difficult in the cryogenic regime. It has been demonstrated by Thurber et al. (J. Magn. Reson., 196 (2009) 84-87) [10] that the temperature dependent spin-lattice relaxation time constant of 79Br in KBr powder can be useful for measuring sample temperature under MAS over a wide temperature range (20-296 K). However the value of T1 exceeds 3 min at temperatures below 20 K, which is inconveniently long. In this communication, we show that the spin-lattice relaxation time constant of 127I in CsI powder can be used to accurately measure sample temperature under MAS within a reasonable experimental time down to 10 K.

  1. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS) - NMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    NASA Astrophysics Data System (ADS)

    Wong, Alan; Boutin, Celine; Aguiar, Pedro

    2014-06-01

    The low sensitivity of Nuclear Magnetic Resonance (NMR) is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30-50 µl for HR-MAS) for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl) whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS). As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  2. 1H high resolution magic-angle coil spinning (HR-MACS) μNMR metabolic profiling of whole Saccharomyces cervisiae cells: a demonstrative study

    PubMed Central

    Wong, Alan; Boutin, Céline; Aguiar, Pedro M.

    2014-01-01

    The low sensitivity and thus need for large sample volume is one of the major drawbacks of Nuclear Magnetic Resonance (NMR) spectroscopy. This is especially problematic for performing rich metabolic profiling of scarce samples such as whole cells or living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volumes (250 nl) of whole cells. We have applied an emerging micro-NMR technology, high-resolution magic-angle coil spinning (HR-MACS), to study whole Saccharomyces cervisiae cells. We find that high-resolution high-sensitivity spectra can be obtained with only 19 million cells and, as a demonstration of the metabolic profiling potential, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging. PMID:24971307

  3. (1)H high resolution magic-angle coil spinning (HR-MACS) μNMR metabolic profiling of whole Saccharomyces cervisiae cells: a demonstrative study.

    PubMed

    Wong, Alan; Boutin, Céline; Aguiar, Pedro M

    2014-01-01

    The low sensitivity and thus need for large sample volume is one of the major drawbacks of Nuclear Magnetic Resonance (NMR) spectroscopy. This is especially problematic for performing rich metabolic profiling of scarce samples such as whole cells or living organisms. This study evaluates a (1)H HR-MAS approach for metabolic profiling of small volumes (250 nl) of whole cells. We have applied an emerging micro-NMR technology, high-resolution magic-angle coil spinning (HR-MACS), to study whole Saccharomyces cervisiae cells. We find that high-resolution high-sensitivity spectra can be obtained with only 19 million cells and, as a demonstration of the metabolic profiling potential, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging. PMID:24971307

  4. Conformational dynamics of phenylene rings in poly(p-phenylene vinylene) as revealed by 13C magic-angle-spinning exchange nuclear magnetic resonance experiments

    NASA Astrophysics Data System (ADS)

    deAzevedo, E. R.; Franco, R. W. A.; Marletta, A.; Faria, R. M.; Bonagamba, T. J.

    2003-08-01

    Poly(p-phenylene vinylene) (PPV) has shown a great potential for electro-optical applications due to its electroluminescent and semiconducting properties. Such properties are directly related with the polymer chain conformation and dynamics. Then, it is important to understand in detail the local chain motions. In this work, three 13C solid-state magic-angle-spinning (MAS) exchange NMR techniques were used to study conformational dynamics of phenylene rings in PPV. The standard 2D MAS exchange experiment was used to identify exchange processes between equivalent and nonequivalent sites. Centerband-only detection of exchange (CODEX) experiments were applied to determine the amplitude of the phenylene ring flips and small-angle oscillations. Additionally, a new version of the CODEX technique, which allows for the selective observation of segments executing exchange between non-equivalent sites, is demonstrated and applied to determine the flipping fractions and the activation energies of the phenylene ring rotations. It was found that, at -15 °C, (26±3)% of the rings undergo 180° flips in the millisecond time scale, with average imprecision of (30±5)° and activation energies of (23±3) kJ/mol. Other (31±10)% of the rings perform only small-angle oscillations with an average amplitude of (9±2)°. These results corroborate previous experimental data and agree with recent ab initio calculations of potential energies barriers in phenylenevinylene oligomers.

