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Sample records for 29si magic angle

  1. Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning 13C and 29Si NMR Enhanced by Dynamic Nuclear Polarization

    SciTech Connect

    Lafon, Olivier; Thankamony, Aany S. Lilly; Kokayashi, Takeshi; Carnevale, Diego; Vitzthum, Veronika; Slowing, Igor I.; Kandel, Kapil; Vezin, Herve; Amoureux, Jean-Paul; Bodenhausen, Geoffrey; Pruski, Marek

    2012-12-21

    We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of 13C and 29Si nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surrounding frozen disordered water. The approach is demonstrated using mesoporous silica nanoparticles (MSN), functionalized with 3-(N-phenylureido)propyl (PUP) groups, filled with the surfactant cetyltrimethylammonium bromide (CTAB). The DNP-enhanced proton magnetization is transported into the mesopores via 1H–1H spin diffusion and transferred to rare spins by cross-polarization, yielding signal enhancements εon/off of around 8. When the CTAB molecules are extracted, so that the radicals can enter the mesopores, the enhancements increase to εon/off ≈ 30 for both nuclei. A quantitative analysis of the signal enhancements in MSN with and without surfactant is based on a one-dimensional proton spin diffusion model. The effect of solvent deuteration is also investigated.

  2. '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.

  3. Magic-angle turning with double acquisition

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tatsuya; Takegoshi, K.

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  4. Magic-angle turning with double acquisition.

    PubMed

    Matsunaga, Tatsuya; Takegoshi, K

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  5. 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

  6. Magic angle spinning NMR of paramagnetic proteins.

    PubMed

    Knight, Michael J; Felli, Isabella C; Pierattelli, Roberta; Emsley, Lyndon; Pintacuda, Guido

    2013-09-17

    Metal ions are ubiquitous in biochemical and cellular processes. Since many metal ions are paramagnetic due to the presence of unpaired electrons, paramagnetic molecules are an important class of targets for research in structural biology and related fields. Today, NMR spectroscopy plays a central role in the investigation of the structure and chemical properties of paramagnetic metalloproteins, linking the observed paramagnetic phenomena directly to electronic and molecular structure. A major step forward in the study of proteins by solid-state NMR came with the advent of ultrafast magic angle spinning (MAS) and the ability to use (1)H detection. Combined, these techniques have allowed investigators to observe nuclei that previously were invisible in highly paramagnetic metalloproteins. In addition, these techniques have enabled quantitative site-specific measurement of a variety of long-range paramagnetic effects. Instead of limiting solid-state NMR studies of biological systems, paramagnetism provides an information-rich phenomenon that can be exploited in these studies. This Account emphasizes state-of-the-art methods and applications of solid-state NMR in paramagnetic systems in biological chemistry. In particular, we discuss the use of ultrafast MAS and (1)H-detection in perdeuterated paramagnetic metalloproteins. Current methodology allows us to determine the structure and dynamics of metalloenzymes, and, as an example, we describe solid-state NMR studies of microcrystalline superoxide dismutase, a 32 kDa dimer. Data were acquired with remarkably short times, and these experiments required only a few milligrams of sample.

  7. 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.

  8. An efficient magic state approach to small angle rotations

    NASA Astrophysics Data System (ADS)

    Campbell, Earl T.; O'Gorman, Joe

    2016-12-01

    Standard error-correction techniques only provide a quantum memory and need extra gadgets to perform computation. Central to quantum algorithms are small angle rotations, which can be fault-tolerantly implemented given a supply of an unconventional species of magic state. We present a low-cost distillation routine for preparing these small angle magic states. Our protocol builds on the work of Duclos-Cianci and Poulin (2015 Phys. Rev. A 91 042315) by compressing their circuit. Additionally, we present a method of diluting magic states that reduces costs associated with very small angle rotations. We quantify performance by the expected number of noisy magic states consumed per rotation, and compare with other protocols. For modest-sized angles, our protocols offer a factor 24 improvement over the best-known gate synthesis protocols and a factor 2 over the Duclos-Cianci and Poulin protocol. For very small angle rotations, the dilution protocol dramatically reduces costs, giving several orders magnitude improvement over competitors. There also exists an intermediary regime of small, but not very small, angles where our approach gives a marginal improvement over gate synthesis. We discuss how different performance metrics may alter these conclusions.

  9. Cross polarization magic-angle spinning NMR at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Macho, V.; Kendrick, R.; Yannoni, C. S.

    A magic angle spinning (MAS) apparatus which can be used for high resolution solid state NMR at temperatures as low as 15 K is described. To demonstrate the utility of this apparatus, 13C spectra of molecules containing methyl groups have been investigated at cryogenic temperatures. The spectra, which are described in detail, provide direct evidence for the slowdown of methyl rotation.

  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. Geminal (2)J((29)Si-O-(29)Si) couplings in oligosiloxanes and their relation to direct (1)J((29) Si-(13)C) couplings.

    PubMed

    Kurfürst, Milan; Blechta, Vratislav; Schraml, Jan

    2011-08-01

    Absolute values of (79) geminal (2)J((29) Si-O-(29)Si) couplings were measured in an extensive series of (55) unstrained siloxanes dissolved in chloroform-d. Signs of (2)J((29)Si-O-(29)Si) in some (9) silicon hydrides were determined relative to (1)J((29)Si-(1)H) which are known to be negative. It is supposed that positive sign of the (2)J((29)Si-O-(29)Si) coupling found in all studied hydrides is common to all siloxanes. Theoretical calculations for simple model compounds failed to reproduce this sign and so their predictions of bond length and angle dependences cannot be taken as reliable. Useful empirical correlations were found between the (2)J((29)Si-O-(29)Si) couplings on one side and the total number m of oxygen atoms bonded to the silicon atoms, sum of (29)Si chemical shifts or product of (1)J((29)Si-(13)C) couplings on the other side. The significance of these correlations is briefly discussed.

  13. Microcoil high-resolution magic angle spinning NMR spectroscopy.

    PubMed

    Janssen, Hans; Brinkmann, Andreas; van Eck, Ernst R H; van Bentum, P Jan M; Kentgens, Arno P M

    2006-07-12

    We report the construction of a dual-channel microcoil nuclear magnetic resonance probehead allowing magic-angle spinning for mass-limited samples. With coils down to 235 mum inner diameter, this allows high-resolution solid-state NMR spectra to be obtained for amounts of materials of a few nanoliters. This is demonstrated by the carbon-13 spectrum of a tripeptide and a single silk rod, prepared from the silk gland of the Bombyx mori silkworm. Furthermore, the microcoil allows for radio frequency field strengths well beyond current probe technology, aiding in getting the highest possible resolution by efficiently decoupling the observed nuclei from the abundantly present proton nuclei.

  14. Methods for magnetic resonance analysis using magic angle technique

    DOEpatents

    Hu, Jian Zhi [Richland, WA; Wind, Robert A [Kennewick, WA; Minard, Kevin R [Kennewick, WA; Majors, Paul D [Kennewick, WA

    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.

  15. Multiple quantum magic-angle spinning using rotary resonance excitation

    NASA Astrophysics Data System (ADS)

    Vosegaard, Thomas; Florian, Pierre; Massiot, Dominique; Grandinetti, Philip J.

    2001-03-01

    We have discovered rotary resonances between rf field strength, ω1, and magic-angle spinning (MAS) frequency, ωR, which dramatically enhance the sensitivity of triple quantum preparation and mixing in the multiple-quantum MAS experiment, particularly for quadrupolar nuclei having low gyromagnetic ratios or experiencing strong quadrupole couplings. Triple quantum excitation efficiency minima occur when 2ω1=nωR, where n is an integer, with significant maxima occurring between these minima. For triple quantum mixing we observe maxima when ω1=nωR. In both preparation and mixing the pulse lengths required to reach maxima exceed one rotor period. We have combined these rotary resonance conditions into a new experiment called FASTER MQ-MAS, and have experimentally demonstrated a factor of 3 enhancement in sensitivity in comparison to conventional MQ-MAS.

  16. Magic angle effects and angular magnetoresistance oscillations as dimensional crossovers.

    PubMed

    Lebed, A G; Bagmet, N N; Naughton, M J

    2004-10-08

    Interference effects between velocity and density of states, which occur as electrons move along open orbits in the extended Brillouin zone in anisotropic conductors, result in a change of wave functions' dimensionality at magic angle (MA) directions of a magnetic field. In particular, these 1D-->2D dimensional crossovers result in the appearance of sharp minima in a resistivity component rho perpendicular (H,alpha), perpendicular to conducting layers. This explains the main qualitative features of MA and angular magnetoresistance oscillations' phenomena observed due to the existence of quasi-one-dimensional sheets of Fermi surface in (TMTSF)2X, (DMET-TSeF)2X, and kappa-(ET)2Cu(NCS)(2) conductors.

  17. Modifier cation effects on (29)Si nuclear shielding anisotropies in silicate glasses.

    PubMed

    Baltisberger, Jay H; Florian, Pierre; Keeler, Eric G; Phyo, Pyae A; Sanders, Kevin J; Grandinetti, Philip J

    2016-07-01

    We have examined variations in the (29)Si nuclear shielding tensor parameters of SiO4 tetrahedra in a series of seven alkali and alkaline earth silicate glass compositions, Cs2O·4.81 SiO2, Rb2O·3.96 SiO2, Rb2O·2.25 SiO2, K2O·4.48 SiO2, Na2O·4.74 SiO2, BaO·2.64 SiO2, and SrO·2.36 SiO2, using natural abundance (29)Si two-dimensional magic-angle flipping (MAF) experiments. Our analyses of these 2D spectra reveal a linear dependence of the (29)Si nuclear shielding anisotropy of Q((3)) sites on the Si-non-bridging oxygen bond length, which in turn depends on the cation potential and coordination of modifier cations to the non-bridging oxygen. We also demonstrate how a combination of Cu(2+) as a paramagnetic dopant combined with echo train acquisition can reduce the total experiment time of (29)Si 2D NMR measurements by two orders of magnitude, enabling higher throughput 2D NMR studies of glass structure.

  18. Modifier cation effects on 29Si nuclear shielding anisotropies in silicate glasses

    NASA Astrophysics Data System (ADS)

    Baltisberger, Jay H.; Florian, Pierre; Keeler, Eric G.; Phyo, Pyae A.; Sanders, Kevin J.; Grandinetti, Philip J.

    2016-07-01

    We have examined variations in the 29Si nuclear shielding tensor parameters of SiO4 tetrahedra in a series of seven alkali and alkaline earth silicate glass compositions, Cs2O · 4.81 SiO2, Rb2O · 3.96 SiO2, Rb2O · 2.25 SiO2, K2O · 4.48 SiO2, Na2O · 4.74 SiO2, BaO · 2.64 SiO2, and SrO · 2.36 SiO2, using natural abundance 29Si two-dimensional magic-angle flipping (MAF) experiments. Our analyses of these 2D spectra reveal a linear dependence of the 29Si nuclear shielding anisotropy of Q(3) sites on the Si-non-bridging oxygen bond length, which in turn depends on the cation potential and coordination of modifier cations to the non-bridging oxygen. We also demonstrate how a combination of Cu2+ as a paramagnetic dopant combined with echo train acquisition can reduce the total experiment time of 29Si 2D NMR measurements by two orders of magnitude, enabling higher throughput 2D NMR studies of glass structure.

  19. Freezing of Molecular Motions Probed by Cryogenic Magic Angle Spinning NMR.

    PubMed

    Concistrè, Maria; Carignani, Elisa; Borsacchi, Silvia; Johannessen, Ole G; Mennucci, Benedetta; Yang, Yifeng; Geppi, Marco; Levitt, Malcolm H

    2014-02-06

    Cryogenic magic angle spinning makes it possible to obtain the NMR spectra of solids at temperatures low enough to freeze out most molecular motions. We have applied cryogenic magic angle spinning NMR to a crystalline small-molecule solid (ibuprofen sodium salt), which displays a variety of molecular dynamics. Magic angle (13)C NMR spectra are shown for a wide range of temperatures, including in the cryogenic regime down to 20 K. The hydrophobic and hydrophilic regions of the molecular structure display different behavior in the cryogenic regime, with the hydrophilic region remaining well-structured, while the hydrophobic region exhibits a broad frozen conformational distribution.

  20. 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.

  1. 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.

  2. 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.

  3. Nuclear Magnetic Resonance Spectroscopy Applications: Proton NMR In Biological Objects Subjected To Magic Angle Spinning

    SciTech Connect

    Wind, Robert A.; Hu, Jian Zhi

    2005-01-01

    Proton NMR in Biological Objects Submitted to Magic Angle Spinning, In Encyclopedia of Analytical Science, Second Edition (Paul J. Worsfold, Alan Townshend and Colin F. Poole, eds.), Elsevier, Oxford 6:333-342. Published January 1, 2005. Proposal Number 10896.

  4. Magic angle magnetic resonance imaging of diode laser induced and naturally occurring lesions in equine tendons.

    PubMed

    Spriet, Mathieu; Murphy, Brian; Vallance, Stuart A; Vidal, Martin A; Whitcomb, Mary Beth; Wisner, Erik R

    2012-01-01

    Magic angle magnetic resonance (MR) imaging consists of imaging tendons at 55° to the magnetic field. In people, magic angle MR imaging is valuable for detection of chronic tendon lesions and allows calculation of tendon T1 values. Increased T1 values occur in people with chronic tendinopathy. The T1 values of normal equine tendons have been reported but there are no available data for abnormal equine tendons. Twelve limbs were studied. Two limbs had diode laser tendon lesions induced postmortem, four limbs had diode laser tendon lesions induced in vivo and six limbs had naturally occurring tendon lesions. The limbs were imaged at 1.5 T using both conventional MR imaging and magic angle MR imaging. The post-mortem laser induced lesions were identified only with magic angle MR imaging. The in vivo induced lesions and naturally occurring lesions were identified with both techniques but had a different appearance with the two imaging techniques. Magic angle imaging was helpful at identifying lesions that were hypointense on conventional imaging. Increased T1 values were observed in all abnormal tendons and in several tendons with a subjectively normal MR appearance. The increased T1 value may reflect diffuse changes in the biochemical composition of tendons. Magic angle imaging has potential as a useful noninvasive tool to assess the changes of the extracellular tendon matrix using T1 values.

  5. 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

  6. 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

  7. 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

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

    SciTech Connect

    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.

  9. A Theoretical Design Approach for Passive Shimming of a Magic-Angle-Spinning NMR Magnet.

    PubMed

    Li, Frank X; Voccio, John P; Sammartino, Michael; Ahn, Minchul; Hahn, Seungyong; Bascuñán, Juan; Iwasa, Yukikazu

    2016-06-01

    This paper presents a passive shimming design approach for a magic-angle-spinning (MAS) NMR magnet. In order to achieve a 1.5-T magic-angle field in NMR samples, we created two independent orthogonal magnetic vector fields by two separate coils: the dipole and solenoid. These two coils create a combined 1.5-T magnetic field vector directed at the magic angle (54.74° from the spinning axis). Additionally, the stringent magnetic field homogeneity requirement of the MAS magnet is the same as that of a solenoidal NMR magnet. The challenge for the magic-angle passive shimming design is to correct both the dipole and solenoid magnetic field spherical harmonics with one set of iron pieces, the so-called ferromagnetic shimming. Furthermore, the magnetization of the iron pieces is produced by both the dipole and solenoid coils. In our design approach, a matrix of 2 mm by 5 mm iron pieces with different thicknesses was attached to a thin-walled tube, 90-mm diameter and 40-mm high. Two sets of spherical harmonic coefficients were calculated for both the dipole and solenoid coil windings. By using the multiple-objective linear programming optimization technique and coordinate transformations, we have designed a passive shimming set that can theoretically reduce 22 lower-order spherical harmonics and improve the homogeneity of our MAS NMR magnet.

  10. 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.

  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 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.

  12. V-shaped nematogens with the "magic bent angle".

    PubMed

    Seltmann, Jens; Müller, Kathrin; Klein, Susanne; Lehmann, Matthias

    2011-06-21

    V-shaped nematogens 1a-c and 2a-b with benzodithiophene bending units have been synthesised. The derivatives 1a-c comprise a flat core with a bending angle of 109°, which is almost the tetrahedral angle proposed to be optimal in the realization of mesogens forming a biaxial nematic thermotropic mesophase.

  13. A 29Si MAS-NMR study of transition metal site occupancy in forsterite

    NASA Astrophysics Data System (ADS)

    Mccarty, R. J.; Palke, A.; Stebbins, J. F.; Hartman, S.

    2012-12-01

    In this study, we address the problem of transition metal site occupancy in Mg-rich olivine using solid-state magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy. Transition metal substitution in olivine can occur in either of the two crystallographically unique octahedral sites: the smaller, more symmetric M1 site or the larger, more distorted M2 site. Site occupancy of the transition metal is expected to correlate with ionic radius and d-orbital structure. In NMR spectroscopy the presence of paramagnetic ions, such as transition metal ions, can produce accessory peaks referred to as "contact shifts," due to the interaction between unpaired electrons on the paramagnetic ion locally associated with the resonating nucleus. The position and intensity of the contact shifts are dependent on the geometrical association such as bond distances and bond angles between the paramagnetic ion and the resonating nucleus. 29Si MAS-NMR spectra collected on synthetic forsterite (Mg2SiO4) doped with minor amounts (0.2-5%) of individual, divalent, paramagnetic, transition metal cations (Mn, Co, Ni, or Cu) substituting for Mg in the octahedral sites, reveals multiple contact shifts. An interpretation of the number of such contact shifts and their relative intensities correlated with structural information of possible 29Si-M1 and 29Si-M2 configurations, potentially allows for the assignment of specific transition metals to individual M1 or M2 sites. An analysis of the MAS-NMR data will potentially bring a new level of confidence to transition metal site occupancy in forsterite.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 29Si NMR study of structural ordering in aluminosilicate geopolymer gels.

    PubMed

    Duxson, Peter; Provis, John L; Lukey, Grant C; Separovic, Frances; van Deventer, Jannie S J

    2005-03-29

    A systematic series of aluminosilicate geopolymer gels was synthesized and then analyzed using 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) in combination with Gaussian peak deconvolution to characterize the short-range ordering in terms of T-O-T bonds (where T is Al or Si). The effect of nominal Na2O/(Na2O + K2O) and Si/Al ratios on short-range network ordering was quantified by deconvolution of the 29Si MAS NMR spectra into individual Gaussian peaks representing different Q4(mAl) silicon centers. The deconvolution procedure developed in this work is applicable to other aluminosilicate gel systems. The short-range ordering observed here indicates that Loewenstein's Rule of perfect aluminum avoidance may not apply strictly to geopolymeric gels, although further analyses are required to quantify the degree of aluminum avoidance. Potassium geopolymers appeared to exhibit a more random Si/Al distribution compared to that of mixed-alkali and sodium systems. This work provides a quantitative account of the silicon and aluminum ordering in geopolymers, which is essential for extending our understanding of the mechanical strength, chemical and thermal stability, and fundamental structure of these systems.

  2. 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.

  3. Structure vs. composition: A solid-state 1H and 29Si NMR study of quenched glasses along the Na 2O-SiO 2-H 2O join

    NASA Astrophysics Data System (ADS)

    Cody, George D.; Mysen, Bjorn O.; Lee, Sung Keun

    2005-05-01

    A suite of six hydrous (7 wt.% H 2O) sodium silicate glasses spanning sodium octasilicate to sodium disilicate in composition were analyzed using 29Si single pulse (SP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, 1H- 29Si cross polarization (CP) MAS NMR, and fast MAS 1H-NMR. From the 29Si SPMAS data it is observed that at low sodium compositions dissolved water significantly depolymerizes the silicate network. At higher sodium contents, however, dissolved H 2O does not affect a significant increase in depolymerization over that predicted based on the Na/Si ratio alone. The fast MAS 1H-NMR data reveal considerable complexity in proton environments in each of the glasses studied. The fast MAS 1H-NMR spectra of the highest sodium concentration glasses do not exhibit evidence of signficantly greater fractions of dissolved water as molecular H 2O than the lower sodium concentration glasses requiring that the decrease in polymerization at high sodium contents involves a change in sodium solution mechanism. Variable contact time 1H- 29Si cross polarization (CP) MAS NMR data reveal an increase in the rotating frame spin lattice relaxation rate constant ( T1ρ*) for various Q n species with increasing sodium content that correlates with a reduction in the average 1H- 29Si coupling strength. At the highest sodium concentration, however, T1ρ* drops significantly, consistent with a change in the Na 2O solution mechanism.

  4. 14N overtone NMR spectra under magic angle spinning: Experiments and numerically exact simulations

    NASA Astrophysics Data System (ADS)

    O'Dell, Luke A.; Brinkmann, Andreas

    2013-02-01

    It was recently shown that high resolution 14N overtone NMR spectra can be obtained directly under magic angle spinning (MAS) conditions [L. A. O'Dell and C. I. Ratcliffe, Chem. Phys. Lett. 514, 168 (2011)], 10.1016/j.cplett.2011.08.030. Preliminary experimental results showed narrowed powder pattern widths, a frequency shift that is dependent on the MAS rate, and an apparent absence of spinning sidebands, observations which appeared to be inconsistent with previous theoretical treatments. Herein, we reproduce these effects using numerically exact simulations that take into account the full nuclear spin Hamiltonian. Under sample spinning, the 14N overtone signal is split into five (0, ±1, ±2) overtone sidebands separated by the spinning frequency. For a powder sample spinning at the magic angle, the +2ωr sideband is dominant while the others show significantly lower signal intensities. The resultant MAS powder patterns show characteristic quadrupolar lineshapes from which the 14N quadrupolar parameters and isotropic chemical shift can be determined. Spinning the sample at other angles is shown to alter both the shapes and relative intensities of the five overtone sidebands, with MAS providing the benefit of averaging dipolar couplings and shielding anisotropy. To demonstrate the advantages of this experimental approach, we present the 14N overtone MAS spectrum obtained from L-histidine, in which powder patterns from all three nitrogen sites are clearly resolved.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

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

    SciTech Connect

    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.

  10. 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.

  11. 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.

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

    SciTech Connect

    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 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. 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.

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

    DOE PAGES

    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

  14. 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.

  15. The effect of Hartmann-Hahn mismatching on polarization inversion spin exchange at the magic angle.

    PubMed

    Fu, Riqiang; Tian, Changlin; Kim, Hyeongnam; Smith, Scott A; Cross, Timothy A

    2002-12-01

    The effect of the Hartmann-Hahn mismatch delta = omega(eff)-omega(1S) during polarization inversion spin exchange at the magic angle (PISEMA) has been investigated, where omega(eff) and omega(1S) represent the amplitudes of the 1H effective spin-locking field at the magic angle and the 15N RF spin-locking field, respectively. During the PISEMA evolution period, the exact Hartmann-Hahn match condition (i.e., delta = 0) yields a maximum dipolar scaling factor of 0.816 for PISEMA experiments, while any mismatch results in two different effective fields for the first and second half of each frequency switched Lee-Goldburg (FSLG) cycle. The mismatch effect on the scaling factor depends strongly on the transition angle from one effective field to the other within each FSLG cycle as well as on the cycle time. At low RF spin-lock amplitudes in which the FSLG cycle time is relatively long, the scaling factor rapidly becomes smaller as omega(1S) becomes greater than omega(eff). On the other hand, when omega(1S) < omega(eff), there is relatively little effect on the scaling factor with variation in delta. As a result, the presence of RF inhomogeneities may significantly broaden the line-width in the dipolar dimension because of the mismatch effect. Higher RF spin-lock amplitudes result in a relatively small variation for the scaling factor. Furthermore, ramped amplitude of the 15N RF spin-lock field in synchronization with the flip-flop of the FSLG sequence minimizes the transition angle between the two effective fields within the FSLG cycle. It is shown experimentally that such a ramped amplitude not only gives rise to the same scaling factor but also results in a narrower dipolar line-width in comparison with the rectangular amplitude.

  16. Rapid Proton-Detected NMR Assignment for Proteins with Fast Magic Angle Spinning

    PubMed Central

    2015-01-01

    Using a set of six 1H-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 2H/1H 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 13C/15N-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

  17. 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 .

  18. 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.

  19. 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.

  20. 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.

  1. 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

    2014-09-03

    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.

  2. High resolution 11B NMR of MgB2 using cryogenic magic-angle spinning

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    Static and magic-angle spinning (MAS) 11B 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. We demonstrate that MAS NMR is possible on type-II superconductors despite the sample rotation. The data provide accurate information on the magnetic shift variation and longitudinal relaxation data 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. Appeared in JCP 137, 114201, http://dx.doi.org/10.1063/1.4751476

  3. 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.

  4. Adiabatic sweep cross-polarization magic-angle-spinning NMR of half-integer quadrupolar spins

    NASA Astrophysics Data System (ADS)

    Wi, Sungsool; Kim, Chul; Schurko, Robert; Frydman, Lucio

    2017-04-01

    The use of frequency-swept radiofrequency (rf) pulses for enhancing signals in the magic-angle spinning (MAS) spectra of half-integer quadrupolar nuclides was explored. The broadband adiabatic inversion cross-polarization magic-angle spinning (BRAIN-CPMAS) method, involving an adiabatic inversion pulse on the S-channel and a simultaneous rectangular spin-lock pulse on the I-channel (1H), was applied to I(1/2) → S(3/2) systems. Optimal BRAIN-CPMAS matching conditions were found to involve low rf pulse strengths for both the I- and S-spin channels. At these low and easily attainable rf field strengths, level-crossing events among the energy levels | 3 / 2 >, | 1 / 2 >, | - 1 / 2 >, | - 3 / 2 > that are known to complicate the CPMAS of quadrupolar nuclei, are mostly avoided. Zero- and double-quantum polarization transfer modes, akin to those we have observed for I(1/2) → S(1/2) polarization transfers, were evidenced by these analyses even in the presence of the quadrupolar interaction. 1H-23Na and 1H-11B BRAIN-CPMAS conditions were experimentally explored on model compounds by optimizing the width of the adiabatic sweep, as well as the rf pulse powers of the 1H and 23Na/11B channels, for different MAS rates. The experimental data obtained on model compounds containing spin-3/2 nuclides, matched well predictions from numerical simulations and from an average Hamiltonian theory model. Extensions to half-integer spin nuclides with higher spins and potential applications of this BRAIN-CPMAS approach are discussed.

  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.

  7. 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

  8. High Resolution H-1 NMR Spectroscopy in a Live Mouse subjected to 1.5 Hz Magic Angle Spinning

    SciTech Connect

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

    2003-12-03

    It is demonstrated that the resolution of the 1H NMR metabolite spectrum in a live mouse can be significantly enhanced by an ultra-slow magic angle spinning of the animal 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 about one hour in a 2T field, while spinning the animal at a speed of 1.5 Hz. It was found 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. It is concluded that in vivo PHORMAT has the potential to significantly increase the utility of 1H NMR spectroscopy for biochemical and biomedical animal research.