  5. Non-destructive testing of the MEGAPIE target

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Wohlmuther, M.; Boutellier, V.; Hahl, S.; Lagotzki, A.; Leu, H.; Linder, H. P.; Schwarz, R.; Spahr, A.; Zanini, L.; Kuster, D.; Gavillet, D.; Wagner, W.

    2016-01-01

    Non-destructive testing (NDT) is one important part of the post-irradiation examination (PIE) of the MEGAPIE target. It includes visual inspection and ultrasonic measurement of the beam window of the T91 LBE container and gamma mapping of the beam window of the AlMg3 safety-container. The visual inspection showed no visible failure in the proton beam window area of the T91 LBE container. The ultrasonic measurement demonstrated no detectable change in the wall thickness of the T91 beam window, which implies no severe corrosion effect induced by flowing LBE during the four-month irradiation period. The gamma mapping provided the distribution of 22Na, a spallation product, in the proton beam window area of the AlMg3 safety-container. The result was used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. A maximum proton fluence of 1.9 × 1025 p/m2 was deduced. The corresponding displacement damage degree in the T91 beam window was 7.1 dpa.

  6. Non-destructive investigation of thermoplastic reinforced composites

    DOE PAGESBeta

    Hassen, Ahmed; Taheri, Hossein; Vaidya, Uday

    2016-05-09

    This paper studies various manufacturing defects in glass fiber/Polypropylene (PP) composite parts and their methods of detection. Foreign Object Inclusion (FOI) of different shapes, sizes, and materials were placed in a glass fiber/PP panel made by compression molding. The paper aims to characterize the fiber orientation and fiber related defects such as fiber waviness in the composite specimen. Comprehensive investigation for different Non Destructive Evaluation (NDE) techniques, namely X-ray radiography and Ultrasonic Testing (UT) techniques to trace and characterize the embedded defects and the composite texture are presented. Conventional X-ray radiography successfully identified the fiber orientation in two dimension (2-D)more » plane; however, information for the sample depth was not captured. The radiography techniques showed low relative errors for the defect size measurements (maximum error was below 9.5%) when compared to the ultrasonic techniques. Ultrasonic techniques were able to map all the embedded artificial defects. Phase Array (PA) ultrasonic technique was able to precisely locate the FOI in the glass fiber/PP specimen. Nerveless, the shape and size of the defects were not accurately determined due to the high signal attenuation and distortion characteristics of the E-glass fiber.« less

  7. Non-Destructive Evaluation of Materials via Ultraviolet Spectroscopy

    NASA Technical Reports Server (NTRS)

    Pugel, Betsy

    2008-01-01

    A document discusses the use of ultraviolet spectroscopy and imaging for the non-destructive evaluation of the degree of cure, aging, and other properties of resin-based composite materials. This method can be used in air, and is portable for field use. This method operates in reflectance, absorbance, and luminescence modes. The ultraviolet source is used to illuminate a composite surface of interest. In reflectance mode, the reflected response is acquired via the imaging system or via the spectrometer. The spectra are analyzed for organic compounds (conjugated organics) and inorganic compounds (semiconducting band-edge states; luminescing defect states such as silicates, used as adhesives for composite aerospace applications; and metal oxides commonly used as thermal coating paints on a wide range of spacecraft). The spectra are compared with a database for variation in conjugation, substitution, or length of molecule (in the case of organics) or band edge position (in the case of inorganics). This approach is useful in the understanding of material quality. It lacks the precision in defining the exact chemical structure that is found in other materials analysis techniques, but it is advantageous over methods such as nuclear magnetic resonance, infrared spectroscopy, and chromatography in that it can be used in the field to assess significant changes in chemical structure that may be linked to concerns associated with weaknesses or variations in structural integrity, without disassembly of or destruction to the structure of interest.