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

    PubMed

    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 (approximately 12 K) 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). (1)H MAS NMR with the coil temperature of approximately 20 K was successfully observed for solid adamantane rotating at room temperature, and signal-to-noise increment due to this cryocoil approach was confirmed.

  10. 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.

  11. Biomolecular solid state NMR with magic-angle spinning at 25 K

    PubMed Central

    Thurber, Kent R.; Tycko, Robert

    2009-01-01

    A magic-angle spinning (MAS) probe has been constructed which allows the sample to be cooled with helium, while the MAS bearing and drive gases are nitrogen. The sample can be cooled to 25 K using roughly 3 liters/hour of liquid helium, while the 4 mm diameter rotor spins at 6.7 kHz with good stability (±5 Hz) for many hours. Proton decoupling fields up to at least 130 kHz can be applied. This helium-cooled MAS probe enables a variety of one-dimensional and two-dimensional NMR experiments on biomolecular solids and other materials at low temperatures, with signal-to-noise proportional to 1/T. We show examples of low-temperature 13C NMR data for two biomolecular samples, namely the peptide Aβ14–23 in the form of amyloid fibrils and the protein HP35 in frozen glycerol/water solution. Issues related to temperature calibration, spin-lattice relaxation at low temperatures, paramagnetic doping of frozen solutions, and 13C MAS NMR linewidths are discussed. PMID:18922715

  12. 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.

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

    PubMed Central

    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

    2016-01-01

    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 1H-1H 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

  14. Magic angle spinning NMR of proteins: high-frequency dynamic nuclear polarization and (1)H detection.

    PubMed

    Su, Yongchao; Andreas, Loren; Griffin, Robert G

    2015-01-01

    Magic angle spinning (MAS) NMR studies of amyloid and membrane proteins and large macromolecular complexes are an important new approach to structural biology. However, the applicability of these experiments, which are based on (13)C- and (15)N-detected spectra, would be enhanced if the sensitivity were improved. Here we discuss two advances that address this problem: high-frequency dynamic nuclear polarization (DNP) and (1)H-detected MAS techniques. DNP is a sensitivity enhancement technique that transfers the high polarization of exogenous unpaired electrons to nuclear spins via microwave irradiation of electron-nuclear transitions. DNP boosts NMR signal intensities by factors of 10(2) to 10(3), thereby overcoming NMR's inherent low sensitivity. Alternatively, it permits structural investigations at the nanomolar scale. In addition, (1)H detection is feasible primarily because of the development of MAS rotors that spin at frequencies of 40 to 60 kHz or higher and the preparation of extensively (2)H-labeled proteins.

  15. Spin dynamics of polarization inversion spin exchange at the magic angle in multiple spin systems.

    PubMed

    Gan, Z

    2000-03-01

    Polarization inversion spin exchange at the magic angle (PISEMA) [J. Magn. Reson. A 109, 270 (1994)] is an important experiment in NMR structural characterization of membrane proteins in oriented lipid bilayers. This paper presents a theoretical and experimental study of the spin dynamics in PISEMA to investigate the line-narrowing mechanism. The study focuses on the effect of neighboring protons on the spin exchange of a strongly coupled spin pair. The spin exchange is solved analytically for simple spin systems and is numerically simulated for many-spin systems. The results show that the dipolar couplings from the neighboring protons of a strongly coupled spin pair perturb the spin exchange only in the second order, therefore it has little contribution to the linewidth of PISEMA spectra in comparison to the separated-local-field spectra. The effects from proton resonance offset and the mismatch of the Hartmann-Hahn condition are also discussed along with experimental results using model single-crystal samples.

  16. 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

  17. 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.

  18. 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.

  19. A permanent MRI magnet for magic angle imaging having its field parallel to the poles

    NASA Astrophysics Data System (ADS)

    McGinley, John V. M.; Ristic, Mihailo; Young, Ian R.

    2016-10-01

    A novel design of open permanent magnet is presented, in which the magnetic field is oriented parallel to the planes of its poles. The paper describes the methods whereby such a magnet can be designed with a field homogeneity suitable for Magnetic Resonance Imaging (MRI). Its primary purpose is to take advantage of the Magic Angle effect in MRI of human extremities, particularly the knee joint, by being capable of rotating the direction of the main magnetic field B0 about two orthogonal axes around a stationary subject and achieve all possible angulations. The magnet comprises a parallel pair of identical profiled arrays of permanent magnets backed by a flat steel yoke such that access in lateral directions is practical. The paper describes the detailed optimization procedure from a target 150 mm DSV to the achievement of a measured uniform field over a 130 mm DSV. Actual performance data of the manufactured magnet, including shimming and a sample image, is presented. The overall magnet system mounting mechanism is presented, including two orthogonal axes of rotation of the magnet about its isocentre.

  20. A permanent MRI magnet for magic angle imaging having its field parallel to the poles.

    PubMed

    McGinley, John V M; Ristic, Mihailo; Young, Ian R

    2016-10-01

    A novel design of open permanent magnet is presented, in which the magnetic field is oriented parallel to the planes of its poles. The paper describes the methods whereby such a magnet can be designed with a field homogeneity suitable for Magnetic Resonance Imaging (MRI). Its primary purpose is to take advantage of the Magic Angle effect in MRI of human extremities, particularly the knee joint, by being capable of rotating the direction of the main magnetic field B0 about two orthogonal axes around a stationary subject and achieve all possible angulations. The magnet comprises a parallel pair of identical profiled arrays of permanent magnets backed by a flat steel yoke such that access in lateral directions is practical. The paper describes the detailed optimization procedure from a target 150mm DSV to the achievement of a measured uniform field over a 130mm DSV. Actual performance data of the manufactured magnet, including shimming and a sample image, is presented. The overall magnet system mounting mechanism is presented, including two orthogonal axes of rotation of the magnet about its isocentre.

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

    PubMed

    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

    2009-06-01

    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 100K which shows 30 Hz linewidths.

  2. Proton-Detected Solid-State NMR Spectroscopy of Bone with Ultrafast Magic Angle Spinning

    NASA Astrophysics Data System (ADS)

    Mroue, Kamal H.; Nishiyama, Yusuke; Kumar Pandey, Manoj; Gong, Bo; McNerny, Erin; Kohn, David H.; Morris, Michael D.; Ramamoorthy, Ayyalusamy

    2015-07-01

    While obtaining high-resolution structural details from bone is highly important to better understand its mechanical strength and the effects of aging and disease on bone ultrastructure, it has been a major challenge to do so with existing biophysical techniques. Though solid-state NMR spectroscopy has the potential to reveal the structural details of bone, it suffers from poor spectral resolution and sensitivity. Nonetheless, recent developments in magic angle spinning (MAS) NMR technology have made it possible to spin solid samples up to 110 kHz frequency. With such remarkable capabilities, 1H-detected NMR experiments that have traditionally been challenging on rigid solids can now be implemented. Here, we report the first application of multidimensional 1H-detected NMR measurements on bone under ultrafast MAS conditions to provide atomistic-level elucidation of the complex heterogeneous structure of bone. Our investigations demonstrate that two-dimensional 1H/1H chemical shift correlation spectra for bone are obtainable using fp-RFDR (finite-pulse radio-frequency-driven dipolar recoupling) pulse sequence under ultrafast MAS. Our results infer that water exhibits distinct 1H-1H dipolar coupling networks with the backbone and side-chain regions in collagen. These results show the promising potential of proton-detected ultrafast MAS NMR for monitoring structural and dynamic changes caused by mechanical loading and disease in bone.

  3. 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.

  4. 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

  5. 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

  6. Ultrashort echo time magnetization transfer (UTE-MT) imaging and modeling: magic angle independent biomarkers of tissue properties.

    PubMed

    Ma, Ya-Jun; Shao, Hongda; Du, Jiang; Chang, Eric Y

    2016-11-01

    MRI biomarkers such as T2 , T2 * and T1rho have been widely used, but are confounded by the magic angle effect. The purpose of this study is to investigate the use of the two-dimensional ultrashort echo time magnetization transfer (UTE-MT) sequence for potential magic angle independent MR biomarkers. Magnetization transfer was investigated in cadaveric Achilles tendon samples using the UTE-MT sequence at five MT powers and five frequency offsets ranging from 2 to 50 kHz. The protocol was applied at five sample orientations ranging from 0 to 90° relative to the B0 field. The results were analyzed with a two-pool quantitative MT model. Multiple TE data were also acquired and mono-exponential T2 * was calculated for each orientation. Macromolecular proton fractions and exchange rates derived from UTE-MT modeling did not appreciably change between the various orientations, whereas the T2 * relaxation time demonstrated up to a sixfold increase from 0° to 55°. The UTE-MT technique with two-pool modeling shows promise as a clinically compatible technique that is resistant to the magic angle effect. This method provides information on the macromolecular proton pool that cannot be directly obtained by other methods, including regular UTE techniques.

  7. 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.

  8. 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.

  9. 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.

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

    PubMed

    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

  11. 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

  12. 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.

  13. In Vivo Detection of the Cyclic Osmoregulated Periplasmic Glucan of Ralstonia solanacearum by High-Resolution Magic Angle Spinning NMR

    NASA Astrophysics Data System (ADS)

    Wieruszeski, J.-M.; Bohin, A.; Bohin, J.-P.; Lippens, G.

    2001-07-01

    We investigate the mobility of the osmoregulated periplasmic glucans of Ralstonia solanacearum in the bacterial periplasm through the use of high-resolution (HR) NMR spectroscopy under static and magic angle spinning (MAS) conditions. Because the nature of periplasm is far from an isotropic aqueous solution, the molecules could be freely diffusing or rather associated to a periplasmic protein, a membrane protein, a lipid, or the peptidoglycan. HR MAS NMR spectroscopy leads to more reproducible results and allows the in vivo detection and characterization of the complex molecule.

  14. Use of rotary echoes in 2H magic-angle spinning NMR for the quantitative study of molecular dynamics

    NASA Astrophysics Data System (ADS)

    Hogg, Naomi H. M.; Boulton, Paul J. T.; Zorin, Vadim E.; Harris, Robin K.; Hodgkinson, Paul

    2009-06-01

    The interaction of sample spinning and chemical dynamics is analysed in the context of 2H magic-angle spinning NMR. We develop previous analyses and show that a metric based on the intensity of rotational echoes allows kinetic information to be derived without the need for full modelling of the NMR response. This approach is illustrated on the conformational exchange of 1,4-dioxane included in the channel solvate hydrate formed with finasteride. An activation barrier in excellent agreement with previous experimental and theoretical estimates is obtained, without the need for modelling which would be very challenging due to the anisotropic tumbling of the solvent molecules.

  15. Parameter independent low-power heteronuclear decoupling for fast magic-angle spinning solid-state NMR

    NASA Astrophysics Data System (ADS)

    Equbal, Asif; Madhu, P. K.; Meier, Beat H.; Nielsen, Niels Chr.; Ernst, Matthias; Agarwal, Vipin

    2017-02-01

    Major advances have recently been made in the field of heteronuclear dipolar decoupling in solid-state nuclear magnetic resonance (NMR). These developments have improved the resolution and sensitivity of the NMR spectrum of spins coupled to protons. One such new scheme, denoted as rCWApA, has proven to be robust with practically no need for parameter optimization [A. Equbal et al. Chem. Phys. Lett., 635, 339 (2015)]. Most of the experiments with rCWApA have been carried out in the regimes of slow to moderate magic-angle spinning while simultaneously applying high decoupling radio-frequency amplitudes. Here, we explore the performance of the rCWApA sequence and its predecessor rCWA in the regime of low-power radio-frequency irradiation and fast magic-angle spinning. The robustness of the refocused continuous-wave (rCW) schemes to experimental parameters such as pulse lengths and offset irradiation is demonstrated. Numerical simulations and analytical theory have been used to understand the effects of various nuclear spin interactions on the decoupling performance of the low-power rCW decoupling scheme relative to other decoupling methods. This has lead to the design of an "optimum low-power decoupling sequence" that can be used without parameter optimization. This result is particularly important in the context of samples with low signal to noise.

  16. Studying Dynamics by Magic-Angle Spinning Solid-State NMR Spectroscopy: Principles and Applications to Biomolecules

    PubMed Central

    Schanda, Paul; Ernst, Matthias

    2016-01-01

    Magic-angle spinning solid-state NMR spectroscopy is an important technique to study molecular structure, dynamics and interactions, and is rapidly gaining importance in biomolecular sciences. Here we provide an overview of experimental approaches to study molecular dynamics by MAS solid-state NMR, with an emphasis on the underlying theoretical concepts and differences of MAS solid-state NMR compared to solution-state NMR. The theoretical foundations of nuclear spin relaxation are revisited, focusing on the particularities of spin relaxation in solid samples under magic-angle spinning. We discuss the range of validity of Redfield theory, as well as the inherent multi-exponential behavior of relaxation in solids. Experimental challenges for measuring relaxation parameters in MAS solid-state NMR and a few recently proposed relaxation approaches are discussed, which provide information about time scales and amplitudes of motions ranging from picoseconds to milliseconds. We also discuss the theoretical basis and experimental measurements of anisotropic interactions (chemical-shift anisotropies, dipolar and quadrupolar couplings), which give direct information about the amplitude of motions. The potential of combining relaxation data with such measurements of dynamically-averaged anisotropic interactions is discussed. Although the focus of this review is on the theoretical foundations of dynamics studies rather than their application, we close by discussing a small number of recent dynamics studies, where the dynamic properties of proteins in crystals are compared to those in solution. PMID:27110043

  17. Parameter independent low-power heteronuclear decoupling for fast magic-angle spinning solid-state NMR.

    PubMed

    Equbal, Asif; Madhu, P K; Meier, Beat H; Nielsen, Niels Chr; Ernst, Matthias; Agarwal, Vipin

    2017-02-28

    Major advances have recently been made in the field of heteronuclear dipolar decoupling in solid-state nuclear magnetic resonance (NMR). These developments have improved the resolution and sensitivity of the NMR spectrum of spins coupled to protons. One such new scheme, denoted as rCW(ApA), has proven to be robust with practically no need for parameter optimization [A. Equbal et al. Chem. Phys. Lett., 635, 339 (2015)]. Most of the experiments with rCW(ApA) have been carried out in the regimes of slow to moderate magic-angle spinning while simultaneously applying high decoupling radio-frequency amplitudes. Here, we explore the performance of the rCW(ApA) sequence and its predecessor rCW(A) in the regime of low-power radio-frequency irradiation and fast magic-angle spinning. The robustness of the refocused continuous-wave (rCW) schemes to experimental parameters such as pulse lengths and offset irradiation is demonstrated. Numerical simulations and analytical theory have been used to understand the effects of various nuclear spin interactions on the decoupling performance of the low-power rCW decoupling scheme relative to other decoupling methods. This has lead to the design of an "optimum low-power decoupling sequence" that can be used without parameter optimization. This result is particularly important in the context of samples with low signal to noise.

  18. 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.

  19. Differential cross sections measurement of 28Si(p,p/γ)28Si and 29Si(p,p/γ)29Si reactions for PIGE applications

    NASA Astrophysics Data System (ADS)

    Jokar, A.; Kakuee, O.; Lamehi-Rachti, M.

    2016-03-01

    Differential cross sections for gamma-ray emission from the 28Si(p,p/γ)28Si (Eγ = 1779 keV) and the 29Si(p,p/γ)29Si (Eγ = 1273 keV) nuclear reactions were measured in the energy range of 2.0-3.2 MeV and 2.0-3.0 MeV, respectively. The thin Si targets were prepared by evaporating natural SiO onto self-supporting Ag films. The gamma-rays and backscattered protons were detected simultaneously. An HPGe detector placed at an angle of 90° with respect to beam direction was employed to collect gamma-rays while an ion implanted Si detector placed at a scattering angle of 165° was used to detect backscattered protons. The great advantage of this work is that differential cross sections were obtained with a procedure irrespective of absolute value of the collected beam charge.

  20. Solid-state {sup 27}Al and {sup 29}Si NMR characterization of hydrates formed in calcium aluminate-silica fume mixtures

    SciTech Connect

    Pena, P.; Rivas Mercury, J.M.

    2008-08-15

    Partially deuterated Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub y}(OH){sub 12-4y}-Al(OH){sub 3} mixtures, prepared by hydration of Ca{sub 3}Al{sub 2}O{sub 6} (C{sub 3}A), Ca{sub 12}Al{sub 14}O{sub 33} (C{sub 12}A{sub 7}) and CaAl{sub 2}O{sub 4} (CA) phases in the presence of silica fume, have been characterized by {sup 29}Si and {sup 27}Al magic-angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies. NMR spectroscopy was used to characterize anhydrous and fully hydrated samples. In hydrated compounds, Ca{sub 3}Al{sub 2}(OH){sub 12} and Al(OH){sub 3} phases were detected. From the quantitative analysis of {sup 27}Al NMR signals, the Al(OH){sub 3}/Ca{sub 3}Al{sub 2}(OH){sub 12} ratio was deduced. The incorporation of Si into the katoite structure, Ca{sub 3}Al{sub 2}(SiO{sub 4}){sub 3-x}(OH){sub 4x}, was followed by {sup 27}Al and {sup 29}Si NMR spectroscopies. Si/OH ratios were determined from the quantitative analysis of {sup 27}Al MAS-NMR components associated with Al(OH){sub 6} and Al(OSi)(OH){sub 5} environments. The {sup 29}Si NMR spectroscopy was also used to quantify the unreacted silica and amorphous calcium aluminosilicate hydrates formed, C-S-H and C-A-S-H for short. From {sup 29}Si NMR spectra, the amount of Si incorporated into different phases was estimated. Si and Al concentrations, deduced by NMR, transmission electron microscopy, energy dispersive spectrometry, and Rietveld analysis of both X-ray and neutron data, indicate that only a part of available Si is incorporated in katoite structures. - Graphical abstract: Transmission electron micrograph of CaAl{sub 2}O{sub 4}-microsilica mixture hydrated at 90 deg. C for 31 days showing a cubic Ca{sub 3}Al{sub 2.0{+-}}{sub 0.2}(SiO{sub 4}){sub 0.9{+-}}{sub 0.2}(OH){sub 1.8} crystal surrounded by unreacted amorphous silica spheres.

  1. 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

  2. Magic Angle Spinning NMR Investigation of Influenza A M218-60: Support for an Allosteric Mechanism of Inhibition

    PubMed Central

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

    2010-01-01

    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. We report magic angle spinning NMR spectra of POPC and DPhPC membrane embedded M218-60, both apo and in the presence of rimantadine. Similar linewidths in spectra of apo and bound M2 indicate that rimantadine 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. A Rmt titration supports a binding stoichiometry of >1 Rmt molecule per channel while showing that nonspecific bindin0g 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

  3. 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.

  4. Measurement of lateral diffusion rates in membranes by pulsed magnetic field gradient, magic angle spinning-proton nuclear magnetic resonance.

    PubMed

    Gawrisch, Klaus; Gaede, Holly C

    2007-01-01

    Membrane organization, including the presence of domains, can be characterized by measuring lateral diffusion rates of lipids and membrane-bound substances. Magic angle spinning (MAS) yields well-resolved proton nuclear magnetic resonance (NMR) of lipids in biomembranes. When combined with pulsed-field gradient NMR (rendering what is called "pulsed magnetic field gradients-MAS-NMR"), it permits precise diffusion measurements on the micrometer lengths scale for any substance with reasonably well-resolved proton MAS-NMR resonances, without the need of preparing oriented samples. Sample preparation procedures, the technical requirements for the NMR equipment, and spectrometer settings are described. Additionally, equations for analysis of diffusion data obtained from unoriented samples, and a method for correcting the data for liposome curvature are provided.

  5. On the use of ultracentrifugal devices for routine sample preparation in biomolecular magic-angle-spinning NMR.

    PubMed

    Mandal, Abhishek; Boatz, Jennifer C; Wheeler, Travis B; van der Wel, Patrick C A

    2017-02-22

    A number of recent advances in the field of magic-angle-spinning (MAS) solid-state NMR have enabled its application to a range of biological systems of ever increasing complexity. To retain biological relevance, these samples are increasingly studied in a hydrated state. At the same time, experimental feasibility requires the sample preparation process to attain a high sample concentration within the final MAS rotor. We discuss these considerations, and how they have led to a number of different approaches to MAS NMR sample preparation. We describe our experience of how custom-made (or commercially available) ultracentrifugal devices can facilitate a simple, fast and reliable sample preparation process. A number of groups have since adopted such tools, in some cases to prepare samples for sedimentation-style MAS NMR experiments. Here we argue for a more widespread adoption of their use for routine MAS NMR sample preparation.

  6. Chemical shift powder spectra enhanced by multiple-contact cross-polarization under slow magic-angle spinning.

    PubMed

    Raya, Jésus; Perrone, Barbara; Hirschinger, Jérôme

    2013-02-01

    A simple multiple-contact cross-polarization (CP) scheme is applied to a powder sample of ferrocene and β-calcium formate under static and magic-angle spinning (MAS) conditions. The method is described analytically through the density matrix formalism. We show that multiple equilibrations-re-equilibrations with the proton spin bath improves the polarization transfer efficiency at short contact times and provides higher signal enhancements than state-of-the art techniques such as adiabatic passage through the Hartmann-Hahn condition CP (APHH-CP) when MAS is applied. The resulting chemical shift powder spectra then are identical to the ones obtained by using ROtor-Directed Exchange of Orientations CP (APHH-RODEO-CP) with intensity gains of a factor 1.1-1.3.

  7. Chemical shift powder spectra enhanced by multiple-contact cross-polarization under slow magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Raya, Jésus; Perrone, Barbara; Hirschinger, Jérôme

    2013-02-01

    A simple multiple-contact cross-polarization (CP) scheme is applied to a powder sample of ferrocene and β-calcium formate under static and magic-angle spinning (MAS) conditions. The method is described analytically through the density matrix formalism. We show that multiple equilibrations-re-equilibrations with the proton spin bath improves the polarization transfer efficiency at short contact times and provides higher signal enhancements than state-of-the art techniques such as adiabatic passage through the Hartmann-Hahn condition CP (APHH-CP) when MAS is applied. The resulting chemical shift powder spectra then are identical to the ones obtained by using ROtor-Directed Exchange of Orientations CP (APHH-RODEO-CP) with intensity gains of a factor 1.1-1.3.

  8. High resolution magic angle spinning NMR applied to the analysis of organic compounds bound to solid supports.

    PubMed

    Espinosa, Juan F

    2011-01-01

    In situ structural characterization of organic compounds attached to solid supports can be achieved by high-resolution magic angle spinning NMR (HRMAS NMR), a technique that provides solution-like spectra for resin-bound molecules. This review outlines the principles of the technique, the influence of the solid support on data quality, and NMR experiments that are useful for obtaining valuable information. The review describes, with multiple examples mainly from the last 7 years, how HRMAS NMR has been applied to monitor solid-phase reactions, elucidate reaction products and quantify compound loading on a solid support. Other applications, such as conformational analysis of immobilized compounds and investigation of molecular interactions with compounds in solution, are also discussed.

  9. Properties of mixtures of cholesterol with phosphatidylcholine or with phosphatidylserine studied by (13)C magic angle spinning nuclear magnetic resonance.

    PubMed Central

    Epand, Richard M; Bain, Alex D; Sayer, Brian G; Bach, Diana; Wachtel, Ellen

    2002-01-01

    The behavior of cholesterol is different in mixtures with phosphatidylcholine as compared with phosphatidylserine. In (13)C cross polarization/magic angle spinning nuclear magnetic resonance spectra, resonance peaks of the vinylic carbons of cholesterol are a doublet in samples containing 0.3 or 0.5 mol fraction cholesterol with 1-palmitoyl-2-oleoyl phosphatidylserine (POPS) or in cholesterol monohydrate crystals, but a singlet with mixtures of cholesterol and 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC). At these molar fractions of cholesterol with POPS, resonances of the C-18 of cholesterol appear at the same chemical shifts as in pure cholesterol monohydrate crystals. These resonances do not appear in samples of POPS with 0.2 mol fraction cholesterol or with POPC up to 0.5 mol fraction cholesterol. In addition, there is another resonance from the cholesterol C18 that appears in all of the mixtures of phospholipid and cholesterol but not in pure cholesterol monohydrate crystals. Using direct polarization, the fraction of cholesterol present as crystallites in POPS with 0.5 mol fraction cholesterol is found to be 80%, whereas with the same mol fraction of cholesterol and POPC none of the cholesterol is crystalline. After many hours of incubation, cholesterol monohydrate crystals in POPS undergo a change that results in an increase in the intensity of certain resonances of cholesterol monohydrate in (13)C cross polarization/magic angle spinning nuclear magnetic resonance, indicating a rigidification of the C and D rings of cholesterol but not other regions of the molecule. PMID:12324423

  10. Water and magmas: insights about the water solution mechanisms in alkali silicate melts from infrared, Raman, and 29Si solid-state NMR spectroscopies

    NASA Astrophysics Data System (ADS)

    Le Losq, Charles; Mysen, Bjorn O.; Cody, George D.

    2015-12-01

    Degassing of water during the ascent of hydrous magma in a volcanic edifice produces dramatic changes in the magma density and viscosity. This can profoundly affect the dynamics of volcanic eruptions. The water exsolution history, in turn, is driven by the water solubility and solution mechanisms in the silicate melt. Previous studies pointed to dissolved water in silicate glasses and melts existing as molecules (H2Omol species) and hydroxyl groups, OH. These latter OH groups commonly are considered bonded to Si4+ but may form other bonds, such as with alkali or alkaline-earth cations, for instance. Those forms of bonding influence the structure of hydrous melts in different ways and, therefore, their properties. As a result, exsolution of water from magmas may have different eruptive consequences depending on the initial bonding mechanisms of the dissolved water. However, despite their importance, the solution mechanisms of water in silicate melts are not clear. In particular, how chemical composition of melts affects water solubility and solution mechanism is not well understood. In the present experimental study, components of such information are reported via determination of how water interacts with the cationic network of alkali (Li, Na, and K) silicate quenched melts. Results from 29Si single-pulse magic-angle spinning nuclear magnetic resonance (29Si SP MAS NMR), infrared, and Raman spectroscopies show that decreasing the ionic radius of alkali metal cation in silicate melts results in decreasing fraction of water dissolved as OH groups. The nature of OH bonding also changes as the alkali ionic radius changes. Therefore, as the speciation and bonding of water controls the degree of polymerization of melts, water will have different effects on the transport properties of silicate melts depending on their chemical composition. This conclusion, in turn, may affect volcanic phenomena related to the viscous relaxation of hydrous magmas, such as for instance the

  11. 29Si{1H} CP-MAS NMR comparison and ATR-FTIR spectroscopic analysis of the diatoms Chaetoceros muelleri and Thalassiosira pseudonana grown at different salinities.

    PubMed

    La Vars, Sian M; Johnston, Martin R; Hayles, John; Gascooke, Jason R; Brown, Melissa H; Leterme, Sophie C; Ellis, Amanda V

    2013-04-01

    Diatoms are key indicators of marine environmental health. To further understand how diatoms respond to varying degrees of salinity, either due to climate change or brine waste discharge into marine environments, two different diatom species were studied. Thalassiosira pseudonana and Chaetoceros muelleri were cultured at three different salinities namely, 26 practical salinity units (PSU or parts per thousand), 36 PSU (standard salinity for culturing of seawater species) and 46 PSU. Changes in silica and organic content within the cultured diatoms were analysed using solid-state (29)Si{(1)H} cross-polarization-magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopies coupled with analysis of variance. (29)Si CP-MAS NMR showed that qualitatively the Q4:Q3 area ratios of C. muelleri, grown away from standard salinities, increased in response to the formation of more condensed (2 ≡SiOH → ≡Si-O-Si≡ + H2O) and/or an increase in closely associated organic matter to the Q4 component of the diatoms. This was not observed for T. pseudonana. However, both species showed the appearance of a new peak centered at 1575-1580 cm(-1) in the ATR-FTIR spectra, designated as the C═N band of nitrogenous purine-type compounds. Further, the C. muelleri species was shown to produce more extracellular polymeric substances at non-standard salinities. On this basis, results suggest that there is a strong relationship between diatom composition and salinity and that C. muelleri is more sensitive to its environment than T. pseudonana.

  12. 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.

  13. Gelified Biofluids for High-Resolution Magic Angle Spinning (1)H NMR Analysis: The Case of Urine.

    PubMed

    Takis, Panteleimon G; Tenori, Leonardo; Ravera, Enrico; Luchinat, Claudio

    2017-01-17

    In this letter, we propose an alternative, effective protocol for metabolomic characterization of biofluids based on their gelification and subsequent application of high-resolution magic angle spinning (HRMAS) (1)H nuclear magnetic resonance (NMR). The sample handling is very rapid and reproducible, and much less than 40 μL of neat urine are needed to obtain a sample. Our results indicate that the HRMAS spectra of gelified urine encompass all metabolites in the NMR fingerprint, as observed by solution NMR. The proposed approach can be efficiently integrated into the NMR based metabolomics analyses routines: multivariate statistical analysis of both solution and HRMAS data produced very similar statistical models, with high classification accuracy. One of the key advantages offered by the gelification approach is the improved short-term (up to 24 h) preservation of nonfrozen HRMAS NMR gel urine samples compared to the solution samples, which could lead to an alternative way for transportation or domestic collection of biofluids, without the need of cold-storage and reducing the risks of leakage.

  14. Structural Analysis of Human Cofilin 2/Filamentous Actin Assemblies: Atomic-Resolution Insights from Magic Angle Spinning NMR Spectroscopy

    PubMed Central

    Yehl, Jenna; Kudryashova, Elena; Reisler, Emil; Kudryashov, Dmitri; Polenova, Tatyana

    2017-01-01

    Cellular actin dynamics is an essential element of numerous cellular processes, such as cell motility, cell division and endocytosis. Actin’s involvement in these processes is mediated by many actin-binding proteins, among which the cofilin family plays unique and essential role in accelerating actin treadmilling in filamentous actin (F-actin) in a nucleotide-state dependent manner. Cofilin preferentially interacts with older filaments by recognizing time-dependent changes in F-actin structure associated with the hydrolysis of ATP and release of inorganic phosphate (Pi) from the nucleotide cleft of actin. The structure of cofilin on F-actin and the details of the intermolecular interface remain poorly understood at atomic resolution. Here we report atomic-level characterization by magic angle spinning (MAS) NMR of the muscle isoform of human cofilin 2 (CFL2) bound to F-actin. We demonstrate that resonance assignments for the majority of atoms are readily accomplished and we derive the intermolecular interface between CFL2 and F-actin. The MAS NMR approach reported here establishes the foundation for atomic-resolution characterization of a broad range of actin-associated proteins bound to F-actin. PMID:28303963

  15. Magic angle spinning NMR study of the ferroelectric transition of KH2PO4: definitive evidence of a displacive component

    NASA Astrophysics Data System (ADS)

    Kweon, Jin Jung; Fu, Riqiang; Choi, Eun Sang; Dalal, Naresh S.

    2017-04-01

    Variable temperature magic angle spinning (MAS) NMR measurements are reported on 1H and 31P nuclei in KH2PO4 (KDP) in the vicinity of its paraelectric–ferroelectric phase transition temperature, T c, of 123 K, to examine the transition mechanism, in particular if this is a model order–disorder type or whether it also involves a displacive component. It has been well established that the temperature variation of the isotropic chemical shift, δ iso, in NMR measurements of the nuclei directly involved in the transition should remain constant or change smoothly through T c for an order–disorder type transition but it should show an anomalous change for a displacive one. Here we demonstrate that the δ iso for both 31P and 1H nuclei in KDP show clear anomalies as a function of temperature around KDP’s T c, providing direct evidence of a displacive component for the phase transition of KDP in contrast to the generally accepted notion that it is a model order–disorder type.

  16. 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.

  17. 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.

  18. Solid state 31P cross-polarization/magic angle sample spinning nuclear magnetic resonance studies of crystalline glycogen phosphorylase b

    PubMed Central

    Taguchi, Jocelyn E.; Heyes, Stephen J.; Barford, David; Johnson, Louise N.; Dobson, Christopher M.

    1993-01-01

    31P cross-polarization/magic angle sample spinning nuclear magnetic resonance spectra have been obtained for pyridoxal 5′-phosphate (PLP) bound to glycogen phosphorylase b (GPb) in two different crystalline forms, monoclinic and tetragonal. Analysis of the intensities of the spinning sidebands in the nuclear magnetic resonance spectra has enabled estimates of the principal values of the 31P chemical shift tensors to be obtained. Differences between the two sets of values suggest differences in the environment of the phosphate moiety of the pyridoxal phosphate in the two crystalline forms. The tensor for the tetragonal crystalline form, T state GPb, is fully consistent with those found for dianionic phosphate groups in model compounds. The spectrum for the monoclinic crystalline form, R state GPb, although closer to that of dianionic than monoanionic model phosphate compounds, deviates significantly from that expected for a simple dianion or monoanion. This is likely to result from specific interactions between the PLP phosphate group and residues in its binding site in the protein. A possible explanation for the spectrum of the monoclinic crystals is that the shift tensor is averaged by a proton exchange process between different ionization states of the PLP associated with the presence of a sulfate ion bound in the vicinity of the PLP. PMID:8457673

  19. Evaluating Human Breast Ductal Carcinomas with High-Resolution Magic-Angle Spinning Proton Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Cheng, Leo Ling; Chang, I.-Wen; Smith, Barbara L.; Gonzalez, R. Gilberto

    1998-11-01

    We report the results of a study of human breast ductal carcinomas, conducted by using high resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1HMRS). This recently developed spectroscopic technique can measure tissue metabolism from intact pathological specimens and identify tissue biochemical changes, which closely correspond to tumorin vivostate. This procedure objectively indicates diagnostic parameters, independent of the skill and experience of the investigator, and has the potential to reduce the sampling errors inherently associated with procedures of conventional histopathology. In this study, we measured 19 cases of female ductal carcinomas. Our results demonstrate that: (1) highly resolved spectra of intact specimens of human breast ductal carcinomas can be obtained; (2) carcinoma-free tissues and carcinomas are distinguishable by alterations in the intensities and the spin-spin relaxation time T2 of cellular metabolites; and (3) tumor metabolic markers, such as phosphocholine, lactate, and lipids, may correlate with the histopathological grade determined from evaluation of the adjacent specimen. Our results suggest that biochemical markers thus measured may function as a valuable adjunct to histopathology to improve the accuracy of and reduce the time frame required for the diagnosis of human breast cancer.

  20. 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

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

    PubMed

    Fuss, Taylor L; Cheng, Leo L

    2016-03-22

    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.

  3. Combination of high-resolution magic angle spinning proton magnetic resonance spectroscopy and microscale genomics to type brain tumor biopsies.

    PubMed

    Tzika, A Aria; Astrakas, Loukas; Cao, Haihui; Mintzopoulos, Dionyssios; Andronesi, Ovidiu C; Mindrinos, Michael; Zhang, Jiangwen; Rahme, Laurence G; Blekas, Konstantinos D; Likas, Aristidis C; Galatsanos, Nikolas P; Carroll, Rona S; Black, Peter M

    2007-08-01

    Advancements in the diagnosis and prognosis of brain tumor patients, and thus in their survival and quality of life, can be achieved using biomarkers that facilitate improved tumor typing. We introduce and implement a combinatorial metabolic and molecular approach that applies state-of-the-art, high-resolution magic angle spinning (HRMAS) proton (1H) MRS and gene transcriptome profiling to intact brain tumor biopsies, to identify unique biomarker profiles of brain tumors. Our results show that samples as small as 2 mg can be successfully processed, the HRMAS 1H MRS procedure does not result in mRNA degradation, and minute mRNA amounts yield high-quality genomic data. The MRS and genomic analyses demonstrate that CNS tumors have altered levels of specific 1H MRS metabolites that directly correspond to altered expression of Kennedy pathway genes; and exhibit rapid phospholipid turnover, which coincides with upregulation of cell proliferation genes. The data also suggest Sonic Hedgehog pathway (SHH) dysregulation may play a role in anaplastic ganglioglioma pathogenesis. That a strong correlation is seen between the HRMAS 1H MRS and genomic data cross-validates and further demonstrates the biological relevance of the MRS results. Our combined metabolic/molecular MRS/genomic approach provides insights into the biology of anaplastic ganglioglioma and a new potential tumor typing methodology that could aid neurologists and neurosurgeons to improve the diagnosis, treatment, and ongoing evaluation of brain tumor patients.

  4. Metabolic Profiling of Intact Arabidopsis thaliana Leaves during Circadian Cycle Using 1H High Resolution Magic Angle Spinning NMR

    PubMed Central

    van Schadewijk, R.; de Groot, H. J. M.; Alia, A.

    2016-01-01

    Arabidopsis thaliana is the most widely used model organism for research in plant biology. While significant advances in understanding plant growth and development have been made by focusing on the molecular genetics of Arabidopsis, extracting and understanding the functional framework of metabolism is challenging, both from a technical perspective due to losses and modification during extraction of metabolites from the leaves, and from the biological perspective, due to random variation obscuring how well the function is performed. The purpose of this work is to establish the in vivo metabolic profile directly from the Arabidopsis thaliana leaves without metabolite extraction, to reduce the complexity of the results by multivariate analysis, and to unravel the mitigation of cellular complexity by predominant functional periodicity. To achieve this, we use the circadian cycle that strongly influences metabolic and physiological processes and exerts control over the photosynthetic machinery. High resolution-magic angle spinning nuclear magnetic resonance (HR-MAS NMR) was applied to obtain the metabolic profile directly from intact Arabidopsis leaves. Combining one- and two-dimensional 1H HR-MAS NMR allowed the identification of several metabolites including sugars and amino acids in intact leaves. Multivariate analysis on HR-MAS NMR spectra of leaves throughout the circadian cycle revealed modules of primary metabolites with significant and consistent variations of their molecular components at different time points of the circadian cycle. Since robust photosynthetic performance in plants relies on the functional periodicity of the circadian rhythm, our results show that HR-MAS NMR promises to be an important non-invasive method that can be used for metabolomics of the Arabidopsis thaliana mutants with altered physiology and photosynthetic efficiency. PMID:27662620

  5. 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

  6. 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.

  7. Alterations in creatine metabolism observed in experimental autoimmune myocarditis using ex vivo proton magic angle spinning MRS.

    PubMed

    Muench, Frédéric; Retel, Joren; Jeuthe, Sarah; O h-Ici, Darach; van Rossum, Barth; Wassilew, Katharina; Schmerler, Patrick; Kuehne, Titus; Berger, Felix; Oschkinat, Hartmut; Messroghli, Daniel R

    2015-12-01

    Experimental autoimmune myocarditis (EAM) in rodents is an accepted model of myocarditis and dilated cardiomyopathy (DCM). Altered metabolism is thought to play an important role in the pathogenesis of DCM and heart failure (HF). Study of the metabolism may provide new diagnostic information and insights into the mechanisms of myocarditis and HF. Proton MRS ((1)H-MRS) has not yet been used to study the changes occurring in myocarditis and subsequent HF. We aimed to explore the changes in creatine metabolism using this model and compare them with the findings in healthy animals. Myocardial function of male young Lewis rats with EAM was quantified by performing left ventricular ejection fraction (LVEF) analysis in short-axis cine images throughout the whole heart. Inflammatory cellular infiltrate was assessed by immunohistochemistry. Myocardial tissue was analyzed using ex vivo proton magic angle spinning MRS ((1)H-MAS-MRS). Myocarditis was confirmed histologically by the presence of an inflammatory cellular infiltrate and CD68 positive staining. A significant increase in the metabolic ratio of Tau/tCr (taurine/total creatine) obtained by (1)H-MAS-MRS was observed in myocarditis compared with healthy controls (21 d acute EAM, 4.38 (±0.23); 21 d control, 2.84 (±0.08); 35 d chronic EAM, 4.47 (±0.83); 35 d control, 2.59 (±0.38); P < 0.001). LVEF was reduced in diseased animals (EAM, 55.2% (±11.3%); control, 72.6% (±3.8%); P < 0.01) and correlated with Tau/tCr ratio (R = 0.937, P < 0.001). Metabolic alterations occur acutely with the development of myocarditis. Myocardial Tau/tCr ratio as detected by (1)H-MRS correlates with LVEF and is able to differentiate between healthy myocardium and myocardium from rats with EAM.

  8. Lipid biomarkers of glioma cell growth arrest and cell death detected by 1 H magic angle spinning MRS.

    PubMed

    Mirbahai, Ladan; Wilson, Martin; Shaw, Christopher S; McConville, Carmel; Malcomson, Roger D G; Kauppinen, Risto A; Peet, Andrew C

    2012-11-01

    Biomarkers of early response to treatment have the potential to improve cancer therapy by allowing treatment to be tailored to the individual. Alterations in lipids detected by in vivo MRS have been suggested as noninvasive biomarkers of cell stress and early indicators of cell death. An improved understanding of the relationship between MRS lipids and cell stress in vitro would aid in the translation of this technique into clinical use. Rat BT4C glioma cells were treated with 50 µ m cis-dichlorodiammineplatinum II (cisplatin), a commonly used chemotherapeutic agent, and harvested at several time points up to 72 h. High-resolution magic angle spinning (1) H MRS of cells was then performed on a 600-MHz NMR spectrometer. The metabolites were quantified using a time domain fitting method, TARQUIN. Increases were detected in saturated and polyunsaturated fatty acid resonances early during the exposure to cisplatin. The fatty acid CH(2) /CH(3) ratio was unaltered by treatment after allowing for contributions of macromolecules. Polyunsaturated fatty acids increased on treatment, with the group -CH=CH-CH(2) -CH=CH- accounting for all the unsaturated fatty acid signals. Transmission electron microscopy, in addition to Nile red and 4',6-diamino-2-phenylindole co-staining, revealed that the lipid increase was associated with cytoplasmic neutral lipid droplets. Small numbers of apoptotic and necrotic cells were detected by trypan blue, annexin V-fluorescein isothiocyanate-labelled flow cytometry and DNA laddering after up to 48 h of cisplatin exposure. Propidium iodide flow cytometry revealed that cells accumulated in the G1 stage of the cell growth cycle. In conclusion, an increase in the size of the lipid droplets is detected in morphologically viable cells during cisplatin exposure. (1) H MRS can detect lipid alterations during cell cycle arrest and progression of cell death, and has the potential to provide a noninvasive biomarker of treatment efficacy in vivo.

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

    PubMed Central

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

    2013-01-01

    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

  10. Surface Interactions and Confinement of Methane: A High Pressure Magic Angle Spinning NMR and Computational Chemistry Study

    DOE PAGES

    Ok, Salim; Hoyt, David W.; Andersen, Amity; ...

    2017-01-18

    Characterization and modeling of the molecular-level behavior of simple hydrocarbon gases, such as methane, in the presence of both nonporous and nanoporous mineral matrices allows for predictive understanding of important processes in engineered and natural systems. In this study, we observed changes in local electromagnetic environments of the carbon atoms in methane under conditions of high pressure (up to 130 bar) and moderate temperature (up to 346 K) with 13C magic-angle spinning (MAS) NMR spectroscopy while the methane gas was mixed with two model solid substrates: a fumed nonporous, 12 nm particle size silica and a mesoporous silica with 200more » nm particle size and 4 nm average pore diameter. Examination of the interactions between methane and the silica systems over temperatures and pressures that include the supercritical regime was allowed by a novel high pressure MAS sample containment system, which provided high resolution spectra collected under in situ conditions. There was no significant thermal effects were found for the observed 13C chemical shifts at all pressures studied here (28.2, 32.6, 56.4, 65.1, 112.7, and 130.3 bar) for pure methane. However, the 13C chemical shifts of resonances arising from confined methane changed slightly with changes in temperature in mixtures with mesoporous silica. The chemical shift values of 13C nuclides in methane change measurably as a function of pressure both in the pure state and in mixtures with both silica matrices, with a more pronounced shift when meso-porous silica is present. Molecular-level simulations utilizing GCMC, MD, and DFT confirm qualitatively that the experimentally measured changes are attributed to interactions of methane with the hydroxylated silica surfaces as well as densification of methane within nanopores and on pore surfaces.« less

  11. 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.

  12. 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.

  13. Investigation of cation environment and framework changes in silicotitanate exchange materials using solid-state 23Na, 29Si, and 133Cs MAS NMR

    NASA Astrophysics Data System (ADS)

    Cherry, Brian R.; Nyman, May; Alam, Todd M.

    2004-06-01

    Crystalline silicotitanate (CST), HNa 3Ti 4Si 2O 14·4H 2O and the Nb-substituted CST (Nb-CST), HNa 2Ti 3NbSi 2O 14·4H 2O, are highly selective Cs + sorbents, which makes them attractive materials for the selective removal of radioactive species from nuclear waste solutions. The structural basis for the improved Cs + selectivity in the niobium analogs was investigated through a series of solid-state magic angle spinning (MAS) NMR experiments. Changes in the local environment of the Na + and Cs + cations in both CST and Nb-CST materials as a function of weight percent cesium exchange were investigated using 23Na and 133Cs MAS NMR. Framework changes induced by Cs + loading and hydration state were investigated with 29Si MAS NMR. Multiple Cs + environments were observed in the CST and Nb-CST material. The relative population of these different Cs + environments varies with the extent of Cs + loading. Marked changes in the framework Si environment were noted with the initial incorporation of Cs +, however with increased Cs + loading the impact to the Si environment becomes less pronounced. The Cs + environment and Si framework structure were influenced by the Nb-substitution and were greatly affected by the amount of water present in the materials. The increased Cs + selectivity of the Nb-CST materials arises from both the chemistry and geometry of the tunnels and pores.

  14. Characterization of divalent metal metavanadates by 51V magic-angle spinning NMR spectroscopy of the central and satellite transitions.

    PubMed

    Nielsen, U G; Jakobsen, H J; Skibsted, J

    2000-05-15

    51V quadrupole coupling and chemical shielding tensors have been determined from 51V magic-angle spinning (MAS) NMR spectra at a magnetic field of 14.1 T for nine divalent metal metavanadates: Mg(VO3)2, Ca(VO3)2, Ca(VO3)(2).4H2O, alpha-Sr(VO3)2, Zn(VO3)2, alpha- and beta-Cd(VO3)2. The manifold of spinning sidebands (ssbs) from the central and satellite transitions, observed in the 15V MAS NMR spectra, have been analyzed using least-squares fitting and numerical error analysis. This has led to a precise determination of the eight NMR parameters characterizing the magnitudes and relative orientations of the quadrupole coupling and chemical shielding tensors. The optimized data show strong similarities between the NMR parameters for the isostructural groups of divalent metal metavanadates. This demonstrates that different types of metavanadates can easily be distinguished by their anisotropic NMR parameters. The brannerite type of divalent metal metavanadates exhibits very strong 51V quadrupole couplings (i.e., CQ = 6.46-7.50 MHz), which reflect the highly distorted octahedral environments for the V5+ ion in these phases. Linear correlations between the principal tensor elements for the 51V quadrupole coupling tensors and electric field gradient tensor elements, estimated from point-monopole calculations, are reported for the divalent metal metavanadates. These correlations are used in the assignment of the NMR parameters for the different crystallographic 51V sites of Ca(VO3)(2).4H2O, Pb(VO3)2, and Ba(VO3)2. For alpha-Sr(VO3)2, with an unknown crystal structure, the 51V NMR data strongly suggest that this metavanadate is isostructural with Ba(VO3)2, for which the crystal structure has been reported. Finally, the chemical shielding parameters for orthovanadates and mono- and divalent metal metavanadates are compared.

  15. 1H–13C hetero-nuclear dipole–dipole couplings of methyl groups in stationary and magic angle spinning solid-state NMR experiments of peptides and proteins

    PubMed Central

    Wu, Chin H.; Das, Bibhuti B.; Opella, Stanley J.

    2010-01-01

    13C NMR of isotopically labeled methyl groups has the potential to combine spectroscopic simplicity with ease of labeling for protein NMR studies. However, in most high resolution separated local field experiments, such as polarization inversion spin exchange at the magic angle (PISEMA), that are used to measure 1H–13C hetero-nuclear dipolar couplings, the four-spin system of the methyl group presents complications. In this study, the properties of the 1H–13C hetero-nuclear dipolar interactions of 13C-labeled methyl groups are revealed through solid-state NMR experiments on a range of samples, including single crystals, stationary powders, and magic angle spinning of powders, of 13C3 labeled alanine alone and incorporated into a protein. The spectral simplifications resulting from proton detected local field (PDLF) experiments are shown to enhance resolution and simplify the interpretation of results on single crystals, magnetically aligned samples, and powders. The complementarity of stationary sample and magic angle spinning (MAS) measurements of dipolar couplings is demonstrated by applying polarization inversion spin exchange at the magic angle and magic angle spinning (PISEMAMAS) to unoriented samples. PMID:19896874

  16. Slow magic angle sample spinning: a non- or minimally invasive method for high-resolution 1H nuclear magnetic resonance (NMR) metabolic profiling.

    PubMed

    Hu, Jian Zhi

    2011-01-01

    High-resolution (1)H magic angle spinning nuclear magnetic resonance (NMR), using a sample spinning rate of several kilohertz 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 minimally 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 H(2)O, where an unusually large magnetic susceptibility field gradient is obtained.

  17. Magic angle effect on low field magnetic resonance images in the superficial digital flexor tendon in the equine proximal pastern region.

    PubMed

    Sherlock, C E; Mair, T S

    2016-11-01

    Recognition of artefacts is an essential component of the accurate interpretation of diagnostic images. This study aimed to investigate the presence of magic angle effect in the superficial digital flexor tendon (SDFT) in the equine proximal pastern region. The proximal pastern of four cadaver limbs was imaged using a 0.27 Tesla magnet with high-resolution sequences that are commonly utilised in clinical equine practice. The limbs were imaged in a neutral position and positions that simulated the horse 'leaning in', 'leaning out' and having internal and external rotation of the distal limb. Signal intensity changes in the SDFT were described and compared. The simulated 'leaning in' and external rotation positions resulted in increased signal intensity in the axial and middle thirds of the lateral half of the SDFT on sequences with short echo times. The simulated 'leaning out' and internal rotation positions resulted in increased signal intensity in the axial and middle thirds of the medial half of the SDFT on sequences with short echo times. These signal intensity changes did not occur or were only mild and inconsistent on T2 fast spin echo sequences with longer echo times. The increases in signal intensity in the SDFT are consistent with a position-induced magic angle artefact that has been noted in clinical cases. Attention to positioning of the equine distal limb is essential during clinical imaging; radiologists should be aware of position-induced artefacts to ensure accurate image interpretation.

  18. Orientation of functional groups of soil organic matter on the surface of water repellent soils determined by pulse saturation magic angle spinning (PSTMAS) nuclear magnetic resonance (NMR) spectroscopy

    NASA Astrophysics Data System (ADS)

    Hiradate, Syuntaro; Kawamoto, Ken; Senani Wijewardana, Nadeeka; Müller, Karin; Møldrup, Per; Clothier, Brent; Komatsu, Toshiko

    2014-05-01

    Orientation of functional groups of soil organic matter on soil particles plays a crucial role in the occurrence of soil water repellency. In addition to a general method to characterize soil organic matter using cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) technique, we determined the surface orientation of functional groups in water repellent soils by using pulse saturation magic angle spinning (PSTMAS) NMR technique. A preliminary experiment confirmed that the PSTMAS NMR spectrum successfully determined the high mobility of methyl group of octadecylsilylated silica gels when a comparison was made with that of CPMAS NMR. This means that the methyl group oriented towards the outside of the silica gel particle. Similarly, for an experimental system consisting of mixtures of octadecylsilylated silica gel and dimethyl sulfoxide (DMSO), the extremely high mobility of methyl group derived from DMSO was detected using the same methodology. For water repellent soils from Japan and New Zealand, it was found that the methyl and methylene groups were highly mobile. In contrast, the NMR signals of aromatic moiety, another hydrophobic moiety of soil organic matter, were not as intense in PSTMAS compared with CPMAS. From these results, we conclude that alkyl moiety (methyl and methylene groups) would be oriented towards the outside of the soil particle and would play an important role in the appearance of water repellency of soils.

  19. 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

  20. A theoretical interpretation of the chemical shift of 29Si NMR peaks in alkali borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Nanba, Tokuro; Nishimura, Mitsunori; Miura, Yoshinari

    2004-12-01

    In 29Si-NMR, it has so far been accepted that the chemical shifts of Q n species (SiO 4 units containing n bridging oxygens) were equivalent between alkali borosilicate and boron-free alkali silicate glasses. In the sodium borosilicate glasses with low sodium content, however, a contradiction was confirmed in the estimation of alkali distribution; 11B NMR suggested that Na ions were entirely distributed to borate groups to form BO 4 units, whereas a -90 ppm component was also observed in 29Si-NMR spectra, which has been attributed to Q 3 species associated with a nonbridging oxygen (NBO). Then, cluster molecular orbital calculations were performed to interpret the -90 ppm component in the borosilicate glasses. It was found that a silicon atom which had two tetrahedral borons (B4) as its second nearest neighbors was similar in atomic charge and Si2p energy to the Q 3 species in boron-free alkali silicates. Unequal distribution of electrons in Si-O-B4 bridging bonds was also found, where much electrons were localized on the Si-O bonds. It was finally concluded that the Si-O-B4 bridges with narrow bond angle were responsible for the -90 ppm 29Si component in the borosilicate glasses. There still remained another interpretation; the Q 3 species were actually present in the glasses, and NBOs in the Q 3 species were derived from the tricluster groups, such as (O 3Si)O(BO 3) 2. In the glasses with low sodium content, however, it was concluded that the tricluster groups were not so abundant to contribute to the -90 ppm component.