  8. Non-destructive investigation of thermoplastic reinforced composites

    SciTech Connect

    Hassen, Ahmed; Vaidya, Uday

    2016-01-01

    This paper studies various manufacturing defects in glass fiber/Polypropylene (PP) composite parts and their methods of detection. Foreign Object Inclusion (FOI) of different shapes, sizes, and materials were placed in a glass fiber/PP panel made by compression molding. The paper aims to characterize the fiber orientation and fiber related defects such as fiber waviness in the composite specimen. Comprehensive investigation for different Non Destructive Evaluation (NDE) techniques, namely X-ray radiography and Ultrasonic Testing (UT) techniques to trace and characterize the embedded defects and the composite texture are presented. Conventional X-ray radiography successfully identified the fiber orientation in two dimension (2-D) plane; however, information for the sample depth was not captured. The radiography techniques showed low relative errors for the defect size measurements (maximum error was below 9.5%) when compared to the ultrasonic techniques. Ultrasonic techniques were able to map all the embedded artificial defects. Phase Array (PA) ultrasonic technique was able to precisely locate the FOI in the glass fiber/PP specimen. Nerveless, the shape and size of the defects were not accurately determined due to the high signal attenuation and distortion characteristics of the E-glass fiber.

  9. A non-destructive method for dating human remains

    USGS Publications Warehouse

    Lail, Warren K.; Sammeth, David; Mahan, Shannon; Nevins, Jason

    2013-01-01

    The skeletal remains of several Native Americans were recovered in an eroded state from a creek bank in northeastern New Mexico. Subsequently stored in a nearby museum, the remains became lost for almost 36 years. In a recent effort to repatriate the remains, it was necessary to fit them into a cultural chronology in order to determine the appropriate tribe(s) for consultation pursuant to the Native American Grave Protection and Repatriation Act (NAGPRA). Because the remains were found in an eroded context with no artifacts or funerary objects, their age was unknown. Having been asked to avoid destructive dating methods such as radiocarbon dating, the authors used Optically Stimulated Luminescence (OSL) to date the sediments embedded in the cranium. The OSL analyses yielded reliable dates between A.D. 1415 and A.D. 1495. Accordingly, we conclude that the remains were interred somewhat earlier than A.D. 1415, but no later than A.D. 1495. We believe the remains are from individuals ancestral to the Ute Mouache Band, which is now being contacted for repatriation efforts. Not only do our methods contribute to the immediate repatriation efforts, they provide archaeologists with a versatile, non-destructive, numerical dating method that can be used in many burial contexts.

  10. Non-destructive monitoring of curing process in precast concrete

    NASA Astrophysics Data System (ADS)

    Aparicio, S.; Ranz, J.; Fernández, R.; Albert, V.; Fuente, J. V.; Hernández, M. G.

    2012-12-01

    Currently, the use of precast concrete elements has gained importance because it offers many advantages over site-cast concrete. A disadvantage of site-cast concrete is that its properties vary according to the manufacturing method, the environment and even the operator who carried out the mixing, pouring and implementation of the concrete. Precast concrete elements are manufactured in a controlled environment (typically referred to as a precast plant) and this reduces the shrinkage and creep. One of the key properties of precast concrete is the capability to gain compressive strength rapidly under the appropriate conditions. The compressive strength determines if the precast can be stripped from the form or manipulated. This parameter is measured using destructive testing over cylindrical or cubic samples. The quality control of precast is derived from the fracture suffered by these elements, resulting in a "pass or fail" evaluation. In most cases, the solution to this problem is to allow the material to cure for a few hours until it acquires sufficient strength to handle the precast element. The focus of this paper is the description of the research project "CUREND". This project aims to design a non-destructive methodology to monitor the curing process in precast concrete. The monitoring will be performed using wireless sensor networks.

  11. Data fusion for automated non-destructive inspection

    PubMed Central

    Brierley, N.; Tippetts, T.; Cawley, P.

    2014-01-01

    In industrial non-destructive evaluation (NDE), it is increasingly common for data acquisition to be automated, driving a recent substantial increase in the availability of data. The collected data need to be analysed, typically necessitating the painstaking manual labour of a skilled operator. Moreover, in automated NDE a region of an inspected component is typically interrogated several times, be it within a single data channel due to multiple probe passes, across several channels acquired simultaneously or over the course of repeated inspections. The systematic combination of these diverse readings is recognized to offer an opportunity to improve the reliability of the inspection, but is not achievable in a manual analysis. This paper describes a data-fusion-based software framework providing a partial automation capability, allowing component regions to be declared defect-free to a very high probability while readily identifying defect indications, thereby optimizing the use of the operator's time. The system is designed to applicable to a wide range of automated NDE scenarios, but the processing is exemplified using the industrial ultrasonic immersion inspection of aerospace turbine discs. Results obtained for industrial datasets demonstrate an orders-of-magnitude reduction in false-call rates, for a given probability of detection, achievable using the developed software system. PMID:25002828