  1. Probing local structures of siliceous zeolite frameworks by solid-state NMR and first-principles calculations of 29Si-O-29Si scalar couplings.

    PubMed

    Cadars, Sylvian; Brouwer, Darren H; Chmelka, Bradley F

    2009-03-21

    Subtle structural details of siliceous zeolites are probed by using two-bond scalar (J) coupling constants to characterize covalently bonded 29Si-O-29Si site pairs and local framework order. Solid-state two-dimensional (2D) 29Si{29Si} NMR measurements and first-principles calculations of 2J(29Si-O-29Si) couplings shed insights on both the local structures of siliceous zeolites Sigma-2 and ZSM-12, as well as the sensitivity of J couplings for detailed characterization analyses. DFT calculations on a model linear silicate dimer show that 2J(Si-O-Si) couplings have complicated multiple angular dependencies that make semi-empirical treatments impractical, but which are amenable to cluster approaches for accurate J-coupling calculations in zeolites. DFT calculations of 2J(29Si-O-29Si) couplings of the siliceous zeolite Sigma-2, whose framework structure is known to high accuracy from single-crystal X-ray diffraction studies, yield excellent agreement between calculated and experimentally measured 2J(Si-O-Si) couplings. For the siliceous zeolite ZSM-12, calculated 2J(29Si-O-29Si) couplings based on less-certain powder X-ray diffraction analyses deviate significantly from experimental values, while a refined structure based on 29Si chemical-shift-tensor analyses shows substantially improved agreement. 29Si J-coupling interactions can be used as sensitive probes of local structures of zeolitic frameworks and offer new opportunities for refining and solving complicated structures, in combination with complementary scattering, modeling, and other nuclear spin interactions.

  2. Characterization of cromolyn sodium hydrates and its formulation by (23) Na-multiquantum and magic-angle spinning nuclear magnetic resonance spectroscopy.

    PubMed

    Umino, Makoto; Higashi, Kenjirou; Masu, Hyuma; Limwikrant, Waree; Yamamoto, Keiji; Moribe, Kunikazu

    2013-08-01

    We characterized cromolyn sodium (CS) hydrates and evaluated their molecular states in low-dose formulations using Na-multiquantum magic-angle spinning (MQMAS) nuclear magnetic resonance (NMR) analysis. Two CS hydrates, low-water-content hydrated form and high-water-content hydrated form containing 2-3 and 5-6 hydrates, respectively, were prepared by humidification. Single-crystal X-ray diffraction and powder X-ray diffraction analysis revealed that these CS hydrates contained sodium channel structures and that water molecules were adsorbed on the sodium nucleus. (13) C-cross-polarization/MAS NMR spectra of these hydrates revealed similar results, confirming that the water molecules were adsorbed not on the cromolyn skeletons but mainly on the sodium nucleus. In contrast, (23) Na-MQMAS NMR analysis allowed us to clearly distinguish these hydrates without discernible effects from quadrupolar interaction. Thus, MQMAS NMR analysis is a valuable tool for evaluating salt drugs and their formulations.

  3. An NMR thermometer for cryogenic magic-angle spinning NMR: the spin-lattice relaxation of (127)I in cesium iodide.

    PubMed

    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 (79)Br in KBr powder can be useful for measuring sample temperature under MAS over a wide temperature range (20-296 K). However the value of T(1) exceeds 3 min at temperatures below 20K, which is inconveniently long. In this communication, we show that the spin-lattice relaxation time constant of (127)I in CsI powder can be used to accurately measure sample temperature under MAS within a reasonable experimental time down to 10 K.

  4. High resolution magic angle spinning NMR spectroscopy reveals that pectoralis muscle dystrophy in chicken is associated with reduced muscle content of anserine and carnosine.

    PubMed

    Sundekilde, Ulrik K; Rasmussen, Martin K; Young, Jette F; Bertram, Hanne Christine

    2017-02-15

    Increased incidences of pectoralis muscle dystrophy are observed in commercial chicken products, but the muscle physiological causes for the condition remain to be identified. In the present study a high-resolution magic angle spinning (HR-MAS) proton ((1)H) NMR spectroscopic examination of intact pectoralis muscle samples (n=77) were conducted to explore metabolite perturbations associated with the muscle dystrophy condition for the very first time. Both in chicken with an age of 21 and 31days, respectively, pectoralis muscle dystrophy was associated with a significantly lower content of anserine (p=0.034), carnosine (p=0.019) and creatine (p=0.049). These findings must be considered intriguing as they corroborate that characteristic muscle di-peptides composed of β-alanine and histidine derivatives such as anserine are extremely important in homeostasis of contractile muscles as a results of their role as buffering, anti-oxidative, and anti-glycation capacities.

  5. 1H-detected 1H- 1H correlation spectroscopy of a stereo-array isotope labeled amino acid under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Kainosho, Masatsune; Akutsu, Hideo; Fujiwara, Toshimichi

    2010-04-01

    The combined use of selective deuteration, stereo-array isotope labeling (SAIL), and fast magic-angle spinning effectively suppresses the 1H-1H dipolar couplings in organic solids. This method provided the high-field 1H NMR linewidths comparable to those achieved by combined rotation and multiple-pulse spectroscopy. This technique was applied to two-dimensional 1H-detected 1H-1H polarization transfer CHH experiments of valine. The signal sensitivity for the 1H-detected CHH experiments was greater than that for the 13C-detected 1H-1H polarization transfer experiments by a factor of 2-4. We obtained the 1H-1H distances in SAIL valine by CHH experiments with an accuracy of about 0.2 Å by using a theory developed for 1H-1H polarization transfer in 13C-labeled organic compounds.

  6. Low-power broadband homonuclear dipolar recoupling without decoupling: Double-quantum 13C NMR correlations at very fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Teymoori, Gholamhasan; Pahari, Bholanath; Stevensson, Baltzar; Edén, Mattias

    2012-09-01

    We report novel symmetry-based radio-frequency (rf) pulse sequences for efficient excitation of double-quantum (2Q) coherences under very fast (>60 kHz) magic-angle spinning (MAS) conditions. The recursively generated pulse-scheme series, R22p1R22p-1(p=1,2,3,…), offers broadband 13C-13C recoupling in organic solids at a very low rf power. No proton decoupling is required. A high-order average Hamiltonian theory analysis reveals a progressively enhanced resonance-offset compensation for increasing p, as verified both by numerical simulations and 2Q filtration NMR experiments on 13C2-glycine, [2,3-13C2]alanine, and [U-13C]tyrosine at 14.1 T and 66 kHz MAS, where the pulse schemes with p⩾3 compare favorably to current state-of-the-art recoupling options.

  7. 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.

  8. A High-Resolution Magic Angle Spinning NMR Study of the Enantiodiscrimination of 3,4-Methylenedioxymethamphetamine (MDMA) by an Immobilized Polysaccharide-Based Chiral Phase

    PubMed Central

    Paixão, Márcio W.; Lourenço, Tiago C.

    2016-01-01

    This paper reports the investigation of the chiral interaction between 3,4-methylenedioxy-methamphetamine (MDMA) enantiomers and an immobilized polysaccharide-based chiral phase. For that, suspended-state high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (1H HR-MAS NMR) was used. 1H HR-MAS longitudinal relaxation time and Saturation Transfer Difference (STD NMR) titration experiments were carried out yielding information at the molecular level of the transient diastereoisomeric complexes of MDMA enantiomers and the chiral stationary phase. The interaction of the enantiomers takes place through the aromatic moiety of MDMA and the aromatic group of the chiral selector by π-π stacking for both enantiomers; however, a stronger interaction was observed for the (R)-enantiomer, which is the second one to elute at the chromatographic conditions. PMID:27668862

  9. Decoupling and recoupling using continuous-wave irradiation in magic-angle-spinning solid-state NMR: A unified description using bimodal Floquet theory

    SciTech Connect

    Ernst, Matthias; Samoson, Ago; Meier, Beat H.

    2005-08-08

    The application of two or more different time-dependent coherent perturbations with, in general, incommensurable frequencies occurs quite commonly in NMR experiments. Here we develop a unified description of the entire class of experiments using bimodal Floquet theory and van Vleck-Primas perturbation theory. This treatment leads to a time-independent effective Hamiltonian in Hilbert space and can be looked at as a generalization of average Hamiltonian theory to several incommensurate time dependencies. As a prototype experiment we treat the application of continuous-wave (cw) radio-frequency irradiation in combination with magic-angle sample spinning. Practically relevant examples of this type of experiments are heteronuclear spin decoupling and recoupling experiments using cw irradiation, e.g., rotary-resonance recoupling. Perturbations up to the third order must be taken into account to explain all experimentally observed resonance conditions.

  10. 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.)

  11. Lead exchange into zeolite and clay minerals: A [sup 29]Si, [sub 27]Al, [sup 23]Na solid-state NMR study

    SciTech Connect

    Liang, J.J.; Sherriff, B.L. )

    1993-08-01

    Chabazite, vermiculite, montmorillonite, hectorite, and kaolinite were used to remove Pb, through ion exchange, from 0.01 M aqueous Pb(NO[sub 3])[sub 2] solutions. These minerals contained 27 (Na-chabazite), 16, 9, 9, and 0.5 wt % of Pb, respectively, after equilibration with the solutions. Ion exchange reached equilibrium within 24 h for Na-chabazite and vermiculite, but in less than 5 min for montmorillonite and hectorite. Na-chabazite took up more Pb than natural (Ca, Na)-chabazite (7 wt % Pb), whereas no such difference was observed in different cation forms of the clay minerals. Calcite impurities, associated with the clay minerals, effectively removed Pb from the aqueous solutions by the precipitation of cerussite (PbCO[sub 3]). [sup 29]Si, [sup 27]Al, and [sup 23]Na magic angle spinning (MAS) nuclear magnetic resonance (NMR), [sup 23]Na double rotation (DOR) NMR, and [sup 23]Na variable-temperature MAS NMR were used to study the ion exchange mechanisms. In Na-chabazite, cations in all three possible sites take part in the fast chemical exchange. The chemical exchange passes from the fast exchange regime to the slow regime at [minus]80 to [minus]100[degrees]C. One site contains a relatively low population of exchangeable cations. The other two more shielded sites contain most of the exchangeable cation. The exchangeable cations in chabazite and vermiculite were found to be close to the SiO[sub 4] and AlO[sub 4] tetrahedra, while those in the other clay minerals were more distant. Two sites (or groups of sites) for exchangeable cations were observed in hectorite. Lead tended to occupy the one which corresponds to the [minus]8 ppM peak on the [sup 23]Na MAS NMR spectrum. The behavior of the exchangeable cations in the interlayer sites was similar in all the clay minerals studied. 27 refs., 7 figs., 4 tabs.

  12. Structural changes in C–S–H gel during dissolution: Small-angle neutron scattering and Si-NMR characterization

    SciTech Connect

    Trapote-Barreira, Ana; Porcar, Lionel; Cama, Jordi; Soler, Josep M.; Allen, Andrew J.

    2015-06-15

    Flow-through experiments were conducted to study the calcium–silicate–hydrate (C–S–H) gel dissolution kinetics. During C–S–H gel dissolution the initial aqueous Ca/Si ratio decreases to reach the stoichiometric value of the Ca/Si ratio of a tobermorite-like phase (Ca/Si = 0.83). As the Ca/Si ratio decreases, the solid C–S–H dissolution rate increases from (4.5 × 10{sup −} {sup 14} to 6.7 × 10{sup −} {sup 12}) mol m{sup −} {sup 2} s{sup −} {sup 1}. The changes in the microstructure of the dissolving C–S–H gel were characterized by small-angle neutron scattering (SANS) and {sup 29}Si magic-angle-spinning nuclear magnetic resonance ({sup 29}Si-MAS NMR). The SANS data were fitted using a fractal model. The SANS specific surface area tends to increase with time and the obtained fit parameters reflect the changes in the nanostructure of the dissolving solid C–S–H within the gel. The {sup 29}Si MAS NMR analyses show that with dissolution the solid C–S–H structure tends to a more ordered tobermorite structure, in agreement with the Ca/Si ratio evolution.

  13. Characterization of white Portland cement hydration and the C-S-H structure in the presence of sodium aluminate by {sup 27}Al and {sup 29}Si MAS NMR spectroscopy

    SciTech Connect

    Andersen, Morten Daugaard; Jakobsen, Hans J.; Skibsted, Joergen

    2004-05-01

    The effects of hydrating a white Portland cement (wPc) in 0.30 and 0.50 M solutions of sodium aluminate (NaAlO{sub 2}) at 5 and 20 deg. C are investigated by {sup 27}Al and {sup 29}Si magic-angle spinning (MAS) NMR spectroscopy. It is demonstrated that NaAlO{sub 2} accelerates the hydration of alite and belite and results in calcium-silicate-hydrate (C-S-H) phases with longer average chain lengths of SiO{sub 4}/AlO{sub 4} tetrahedra. The C-S-H phases are investigated in detail and it is shown that the Al/Si ratio for the chains of tetrahedra is quite constant during the time studied for the hydration (6 h to 2 years) but increases for higher concentration of the NaAlO{sub 2} solution. The average chain lengths of 'pure' silicate and SiO{sub 4}/AlO{sub 4} tetrahedra demonstrate that Al acts as a linker for the silicate chains, thereby producing aluminosilicate chains with longer average chain lengths. Finally, it is shown that NaAlO{sub 2} reduces the quantity of ettringite and results in larger quantities of monosulfate and a calcium aluminate hydrate phase.

  14. A nuclear magnetic resonance spectrometer concept for hermetically sealed magic angle spinning investigations on highly toxic, radiotoxic, or air sensitive materials

    NASA Astrophysics Data System (ADS)

    Martel, L.; Somers, J.; Berkmann, C.; Koepp, F.; Rothermel, A.; Pauvert, O.; Selfslag, C.; Farnan, I.

    2013-05-01

    A concept to integrate a commercial high-resolution, magic angle spinning nuclear magnetic resonance (MAS-NMR) probe capable of very rapid rotation rates (70 kHz) in a hermetically sealed enclosure for the study of highly radiotoxic materials has been developed and successfully demonstrated. The concept centres on a conventional wide bore (89 mm) solid-state NMR magnet operating with industry standard 54 mm diameter probes designed for narrow bore magnets. Rotor insertion and probe tuning take place within a hermetically enclosed glovebox, which extends into the bore of the magnet, in the space between the probe and the magnet shim system. Oxygen-17 MAS-NMR measurements demonstrate the possibility of obtaining high quality spectra from small sample masses (˜10 mg) of highly radiotoxic material and the need for high spinning speeds to improve the spectral resolution when working with actinides. The large paramagnetic susceptibility arising from actinide paramagnetism in (Th1-xUx)O2 solid solutions gives rise to extensive spinning sidebands and poor resolution at 15 kHz, which is dramatically improved at 55 kHz. The first 17O MAS-NMR measurements on NpO2+x samples spinning at 55 kHz are also reported. The glovebox approach developed here for radiotoxic materials can be easily adapted to work with other hazardous or even air sensitive materials.

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

    PubMed

    Thurber, Kent R; Tycko, Robert

    2014-05-14

    We report solid state (13)C and (1)H 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, (1)H and cross-polarized (13)C NMR signals from (15)N,(13)C-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.

  16. 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

  17. Probing molecular dynamics in chromatographic systems using high-resolution 1H magic-angle-spinning NMR spectroscopy: interaction between p-Xylene and C18-bonded silica.

    PubMed

    Coen, Muireann; Wilson, Ian D; Nicholson, Jeremy K; Tang, Huiru; Lindon, John C

    2004-06-01

    The exact nature of the interaction between small molecules and chromatographic solid phases has been the subject of much research, but detailed understanding of the molecular dynamics in such systems remains elusive. High-resolution (1)H magic-angle-spinning (MAS) NMR spectroscopy has been applied to the investigation of C18-bonded silica material as used in chromatographic separation techniques together with an adsorbed model analyte, p-xylene. Two distinct p-xylene and water environments were identified within the C18-bonded silica through the measurement of (1)H NMR chemical shifts, T(1) and T(2) relaxation times and diffusion coefficients, including their temperature dependence. The results have been analyzed in terms of two environments, p-xylene within the C18 chains, in slow exchange on the NMR time scale with p-xylene in a more mobile state adsorbed as a layer in close proximity to the C18 particles, but which is distinct from free liquid p-xylene. The techniques used here could have more general applications, including the study of drug molecules bound into phospholipid membranes in micelles or vesicles.

  18. Taurine detected using high-resolution magic angle spinning 1H nuclear magnetic resonance: A potential indicator of early myocardial infarction

    PubMed Central

    YANG, YUNLONG; YANG, LIN; ZHANG, YUE; GU, XINGHUA; XU, DANLING; FANG, FANG; SUN, AIJUN; WANG, KEQIANG; YU, YIHUA; ZUO, JI; GE, JUNBO

    2013-01-01

    Magnetic resonance spectroscopy (MRS) is a unique non-invasive method for detecting cardiac metabolic changes. However, MRS in cardiac diagnosis is limited due to insensitivity and low efficiency. Taurine (Tau) is the most abundant free amino acid in the myocardium. We hypothesized that Tau levels may indicate myocardial ischemia and early infarction. Sprague-Dawley rats were divided into seven groups according to different time points during the course of myocardial ischemia, which was induced by left anterior descending coronary artery ligation. Infarcted myocardial tissue was obtained for high-resolution magic angle spinning 1H nuclear magnetic resonance (NMR) analysis. Results were validated via high-performance liquid chromatography. The Tau levels in the ischemic myocardial tissue were reduced significantly within 5 min compared with those in the control group (relative ratio from 20.27±6.48 to 8.81±0.04, P<0.05) and were maintained for 6 h post-ischemia. Tau levels declined more markedly (56.5%) than creatine levels (48.5%) at 5 min after ligation. This suggests that Tau may have potential as an indicator in the early detection of myocardial ischemia by 1H MRS. PMID:23408155

  19. Magic angle Lee-Goldburg frequency offset irradiation improves the efficiency and selectivity of SPECIFIC-CP in triple-resonance MAS solid-state NMR.

    PubMed

    Wu, Chin H; De Angelis, Anna A; Opella, Stanley J

    2014-09-01

    The efficiency and selectivity of SPECIFIC-CP, a widely used method for selective double cross-polarization in triple-resonance magic angle spinning solid-state NMR, is improved by performing the tangential-shaped (13)C irradiation at an offset frequency that meets the Lee-Goldburg condition (LG-SPECIFIC-CP). This is demonstrated on polycrystalline samples of uniformly (13)C, (15)N labeled N-acetyl-leucine and N-formyl-Met-Leu-Phe-OH (MLF) at 700MHz and 900MHz (1)H resonance frequencies, respectively. For the single (13)Cα of N-acetyl-leucine, relative to conventional broad band cross-polarization, the SPECIFIC-CP signal has 47% of the intensity. Notably, the LG-SPECIFIC-CP signal has 72% of the intensity, essentially the theoretical maximum. There were no other changes in the experimental parameters. The three (13)Cα signals in MLF show some variation in intensities, reflecting the relatively narrow bandwidth of a frequency-offset procedure, and pointing to future developments for this class of experiment.

  20. The use of a selective saturation pulse to suppress t1 noise in two-dimensional 1H fast magic angle spinning solid-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Robertson, Aiden J.; Pandey, Manoj Kumar; Marsh, Andrew; Nishiyama, Yusuke; Brown, Steven P.

    2015-11-01

    A selective saturation pulse at fast magic angle spinning (MAS) frequencies (60+ kHz) suppresses t1 noise in the indirect dimension of two-dimensional 1H MAS NMR spectra. The method is applied to a synthetic nucleoside with an intense methyl 1H signal due to triisopropylsilyl (TIPS) protecting groups. Enhanced performance in terms of suppressing the methyl signal while minimising the loss of signal intensity of nearby resonances of interest relies on reducing spin diffusion - this is quantified by comparing two-dimensional 1H NOESY-like spin diffusion spectra recorded at 30-70 kHz MAS. For a saturation pulse centred at the methyl resonance, the effect of changing the nutation frequency at different MAS frequencies as well as the effect of changing the pulse duration is investigated. By applying a pulse of duration 30 ms and nutation frequency 725 Hz at 70 kHz MAS, a good compromise of significant suppression of the methyl resonance combined with the signal intensity of resonances greater than 5 ppm away from the methyl resonance being largely unaffected is achieved. The effectiveness of using a selective saturation pulse is demonstrated for both homonuclear 1H-1H double quantum (DQ)/single quantum (SQ) MAS and 14N-1H heteronuclear multiple quantum coherence (HMQC) two-dimensional solid-state NMR experiments.

  1. Solid-state NMR adiabatic TOBSY sequences provide enhanced sensitivity for multidimensional high-resolution magic-angle-spinning 1H MR spectroscopy

    NASA Astrophysics Data System (ADS)

    Andronesi, Ovidiu C.; Mintzopoulos, Dionyssios; Struppe, Jochem; Black, Peter M.; Tzika, A. Aria

    2008-08-01

    We propose a solid-state NMR method that maximizes the advantages of high-resolution magic-angle-spinning (HRMAS) applied to intact biopsies when compared to more conventional liquid-state NMR approaches. Theoretical treatment, numerical simulations and experimental results on intact human brain biopsies are presented. Experimentally, it is proven that an optimized adiabatic TOBSY (TOtal through Bond correlation SpectroscopY) solid-state NMR pulse sequence for two-dimensional 1H- 1H homonuclear scalar-coupling longitudinal isotropic mixing provides a 20%-50% improvement in signal-to-noise ratio relative to its liquid-state analogue TOCSY (TOtal Correlation SpectroscopY). For this purpose we have refined the C9151 symmetry-based 13C TOBSY pulse sequence for 1H MRS use and compared it to MLEV-16 TOCSY sequence. Both sequences were rotor-synchronized and implemented using WURST-8 adiabatic inversion pulses. As discussed theoretically and shown in simulations, the improved magnetization-transfer comes from actively removing residual dipolar couplings from the average Hamiltonian. Importantly, the solid-state NMR techniques are tailored to perform measurements at low temperatures where sample degradation is reduced. This is the first demonstration of such a concept for HRMAS metabolic profiling of disease processes, including cancer, from biopsies requiring reduced sample degradation for further genomic analysis.

  2. Elucidating connectivity and metal-binding structures of unlabeled paramagnetic complexes by 13C and 1H solid-state NMR under fast magic angle spinning.

    PubMed

    Wickramasinghe, Nalinda P; Shaibat, Medhat A; Ishii, Yoshitaka

    2007-08-23

    Characterizing paramagnetic complexes in solids is an essential step toward understanding their molecular functions. However, methodologies to characterize chemical and electronic structures of paramagnetic systems at the molecular level have been notably limited, particularly for noncrystalline solids. We present an approach to obtain connectivities of chemical groups and metal-binding structures for unlabeled paramagnetic complexes by 13C and 1H high-resolution solid-state NMR (SSNMR) using very fast magic angle spinning (VFMAS, spinning speed >or=20 kHz). It is experimentally shown for unlabeled Cu(II)(Ala-Thr) that 2D 13C/1H correlation SSNMR under VFMAS provides the connectivity of chemical groups and assignments for the characterization of unlabeled paramagnetic systems in solids. We demonstrate that on the basis of the assignments provided by the VFMAS approach multiple 13C-metal distances can be simultaneously elucidated by a combination of measurements of 13C anisotropic hyperfine shifts and 13C T1 relaxation due to hyperfine interactions for this peptide-Cu(II) complex. It is also shown that an analysis of 1H anisotropic hyperfine shifts allows for the determination of electron-spin states in Fe(III)-chloroprotoporphyin-IX in solid states.

  3. A Monte Carlo/simulated annealing algorithm for sequential resonance assignment in solid state NMR of uniformly labeled proteins with magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Tycko, Robert; Hu, Kan-Nian

    2010-08-01

    We describe a computational approach to sequential resonance assignment in solid state NMR studies of uniformly 15N, 13C-labeled proteins with magic-angle spinning. As input, the algorithm uses only the protein sequence and lists of 15N/ 13C α crosspeaks from 2D NCACX and NCOCX spectra that include possible residue-type assignments of each crosspeak. Assignment of crosspeaks to specific residues is carried out by a Monte Carlo/simulated annealing algorithm, implemented in the program MC_ASSIGN1. The algorithm tolerates substantial ambiguity in residue-type assignments and coexistence of visible and invisible segments in the protein sequence. We use MC_ASSIGN1 and our own 2D spectra to replicate and extend the sequential assignments for uniformly-labeled HET-s(218-289) fibrils previously determined manually by Siemer et al. (J. Biomol. NMR, 34 (2006) 75-87) from a more extensive set of 2D and 3D spectra. Accurate assignments by MC_ASSIGN1 do not require data that are of exceptionally high quality. Use of MC_ASSIGN1 (and its extensions to other types of 2D and 3D data) is likely to alleviate many of the difficulties and uncertainties associated with manual resonance assignments in solid state NMR studies of uniformly labeled proteins, where spectral resolution and signal-to-noise are often sub-optimal.

  4. A Solid-State Study of a Novel 31P Spin Pair Using Magic-Angle-Spinning Nuclear Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Challoner, R.; Mcdowell, C. A.; Yoshifuji, M.; Toyota, K.; Tossell, J. A.

    The present investigation concerns the solid-state nuclear magnetic resonance spectroscopy of the 31P spin pair in the novel three-membered heterocyclic compound 3-(dichloromethylene)- trans-1,2-bis( 2,4,6-tri- tert-butylphenyl)- 1,2-diphosphirane using the magic-angle-spinning (MAS) technique. The homogeneous 31P lineshapes are analyzed to extract the principal components of the shielding tensors using the Maricq and Waugh description of homonuclear spin-pair systems by average-Hamiltonian theory, modified to encompass the n = 0 rotational resonance situation. The experimental values of the shielding-tensor components are compared with those obtained from ab initio calculations performed on the model molecule P 2C 2H 4 to aid further the interpretation of the 31P MAS NMR spectrum of the chloromethylene-diphosphirane. The magnitudes and orientations of calculated shielding-tensor components of the model compound methylene-diphosphirane P 2C 2H 4 are compared with those for the phosphorus spin pair in the molecular environments of P 2, P 2H 2, and P 2H 4. The electronic structures and bonding in all of those molecular species are discussed.

  5. Vibrational 13C-cross-polarization/magic angle spinning NMR spectroscopic and thermal characterization of poly(alanine-glycine) as model for silk I Bombyx mori fibroin.

    PubMed

    Monti, Patrizia; Taddei, Paola; Freddi, Giuliano; Ohgo, Kosuke; Asakura, Tetsuo

    2003-01-01

    This study focuses on the conformational characterization of poly(alanine-glycine) II (pAG II) as a model for a Bombyx mori fibroin silk I structure. Raman, IR, and 13C-cross-polarization/magic angle spinning NMR spectra of pAG II are discussed in comparison with those of the crystalline fraction of B. mori silk fibroin (chymotryptic precipitate, Cp) with a silk I (silk I-Cp) structure. The spectral data give evidence that silk I-Cp and the synthetic copolypeptide pAG II have similar conformations. Moreover, the spectral findings reveal that silk I-Cp is more crystalline than pAG II; consequently, the latter contains a larger amount of the random coil conformation. Differential scanning calorimetry measurements confirm this result. N-Deuteration experiments on pAG II allow us to attribute the Raman component at 1320 cm(-1) to the amide III mode of a beta-turn type II conformation, thus confirming the results of those who propose a repeated beta-turn type II structure for silk I. The analysis of the Raman spectra in the nuNH region confirms that the silk I structure is characterized by the presence of different types of H-bonding arrangements, in agreement with the above model.

  6. 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.

  7. High-resolution magic angle spinning (1)H magnetic resonance spectroscopy detects choline as a biomarker in a swine obstructive chronic pancreatitis model at an early stage.

    PubMed

    Sun, Gaofeng; Wang, Jianhua; Zhang, Jian; Ma, Chao; Shao, Chengwei; Hao, Jun; Zheng, Jianming; Feng, Xiaoyuan; Zuo, Changjing

    2014-03-04

    Chronic pancreatitis (CP) is a progressive inflammatory and fibrotic disease of the pancreas which encompasses a variety of clinical syndromes ranging from mild to life-threatening complications. Metabolomics has increasingly been applied to identify biomarkers for disease diagnosis with particular interest in diseases at an early stage. In this study, we tested a swine obstructive CP model by subtotal ligation of the main pancreatic duct, and the metabolic profiles of the Bama miniature swine pancreas were investigated using high-resolution magic angle spinning proton magnetic resonance spectroscopy (HR MAS (1)H MRS) combined with principal components analysis (PCA). Increases in lactate and choline for mild CP and decreases in glycerophosphocholine, phosphocholine, betaine and glycine were observed from normal pancreas to mild, moderate and severe CP. PCA results showed visual separations among the groups. The increase of choline at an early stage of CP and the decrease of glycerophosphocholine, phosphocholine, betaine and glycine reveal the pathogenesis of CP at a molecular level. The MRS results presented here demonstrate the potential of metabolic profiles in discriminating a normal pancreas from different stages of CP, which may be used to achieve CP early diagnosis and timely intervention to prevent irreversible destruction of the pancreas.

  8. Metabolomics by Proton High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance of Tomato Plants Treated with Two Secondary Metabolites Isolated from Trichoderma.

    PubMed

    Mazzei, Pierluigi; Vinale, Francesco; Woo, Sheridan Lois; Pascale, Alberto; Lorito, Matteo; Piccolo, Alessandro

    2016-05-11

    Trichoderma fungi release 6-pentyl-2H-pyran-2-one (1) and harzianic acid (2) secondary metabolites to improve plant growth and health protection. We isolated metabolites 1 and 2 from Trichoderma strains, whose different concentrations were used to treat seeds of Solanum lycopersicum. The metabolic profile in the resulting 15 day old tomato leaves was studied by high-resolution magic-angle-spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy directly on the whole samples without any preliminary extraction. Principal component analysis (PCA) of HRMAS NMR showed significantly enhanced acetylcholine and γ-aminobutyric acid (GABA) content accompanied by variable amount of amino acids in samples treated with both Trichoderma secondary metabolites. Seed germination rates, seedling fresh weight, and the metabolome of tomato leaves were also dependent upon doses of metabolites 1 and 2 treatments. HRMAS NMR spectroscopy was proven to represent a rapid and reliable technique for evaluating specific changes in the metabolome of plant leaves and calibrating the best concentration of bioactive compounds required to stimulate plant growth.

  9. Atomic-resolution structure of the CAP-Gly domain of dynactin on polymeric microtubules determined by magic angle spinning NMR spectroscopy.

    PubMed

    Yan, Si; Guo, Changmiao; Hou, Guangjin; Zhang, Huilan; Lu, Xingyu; Williams, John Charles; Polenova, Tatyana

    2015-11-24

    Microtubules and their associated proteins perform a broad array of essential physiological functions, including mitosis, polarization and differentiation, cell migration, and vesicle and organelle transport. As such, they have been extensively studied at multiple levels of resolution (e.g., from structural biology to cell biology). Despite these efforts, there remain significant gaps in our knowledge concerning how microtubule-binding proteins bind to microtubules, how dynamics connect different conformational states, and how these interactions and dynamics affect cellular processes. Structures of microtubule-associated proteins assembled on polymeric microtubules are not known at atomic resolution. Here, we report a structure of the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain of dynactin motor on polymeric microtubules, solved by magic angle spinning NMR spectroscopy. We present the intermolecular interface of CAP-Gly with microtubules, derived by recording direct dipolar contacts between CAP-Gly and tubulin using double rotational echo double resonance (dREDOR)-filtered experiments. Our results indicate that the structure adopted by CAP-Gly varies, particularly around its loop regions, permitting its interaction with multiple binding partners and with the microtubules. To our knowledge, this study reports the first atomic-resolution structure of a microtubule-associated protein on polymeric microtubules. Our approach lays the foundation for atomic-resolution structural analysis of other microtubule-associated motors.

  10. 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

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

    NASA Astrophysics Data System (ADS)

    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 rCWApA, 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 40 kHz) 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 1H irradiation of ca.195 kHz.

  12. Measurement of sample temperatures under magic-angle spinning from the chemical shift and spin-lattice relaxation rate of 79Br in KBr powder

    NASA Astrophysics Data System (ADS)

    Thurber, Kent R.; Tycko, Robert

    2009-01-01

    Accurate determination of sample temperatures in solid state nuclear magnetic resonance (NMR) with magic-angle spinning (MAS) can be problematic, particularly because frictional heating and heating by radio-frequency irradiation can make the internal sample temperature significantly different from the temperature outside the MAS rotor. This paper demonstrates the use of 79Br chemical shifts and spin-lattice relaxation rates in KBr powder as temperature-dependent parameters for the determination of internal sample temperatures. Advantages of this method include high signal-to-noise, proximity of the 79Br NMR frequency to that of 13C, applicability from 20 K to 320 K or higher, and simultaneity with adjustment of the MAS axis direction. We show that spin-lattice relaxation in KBr is driven by a quadrupolar mechanism. We demonstrate a simple approach to including KBr powder in hydrated samples, such as biological membrane samples, hydrated amyloid fibrils, and hydrated microcrystalline proteins, that allows direct assessment of the effects of frictional and radio-frequency heating under experimentally relevant conditions.

  13. The use of a selective saturation pulse to suppress t1 noise in two-dimensional (1)H fast magic angle spinning solid-state NMR spectroscopy.

    PubMed

    Robertson, Aiden J; Pandey, Manoj Kumar; Marsh, Andrew; Nishiyama, Yusuke; Brown, Steven P

    2015-11-01

    A selective saturation pulse at fast magic angle spinning (MAS) frequencies (60+kHz) suppresses t1 noise in the indirect dimension of two-dimensional (1)H MAS NMR spectra. The method is applied to a synthetic nucleoside with an intense methyl (1)H signal due to triisopropylsilyl (TIPS) protecting groups. Enhanced performance in terms of suppressing the methyl signal while minimising the loss of signal intensity of nearby resonances of interest relies on reducing spin diffusion--this is quantified by comparing two-dimensional (1)H NOESY-like spin diffusion spectra recorded at 30-70 kHz MAS. For a saturation pulse centred at the methyl resonance, the effect of changing the nutation frequency at different MAS frequencies as well as the effect of changing the pulse duration is investigated. By applying a pulse of duration 30 ms and nutation frequency 725 Hz at 70 kHz MAS, a good compromise of significant suppression of the methyl resonance combined with the signal intensity of resonances greater than 5 ppm away from the methyl resonance being largely unaffected is achieved. The effectiveness of using a selective saturation pulse is demonstrated for both homonuclear (1)H-(1)H double quantum (DQ)/single quantum (SQ) MAS and (14)N-(1)H heteronuclear multiple quantum coherence (HMQC) two-dimensional solid-state NMR experiments.

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

    SciTech Connect

    Thurber, Kent R. Tycko, Robert

    2014-05-14

    We report solid state {sup 13}C and {sup 1}H 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, {sup 1}H and cross-polarized {sup 13}C NMR signals from {sup 15}N,{sup 13}C-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 T{sub 1e} 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.

  15. Characterization of fungal-degraded lime wood by X-ray diffraction and cross-polarization magic-angle-spinning 13C-nuclear magnetic resonance spectroscopy.

    PubMed

    Popescu, Carmen-Mihaela; Larsson, Per Tomas; Tibirna, Carmen Mihaela; Vasile, Cornelia

    2010-09-01

    X-ray diffraction, scanning electron microscopy (SEM), and solid-state cross-polarization magic-angle-spinning (CP/MAS) (13)C-NMR spectroscopy were applied to determine changes over time in the morphology and crystallinity of lime wood (Tilia cordata Miller) generated by the soft-rot fungi. Wood samples were inoculated with Trichoderma viride Pers for various durations up to 84 days. Structural and morphological modifications were assessed by comparing the structural features of decayed lime wood samples with references. Significant morphology changes such as defibration or small cavities were clearly observed on the SEM micrographs of lime wood samples exposed to fungi. Following the deconvolution process of the diffraction patterns, the degree of crystallinity, apparent lateral crystallite size, the proportion of crystallite interior chains, and the cellulose fraction have been determined. It was found that all crystallographic data vary with the duration of exposure to fungi. The degree of crystallinity and cellulose fraction tend to decrease, whereas the apparent lateral crystallite size and the proportion of crystallite interior chains increase with prolonged biodegradation processes. The most relevant signals in CP/MAS (13)C-NMR spectra were assigned according to literature data. The differences observed were discussed in terms of lignin and cellulose composition: by fixing the lignin reference signal intensity, the cellulose and hemicelluloses moieties showed a relative decrease compared to the lignin signals in decayed wood.

  16. Switchable resonant hyperpolarization transfer to 29Si spins in natural silicon

    NASA Astrophysics Data System (ADS)

    Dluhy, Phillip; Salvail, Jeff Z.; Saeedi, Kamyar; Thewalt, Mike L. W.; Simmons, Stephanie

    2015-05-01

    Silicon nano- and microparticles containing polarized 29Si spins are promising inexpensive and biocompatible medical imaging agents, particularly for magnetic resonance imaging (MRI). Maximizing out-of-equilibrium polarization (i.e., hyperpolarization) of the 29Si nuclear spins as efficiently as possible is critical for such an application. Here we identify and exploit a frequency-matched resonant transfer process between easily hyperpolarized bulk 31P and otherwise insensitive 29Si nuclear spins in natural silicon, boosting the 29Si signal to over 200 times its thermal equilibrium signal. This technique could be used in tandem with microwave-based hyperpolarization schemes for even higher efficiencies. Lastly, this hyperpolarization buildup process does not necessarily introduce an additional source of decoherence; after hyperpolarization the resonant transfer process can be switched off to recover the ultralong lifetimes of 29Si spins for in vivo imaging.

  17. Selective excitation enables assignment of proton resonances and (1)H-(1)H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy.

    PubMed

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of (1)H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as (13)C or (15)N. In this method, after the initial preparation of proton magnetization and cross-polarization to (13)C nuclei, transverse magnetization of desired (13)C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific (13)C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of (1)H-(1)H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  18. Carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance investigation of the interactions between maleic anhydride grafted polypropylene and wood polymers.

    PubMed

    Rude, Erica; Laborie, Marie-Pierre G

    2008-05-01

    The chemical interactions between maleic anhydride grafted polypropylene (MAPP) and wood were studied with solid-state carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance ((13)C CPMAS NMR) spectroscopy. MAPP was synthesized with 100% (13)C enrichment at the C(1) and C(4) carbons to allow detection of the [1,4-(13)C(2)]MAPP functional groups and was melt blended with cellulose, lignin, and maple wood. In the cellulose/MAPP blend, changes in (13)C CPMAS NMR corrected signal intensities for the anhydride and dicarboxylic maleic acid functionalities suggested that esterification may have occurred predominantly from the more numerous diacid carbons. A single proton longitudinal relaxation in the rotating frame, (H)T(1rho), for the MAPP and the cellulose carbons in the blend suggested that they were spin coupled, i.e., homogeneous on a 10-200 Angstrom scale. Esterification was also suggested in the lignin/MAPP blend. Furthermore, the more significant changes in the intensities of the carbonyl signals and (H)T(1rho) values suggested that lignin may be more reactive to MAPP than cellulose. Finally, when maple was melt blended with MAPP, the same trends in the (13)C CP-MAS NMR spectra and (H)T(1rho) behavior were observed as when MAPP was blended with cellulose or lignin. This study therefore clarifies that during melt compounding of wood with MAPP, esterification occurs with wood polymers, preferentially with lignin. Understanding the interactions of MAPP with wood is of significance for the development of natural-fiber-reinforced thermoplastic composites.

  19. Fast Magic-Angle Spinning Three-Dimensional NMR Experiment for Simultaneously Probing H-H and N-H Proximities in Solids.

    PubMed

    Reddy, G N Manjunatha; Malon, Michal; Marsh, Andrew; Nishiyama, Yusuke; Brown, Steven P

    2016-12-06

    A fast magic-angle spinning (MAS, 70 kHz) solid-state NMR experiment is presented that combines (1)H Double-Quantum (DQ) and (14)N-(1)H HMQC (Heteronuclear Multiple-Quantum Coherence) pulse-sequence elements, so as to simultaneously probe H-H and N-H proximities in molecular solids. The proposed experiment can be employed in both two-dimensional (2D) and three-dimensional (3D) versions: first, a 2D (14)N HMQC-filtered (1)H-DQ experiment provides specific DQ-SQ correlation peaks for proton pairs that are in close proximities to the nitrogen sites, thereby achieving spectral filtration. Second, a proton-detected three-dimensional (3D) (1)H(DQ)-(14)N(SQ)-(1)H(SQ) experiment correlates (1)H(DQ)-(1)H(SQ) chemical shifts with (14)N shifts such that longer range N···H-H correlations are observed between protons and nitrogen atoms with internuclear NH distances exceeding 3 Å. Both 2D and 3D versions of the proposed experiment are demonstrated for an amino acid hydrochloride salt, l-histidine·HCl·H2O, and a DNA nucleoside, guanosine·2H2O. In the latter case, the achieved spectral filtration ensures that DQ cross peaks are only observed for guanine NH and CH8 (1)H resonances and not ribose and water (1)H resonances, thus providing insight into the changes in the solid-state structure of this hydrate that occur over time; significant changes are observed in the NH and NH2(1)H chemical shifts as compared to the freshly recrystallized sample previously studied by Reddy et al., Cryst. Growth Des. 2015, 15, 5945.

  20. Selective excitation enables assignment of proton resonances and 1H-1H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-01

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of 1H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as 13C or 15N. In this method, after the initial preparation of proton magnetization and cross-polarization to 13C nuclei, transverse magnetization of desired 13C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific 13C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of 1H-1H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  1. Magic Angle Spinning Nuclear Magnetic Resonance Characterization of Voltage-Dependent Anion Channel Gating in Two-Dimensional Lipid Crystalline Bilayers

    PubMed Central

    2015-01-01

    The N-terminus of the voltage-dependent anion channel (VDAC) has been proposed to contain the mechanistically important gating helices that modulate channel opening and closing. In this study, we utilize magic angle spinning nuclear magnetic resonance (MAS NMR) to determine the location and structure of the N-terminus for functional channels in lipid bilayers by measuring long-range 13C–13C distances between residues in the N-terminus and other domains of VDAC reconstituted into DMPC lipid bilayers. Our structural studies show that the distance between A14 Cβ in the N-terminal helix and S193 Cβ is ∼4–6 Å. Furthermore, VDAC phosphorylation by a mitochondrial kinase at residue S193 has been claimed to delay mitochondrial cell death by causing a conformational change that closes the channel, and a VDAC-Ser193Glu mutant has been reported to show properties very similar to those of phosphorylated VDAC in a cellular context. We expressed VDAC-S193E and reconstituted it into DMPC lipid bilayers. Two-dimensional 13C–13C correlation experiments showed chemical shift perturbations for residues located in the N-terminus, indicating possible structural perturbations to that region. However, electrophysiological data recorded on VDAC-S193E showed that channel characteristics were identical to those of wild type samples, indicating that phosphorylation of S193 does not directly affect channel gating. The combination of NMR and electrophysiological results allows us to discuss the validity of proposed gating models. PMID:25545271

  2. A Large Sample Volume Magic Angle Spinning Nuclear Magnetic Resonance Probe for In-Situ Investigations with Constant Flow of Reactants

    SciTech Connect

    Hu, Jian Z.; Sears, Jesse A.; Mehta, Hardeep S.; Ford, Joseph J.; Kwak, Ja Hun; Zhu, Kake; Wang, Yong; Liu, Jun; Hoyt, David W.; Peden, Charles HF

    2012-02-21

    A large-sample-volume constant-flow magic angle sample spinning (CF-MAS) NMR probe is reported for in-situ studies of the reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions. In our approach, the reactants are introduced into the catalyst bed using a fixed tube at one end of the MAS rotor while a second fixed tube, linked to a vacuum pump, is attached at the other end of the rotor. The pressure difference between both ends of the catalyst bed inside the sample cell space forces the reactants flowing through the catalyst bed, which improves the diffusion of the reactants and products. This design allows the use of a large sample volume for enhanced sensitivity and thus permitting in-situ 13C CF-MAS studies at natural abundance. As an example of application, we show that reactants, products and reaction transition states associated with the 2-butanol dehydration reaction over a mesoporous silicalite supported heteropoly acid catalyst (HPA/meso-silicalite-1) can all be detected in a single 13C CF-MAS NMR spectrum at natural abundance. Coke products can also be detected at natural 13C abundance and under the stopped flow condition. Furthermore, 1H CF-MAS NMR is used to identify the surface functional groups of HPA/meso-silicalite-1 under the condition of in-situ drying . We also show that the reaction dynamics of 2-butanol dehydration using HPA/meso-silicalite-1 as a catalyst can be explored using 1H CF-MAS NMR.

  3. Nanostructures of Mg0.65Ti0.35Dx studied with x-ray diffraction, neutron diffraction, and magic-angle-spinning H2 NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Srinivasan, S.; Magusin, P. C. M. M.; Kalisvaart, W. P.; Notten, P. H. L.; Cuevas, F.; Latroche, M.; van Santen, R. A.

    2010-02-01

    Magnesium transition-metal alloys have a high hydrogen-storage capacity and show improved hydrogen-uptake and -release kinetics compared to magnesium alone. In the present study we have investigated the structure of bulk magnesium-titanium deuteride Mg0.65Ti0.35Dx prepared via mechanical alloying and gas-phase deuterium absorption by combined use of x-ray diffraction (XRD), neutron diffraction, and magic-angle-spinning H2 nuclear magnetic resonance (NMR). The initial ball-milled alloy has two XRD-distinct Mg and Ti fcc phases. Even after prolonged exposure to deuterium gas at 75 bar and 175°C the materials with and without palladium catalyst are only partly deuterated. Deuterium loading causes the formation of, on the one hand, bct (rutile) MgD2 nanodomains with interdispersed TiDy layers and, on the other hand, a separate fcc (fluorite) TiDz phase. The TiDy phase is XRD invisible, but shows clearly up at a H2 NMR shift of -43ppm between the shift of MgD2 (3 ppm) and the Knight shift of the TiDz phase (-143ppm) . Exchange NMR indicates complete deuterium exchange at 25°C between the MgD2 and TiDy phase within 1 s, as consistent with intimate contacts between these phases. Combined analysis of the XRD and NMR peak areas suggests that the deuterium concentrations y and z in the TiDy and TiDz domains are about 1.5 and 2.0, respectively. Comparing the intrinsic cell parameters of rutile MgH2 and fluorite TiH2 , we propose that stabilization of the mixed nanocomposite may arise from a coherent coupling between the crystal structures of the rutile MgD2 nanodomains and the thin layers of fcc TiDy .

  4. High-Resolution Magic-Angle Spinning-(1)H NMR Spectroscopy-Based Metabolic Profiling of Hippocampal Tissue in Rats with Depression-Like Symptoms.

    PubMed

    Akimoto, Hayato; Oshima, Shinji; Ohara, Kousuke; Negishi, Akio; Hiroyama, Hanako; Nemoto, Tadashi; Kobayashi, Daisuke

    2017-03-04

    Depressive disorders cause large socioeconomic effects influencing not only the patients themselves but also their family and broader community as well. To better understand the physiologic factors underlying depression, in this study, we performed metabolomics analysis, an omics technique that comprehensively analyzes small molecule metabolites in biological samples. Specifically, we utilized high-resolution magic-angle spinning-(1)H NMR (HRMAS-(1)H NMR) spectroscopy to comprehensively analyze the changes in metabolites in the hippocampal tissue of rats exposed to chronic stress (CS) via multi-step principal component analysis (multi-step PCA). The rats subjected to CS exhibited obvious depression-like behaviors. High correlations were observed between the first principal component (PC1) score in the score plot obtained using multi-step PCA and measurements from depression-like behavioral testing (body weight, sucrose preference test, and open field test). Alanine, glutamate, glutamine, and aspartate levels in the hippocampal tissue were significantly lower, whereas N-acetylaspartate, myo-inositol, and creatine were significantly higher in the CS group compared to the control (non-CS) group. As alanine, glutamate, and glutamine are known to be involved in energy metabolism, especially in the TCA cycle, chronic exogenous stress may have induced abnormalities in energy metabolism in the brains of the rats. The results suggest that N-acetylaspartate and creatine levels may have increased in order to complement the loss of energy-producing activity resulting from the development of the depression-like disorder. Multi-step PCA therefore allowed an exploration of the degree of depression-like symptoms as represented by changes in intrinsic metabolites.

  5. Insights into atomic-level interaction between mefenamic acid and eudragit EPO in a supersaturated solution by high-resolution magic-angle spinning NMR spectroscopy.

    PubMed

    Higashi, Kenjirou; Yamamoto, Kazutoshi; Pandey, Manoj Kumar; Mroue, Kamal H; Moribe, Kunikazu; Yamamoto, Keiji; Ramamoorthy, Ayyalusamy

    2014-01-06

    The intermolecular interaction between mefenamic acid (MFA), a poorly water-soluble nonsteroidal anti-inflammatory drug, and Eudragit EPO (EPO), a water-soluble polymer, is investigated in their supersaturated solution using high-resolution magic-angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy. The stable supersaturated solution with a high MFA concentration of 3.0 mg/mL is prepared by dispersing the amorphous solid dispersion into a d-acetate buffer at pH 5.5 and 37 °C. By virtue of MAS at 2.7 kHz, the extremely broad and unresolved (1)H resonances of MFA in one-dimensional (1)H NMR spectrum of the supersaturated solution are well-resolved, thus enabling the complete assignment of MFA (1)H resonances in the aqueous solution. Two-dimensional (2D) (1)H/(1)H nuclear Overhauser effect spectroscopy (NOESY) and radio frequency-driven recoupling (RFDR) under MAS conditions reveal the interaction of MFA with EPO in the supersaturated solution at an atomic level. The strong cross-correlations observed in the 2D (1)H/(1)H NMR spectra indicate a hydrophobic interaction between the aromatic group of MFA and the backbone of EPO. Furthermore, the aminoalkyl group in the side chain of EPO forms a hydrophilic interaction, which can be either electrostatic or hydrogen bonding, with the carboxyl group of MFA. We believe these hydrophobic and hydrophilic interactions between MFA and EPO molecules play a key role in the formation of this extremely stable supersaturated solution. In addition, 2D (1)H/(1)H RFDR demonstrates that the molecular MFA-EPO interaction is quite flexible and dynamic.

  6. Selective excitation enables assignment of proton resonances and {sup 1}H-{sup 1}H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    SciTech Connect

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of {sup 1}H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as {sup 13}C or {sup 15}N. In this method, after the initial preparation of proton magnetization and cross-polarization to {sup 13}C nuclei, transverse magnetization of desired {sup 13}C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific {sup 13}C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of {sup 1}H-{sup 1}H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  7. Analysis of metabolic characteristics in a rat model of chronic pancreatitis using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy.

    PubMed

    Tian, Bing; Ma, Chao; Wang, Jian; Pan, Chun-Shu; Yang, Gen-Jin; Lu, Jian-Ping

    2015-01-01

    Pathological and metabolic alterations co-exist and co-develop in the progression of chronic pancreatitis (CP). The aim of the present study was to investigate the metabolic characteristics and disease severity of a rat model of CP in order to determine associations in the observed pathology and the metabolites of CP using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). Wistar rats (n=36) were randomly assigned into 6 groups (n=6 per group). CP was established by administering dibutyltin dichloride solution into the tail vein. After 0, 7, 14, 21, 28 and 35 days, the pancreatic tissues were collected for pathological scoring or for HR-MAS NMR. Correlation analyses between the major pathological scores and the integral areas of the major metabolites were determined. The most representative metabolites, aspartate, betaine and fatty acids, were identified as possessing the greatest discriminatory significance. The Spearman's rank correlation coefficients between the pathology and metabolites of the pancreatic tissues were as follows: Betaine and fibrosis, 0.454 (P=0.044); betaine and inflammatory cell infiltration, 0.716 (P=0.0001); aspartate and fibrosis, -0.768 (P=0.0001); aspartate and inflammatory cell infiltration, -0.394 (P=0.085); fatty acid and fibrosis, -0.764 (P=0.0001); and fatty acid and inflammatory cell infiltration, -0.619 (P=0.004). The metabolite betaine positively correlated with fibrosis and inflammatory cell infiltration in CP. In addition, aspartate negatively correlated with fibrosis, but exhibited no significant correlation with inflammatory cell infiltration. Furthermore, the presence of fatty acids negatively correlated with fibrosis and inflammatory cell infiltration in CP. HR-MAS NMR may be used to analyze metabolic characteristics in a rat model of different degrees of chronic pancreatitis.

  8. Solution state structure determination of silicate oligomers by 29SI NMR spectroscopy and molecular modeling.

    PubMed

    Cho, Herman; Felmy, Andrew R; Craciun, Raluca; Keenum, J Patrick; Shah, Neil; Dixon, David A

    2006-02-22

    Evidence for nine new solution state silicate oligomers has been discovered by (29)Si NMR homonuclear correlation experiments of (29)Si-enriched samples. In addition to enhancing signal sensitivity, the isotopic enrichment increases the probability of the (29)Si-(29)Si two-bond scalar couplings that are necessary for the observation of internuclear correlations in 2-D experiments. The proposed assignments are validated by comparisons of experimental and simulated cross-peaks obtained with high digital resolution. The internuclear connectivity indicated by the NMR data suggests that several of these oligomers can have multiple stereoisomers, including conformers and/or diastereomers. The stabilities of these oligomers and their possible stereoisomers have been investigated by electronic structure calculations.