  12. FIRST 100 T NON-DESTRUCTIVE MAGNET OUTER COIL SET

    SciTech Connect

    J. BACON; A. BACA; ET AL

    1999-09-01

    The controlled power outer coil set of the first 100 T non-destructive (100 T ND) magnet is described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND controlled power outer coil set consists of seven nested, mechanically independent externally reinforced coils. These coils, in combination, will produce a 47 T platform field in a 225-mm diameter bore. Using inertial energy storage a synchronous motor/generator provides ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. Each coil consists of a multi-layer winding of high strength conductor supported by an external high strength stainless steel shell. Coils with the highest magnetic loads will utilize a reinforcing shell fabricated from highly cold worked 301 stainless steel strip. The autofrettage conditioning method will be used to pre-stress the coils and thereby limit conductor and reinforcement strains to the elastic range. The purpose of pre-stressing the coils is to attain a design life of 10,000 full field pulses. The operation and conditioning of the coil set will be described along with special features of its design, magnetic and structural analyses and construction.

  13. Non-destructive evaluation of anchorage zones by ultrasonics techniques.

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

    This work aims to evaluate the efficiency and reliability of two Non-Destructive Testing (NDT) methods for damage assessment in bridges' anchorages. The Acousto-Ultrasonic (AU) technique is compared to classical Ultrasonic Testing (UT) in terms of defect detection and structural health classification. The AU technique is firstly used on single seven-wire strands damaged by artificial defects. The effect of growing defects on the waves traveling through the strands is evaluated. Thereafter, three specimens of anchorages with unknown defects are inspected by the AU and UT techniques. Damage assessment results from both techniques are then compared. The structural health conditions of the specimens can be then classified by a damage severity criterion. Finally, a damaged anchorage socket with mastered defects is controlled by the same techniques. The UT allows the detection and localization of damaged wires. The AU technique is used to bring out the effect of defects on acoustic features by comparing a healthy and damaged anchorage sockets. It is concluded that the UT method is suitable for local and crack-like defects, whereas the AU technique enables the assessment of the global structural health of the anchorage zones. PMID:25824342

  14. Non-Destructive Evaluation (NDE) Applications of THz Radiation

    NASA Astrophysics Data System (ADS)

    Zimdars, David

    2005-03-01

    The technology and applications of time domain terahertz (THz) imaging to non-destructive evaluation (NDE) will be discussed. THz imaging has shown great promise in 2 and 3 dimensional non-contact inspection of non-conductive materials such as plastics, foam, composites, ceramics, paper, wood and glass. THz imaging employs safe low power non-ionizing electromagnetic pulses, with lateral resolution < 200 um, and depth resolution < 50 um. THz pulses can be analyzed spectroscopically to reveal chemical content. Recently, highly integrated turn-key THz imaging systems have been introduced commercially. We will demonstrate the detection of voids and disbonds intentionally incorporated within the sprayed on foam insulation of a space shuttle external tank mock-up segments. An industrially hardened THz scanning system which has been deployed to scan the space shuttle tank with small remote transceiver will be described. Additional terahertz security imaging applications for the detection of weapons and explosives will also be discussed, as well as the application of terahertz sensors for high speed industrial process monitoring and quality control.

  15. Complex Archaeological Prospection Using Combination of Non-destructive Techniques

    NASA Astrophysics Data System (ADS)

    Faltýnová, M.; Pavelka, K.; Nový, P.; Šedina, J.