  9. (29)Si NMR and SAXS investigation of the hybrid organic-inorganic glasses obtained by consolidation of the melting gels.

    PubMed

    Jitianu, Andrei; Cadars, Sylvian; Zhang, Fan; Rodriguez, Gabriela; Picard, Quentin; Aparicio, Mario; Mosa, Jadra; Klein, Lisa C

    2017-03-14

    This study is focused on structural characterization of hybrid glasses obtained by consolidation of melting gels. The melting gels were prepared in molar ratios of methyltriethoxysilane (MTES) and dimethyldiethoxysilane (DMDES) of 75%MTES-25%DMDES and 65%MTES-35%DMDES. Following consolidation, the hybrid glasses were characterized using Raman, (29)Si and (13)C Nuclear Magnetic Resonance (NMR) spectroscopies, synchrotron Small Angle X-Ray Scattering (SAXS) and scanning electron microscopy (SEM). Raman spectroscopy revealed the presence of Si-C bonds in the hybrid glasses and 8-membered ring structures in the Si-O-Si network. Qualitative NMR spectroscopy identified the main molecular species, while quantitative NMR data showed that the ratio of trimers (T) to dimers (D) varied between 4.6 and 3.8. Two-dimensional (29)Si NMR data were used to identify two distinct types of T(3) environments. SAXS data showed that the glasses are homogeneous across the nm to micrometer length scales. The scattering cross section was one thousand times lower than what is expected when phase separation occurs. The SEM images show a uniform surface without defects, in agreement with the SAXS results, which further supports that the hybrid glasses are nonporous.

  10. Magic Angle Spinning NMR Metabolomics

    SciTech Connect

    Zhi Hu, Jian

    2016-01-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is a non-destructive, quantitative, reproducible, untargeted and unbiased method that requires no or minimal sample preparation, and is one of the leading analytical tools for metabonomics research [1-3]. The easy quantification and the no need of prior knowledge about compounds present in a sample associated with NMR are advantageous over other techniques [1,4]. 1H NMR is especially attractive because protons are present in virtually all metabolites and its NMR sensitivity is high, enabling the simultaneous identification and monitoring of a wide range of low molecular weight metabolites.

  11. Dynamic High-Resolution H-1 and P-31 NMR Spectroscopy and H-1 T-2 Measurements in Postmortem Rabbit Muscles Using Slow Magic Angle Spinning

    SciTech Connect

    Bertram, Hanne Christine; Hu, Jian Zhi; Rommereim, Donald N.; Wind, Robert A.; Andersen, Henrik J.

    2004-05-05

    Postmortem changes in rabbit muscle tissue with different glycogen status (normal vs low) were followed continuously from 13 min postmortem until 8 h postmortem and again 20 h postmortem using simultaneous magic angle spinning 1H and 31P NMR spectroscopy together with measurement of the transverse relaxation time, T2, of the muscle water. The 1H metabolite spectra were measured using the phase-altered spinning sidebands (PASS) technique at a spinning rate of 40 Hz. pH values calculated from the 31P NMR spectra using the chemical shifts of the C-6 line of histidine in the 1H spectra and the chemical shifts of inorganic phosphate in the 31P spectra confirmed the different muscle glycogen status in the tissues. High-resolution 1H spectra obtained from the PASS technique revealed the presence of a new resonance line at 6.8 ppm during the postmortem period, which were absent in muscles with low muscle glycogen content. This new resonance line may originate from the aminoprotons in creatine, and its appearance may be a result of a pH effect on the exchange rate between the amino and the water protons and thereby the NMR visibility. Alternatively, the new resonance line may originate from the aromatic protons in tyrosine, and its appearance may be a result of a pH-induced protein unfolding exposing hydrophobic amino acid residues to the aqueous environment. Further studies are needed to evaluate these hypotheses. Finally, distributed analysis of the water T2 relaxation data revealed three relaxation populations and an increase in the population believed to reflect extramyofibrillar water through the postmortem period. This increase was significantly reduced (p < 0.0001) in samples from animals with low muscle glycogen content, indicating that the pH is controlling the extent of postmortem expulsion of water from myofibrillar structures. The significance of the postmortem increase in the amount extramyofibrillar water on the water-holding capacity was verified by

  12. Magic-angle spinning NMR studies of molecular organization in multibilayers formed by 1-octadecanoyl-2-decanoyl-sn-glycero-3-phosphocholine.

    PubMed Central

    Halladay, H N; Stark, R E; Ali, S; Bittman, R

    1990-01-01

    Magic-angle spinning 1H and 13C nuclear magnetic resonance (NMR) have been employed to study 50%-by-weight aqueous dispersions of 1-octadecanoyl-2-decanoyl-sn-glycero-3-phosphocholine (C[18]:C[10]PC) and 1-octadecanoyl-2-d19-decanoyl-PC (C[18]:C[10]PC-d19), mixed-chain phospholipids which can form interdigitated multibilayers. The 1H NMR linewidth for methyl protons of the choline headgroup has been used to monitor the liquid crystalline-to-gel (LC-to-G) phase transition and confirm variations between freezing and melting temperatures. Both 1H and 13C spin-lattice relaxation times indicate unusual restrictions on segmental reorientation at megahertz frequencies for C(18):C(10)PC as compared with symmetric-chain species in the LC state; nevertheless each chemical moiety of the mixed-chain phospholipid exhibits motional behavior that may be classified as liquidlike. Two-dimensional nuclear Overhauser spectroscopy (NOESY) on C(18):C(10)PC and C(18):C(10)PC-d19 reveals cross-peaks between the omega-methyl protons of the C18 chain and the N-methyl protons of the phosphocholine headgroup, and several experimental and theoretical considerations argue against an interpretation based on spin diffusion. Using NMR relaxation times and NOESY connectivities along with a computational formalism for four-spin systems (Keepers, J. W., and T. L. James. 1984. J. Magn. Reson. 57:404-426), an estimate of 3.5 A is obtained for the average distance between the omega-methyl protons of the C18 chain and the N-methyl protons of the phosphocholine headgroup. This finding is consistent with a degree of interdigitation similar to that proposed for organized assemblies of gel-state phosphatidylcholine molecules with widely disparate acyl-chain lengths (Hui, S. W., and C.-H. Huang. 1986. Biochemistry. 25:1330-1335); however, acyl-chain bendback or other intermolecular interactions may also contribute to the NOESY results. For multibilayers of C(18):C(10)PC in the gel phase, 13C chemical

  13. High-resolution mono- and multidimensional magic angle spinning 1H nuclear magnetic resonance of membrane peptides in nondeuterated lipid membranes and H2O.

    PubMed Central

    Le Guernevé, C; Seigneuret, M

    1996-01-01

    High-speed (14 kHz) solid-state magic angle spinning (MAS) 1H NMR has been applied to several membrane peptides incorporated into nondeuterated dilauroyl or dimyristoylphosphatidylcholine membranes suspended in H2O. It is shown that solvent suppression methods derived from solution NMR, such as presaturation or jump-return, can be used to reduce water resonance, even at relatively high water content. In addition, regioselective excitation of 1H peptide resonances promotes an efficient suppression of lipid resonances, even in cases where these are initially two orders of magnitude more intense. As a consequence, 1H MAS spectra of the peptide low-field region are obtained without interference from water and lipid signals. These display resonances from amide and other exchangeable 1H as well as from aromatic nonexchangeable 1H. The spectral resolution depends on the specific types of resonance and membrane peptide. For small amphiphilic or hydrophobic oligopeptides, resolution of most individual amide resonance is achieved, whereas for the transmembrane peptide gramicidin A, an unresolved amide spectrum is obtained. Partial resolution of aromatic 1H occurs in all cases. Multidimensional 1H-MAS spectra of membrane peptides can also be obtained by using water suppression and regioselective excitation. For gramicidin A, F2-regioselective 2D nuclear Overhauser effect spectroscopy (NOESY) spectra are dominated by intermolecular through-space connectivities between peptide aromatic or formyl 1H and lipid 1H. These appear to be compatible with the known structure and topography of the gramicidin pore. On the other hand, for the amphiphilic peptide leucine-enkephalin, F2-regioselective NOESY spectra mostly display cross-peaks originating from though-space proximities of amide or aromatic 1H with themselves and with aliphatic 1H. F3-regioselective 3D NOESY-NOESY spectra can be used to obtain through-space correlations within aliphatic 1H. Such intrapeptide proximities should

  14. Magical Boxes

    ERIC Educational Resources Information Center

    Costello, Judith

    2005-01-01

    Students get excited when they realize that they can transform a flat sheet of paper into a box. By using different sizes of paper, they can make different sizes of boxes and put a box inside a box, inside a box. These magical boxes within boxes can contain unwanted emotions or special treasures. The project described in this article incorporates…

  15. Magic Mirrors

    ERIC Educational Resources Information Center

    Mills, Allan

    2011-01-01

    "Magic mirrors" were so named because, when they were positioned to throw a reflected patch of sunlight on a nearby wall, this area contained an outline of a design cast on the back of the (bronze) mirror. Investigations begun in the 19th century showed that this was a response to heavy localized pressures exerted on the face of the thin mirror…

  16. Matisse Magic.

    ERIC Educational Resources Information Center

    Gibson, Marcia

    2002-01-01

    Presents an art lesson in which kindergarten and first-grade students learn about Henri Matisse and his art work. Explains that the students use "Model Magic" to create Matisse style face refrigerator magnets. Discusses in detail how to create the magnets. (CMK)

  17. Mummies & Magic.

    ERIC Educational Resources Information Center

    Casey, Jeanne E.

    1989-01-01

    Covers the cultural and aesthetic significance of Egyptian mummies, as explained in an exhibition at Boston's Museum of Fine Arts. The display, "Mummies & Magic: The Funerary Arts of Ancient Egypt," allowed for restoration work which did much to advance modern knowledge of Egyptian culture and funerary art. (LS)

  18. Solution State Structure Determination of Silicate Oligomers by 29Si NMR Spectroscopy and Molecular Modeling

    SciTech Connect

    Cho, Herman M.; Felmy, Andrew R.; Craciun, Raluca; Keenum, Johnathan P.; Shah, Neil K.; Dixon, David A.

    2006-02-22

    Evidence for nine new solution state silicate oligomers has been discovered by 29Si NMR homonuclear correlation experiments of 29Si-enriched samples. In addition to enhancing signal sensitivity, the isotopic enrichment increases the probability of the 29Si–29Si two-bond scalar couplings that are necessary for the observation of internuclear correlations in 2-D experiments. The proposed assignments are validated by comparisons of experimental and simulated crosspeaks obtained with high digital resolution. The internuclear connectivity indicated by the NMR data suggests that several of these oligomers can have multiple stereoisomers, including conformers and/or diastereomers. The stability of these oligomers and their possible stereoisomers have been investigated by electronic structure calculations.

  19. 29Si NMR spin-echo decay in YbRh2Si2

    NASA Astrophysics Data System (ADS)

    Kambe, S.; Sakai, H.; Tokunaga, Y.; Hattori, T.; Lapertot, G.; Matsuda, T. D.; Knebel, G.; Flouquet, J.; Walstedt, R. E.

    2016-02-01

    29Si nuclear magnetic resonance (NMR) has been measured in a 29Si-enriched single crystal sample of YbRh2Si2. The spin-echo decay for applied field H ∥, ⊥ the c-axes has been measured at 100 K. A clear spin-echo decay oscillation is observed for both cases, possibly reflecting the Ruderman-Kittel (RK) interaction. Since the observed oscillation frequency depends on the direction of applied magnetic field, anisotropic RK coupling and pseudo-dipolar (PD) interactions may not be negligible in this compound. The origin of spin-echo decay oscillations is discussed.

  20. Insight into hydrogen bonding of uranyl hydroxide layers and capsules by use of 1H magic-angle spinning NMR spectroscopy [Insight into the hydrogen bonding for uranyl hydroxides using 1H MAS NMR spectroscopy

    DOE PAGES

    Alam, Todd M.; Liao, Zuolei; Nyman, May; ...

    2016-04-27

    Solid-state 1H magic-angle spinning (MAS) NMR was used to investigate local proton environments in anhydrous [UO2(OH)2] (α-UOH) and hydrated uranyl hydroxide [(UO2)4O(OH)6·5H2O (metaschoepite). For the metaschoepite material, proton resonances of the μ2-OH hydroxyl and interlayer waters were resolved, with two-dimensional (2D) double-quantum (DQ) 1H–1H NMR correlation experiments revealing strong dipolar interactions between these different proton species. The experimental NMR results were combined with first-principles CASTEP GIPAW (gauge including projector-augmented wave) chemical shift calculations to develop correlations between hydrogen-bond strength and observed 1H NMR chemical shifts. Furthermore, these NMR correlations allowed characterization of local hydrogen-bond environments in uranyl U24 capsules andmore » of changes in hydrogen bonding that occurred during thermal dehydration of metaschoepite.« less

  1. MAGIC highlights

    NASA Astrophysics Data System (ADS)

    López-Coto, Rubén

    2016-07-01

    The present generation of Imaging Air Cherenkov Telescopes (IACTs) has greatly improved our knowledge on the Very High Energy (VHE) side of our Universe. The MAGIC IACTs operate since 2004 with one telescope and since 2009 as a two telescope stereoscopic system. I will outline a few of our latest and most relevant results: the discovery of pulsed emission from the Crab pulsar at VHE, recently found to extend up to 400 GeV and along the "bridge" of the light curve, the measurement of the Crab nebula spectrum over three decades of energy, the discovery of VHE γ-ray emission from the PWN 3C 58, the very rapid emission of IC 310, in addition to dark matter studies. The results that will be described here and the planned deep observations in the next years will pave the path for the future generation of IACTs.

  2. Chiral Magnetism in an Itinerant Helical Magnet, MnSi - An Extended 29Si NMR Study

    NASA Astrophysics Data System (ADS)

    Yasuoka, Hiroshi; Motoya, Kiyoichiro; Majumder, Mayukh; Witt, Sebastian; Krellner, Cornelius; Baenitz, Michael

    2016-07-01

    The microscopic magnetism in the helical, conical and ferromagnetically polarized phases in an itinerant helical magnet, MnSi, has been studied by an extended 29Si NMR at zero field and under external magnetic fields. The temperature dependence of the staggered moment, MQ(T), determined by the 29Si NMR frequency, ν(T), and the nuclear relaxation rate, 1/T1(T), at zero field is in general accord with the SCR theory for weak itinerant ferromagnetic metals and its extension to helical magnets. The external field dependence of resonance frequency, ν(H), follows a vector sum of the contributions from the atomic hyperfine and macroscopic fields with a field induced moment characteristic to itinerant magnets. A discontinuous jump of the resonance frequency at the critical field, Hc, between the conical and the polarized phases has also been found, which suggests a first order like change of the electronic states at Hc.

  3. 29Si NMR Chemical Shift Calculation for Silicate Species by Gaussian Software

    NASA Astrophysics Data System (ADS)

    Azizi, S. N.; Rostami, A. A.; Godarzian, A.

    2005-05-01

    Hartree-Fock self-consistent-field (HF-SCF) theory and the Gauge-including atomic orbital (GIAO) methods are used in the calculation of 29Si NMR chemical shifts for ABOUT 90 units of 19 compounds of various silicate species of precursors for zeolites. Calculations have been performed at geometries optimized at the AM1 semi-empirical method. The GIAO-HF-SCF calculations were carried out with using three different basis sets: 6-31G*, 6-31+G** and 6-311+G(2d,p). To demonstrate the quality of the calculations the calculated chemical shifts, δ, were compared with the corresponding experimental values for the compounds in study. The results, especially with 6-31+g** are in excellent agreement with experimental values. The calculated chemical shifts, in practical point of view, appear to be accurate enough to aid in experimental peak assignments. The difference between the experimental and calculated 29Si chemical shift values not only depends on the Qn units but also it seems that basis set effects and the level of theory is more important. For the series of molecules studied here, the standard deviations and mean absolute errors for 29Si chemical shifts relative to TMS determined using Hartree--Fock 6-31+G** basis is nearly in all cases smaller than the errors for shifts determined using HF/6-311+G(2d,p).

  4. Elemental and isotopic ( 29Si and 18O) tracing of glass alteration mechanisms

    NASA Astrophysics Data System (ADS)

    Valle, Nathalie; Verney-Carron, Aurélie; Sterpenich, Jérôme; Libourel, Guy; Deloule, Etienne; Jollivet, Patrick

    2010-06-01

    To better understand glass alteration mechanisms, especially alteration layers formation, leaching experiments of a borosilicate glass (SON68) doped with a different rare earth element (La, Ce, or Nd) with solutions rich in 29Si and 18O were carried out. The coupled analyses of glass, alteration products, and solution led to a complete elemental and isotopic ( 29Si and 18O) budget. They revealed different behaviours of elements that depend not only on their structural role in the glass, but also on their affinity for alteration products (gel, phyllosilicates, phosphates). However, analyses of both glass and solution are not sufficient to describe the real exchanges occurring between glass and solution. The use of 29Si and 18O tracers gives new insights on the formation of alteration layers. During alteration the phyllosilicates records the isotopic variations of the leaching solution. Their isotopic signatures highlight a mechanism of dissolution/precipitation, which implies equilibrium between the secondary phases and the solution. On the other hand the gel isotopic signature, that is intermediate between the glass and the solution, substantiates the hypothesis that the gel is formed by hydrolysis/condensation reactions. This mechanism can thus explain the influence of the gel formation conditions (alteration conditions, solution saturation) on the structure (reorganisation) and texture (porosity) of this layer and on its protective effect. These hydrolysis/condensation reactions are also certainly involved in the aluminosilicate glass alteration and in the formation of palagonite.

  5. The Versatile Magic Square.

    ERIC Educational Resources Information Center

    Watson, Gale A.

    2003-01-01

    Demonstrates the transformations that are possible to construct a variety of magic squares, including modifications to challenge students from elementary grades through algebra. Presents an example of using magic squares with students who have special needs. (YDS)

  6. Optical hyperpolarization and inductive readout of 31P donor nuclei in natural abundance single crystal 29Si

    NASA Astrophysics Data System (ADS)

    Alexander, Thomas; Haas, Holger; Deshpande, Rahul; Gumann, Patryk; Cory, David

    2016-05-01

    We optically polarize and inductively detect 31P donor nuclei in single crystal silicon at high magnetic fields (6 . 7T). Samples include both natural abundance 29Si and an isotopically purified 28Si sample. We observe dipolar order in the 29Si nuclear spins through a spin-locking measurement. This provides a means of characterizing spin transport in the vicinity of the 31P donors.

  7. Probing Hydronium Ion Histidine NH Exchange Rate Constants in the M2 Channel via Indirect Observation of Dipolar-Dephased (15)N Signals in Magic-Angle-Spinning NMR.

    PubMed

    Fu, Riqiang; Miao, Yimin; Qin, Huajun; Cross, Timothy A

    2016-12-14

    Water-protein chemical exchange in membrane-bound proteins is an important parameter for understanding how proteins interact with their aqueous environment, but has been difficult to observe in membrane-bound biological systems. Here, we demonstrate the feasibility of probing specific water-protein chemical exchange in membrane-bound proteins in solid-state MAS NMR. By spin-locking the (1)H magnetization along the magic angle, the (1)H spin diffusion is suppressed such that a water-protein chemical exchange process can be monitored indirectly by dipolar-dephased (15)N signals through polarization transfer from (1)H. In the example of the Influenza A full length M2 protein, the buildup of dipolar-dephased (15)N signals from the tetrad of His37 side chains have been observed as a function of spin-lock time. This confirms that hydronium ions are in exchange with protons in the His37 NH bonds at the heart of the M2 proton conduction mechanism, with an exchange rate constant of ∼1750 s(-1) for pH 6.2 at -10 °C.

  8. 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

  9. Protein-chromophore interactions in alpha-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. A study by 13C magic angle spinning NMR.

    PubMed

    Weesie, R J; Askin, D; Jansen, F J; de Groot, H J; Lugtenburg, J; Britton, G

    1995-03-27

    MAS (magic angle spinning) 13C NMR has been used to study protein-chromophore interactions in alpha-crustacyanin, the blue astaxanthin-binding carotenoprotein of the lobster, Homarus gammarus, reconstituted with astaxanthins labelled with 13C at the 14,14' or 15,15' positions. Two signals are seen for alpha-crustacyanin containing [14,14'-13C2]astaxanthin, shifted 6.9 and 4.0 ppm downfield from the 134.1 ppm signal of uncomplexed astaxanthin in the solid state. With alpha-crustacyanin containing [15,15'-13C2]astaxanthin, one essentially unshifted broad signal is seen. Hence binding to the protein causes a decrease in electronic charge density, providing the first experimental evidence that a charge redistribution mechanism contributes to the bathochromic shift of the astaxanthin in alpha-crustacyanin, in agreement with inferences based on resonance Raman data [Salares, et al. (1979) Biochim. Biophys. Acta 576, 176-191]. The splitting of the 14 and 14' signals provides evidence for asymmetric binding of each astaxanthin molecule by the protein.

  10. Synthesis of Long-T1 Silicon Nanoparticles for Hyperpolarized 29Si Magnetic Resonance Imaging

    PubMed Central

    Atkins, Tonya M.; Cassidy, Maja C.; Lee, Menyoung; Ganguly, Shreyashi; Marcus, Charles M.; Kauzlarich, Susan M.

    2013-01-01

    We describe the synthesis, materials characterization and dynamic nuclear polarization (DNP) of amorphous and crystalline silicon nanoparticles for use as hyperpolarized magnetic resonance imaging (MRI) agents. The particles were synthesized by means of a metathesis reaction between sodium silicide (Na4Si4) and silicon tetrachloride (SiCl4) and were surface functionalized with a variety of passivating ligands. The synthesis scheme results in particles of diameter ~10 nm with long size-adjusted 29Si spin lattice relaxation (T1) times (> 600 s), which are retained after hyperpolarization by low temperature DNP. PMID:23350651

  11. The Magic of Balanced Groups: Educational Applications of Magic Squares

    ERIC Educational Resources Information Center

    Bosse, Michael J.; Nandakumar, N. R.; Ore, Melanie L.

    2007-01-01

    This paper provides students with many interesting observations regarding the nature of magic squares, magic rectangles, and quasi-magic squares and provides tools for teachers to group students into ability-balanced cooperative learning groups.

  12. {sup 27}Al and {sup 29}Si MAS spectroscopy of layer silicates in Argonne premium coals.

    SciTech Connect

    Thompson, A. R.; Botto, R. E.; Chemistry; DOA

    2001-01-01

    High-resolution {sup 27}Al and {sup 29}Si NMR were employed to characterize layered silicates in the suite of eight Argonne Premium coals. Analyses were performed on native coals directly, or fractions isolated by sink-float techniques. Mineral phases of kaolinite, quartz, and illite-montmorillinite clays could readily be distinguished nonquantitatively by {sup 29}Si NMR techniques using direct detection or cross polarization. {sup 27}Al NMR was used to determine quantitatively the amounts of tetrahedral and octahedral aluminum forms present. The {sup 27}Al NMR results were consistent with mineralogical analyses by XRD, showing that increases in tetrahedral content paralleled illitization of the clay minerals. A remarkably good relationship also was found between the total amount of tetrahedral aluminum associated with the mineral matter and degree of maturation of the organic matter in the coal. The data suggest that illitization of the clays can be used as a mineralogical thermal maturity indicator for Type II kerogens, as demonstrated for the Argonne Premium coals, provided that contributions from organo-chelated aluminum species and detrital mineral matter are taken into account.

  13. Structure of model peptides based on Nephila clavipes dragline silk spidroin (MaSp1) studied by 13C cross polarization/magic angle spinning NMR.

    PubMed

    Yang, Mingying; Nakazawa, Yasumoto; Yamauchi, Kazuo; Knight, David; Asakura, Tetsuo

    2005-01-01

    To obtain detailed structural information for spider dragline spidroin (MaSp1), we prepared three versions of the consensus peptide GGLGGQGAGAAAAAAGGAGQGGYGGLGSQGAGR labeled with 13C at six different sites. The 13C CP/MAS NMR spectra were observed after treating the peptides with different reagents known to alter silk protein conformations. The conformation-dependent 13C NMR chemical shifts and peak deconvolution were used to determine the local structure and the fractional compositions of the conformations, respectively. After trifluoroacetic acid (solvent)/diethyl ether (coagulant) treatment, the N-terminal region of poly-Ala (PLA) sequence, Ala8 and Ala10, adopted predominantly the alpha-helix with a substantial amount of beta-sheet. The central region, Ala15, Ala18, and Leu26, and C-terminal region, Ala31, of the peptide were dominated by either 3(1)-helix or alpha-helix. There was no indication of beta-sheet, although peak broadening indicates that the torsion angle distribution is relatively large. After 9 M LiBr/dialysis treatment, three kinds of conformation, beta-sheet, random coil, and 3(1)-helix, appeared, in almost equal amounts of beta-sheet and random coil conformations for Ala8 and Ala10 residues and distorted 3(1)-helix at the central region of the peptide. In contrast, after formic acid/methanol and 8 M urea/acetonitrile treatments, all of the local structure tends to beta-sheet, although small amounts of random coil are also observed. The peak pattern of the Ala Cbeta carbon after 8 M urea/acetonitrile treatment is similar to the corresponding patterns of silk fiber from Bombyx mori and Samia cynthia ricini. We also synthesized a longer 13C-labeled peptide containing two PLA blocks and three Gly-rich blocks. After 8 M urea/acetonitrile treatment, the conformation pattern was closely similar to that of the shorter peptide.

  14. A 23Na magic angle spinning nuclear magnetic resonance, XANES, and high-temperature X-ray diffraction study of NaUO3, Na4UO5, and Na2U2O7.

    PubMed

    Smith, A L; Raison, P E; Martel, L; Charpentier, T; Farnan, I; Prieur, D; Hennig, C; Scheinost, A C; Konings, R J M; Cheetham, A K

    2014-01-06

    The valence state of uranium has been confirmed for the three sodium uranates NaU(V)O3/[Rn](5f(1)), Na4U(VI)O5/[Rn](5f(0)), and Na2U(VI)2O7/[Rn](5f(0)), using X-ray absorption near-edge structure (XANES) spectroscopy. Solid-state (23)Na magic angle spinning nuclear magnetic resonance (MAS NMR) measurements have been performed for the first time, yielding chemical shifts at -29.1 (NaUO3), 15.1 (Na4UO5), and -14.1 and -19 ppm (Na1 8-fold coordinated and Na2 7-fold coordinated in Na2U2O7), respectively. The [Rn]5f(1) electronic structure of uranium in NaUO3 causes a paramagnetic shift in comparison to Na4UO5 and Na2U2O7, where the electronic structure is [Rn]5f(0). A (23)Na multi quantum magic angle spinning (MQMAS) study on Na2U2O7 has confirmed a monoclinic rather than rhombohedral structure with evidence for two distinct Na sites. DFT calculations of the NMR parameters on the nonmagnetic compounds Na4UO5 and Na2U2O7 have permitted the differentiation between the two Na sites of the Na2U2O7 structure. The linear thermal expansion coefficients of all three compounds have been determined using high-temperature X-ray diffraction: αa = 22.7 × 10(-6) K(-1), αb = 12.9 × 10(-6) K(-1), αc = 16.2 × 10(-6) K(-1), and αvol = 52.8 × 10(-6) K(-1) for NaUO3 in the range 298-1273 K; αa = 37.1 × 10(-6) K(-1), αc = 6.2 × 10(-6) K(-1), and αvol = 81.8 × 10(-6) K(-1) for Na4UO5 in the range 298-1073 K; αa = 6.7 × 10(-6) K(-1), αb = 14.4 × 10(-6) K(-1), αc = 26.8 × 10(-6) K(-1), αβ = -7.8 × 10(-6) K(-1), and αvol = -217.6 × 10(-6) K(-1) for Na2U2O7 in the range 298-573 K. The α to β phase transition reported for the last compound above about 600 K was not observed in the present studies, either by high-temperature X-ray diffraction or by differential scanning calorimetry.

  15. The Role of High-Resolution Magic Angle Spinning 1H Nuclear Magnetic Resonance Spectroscopy for Predicting the Invasive Component in Patients with Ductal Carcinoma In Situ Diagnosed on Preoperative Biopsy

    PubMed Central

    Chae, Eun Young; Kim, Suhkmann; Baek, Hyeon-Man; Yoon, Dahye; Kim, Siwon; Shim, Ye Eun; Kim, Hak Hee; Cha, Joo Hee; Choi, Woo Jung; Lee, Jeong Hyun; Shin, Ji Hoon; Lee, Hee Jin; Gong, Gyungyub

    2016-01-01

    The purpose of this study was to evaluate the role of high-resolution magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy in patients with ductal carcinoma in situ (DCIS) diagnosed on preoperative biopsy. We investigated whether the metabolic profiling of tissue samples using HR-MAS 1H NMR spectroscopy could be used to distinguish between DCIS lesions with or without an invasive component. Our institutional review board approved this combined retrospective and prospective study. Tissue samples were collected from 30 patients with pure DCIS and from 30 with DCIS accompanying invasive carcinoma. All patients were diagnosed with DCIS by preoperative core-needle biopsy and underwent surgical resection. The metabolic profiling of tissue samples was performed by HR-MAS 1H NMR spectroscopy. All observable metabolite signals were identified and quantified in all tissue samples. Metabolite intensity normalized by total spectral intensities was compared according to the tumor type using the Mann-Whitney test. Multivariate analysis was performed with orthogonal projections to latent structure-discriminant analysis (OPLS-DA). By univariate analysis, the metabolite concentrations of choline-containing compounds obtained with HR-MAS 1H NMR spectroscopy did not differ significantly between the pure DCIS and DCIS accompanying invasive carcinoma groups. However, the GPC/PC ratio was higher in the pure DCIS group than in the DCIS accompanying invasive carcinoma group (p = 0.004, Bonferroni-corrected p = 0.064), as well as the concentration of myo-inositol and succinate. By multivariate analysis, the OPLS-DA models built with HR-MAS MR metabolic profiles could clearly discriminate between pure DCIS and DCIS accompanying invasive carcinoma. Our preliminary results suggest that HR-MAS MR metabolomics on breast tissue may be able to distinguish between DCIS lesions with or without an invasive component. PMID:27560937

  16. Study of the mechanism of diatom cell division by means of 29Si isotope tracing

    NASA Astrophysics Data System (ADS)

    Audinot, J.-N.; Guignard, C.; Migeon, H.-N.; Hoffmann, L.

    2006-07-01

    Diatoms are delicate unicellular organisms enclosed in a silica frustule, that is made up of two valves. Multiplication of the diatoms occurs by ordinary mitotic cell division. During cell division each cell produces two daughter cells, each of them keeping one of the two valves of the mother cell and producing a new valve by absorbing the silicon present in the environment. The NanoSIMS 50 allows ion imaging to be performed on diatoms in order to determine the site of fixation of silicon. The aim of this study was to observe and compare the mechanism of the construction of the new valve after cell division. To this end, different types of diatoms have been transferred in a culture medium enriched with 29Si and after several days, the distribution of the different isotopes of silicon has been determined by NanoSIMS50 imaging. The construction of new valves has been observed and the isotopic ratio has been determined.

  17. (29)Si hyperfine structure of the E(')(alpha) center in amorphous silicon dioxide.

    PubMed

    Buscarino, G; Agnello, S; Gelardi, F M

    2006-09-29

    We report a study by electron paramagnetic resonance on the E'(alpha) point defect in amorphous silicon dioxide (a-SiO(2)). Our experiments were performed on gamma-ray irradiated oxygen-deficient materials and pointed out that the (29)Si hyperfine structure of the E'(alpha) consists of a pair of lines split by approximately 49 mT. On the basis of the experimental results, a microscopic model is proposed for the E'(alpha) center, consisting of a hole trapped in an oxygen vacancy with the unpaired electron sp(3) orbital pointing away from the vacancy in a back-projected configuration and interacting with an extra oxygen atom of the a-SiO(2) matrix.

  18. Structure of Amantadine-Bound M2 Transmembrane Peptide of Influenza A in Lipid Bilayers from Magic-Angle-Spinning Solid-State NMR: the Role of Ser31 in Amantadine Binding

    PubMed Central

    Cady, Sarah D.; Mishanina, Tatiana V.; Hong, Mei

    2014-01-01

    The M2 proton channel of influenza A is the target of the antiviral drugs amantadine and rimantadine, whose effectiveness has been abolished by a single-site mutation of Ser31 to Asn in the transmembrane domain of the protein. Recent high-resolution structures of the M2 transmembrane domain obtained from detergent-solubilized protein in solution and crystal environments gave conflicting drug binding sites. We present magic-angle-spinning solid-state NMR results of Ser31 and a number of other residues in the M2 transmembrane peptide (M2TMP) bound to lipid bilayers. Comparison of the spectra of the membrane-bound apo and complexed M2TMP indicates that Ser31 is the site of the largest chemical shift perturbation by amantadine. The chemical shift constraints lead to a monomer structure with a small kink of the helical axis at Gly34. A tetramer model is then constructed using the helix tilt angle and several interhelical distances previously measured on unoriented bilayer samples. This tetramer model differs from the solution and crystal structures in terms of the openness of the N-terminus of the channel, the constriction at Ser31, and the sidechain conformations of Trp41, a residue important for channel gating. Moreover, the tetramer model suggests that Ser31 may interact with amantadine amine via hydrogen bonding. While the apo and drug-bound M2TMP have similar average structures, the complexed peptide has much narrower linewidths at physiological temperature, indicating drug-induced changes of the protein dynamics in the membrane. Further, at low temperature, several residues show narrower lines in the complexed peptide than the apo peptide, indicating that amantadine binding reduces the conformational heterogeneity of specific residues. The differences of the current solid-state NMR structure of the bilayer-bound M2TMP from the detergent-based M2 structures suggest that the M2 conformation is sensitive to the environment, and care must be taken when interpreting

  19. The "Magic" String

    ERIC Educational Resources Information Center

    Hoover, Todd F.

    2010-01-01

    The "Magic" String is a discrepant event that includes a canister with what appears to be the end of two strings protruding from opposite sides of it. Due to the way the strings are attached inside the canister, it appears as if the strings can magically switch the way they are connected. When one string end is pulled, the observer's expectation…

  20. Chinese "Magic" Mirrors.

    ERIC Educational Resources Information Center

    Swinson, Derek B.

    1992-01-01

    Chinese "magic" mirrors are made from bronze with the front side a mirror and the reverse side a molded image. When light is reflected from the mirror,the image on the reverse side appears. Discusses reflections of conventional mirrors, possible explanations for the magic mirror phenomenon, and applications of the phenomenon to…

  1. Discovering the Magic of Magic Squares

    ERIC Educational Resources Information Center

    Semanisinova, Ingrid; Trenkler, Marian

    2007-01-01

    The purpose of this article is to present a collection of problems that allow students to investigate magic squares and Latin squares, formulate their own conjectures about these mathematical objects, look for arguments supporting or disproving their conjectures, and finally establish and prove mathematical assertions. Each problem is completed…

  2. Lenz's Law Magic Trick

    NASA Astrophysics Data System (ADS)

    Ruiz, Michael J.

    2006-02-01

    The demonstration of Lenz's law by dropping a powerful magnet down a nonmagnetic metal pipe has become a classic lecture-hall demonstration.1,2 An inexpensive version is packaged as a professional magic trick3 called "Newton's Nightmare." Combining sleight-of-hand with a demonstration of Lenz's law is a surefire way to heighten student interest. The subsequent student discussion motivated by a desire to understand the magic trick can lead to a memorable physics lesson. This paper will discuss Lenz's law magic and review literature that reveals the subtlety of the physics.

  3. Investigation of the Curvature Induction and Membrane Localization of the Influenza Virus M2 Protein Using Static and Off-Magic-Angle Spinning Solid-State NMR of Oriented Bicelles

    PubMed Central

    Wang, Tuo; Hong, Mei

    2015-01-01

    A wide variety of membrane proteins induce membrane curvature for function, thus it is important to develop new methods to simultaneously determine membrane curvature and protein binding sites in membranes with multiple curvatures. We introduce solid-state NMR methods based on magnetically oriented bicelles and off-magic-angle spinning (OMAS) to measure membrane curvature and the binding site of proteins in mixed-curvature membranes. We demonstrate these methods on the influenza virus M2 protein, which not only acts as a proton channel but also mediates virus assembly and membrane scission. An M2 peptide encompassing the transmembrane (TM) domain and an amphipathic helix, M2(21-61), was studied and compared with the TM peptide (M2TM). Static 31P NMR spectra of magnetically oriented DMPC/DHPC bicelles exhibit a temperature-independent isotropic chemical shift in the presence of M2(21-61) but not M2TM, indicating that the amphipathic helix confers the peptide with the ability to generate a high-curvature phase. 2D 31P spectra indicate that this high-curvature phase is associated with the DHPC bicelle edges, suggestive of the structure of budding viruses from the host cell. 31P- and 13C-detected 1H relaxation times of the lipids indicate that the majority of M2(21-61) is bound to the high-curvature phase. Using OMAS experiments, we resolved the 31P signals of lipids with identical headgroups based on their distinct chemical shift anisotropies. Based on this resolution, 2D 1H-31P correlation spectra show that the amide protons in M2(21-61) correlate with the DMPC but not the DHPC 31P signal of the bicelle, indicating that a small percentage of M2(21-61) partitions into the planar region of the bicelles. These results show that the M2 amphipathic helix induces high membrane curvature and localizes the protein to this phase, in excellent agreement with the membrane-scission function of the protein. These bicelle-based relaxation and OMAS solid-state NMR techniques are

  4. Crystal structure solid-state cross polarization magic angle spinning 13C NMR correlation in luminescent d10 metal-organic frameworks constructed with the 1,2-Bis(1,2,4-triazol-4-yl)ethane ligand.

    PubMed

    Habib, Hesham A; Hoffmann, Anke; Höppe, Henning A; Steinfeld, Gunther; Janiak, Christoph

    2009-03-02

    Hydrothermal reactions of 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) with copper(II), zinc(II), and cadmium(II) salts have yielded the dinuclear complexes [Zn2Cl4(mu2-btre)2] (1) and [Zn2Br4(mu2-btre)2] (2), the one-dimensional coordination polymer infinity1[Zn(NCS)2(2-btre)] (3), the two-dimensional networks infinity2[Cu2(mu2-Cl)2(mu4-btre)] (4), infinity2[Cu2(mu2-Br)2(mu4-btre)] (5), and infinity2{[Cd6(mu3-OH)2(mu3-SO4)4(mu4-btre)3(H2O)6](SO4).6H2O} (6), and the three-dimensional frameworks infinity3{[Cu(mu4-btre)]ClO4.0.25H2O} (7), 3{[Zn(mu4-btre)(mu2-btre)](ClO4)2} (8), infinity3{[Cd(mu4-btre)(mu2-btre)](ClO4)2} (9), and infinity3[Cu2(mu2-CN)2(mu4-btre)] (10, 2-fold 3D interpenetrated framework). The copper-containing products 4, 5, 7, and 10 contain the metal in the +1 oxidation state, from a simultaneous redox and self-assembly reaction of the Cu(II) starting materials. The cyanide-containing framework 10 has captured the CN- ions from the oxidative btre decomposition. The perchlorate frameworks 7, 8, or 9 react in an aqueous NH4+PF6- solution with formation of the related PF6--containing frameworks. The differences in the metal-btre bridging mode (mu2-kappaN1:N1', mu2-kappaN1:N2 or mu4-kappaN1:N2:N1':N2') and the btre ligand symmetry can be correlated with different signal patterns in the 13C cross polarization magic angle spinning (CPMAS) NMR spectra. Compounds 2, 4, 5 and 7 to 10 exhibit fluorescence at 403-481 nm upon excitation at 270-373 nm which is not seen in the free btre ligand.

  5. Magic of Light

    NASA Astrophysics Data System (ADS)

    Curticapean, Dan

    2010-08-01

    This paper focuses on the concept of the website "Magic of Light", an internet platform that offers podcasts, slides, pictures, Flash animations and educational materials to allow a better understanding in optics and photonics.

  6. About Magic Rectangles

    ERIC Educational Resources Information Center

    Hakopian, Yuri R.; Eloyan, Ani N.; Khachatryan, David E.

    2006-01-01

    This paper introduces a class of matrices, the rows and columns of which add up to identical constants (generally speaking, different for rows and columns). Some properties of these matrices, which will be called "magic rectangles" are discussed.

  7. Let's Make Magic.

    ERIC Educational Resources Information Center

    Bang-Jensen, Valerie

    1986-01-01

    A learning experience designed to expand primary students' knowledge of what is and is not magic is described. Included are activities involving language arts, math, art, class discussion, and motor skills. (MT)

  8. Deteriorated hardened cement paste structure analyzed by XPS and {sup 29}Si NMR techniques

    SciTech Connect

    Kurumisawa, Kiyofumi; Nawa, Toyoharu; Owada, Hitoshi; Shibata, Masahito

    2013-10-15

    In this report, X-ray photoelectron spectroscopy (XPS) and {sup 29}Si-MAS-NMR was used for the evaluation of deteriorated hardened cement pastes. The deterioration by ammonium nitrate solution was accompanied by changes in the pore structure as well as by structural changes in the C–S–H in the hardened cement paste. The CaO/SiO{sub 2} ratio of the C–S–H decreased with the progress of deterioration, there was also polymerization of the silicate in the C–S–H. It was confirmed that the degree of polymerization of silicate of the C–S–H in hardened cement paste can be determined by XPS. It was also shown that the polymerization depends on the structure of the C–S–H. -- Highlights: •The polymerization of silicate of the C–S–H in the HCP can be observed by XPS. •The structure of C–S–H changed with the degree of calcium leaching. •The NMR result about silicate in C–S–H was in good agreement with the XPS result.

  9. Spinning angle optical calibration apparatus

    DOEpatents

    Beer, Stephen K.; Pratt, II, Harold R.

    1991-01-01

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

  10. Partitioning of aluminum atoms in crystallographically non-equivalent tetrahedral sites of the zeolite offretite by 29Si MAS NMR

    NASA Astrophysics Data System (ADS)

    Chen, T. H.; Wang, K. X.; Luo, W. L.; Yuan, Z. Y.; Wang, J. Z.; Ding, D. T.; Li, H. X.; Hu, C.

    1996-04-01

    For the zeolite offretite, a formula is proposed which includes the framework Si/Al ratio ( R), the partitioning ratio of Al over two crystallographically non-equivalent tetrahedral sites ( r) and intensities of the observed peaks in the 29Si MAS NMR spectrum. By this formula, the framework Si/Al ratio of offretite can be estimated from the 29Si MAS NMR spectrum. Combined with chemical analysis of the Si/Al ratio, Al partitioning in two kinds of T sites can also be deduced. It is concluded that the T B sites are favored by Al atoms in parent offretites and Al atoms at T B sites can more easily be substituted isomorphously by Si when treated with (NH 4) 2SiF 6. The formula proposed here is based only on experiments and may be used to testify some statistical models of Al distributions in offretites.

  11. The calculated magnetic, electronic and thermodynamic properties of Ce3Co29Si4B10 compound

    NASA Astrophysics Data System (ADS)

    Huo, Jin-Rong; Wang, Xiao-Xu; Hu, Yao-Wen; Zhang, Guo-Hua; Cheng, Hai-Xia; Li, Lu; Qian, Ping

    2016-05-01

    The magnetic moment, lattice parameter and atom fraction coordinates for Ce3Co29Si4B10 are calculated by the first-principles GGA+U method, and the results indicate that the calculated and experimental values are basically accordant when U=2.6 eV. We study the interaction effect and orbital hybridization between Co and Ce atoms. The projected density of states at U=2.6 eV which provided by Co-2c, Ce-2b and Ce-4d sites are contrasted with else U values. Meanwhile the electron density of states for different sites and the distance between various atoms are exhibited. In addition, the thermodynamic properties of Ce3Co29Si4B10 are evaluated by using a series of interatomic pair potentials.

  12. Effect of plastic deformation on the magnetic properties and dislocation luminescence of isotopically enriched silicon {sup 29}Si:B

    SciTech Connect

    Koplak, O. V.; Shteynman, E. A.; Tereschenko, A. N.; Morgunov, R. B.

    2015-09-15

    A correlation between the temperature dependences of the D1-line intensity of dislocation luminescence and the magnetic moment of plastically deformed isotopically enriched crystals {sup 29}Si:B is found. It is established that the magnetic susceptibility of the deformed crystals obtained by integration of the spectra of electron spin resonance and the D1-line intensity undergo similar nonmonotonic variations with temperature varying in the range of 20–32 K.

  13. Effects of temperature on the structures of silicate liquids: 29Si NMR results

    NASA Astrophysics Data System (ADS)

    Brandriss, Mark E.; Stebbins, Jonathan F.

    1988-11-01

    The effect of temperature on the structures of three silicate liquids has been studied by 29Si NMR spectroscopy on glass samples prepared with different glass transition temperatures. The compositions studied are (Na 2O) .34(SiO 2) .66 and (CaO) .10(Na 2O) .15(SiO 2) .75 and (CaO) .25(MgO) .25(SiO 2) .50. In the first two, the abundance of SiO 4 tetrahedra with four bridging oxygens ( Q 4) increases significantly with temperature. This change results from the disproportionation reaction 2Q 3ái Q 2 + Q 4 ( Q n is a SiO 4 tetrahedron with n bridging oxygens), with the observed increase in disproportionation at higher temperatures implying increased randomization of the anionic structure. In the (Na 2O) .34(SiO 2) .66 composition, the temperature dependence of Q 4 abundance enables us to estimate ΔH 0 for this reaction to be 30 ± 15 kJ per mole of Si. Although this reaction thus makes only a minor contribution to the conngurational heat capacity of each liquid, it probably has a major influence on the thermodynamic activity of SiO 2. Widening of the (CaO) .25(MgO) .25(SiO 2) .50 spectral peak with increasing temperature likewise implies increasing randomization of the anionic structure, although specific structural contributions to this widening are not identified. Models of melt structures at liquidus temperatures will be limited in accuracy if they assume that the speciation observed in glasses is unaffected by temperature change.

  14. [Homeopathic medicine and magic].

    PubMed

    Angutek, Dorota

    2007-01-01

    The article compares homeopathic medicine and primitive magic. The author realises formal similarities beetwen these two fields of knowledge. The primitive homeopathic magic characterised by J. G. Frazer in his The Golden Bought announces that "similar courses similar". M. Mauss and H. Hubert added to this "low" an another formula: "similar acts on similar that courses a contrary phenomenon". The last formula is an identic one with the "low" of homeopathic medicine. Moreover there is a similarity between pantheistic religion of Hahnemann and magician beliefs in the power named mana in Melanesia and Polinesia or orenda, wakan, manitou and so on, by the Indians from The North America. The amazing thing is that homeopathic chemists belive that kinetic power transforms itself into esoteric one, during preparation of homeopathic medicines.In the end of this article the author ascertains that homeopathic medicine and magic has certain paradigm in common what is opposit to racionalism of official European paradigm of thinking.

  15. Solvated Electrons in Clusters: Magic Numbers for the Photoelectron Anisotropy.

    PubMed

    West, Adam H C; Yoder, Bruce L; Luckhaus, David; Signorell, Ruth

    2015-12-17

    This paper reports on a curiosity concerning magic numbers in neutral molecular clusters, namely on magic numbers related to the photoelectron anisotropy in angle-resolved photoelectron spectra. With a combination of density functional calculations and experiment, we search for magic numbers in Na(H2O)n, Na(NH3)n, Na(CH3OH)n, and Na(CH3OCH3)n clusters. In clusters of high symmetry, the highest occupied molecular orbital can be delocalized over an extended region, forming a symmetric charge distribution of high s character, which results in a pronounced anisotropy in the photoelectron angular distribution. We find magic numbers at n = 6 and 4 for sodium-doped dimethyl ether and ammonia clusters, respectively, but not for sodium-doped water and methanol clusters, which is likely a consequence of the degree of hydrogen bonding and the number of structural isomers.

  16. Spin dependent recombination; A sup 29 Si hyperfine study of radiation-induced P sub b centers at the Si/SiO sub 2 interface

    SciTech Connect

    Jupina, M.A.; Lenahan, P.M. )

    1990-12-01

    The spin dependent recombination (SDR) technique is used to observe the {sup 29}Si hyperfine spectra of radiation-induced P{sub b} centers at the Si/SiO{sub 2} interface in a MOSFET. The P{sub b} center is a paramagnetic, trivalent silicon defect that is the dominant radiation-induced interface state. The {sup 29}Si hyperfine spectra give detailed atomic scale information about the P{sub b} center. The authors' SDR results show that the {sup 29}Si hyperfine spectra vary with surface potential. This result indicates that differences in the defect's local geometry lead to substantial differences in the defect's energy level. However, the {sup 29}Si hyperfine spectra are found to be relatively independent of the ionizing radiation dosage.

  17. Isotopic tracing (D, 18O and 29Si) to understand the alteration on historic glass

    NASA Astrophysics Data System (ADS)

    Verney-Carron, Aurélie; Saheb, Mandana; Valle, Nathalie; Mangin, Denis; Remusat, Laurent; Loisel, Claudine

    2015-04-01

    In order to better preserve historic glasses, e.g. stained glass windows, the understanding of their alteration mechanisms and of what controls the kinetics corresponding to each process is required. The ancient stained glasses are characterized by thick alteration layers, continuous or as pits, that are cracked or lost. Therefore, if a passivating role of the alteration layer has been proved on some other kinds of glass (such as basaltic or nuclear glass) in aqueous medium, the issue can be addressed for low durable stained glass weathered in varying atmospheric conditions. The mechanism of alteration layer formation was first investigated by performing dynamic and static experiments on model medieval glasses altered with a solution doped in 29Si at different concentrations (or saturation degrees). Solid analyses were carried out by SIMS and solution by HR-ICP-MS. Medieval stained glass has mainly a potash-lime-silica composition with a low content in alumina. The alkaline and alkaline-earth elements have thus a modifier role in the glassy network. This structural difference compared to boro- or alumino-silicate glasses could induce differences in the alteration mechanisms. However, the analysis of the Si isotopic signature of the gel layer highlighted that diffusion, but also hydrolysis/condensation reactions, are also involved in the gel layer formation process, leading to a structural and textural reorganization. The second objective was to determine the kinetic role of the alteration layer, and especially to trace the circulation of water once the altered layer is formed. For that, ancient glasses were exposed to simulated rainfall events / drying periods cycles during 3 months by using a solution doped in D and 18O. NanoSIMS analyses have shown that the transport in the alteration layer is mainly driven by diffusion in the porosity despite the presence of cracks that could have been preferential ways of circulation. This demonstrates also a potential

  18. Manufacturing Magic and Computational Creativity

    PubMed Central

    Williams, Howard; McOwan, Peter W.

    2016-01-01

    This paper describes techniques in computational creativity, blending mathematical modeling and psychological insight, to generate new magic tricks. The details of an explicit computational framework capable of creating new magic tricks are summarized, and evaluated against a range of contemporary theories about what constitutes a creative system. To allow further development of the proposed system we situate this approach to the generation of magic in the wider context of other areas of application in computational creativity in performance arts. We show how approaches in these domains could be incorporated to enhance future magic generation systems, and critically review possible future applications of such magic generating computers. PMID:27375533

  19. Manufacturing Magic and Computational Creativity.

    PubMed

    Williams, Howard; McOwan, Peter W

    2016-01-01

    This paper describes techniques in computational creativity, blending mathematical modeling and psychological insight, to generate new magic tricks. The details of an explicit computational framework capable of creating new magic tricks are summarized, and evaluated against a range of contemporary theories about what constitutes a creative system. To allow further development of the proposed system we situate this approach to the generation of magic in the wider context of other areas of application in computational creativity in performance arts. We show how approaches in these domains could be incorporated to enhance future magic generation systems, and critically review possible future applications of such magic generating computers.

  20. Helping, Manipulation, and Magic

    ERIC Educational Resources Information Center

    Frey, Louise A.; Edinburg, Golda M.

    1978-01-01

    The thesis of this article is that an understanding of the primitive origins of the helping process in myth, magic, and ritual may prevent social workers from engaging in practices that negate their clients' ability to work out their own solutions to problems. (Author)

  1. Magic, Morals and Health

    ERIC Educational Resources Information Center

    Johnson, Warren R.

    2010-01-01

    Magic has to do with the supernatural and the unnatural. It is indifferent to natural law and science and is aloof from scientific inquiry. Its existence depends upon unquestioning faith. Granted such faith, it is extraordinarily potent. If it does not move mountains, it convinces the faithful that it can. It can damage health and perhaps, restore…

  2. Neuroscience, Magic, and Counseling

    ERIC Educational Resources Information Center

    Echterling, Lennis G.; Presbury, Jack; Cowan, Eric

    2012-01-01

    Recent findings in neuroscience have identified principles, such as attention management and change blindness, which stage magicians exploit to create illusions. Neuroscientists have also revealed how mirror neurons and oxytocin enhance the impact of magic. In other words, magicians are just as much practitioners of sleight of mind as they are of…

  3. The Magic of Mathematics.

    ERIC Educational Resources Information Center

    Morgan, John L.; Ginther, John L.