    2015-08-01

    This article describes the use of a combination of non-destructive techniques for the complex documentation of a fabulous historical site called Devil's Furrow, an unusual linear formation lying in the landscape of central Bohemia. In spite of many efforts towards interpretation of the formation, its original form and purpose have not yet been explained in a satisfactory manner. The study focuses on the northern part of the furrow which appears to be a dissimilar element within the scope of the whole Devil's Furrow. This article presents detailed description of relics of the formation based on historical map searches and modern investigation methods including airborne laser scanning, aerial photogrammetry (based on airplane and RPAS) and ground-penetrating radar. Airborne laser scanning data and aerial orthoimages acquired by the Czech Office for Surveying, Mapping and Cadastre were used. Other measurements were conducted by our laboratory. Data acquired by various methods provide sufficient information to determine the probable original shape of the formation and proves explicitly the anthropological origin of the northern part of the formation (around village Lipany).

  16. Non-destructive compositional analysis of historic organ reed pipes

    NASA Astrophysics Data System (ADS)

    Manescu, A.; Fiori, F.; Giuliani, A.; Kardjilov, N.; Kasztovszky, Z.; Rustichelli, F.; Straumal, B.

    2008-03-01

    In order to be able to reproduce historic organ reed pipes, a bulk non-destructive chemical composition analysis was performed on the tongues and shallots, focusing mainly on the ratio between copper and zinc and on the presence of lead. Prompt gamma activation analysis results allowed us to observe for the first time that the ratio between the two main components of the brass alloy changed from Cu:Zn = 3:1 for the old tongues and shallots to Cu:Zn = 2:1 around the middle of the 18th century, which is typical also for the modern alloys offered to the organ builders nowadays. We also discovered that the Pb content in the old historic brass alloy diminished until the middle of 18th century when the brass alloy became mainly Pb free. The non-uniform lead distribution inside one of the shallots obtained from a prompt gamma activation analysis (PGAA) experiment was studied by neutron tomography. It gave us a three-dimensonal (3D) distribution of the lead inclusions inside the shallots. The lead particles are concentrated towards the base of the shallot.

  17. Magic Physics?

    ERIC Educational Resources Information Center

    Featonby, David

    2010-01-01

    This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)

  18. Creating Magic Squares.

    ERIC Educational Resources Information Center

    Lyon, Betty Clayton

    1990-01-01

    One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)

  19. Geophysical Methods for Non-Destructive Testing in Civil Engineering

    NASA Astrophysics Data System (ADS)

    Niederleithinger, E.

    2013-12-01

    Many non-destructive testing (NDT) methods for civil engineering (e. g. ultrasonics, radar) are similar to geophysical techniques. They just differ in scale, material under investigation and vocabulary used. In spite of the fact that the same principles of physics and mathematics apply to both fields, exchange has been limited in the past. But since a few years more and more geophysical knowledge is used in civil engineering. One of the focal points in research is to improve ultrasonic testing of concrete to be able to image the inside even of large, complex structures and to detect any deterioration as early as possible. One of the main issues is the heterogeneity of concrete, including aggregates, reinforcement, cracks and many other features. Our current research focuses on three points. One is the application of state of the art geophysical migration techniques as Reverse Time Migration (RTM) to image vertical faces or the backside of voids and ducts in thick concrete structures, which isn't possible with conventional techniques used in NDT. Second, we have started to use seismic interferometric techniques to interpolate ultrasonic traces, which can't be measured directly for technical reasons. Third, we are using coda wave interferometry to detect concrete degradation due to load, fatigue, temperature or other influences as early as possible. Practical examples of the application of these techniques are given and potential future research directions will be discussed. It will be shown, how a subset of these techniques can be used for innovative monitoring systems for civil infrastructure. Imaging the interior of a concrete body by ultrasonics and reverse time migration(simulated data).

  20. Accuracy of Non-Destructive Testing of PBRs to Estimate Fragilities

    NASA Astrophysics Data System (ADS)

    Brune, J. N.; Brune, R.; Biasi, G. P.; Anooshehpoor, R.; Purvance, M.

    2011-12-01

    Prior studies of Precariously Balanced Rocks (PBRs) have involved various methods of documenting rock shapes and fragilities. These have included non-destructive testing (NDT) methods such as photomodeling, and potentially destructive testing (PDT) such as forced tilt tests. PDT methods usually have the potential of damaging or disturbing the rock or its pedestal so that the PBR usefulness for future generations is compromised. To date we have force-tilt tested approximately 28 PBRs, and of these we believe 7 have been compromised. We suggest here that given other inherent uncertainties in the current methodologies, NDT methods are now sufficiently advanced as to be adequate for the current state of the art use for comparison with Ground Motion Prediction Equations (GMPEs) and seismic hazard maps (SHMs). Here we compare tilt-test static toppling estimates to three non-destructive methods: (1) 3-D photographic modeling (2) profile analysis assuming the rock is 2-D, and (3) expert judgments from photographs. 3-D modeling uses the commercial Photomodeler program and photographs in the field taken from numerous directions around the rock. The output polyhedral shape is analyzed in Matlab determine the center of mass and in Autocad to estimate the static overturning angle alpha. For the 2-D method we chose the photograph in profile looking perpendicular to the estimated direction of toppling. The rock is outlined as a 2-D object in Matlab. Rock dimensions, rocking points, and a vertical reference are supplied by the photo analyst to estimate the center of gravity and static force overturning angles. For the expert opinion method we used additional photographs taken from different directions to improve the estimates of the center of mass and the rocking points. We used 7 rocks for comparisons. The error in estimating tan alpha from 3-D modeling is about 0.05. For 2-D estimates an average error is about 0.1 (?). For expert opinion estimates the error is about 0.06. For

  1. Recent advances in the use of non-destructive near infrared spectroscopy on intact olive fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this review is to illustrate the state of the art in the use of non-destructive near infrared (NIR) spectroscopy for quality evaluation of intact fruit in the olive industry. First, the most recent studies regarding the application of non-destructive NIR spectroscopy methods to asse...

  2. Non-destructive evaluation of TBC by electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Jianqi

    suggested. An alternative electrolyte (trifluoroacetic acid) was investigated using EIS in order to be used as compatible or friendly solution to TBC. A similar characteristic EIS result was found using the alternative electrolyte compared with the commonly used electrolyte [Fe(CN)6]-3/[Fe(CN) 6]-4 in this work. It has indicated that a friendly electrolyte be viable for EIS technique to be used for non-destructive evaluation of TBC. Visualization of a flexible probe for EIS field detection has also been designed. (Abstract shortened by UMI.)

  3. Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

    PubMed Central

    Thurber, Kent R.; Tycko, Robert

    2014-01-01

    We report solid state 13C and 1H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, 1H and cross-polarized 13C NMR signals from 15N,13C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T1e is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations. PMID:24832263

  4. Theory for cross effect dynamic nuclear polarization under magic-angle spinning in solid state nuclear magnetic resonance: the importance of level crossings.

    PubMed

    Thurber, Kent R; Tycko, Robert

    2012-08-28

    We present theoretical calculations of dynamic nuclear polarization (DNP) due to the cross effect in nuclear magnetic resonance under magic-angle spinning (MAS). Using a three-spin model (two electrons and one nucleus), cross effect DNP with MAS for electron spins with a large g-anisotropy can be seen as a series of spin transitions at avoided crossings of the energy levels, with varying degrees of adiabaticity. If the electron spin-lattice relaxation time T(1e) is large relative to the MAS rotation period, the cross effect can happen as two separate events: (i) partial saturation of one electron spin by the applied microwaves as one electron spin resonance (ESR) frequency crosses the microwave frequency and (ii) flip of all three spins, when the difference of the two ESR frequencies crosses the nuclear frequency, which transfers polarization to the nuclear spin if the two electron spins have different polarizations. In addition, adiabatic level crossings at which the two ESR frequencies become equal serve to maintain non-uniform saturation across the ESR line. We present analytical results based on the Landau-Zener theory of adiabatic transitions, as well as numerical quantum mechanical calculations for the evolution of the time-dependent three-spin system. These calculations provide insight into the dependence of cross effect DNP on various experimental parameters, including MAS frequency, microwave field strength, spin relaxation rates, hyperfine and electron-electron dipole coupling strengths, and the nature of the biradical dopants. PMID:22938251

  5. Multidimensional High-Resolution Magic Angle Spinning and Solution-State NMR Characterization of 13C-labeled Plant Metabolites and Lignocellulose

    PubMed Central

    Mori, Tetsuya; Tsuboi, Yuuri; Ishida, Nobuhiro; Nishikubo, Nobuyuki; Demura, Taku; Kikuchi, Jun

    2015-01-01

    Lignocellulose, which includes mainly cellulose, hemicellulose, and lignin, is a potential resource for the production of chemicals and for other applications. For effective production of materials derived from biomass, it is important to characterize the metabolites and polymeric components of the biomass. Nuclear magnetic resonance (NMR) spectroscopy has been used to identify biomass components; however, the NMR spectra of metabolites and lignocellulose components are ambiguously assigned in many cases due to overlapping chemical shift peaks. Using our 13C-labeling technique in higher plants such as poplar samples, we demonstrated that overlapping peaks could be resolved by three-dimensional NMR experiments to more accurately assign chemical shifts compared with two-dimensional NMR measurements. Metabolites of the 13C-poplar were measured by high-resolution magic angle spinning NMR spectroscopy, which allows sample analysis without solvent extraction, while lignocellulose components of the 13C-poplar dissolved in dimethylsulfoxide/pyridine solvent were analyzed by solution-state NMR techniques. Using these methods, we were able to unambiguously assign chemical shifts of small and macromolecular components in 13C-poplar samples. Furthermore, using samples of less than 5 mg, we could differentiate between two kinds of genes that were overexpressed in poplar samples, which produced clearly modified plant cell wall components. PMID:26143886

  6. Recoupling of native homonuclear dipolar couplings in magic-angle-spinning solid-state NMR by the double-oscillating field technique

    NASA Astrophysics Data System (ADS)

    Straasø, Lasse Arnt; Nielsen, Niels Chr.

    2010-08-01

    A new solid-state NMR method, the double-oscillating field technique (DUO), that under magic-angle-spinning conditions produces an effective Hamiltonian proportional to the native high-field homonuclear dipole-dipole coupling operator is presented. The method exploits one part of the radio frequency (rf) field to recouple the dipolar coupling interaction with a relatively high scaling factor and to eliminate offset effects over a reasonable bandwidth while in the recoupling frame, the other part gives rise to a sufficiently large longitudinal component of the residual rf field that averages nonsecular terms and in addition ensures stability toward rf inhomogeneity and rf miscalibration. The capability of the DUO experiment to mediate transfer of polarization is described theoretically and compared numerically and experimentally with finite pulse rf driven recoupling and experimentally with dipolar-assisted rotational resonance. Two-dimensional recoupling experiments were performed on antiparallel amyloid fibrils of the decapeptide SNNFGAILSS with the FGAIL fragment uniformly labeled with C13 and N15.

  7. Trifluoroethanol and 19F magic angle spinning nuclear magnetic resonance as a basic surface hydroxyl reactivity probe for zirconium(IV) hydroxide structures.

    PubMed

    DeCoste, Jared B; Glover, T Grant; Mogilevsky, Gregory; Peterson, Gregory W; Wagner, George W

    2011-08-01

    A novel technique for determining the relative accessibility and reactivity of basic surface hydroxyl sites by reacting various zirconium(IV) hydroxide materials with 2,2,2-trifluoroethanol (TFE) and characterizing the resulting material using (19)F magic angle spinning (MAS) nuclear magnetic resonance (NMR) is presented here. Studied here are three zirconium hydroxide samples, two unperturbed commercial materials, and one commercial material that is crushed by a pellet press. Factors, such as the ratio of bridging/terminal hydroxyls, surface area, and pore size distribution, are examined and found to affect the ability of the zirconium(IV) hydroxide to react with TFE. X-ray diffraction, nitrogen isotherms, and (1)H MAS NMR were used to characterize the unperturbed materials, while thermogravitric analysis with gas chromatography and mass spectrometry along with the (19)F MAS NMR were used to characterize the materials that were reacted with TFE. Zirconium hydroxide materials with a high surface area and a low bridging/terminal hydroxyl ratio were found to react TFE in the greatest amounts. PMID:21699226

  8. Magic Angle Spinning NMR Reveals Sequence-Dependent Structural Plasticity, Dynamics, and the Spacer Peptide 1 Conformation in HIV-1 Capsid Protein Assemblies

    SciTech Connect

    Han, Yun; Hou, Guangjin; Suiter, Christopher L.; Ahn, Jinwoo; Byeon, In-Ja L.; Lipton, Andrew S.; Burton, Sarah D.; Hung, Ivan; Gorkov, Peter L.; Gan, Zhehong; Brey, William W.; Rice, David M.; Gronenborn, Angela M.; Polenova, Tatyana E.

    2013-11-27

    Maturation of HIV-1 virus into an infectious virion requires cleavage of the Gag polyprotein into its constituent domains and formation of a conical capsid core that encloses viral RNA and a small complement of proteins for replication. The final step of this process is the cleavage of the SP1 peptide from the CA-SP1 maturation intermediate, which triggers the condensation of the CA protein into a conical capsid. The mechanism of this step, including the conformation of the SP1 peptide in CA-SP1, is under intense debate. In this report, we examine the tubular assemblies of CA and the CA-SP1 maturation intermediate using Magic Angle Spinning NMR spectroscopy. At the magnetic fields of 19.9 T and above, tubular CA and CA-SP1 assemblies yield outstanding-quality 2D and 3D MAS NMR spectra, which are amenable to resonance assignments and detailed structural characterization. Dipolar- and scalar-based correlation experiments unequivocally indicate that SP1 peptide is in a random coil conformation and mobile in the assembled CA-SP1. Analysis of two sequence variants reveals that remarkably, the conformation of SP1 tail, of the functionally important CypA loop, and of the loop preceding helix 8 are sequence dependent and modulated by the residue variations at distal sites. These findings challenge the role of SP1 as a conformational switch in the maturation process and establish sequence-dependent conformational plasticity in CA.

  9. Systematic evaluation of heteronuclear spin decoupling in solid-state NMR at the rotary-resonance conditions in the regime of fast magic-angle spinning.

    PubMed

    Sharma, Kshama; Madhu, P K; Agarwal, Vipin

    2016-09-01

    The performance of heteronuclear spin decoupling sequences in solid-state NMR severely degrades when the proton radiofrequency (RF) nutation frequencies (ν1) are close to or at multiples of magic-angle spinning (MAS) frequency (νr) that are referred to as rotary-resonance recoupling conditions (ν1=n·νr). Recently, two schemes, namely, PISSARRO and rCW(ApA), have been shown to be less affected by the problem of MAS and RF interference, specifically at the n=2 rotary-resonance recoupling condition, especially in the fast MAS regime. Here, we systematically evaluate the loss in intensity of several heteronuclear spin decoupling sequences at the n=1, 2 conditions compared to high-power decoupling in the fast-MAS regime. We propose that in the fast-MAS regime (above 40kHz) the entire discussion about RF and MAS interference can be avoided by using appropriate low-power decoupling sequences which give comparable performance to decoupling sequences with high-power (1)H irradiation of ca.195kHz. PMID:27472380

  10. Cross-Correlated Relaxation of Dipolar Coupling and Chemical-Shift Anisotropy in Magic-Angle Spinning R1ρ NMR Measurements: Application to Protein Backbone Dynamics Measurements.

    PubMed

    Kurauskas, Vilius; Weber, Emmanuelle; Hessel, Audrey; Ayala, Isabel; Marion, Dominique; Schanda, Paul

    2016-09-01

    Transverse relaxation rate measurements in magic-angle spinning solid-state nuclear magnetic resonance provide information about molecular motions occurring on nanosecond-to-millisecond (ns-ms) time scales. The measurement of heteronuclear ((13)C, (15)N) relaxation rate constants in the presence of a spin-lock radiofrequency field (R1ρ relaxation) provides access to such motions, and an increasing number of studies involving R1ρ relaxation in proteins have been reported. However, two factors that influence the observed relaxation rate constants have so far been neglected, namely, (1) the role of CSA/dipolar cross-correlated relaxation (CCR) and (2) the impact of fast proton spin flips (i.e., proton spin diffusion and relaxation). We show that CSA/D CCR in R1ρ experiments is measurable and that the CCR rate constant depends on ns-ms motions; it can thus provide insight into dynamics. We find that proton spin diffusion attenuates this CCR due to its decoupling effect on the doublet components. For measurements of dynamics, the use of R1ρ rate constants has practical advantages over the use of CCR rates, and this article reveals factors that have so far been disregarded and which are important for accurate measurements and interpretation. PMID:27500976