    1994-01-01

    Describes the effect, method, and mathematics of the following magic tricks which can be used in introducing mathematics lessons: the Ninth Card, Fibonacci Revealed, the Case of the Missing Area, I've Got Your Numbers, and the Card That Turns Inside Out. (MKR)

  4. Inspecting Magic Words.

    ERIC Educational Resources Information Center

    White, John Howell

    1998-01-01

    Considers neopragmatism's use-value for art educators as they inspect the magic words, images, and practices that influence curriculum and instruction. Explains that neopragmatism offers art educators three concepts (contingency, demystification, and recontextualization) as tools to interpret educational beliefs and classroom practices. (CMK)

  5. [Magical and physical reality].

    PubMed

    Kállai, János

    2016-01-01

    In the postmodern countries the computer generated virtual reality provides new perceptual domains wherein the evaluation of real and unreal contents generates an essential challenge for both children and adults. The expectances to perceive unreal content which is contradictory with the common sense experiences become seductive for most of people. The time in front of the screen that emits the magic reality gradually rises. The sudden advance in generation of alternative realities demands that we have to recall the basic principles of psychological reality testing and the involving mechanism that produces a distinction between phantasy and reality for both healthy and pathological mind. Frame of reference usually restrains the thinking. This review contains two parts, the first is focuses on the historical aspect of magical and physical reality and the second one, that will be published in a next issue, will present an evaluation of the boundary between self and another person in point of view of the psychopathological phenomenon. This analysis will focus on how the boundary of the self behaves in physically real and magic computer generated environment.

  6. CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR

    DOE PAGES

    Li, Qinfei; Ge, Yong; Geng, Guoqing; ...

    2015-01-01

    Tmore » he effect of calcium chloride (CaCl 2 ) on tricalcium silicate (C 3 S) hydration was investigated by scanning transmission X-ray microscopy (STXM) with Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra and 29 Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement-based hydration system.he Ca L 3,2 -edge NEXAFS spectra obtained by examining C 3 S hydration in the presence of CaCl 2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C-S-H), which is the primary hydration product. O K-edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C 3 S. Based on the Ca L 3,2 -edge spectra and chemical component mapping, we concluded that CaCl 2 prefers to coexist with unhydrated C 3 S instead of C-S-H. In Si K-edge NEXAFS analysis, CaCl 2 increases the degree of silicate polymerization of C-S-H in agreement with the 29 Si CP/MAS NMR results, which show that the presence of CaCl 2 in hydrated C 3 S considerably accelerates the formation of middle groups ( Q 2 ) and branch sites ( Q 3 ) in the silicate chains of C-S-H gel at 1-day hydration.« less

  7. Magical Landscapes: Two Love Stories.

    ERIC Educational Resources Information Center

    Moore, John Noell

    2002-01-01

    Introduces two books about magic, one a collection of essays "Ex Libris: Confessions of a Common Reader," which describes the author's inherited lifelong passion for books and reading; and the other a novel, "Mangos, Bananas and Coconuts: A Cuban Love Story," which tells a story of love and magic that seems both real and…

  8. The lure of magic thinking.

    PubMed

    Wilder, J

    1975-01-01

    The development of the thinking processes from childhood to maturity is analyzed and three stages are distinguished: the magic omnipotent stage of the preschool child, the development of the realistic ego, and the future-directed value-building superego. The role of the lure to return to the magic thinking in our culture is described.

  9. Garden Gnomes: Magical or Tacky?

    ERIC Educational Resources Information Center

    Flynt, Deborah

    2012-01-01

    Garden gnomes: magical or tacky? Well, art is in the eye of the beholder, and for the author's advanced seventh-grade art class, garden gnomes are magical. Gnomes have a very long history, dating back to medieval times. A fairytale describes them as brownie-like creatures that are nocturnal helpers. In this article, the author describes how her…

  10. Old and New Magic Numbers

    SciTech Connect

    Talmi, Igal

    2008-11-11

    The discovery of magic numbers led to the shell model. They indicated closure of major shells and are robust: proton magic numbers are rather independent of the occupation of neutron orbits and vice versa. Recently the magic property became less stringent and we hear a lot about the discovery of new magic numbers. These, however, indicate sub-shell closures and strongly depend on occupation numbers and hence, may be called quasi-magic numbers. Some of these have been known for many years and the mechanism for their appearance as well as disappearance, was well understood within the simple shell model. The situation will be illustrated by a few examples which demonstrate the simple features of the shell model. Will this simplicity emerge from the complex computations of nuclear many-body theory?.

  11. Oxygen-17 NMR in solids by dynamic-angle spinning and double rotation

    NASA Astrophysics Data System (ADS)

    Chmelka, B. F.; Mueller, K. T.; Pines, A.; Stebbins, J.; Wu, Y.; Zwanziger, J. W.

    1989-05-01

    IT is widely lamented that despite its unqualified success with spin-1/2 nuclei such as 13C, 29Si and31P, the popular NMR technique of magic-angle spinning (MAS) has experienced a somewhat restricted applicability among quadrupolar nuclei such as 17O, 23Na and 27A1 (refs 1-3). The resolution in the central (1/2 lrarr-1/2) transition of these non-integer quadrupolar spins under MAS is thought to be limited primarily by second-order quadrupolar broadening. Such effects of second-order spatial anisotropy cannot be eliminated by rotation about a fixed axis or by multiple-pulse techniques4,5. More general mechanisms of sample reorientation (refs 6-8 and A. Samoson and A. Pines, manuscript in preparation) can, however, make high-resolution NMR of quadrupolar nuclei feasible. MAS is implemented by spinning a sample about a single axis so that second-rank spherical harmonics (which give rise to first-order broadening through anisotropy of electrical and magnetic interactions) are averaged away. But dynamic-angle-spinning (DAS) and double-rotation (DOR) NMR involve spinning around two axes, averaging away both the second- and fourth-rank spherical harmonics, which are responsible for second-order broadening. Here we present the application of these new techniques to 17O in two minerals, cristobalite (SiO2) and diopside (CaMgSi2O6). This work goes beyond previous results on 23Na (ref. 8) by showing the first experimental results using DAS and by demonstrating the application of DOR to the resolution of distinct oxygen sites in an important class of oxide materials.

  12. Isomer ratio measurements for the reaction 29Si( 18O, p2n) 44m, 44gSc

    NASA Astrophysics Data System (ADS)

    Groening, H.; Aleklett, K.; Moody, K. J.; McGaughey, P. L.; Loveland, W.; Seaborg, G. T.

    1982-11-01

    Isomer ratios for the reaction 29Si( 18O, p2n) 44gSc, 44gSc have been deduced from activity measurements for projectile energies between 30 and 99 MeV. Statistical model calculations show that the isomer ratio dependence on projectile energy up to about 80 MeV can be adequately described by assuming a fixed ratio of quadrupole to dipole γ-ray strengths. Such a ratio of E2/E1 strengths agrees with corresponding values deduced from the literature. The values of the γ-ray strength ratios needed to fit the experimental isomer ratios are extremely sensitive to the relative amounts of quadrupole γ-ray admixture and to the presence of discrete levels other than those which conform to the yrast line.

  13. "Magic" Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  14. Revealing ontological commitments by magic.

    PubMed

    Griffiths, Thomas L

    2015-03-01

    Considering the appeal of different magical transformations exposes some systematic asymmetries. For example, it is more interesting to transform a vase into a rose than a rose into a vase. An experiment in which people judged how interesting they found different magic tricks showed that these asymmetries reflect the direction a transformation moves in an ontological hierarchy: transformations in the direction of animacy and intelligence are favored over the opposite. A second and third experiment demonstrated that judgments of the plausibility of machines that perform the same transformations do not show the same asymmetries, but judgments of the interestingness of such machines do. A formal argument relates this sense of interestingness to evidence for an alternative to our current physical theory, with magic tricks being a particularly pure source of such evidence. These results suggest that people's intuitions about magic tricks can reveal the ontological commitments that underlie human cognition.

  15. Calculation of 29Si NMR shifts of silicate complexes with carbohydrates, amino acids, and muhicarboxylic acids: potential role in biological silica utilization

    NASA Astrophysics Data System (ADS)

    Sahai, Nita

    2004-01-01

    The existence of ether or ester-like complexes of silicate with organic compounds has long been debated in the literature on biological utilization of silicon. Comparison of theoretically calculated 29Si NMR chemical shifts for such complexes with experimentally measured values in biological systems could provide a diagnostic tool for identifying which, if any of these molecules exist under physiological conditions. Results are presented here for ab initio molecular orbital calculations of 29Si NMR shifts and formation energies of silicate complexes with polyalcohols, sugar-acids, pyranose sugars, amino acids and multicarboxylic acids. The effects of functional group and molecular structure including ligand size, denticity, ring size, silicon polymerization and coordination number on calculated 29Si shifts were considered. The potential role of such compounds in biological silica utilization pathways is discussed. 29Si NMR shifts and energies were calculated at the HF/6-311+G(2d,p)//HF/6-31G* level. The main result is that only five-membered rings containing penta- and hexa-coordinated Si can explain experimentally observed resonances at ˜ -101 and -141 ppm. Further, the heptet observed in 1H- 29Si coupled spectra can only be explained by structures where Si bonds to oxygens atoms in H-C-O-Si linkages with six symmetrically equivalent H atoms. While compounds containing quadra-coordinated silicon may exist in intracellular silicon storage pools within diatoms, calculated reaction energies suggest that the organism has no thermodynamic advantage in taking up extracellular organ-silicate compounds, instead of silicic acid, from the ambient aqueous environment. Hyper-coordinated complexes are deemed unlikely for transport and storage, though they may exist as transient reactive intermediates or activated complexes during enzymatically- catalyzed silica polymerization, as known previously from sol-gel silica synthesis studies.

  16. The family of ferrocene-stabilized silylium ions: synthesis, 29Si NMR characterization, Lewis acidity, substituent scrambling, and quantum-chemical analyses.

    PubMed

    Müther, Kristine; Hrobárik, Peter; Hrobáriková, Veronika; Kaupp, Martin; Oestreich, Martin

    2013-12-02

    The purpose of this systematic experimental and theoretical study is to deeply understand the unique bonding situation in ferrocene-stabilized silylium ions as a function of the substituents at the silicon atom and to learn about the structure parameters that determine the (29)Si NMR chemical shift and electrophilicity of these strong Lewis acids. For this, ten new members of the family of ferrocene-stabilized silicon cations were prepared by a hydride abstraction reaction from silanes with the trityl cation and characterized by multinuclear (1)H and (29)Si NMR spectroscopy. A closer look at the NMR spectra revealed that additional minor sets of signals were not impurities but silylium ions with substitution patterns different from that of the initially formed cation. Careful assignment of these signals furnished experimental proof that sterically less hindered silylium ions are capable of exchanging substituents with unreacted silane precursors. Density functional theory calculations provided mechanistic insight into that substituent transfer in which the migrating group is exchanged between two silicon fragments in a concerted process involving a ferrocene-bridged intermediate. Moreover, the quantum-chemical analysis of the (29)Si NMR chemical shifts revealed a linear relationship between δ((29)Si) values and the Fe···Si distance for subsets of silicon cations. An electron localization function and electron localizability indicator analysis shows a three-center two-electron bonding attractor between the iron, silicon, and C'(ipso) atoms, clearly distinguishing the silicon cations from the corresponding carbenium ions and boranes. Correlations between (29)Si NMR chemical shifts and Lewis acidity, evaluated in terms of fluoride ion affinities, are seen only for subsets of silylium ions, sometimes with non-intuitive trends, indicating a complicated interplay of steric and electronic effects on the degree of the Fe···Si interaction.

  17. Insight into hydrogen bonding of uranyl hydroxide layers and capsules by use of 1H magic-angle spinning NMR spectroscopy [Insight into the hydrogen bonding for uranyl hydroxides using 1H MAS NMR spectroscopy

    SciTech Connect

    Alam, Todd M.; Liao, Zuolei; Nyman, May; Yates, Jonathan

    2016-04-27

    Solid-state 1H magic-angle spinning (MAS) NMR was used to investigate local proton environments in anhydrous [UO2(OH)2] (α-UOH) and hydrated uranyl hydroxide [(UO2)4O(OH)6·5H2O (metaschoepite). For the metaschoepite material, proton resonances of the μ2-OH hydroxyl and interlayer waters were resolved, with two-dimensional (2D) double-quantum (DQ) 1H–1H NMR correlation experiments revealing strong dipolar interactions between these different proton species. The experimental NMR results were combined with first-principles CASTEP GIPAW (gauge including projector-augmented wave) chemical shift calculations to develop correlations between hydrogen-bond strength and observed 1H NMR chemical shifts. Furthermore, these NMR correlations allowed characterization of local hydrogen-bond environments in uranyl U24 capsules and of changes in hydrogen bonding that occurred during thermal dehydration of metaschoepite.

  18. Solid-State NMR Study of Paramagnetic Bis(alaninato-κ(2)N,O)copper(II) and Bis(1-amino(cyclo)alkane-1-carboxylato-κ(2)N,O)copper(II) Complexes: Reflection of Stereoisomerism and Molecular Mobility in (13)C and (2)H Fast Magic Angle Spinning Spectra.

    PubMed

    Szalontai, Gábor; Csonka, Róbert; Speier, Gábor; Kaizer, József; Sabolović, Jasmina

    2015-05-18

    Solid-state stereochemistry and mobility of paramagnetic copper(II) complexes formed by aliphatic amino acids (l-alanine, d,l-alanine, 1-amino-2-methyl-alanine) and 1-amino(cyclo)alkane-1-carboxylic acids (alkane = propane, butane, pentane, hexane) as bidentate ligands has been studied by (13)C and (2)H solid-state fast magic angle spinning (MAS) NMR spectroscopy. We examined the prospective method to characterize solid-state paramagnetic compounds in a routine way. Both (13)C and (2)H MAS spectra can distinguish d,l and l,l diastereomers of natural and polydeuterated bis([Dn]alaninato)copper(II) (n = 0, 2, 8) complexes with axial and/or equatorial methyl positions (conformations) primarily due to different Fermi-contact (FC) contributions. The three-bond hyperfine couplings clearly show Karplus-like dependence on the torsional angles which turned out to be a useful assignment aid. Density functional theory calculations of the FC term and crystal structures were also used to aid the final assignments. The correlations obtained for bis(alaninato-κ(2)N,O)copper(II) complexes were successfully used to characterize other complexes. The usefulness of the (2)H MAS spectra of the deuterated complexes was underlined. Even the spectra of the easily exchangeable amine protons contained essential stereochemical information. In the case of a dimer structure of bis(1-aminohexane-1-carboxylato-κ(2)N,O)copper(II) both the (13)C and (2)H resolutions were good enough to confirm the presence of the cis and trans forms in the asymmetric unit. With regard to the internal solid-state motions in the crystal lattice, the obtained quadrupolar tensor parameters were similar for the d,l- and l,l-alaninato isomers and also for the cis-trans forms suggesting similar crystal packing effects, static amine deuterons involved in hydrogen bonding, and fast rotating methyl groups.

  19. Calcium silicate hydrates investigated by solid-state high resolution {sup 1}H and {sup 29}Si nuclear magnetic resonance

    SciTech Connect

    Meducin, Fabienne . E-mail: meducin@cnrs-orleans.fr; Bresson, Bruno; Lequeux, Nicolas; Noirfontaine, Marie-Noelle de; Zanni, Helene

    2007-05-15

    This work focuses on phases formed during cement hydration under high pressure and temperature: portlandite Ca(OH){sub 2} (CH); hillebrandite Ca{sub 2}(SiO{sub 3})(OH){sub 2} ({beta}-dicalcium silicate hydrate); calcium silicate hydrate (C-S-H); jaffeite Ca{sub 6}(Si{sub 2}O{sub 7})(OH){sub 6} (tricalcium silicate hydrate); {alpha}-C{sub 2}SH Ca{sub 2}(SiO{sub 3})(OH){sub 2} ({alpha}-dicalcium silicate hydrate); xonotlite Ca{sub 6}(Si{sub 6}O{sub 17})(OH){sub 2} and kilchoanite Ca{sub 6}(SiO{sub 4})(Si{sub 3}O{sub 10}). Portlandite and hillebrandite were synthesized and characterised by high resolution solid-state {sup 1}H and {sup 29}Si Nuclear Magnetic Resonance. In addition, information from the literature concerning the last five phases was gathered. In certain cases, a schematic 3D-structure could be determined. These data allow identification of the other phases present in a mixture. Their morphology was also observed by Scanning Electron Microscopy.

  20. Computer simulations of the Al-Si disorder in synthetic cordierites: Configuraltional entropy constrained by 29Si NMR data

    NASA Astrophysics Data System (ADS)

    Vinograd, Victor L.

    1996-08-01

    The published 29Si NMR data on synthetic Mg-cordierites have been used to estimate the changes in configurational Al-Si entropy of the samples due to metastable disorder. The results show that with the increase of the time of annealing in the range of 2 min-2000 h at 1185 °C the entropy of disorder in cordierite decreases from 17.1 to 6.4 J/mol K, while at 1400 °C in the range of 2 min 88 h the entropy changes from 15.4 to 8.8 J/mol K. The decrease in entropy is followed by the appearance and increase of long-range ordering which is reflected in changes of T1 and T2 site occupancies, decrease in the number of Si-O-Si and Al-O-Al groupings around O1 oxygens and in a decrease in the number of Al-O-Si-O-Al contacts among hexagonal 6T2-rings. The derived values of entropy effects together with published calorimetric data suggest that the enthalpy of metastable disordering strongly depends on the temperature of annealing.

  1. Nucleon momentum distributions and elastic electron scattering from 19F, 25Mg, 27Al, and 29Si nuclei

    NASA Astrophysics Data System (ADS)

    Al-Rahmani, A.

    2016-04-01

    The nucleon momentum distributions and elastic electron scattering form factors of the ground state for some odd 2 s-1 d shell nuclei, such as 19F, 25Mg, 27Al, and 29Si, have been investigated using the coherent density fluctuation model and expressed in terms of the fluctuation function (weight function) | f( x)|2. The fluctuation function has been related to the nucleon density distribution of the nuclei and determined from the theory. The property of the long-tail manner at high-momentum region of the nucleon momentum distribution has been obtained by theoretical fluctuation function. The calculated form factors F( q) of all nuclei under study are in very good agreement with those of experimental data throughout all values of momentum transfer q. It is concluded that the contributions of the quadrupole form factor F C2( q) in 25Mg and 27Al nuclei, which are characterized by the undeformed 2 s-1 d shell model, are necessary for getting a remarkable agreement between the theoretical and experimental form factors.

  2. "Magic" Ionization Mass Spectrometry.

    PubMed

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The “magic” that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  3. Abject Magic: Reasoning Madness in Justine Larbalestier's "Magic or Madness" Trilogy

    ERIC Educational Resources Information Center

    Potter, Troy

    2013-01-01

    This paper explores the representation of magic and madness in Justine Larbalestier's "Magic or Madness" trilogy (2005-2007). Throughout the series, magic is constructed as an abject and disabling force that threatens to disable magic-wielders, either through madness or death. Despite being represented as a ubiquitous force, the…

  4. Finding All Solutions to the Magic Hexagram

    ERIC Educational Resources Information Center

    Holland, Jason; Karabegov, Alexander

    2008-01-01

    In this article, a systematic approach is given for solving a magic star puzzle that usually is accomplished by trial and error or "brute force." A connection is made to the symmetries of a cube, thus the name Magic Hexahedron.

  5. Airbag Trail Dubbed 'Magic Carpet'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for Airbag Trail Dubbed 'Magic Carpet' (QTVR)

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Magic Carpet Close-upMagic Carpet Close-up HD

    This section of the first color image from the Mars Exploration Rover Spirit has been further processed to produce a sharper look at a trail left by the one of rover's airbags. The drag mark was made after the rover landed and its airbags were deflated and retracted. Scientists have dubbed the region the 'Magic Carpet' after a crumpled portion of the soil that appears to have been peeled away (lower left side of the drag mark). Rocks were also dragged by the airbags, leaving impressions and 'bow waves' in the soil. The mission team plans to drive the rover over to this site to look for additional clues about the composition of the martian soil. This image was taken by Spirit's panoramic camera.

    This extreme close-up image (see insets above) highlights the martian feature that scientists have named 'Magic Carpet' because of its resemblance to a crumpled carpet fold. Scientists think the soil here may have detached from its underlying layer, possibly due to interaction with the Mars Exploration Rover Spirit's airbag after landing. This image was taken on Mars by the rover's panoramic camera.

  6. A magic pyramid of supergravities

    NASA Astrophysics Data System (ADS)

    Anastasiou, A.; Borsten, L.; Duff, M. J.; Hughes, L. J.; Nagy, S.

    2014-04-01

    By formulating = 1, 2, 4, 8, D = 3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in , it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D = 3 supergravities. This was subsequently tied in with the more familiar description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D = 3, 4, 6, 10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D = 3 is the known 4 × 4 magic square, while the higher levels are comprised of a 3 × 3 square in D = 4, a 2 × 2 square in D = 6 and Type II supergravity at the apex in D = 10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also construct a conformal magic pyramid by tensoring conformal supermultiplets in D = 3, 4, 6. The missing entry in D = 10 is suggestive of anexotic theory with G/ H duality structure F 4(4)/Sp(3) × Sp(1).

  7. Inherent interface defects in thermal (211)Si/SiO{sub 2}:{sup 29}Si hyperfine interaction

    SciTech Connect

    Iacovo, Serena E-mail: andre.stesmans@fys.kuleuven.be; Stesmans, Andre E-mail: andre.stesmans@fys.kuleuven.be

    2014-10-21

    Low temperature electron spin resonance (ESR) studies were carried out on ‘higher index’ (211)Si/SiO{sub 2} interfaces thermally grown in the temperature range T{sub ox} = 400–1066°C. The data reveal the presence of two species of a P{sub b}-type interface defect, exhibiting a significant difference in defect density. On the basis of the pertinent ESR parameters and interface symmetry, the basic defect is typified as P{sub b0}{sup (211)}, close to the Pb0 center observed in standard (100)Si/SiO{sub 2}. The dominant type is found to pertain to defected Si atoms at (111)Si-face terraces with the dangling bond along the [111] direction at ∼19.5°C with the interface normal, these sites thus apparently predominantly accounting for interface mismatch adaptation. The total of the P{sub b}-type defect appearance clearly reflects the higher-index nature of the interface. It is found that T{sub ox} = 750°C is required to minimize the P{sub b0}{sup (211)} defect density through relaxation of the oxide (interface). Q-band ESR saturation spectroscopy reveals an anisotropic {sup 29}Si (nuclear spin I=1/2) hyperfine (hf) doublet associated with the central P{sub b0}{sup (211)} Zeeman signal, with hf parameters closest to those of the similar hf structure of the P{sub b0}{sup (110)} defect in thermal (110)Si/SiO{sub 2}, adducing independent support to the P{sub b0}{sup (211)} typification.

  8. Magical attachment: Children in magical relations with hospital clowns

    PubMed Central

    2012-01-01

    The aim of the present study was to achieve a theoretical understanding of several different-age children's experiences of magic relations with hospital clowns in the context of medical care, and to do so using psychological theory and a child perspective. The method used was qualitative and focused on nine children. The results showed that age was important to consider in better understanding how the children experienced the relation with the hospital clowns, how they described the magical aspects of the encounter and how they viewed the importance of clown encounters to their own well-being. The present theoretical interpretation characterized the encounter with hospital clowns as a magical safe area, an intermediate area between fantasy and reality. The discussion presented a line of reasoning concerning a magical attachment between the child and the hospital clowns, stating that this attachment: a) comprised a temporary relation; b) gave anonymity; c) entailed reversed roles; and d) created an emotional experience of boundary-transcending opportunities. PMID:22371813

  9. It's magic: a unique practice management strategy.

    PubMed

    Schwartz, Steven

    2003-11-15

    For thousands of years prior to the advent of modern dentistry, magic has been used to entertain, impress, and motivate individuals. Today's dental professionals are using the concept of The Magic of a Healthy Smile through their use of modern clinical techniques and as a means for practice marketing, patient education, and the reduction of patient stress and fear. This article describes how dentists/magicians have incorporated magic into their practices and the benefits of this useful patient management strategy. A script of the "Happy Tooth Magic Show" and resources for dentists to create their own dental magic show are provided.

  10. Magic User’s Manual 2006

    DTIC Science & Technology

    2006-12-01

    starts MAGIC2D single precision. If the open file in Mugman is a . m2d or .mgc file, it will be used as the input file. Magic3D-Sng This button starts...precision. If the open file in Mugman is a . m2d or .mgc file, it will be used as the input file. 1W Magic3DDbl This button starts MAGIC3D double precision. If...type: [All - -] Cancel Magic [l.mgc;-. m2d ;-.m3d] Magic 2D [(. m2d ;x.log] Magic 3D [’.m3d;’.log) Review [*.toc;’.obr;x.obi;x.obs) Log (’.log] Text (R.txt

  11. GRB neutrino search with MAGIC

    SciTech Connect

    Becker, Julia K.; Rhode, Wolfgang; Gaug, Markus

    2008-05-22

    The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope was designed for the detection of photon sources > or approx. 50 GeV. The measurement of highly-inclined air showers renders possible the search for high-energy neutrinos, too. Only neutrinos can traverse the Earth without interaction, and therefore, events close to the horizon can be identified as neutrino-induced rather than photon-induced or hadronic events. In this paper, Swift-XRT-detected GRBs with given spectral information are used in order to calculate the potential neutrino energy spectrum from prompt and afterglow emission for each individual GRB. The event rate in MAGIC is estimated assuming that the GRB happens within the field of view of MAGIC. A sample of 568 long GRBs as detected by BATSE is used to compare the detection rates with 163 Swift-detected bursts. BATSE has properties similar to the Gamma-ray Burst Monitor (GBM) on board of GLAST. Therefore the estimated rates give an estimate for the possibilities of neutrino detection with MAGIC from GLAST-triggered bursts.

  12. Magic and the aesthetic illusion.

    PubMed

    Balter, Leon

    2002-01-01

    The aesthetic illusion is the subjective experience that the content of a work of art is reality. It has an intrinsic relation to magic, an intrapsychic maneuver oriented toward modification and control of the extraspyschic world, principally through ego functioning. Magic is ontogenetically and culturally archaic, expresses the omnipotence inherent in primary narcissism, and operates according to the logic of the primary process. Magic is a constituent of all ego functioning, usually latent in later development. It may persist as an archaic feature or may be evoked regressively in global or circumscribed ways. It causes a general disinhibition of instincts and impulses attended by a sense of confidence, exhiliration, and exuberance. The aesthetic illusion is a combination of illusions: (1) that the daydream embodied by the work of art is the beholder's own, the artist being ignored, and (2) that the artistically described protagonist is a real person with a real "world." The first illusion arises through the beholder's emotional-instinctual gratification from his or her own fantasy-memory constellations; the second comes about because the beholder, by taking the protagonist as proxy, mobilizes the subjective experience of the imaginary protagonist's "reality." The first illusion is necessary for the second to take place; the second establishes the aesthetic illusion proper. Both illusions are instances of magic. Accordingly, the aesthetic illusion is accompanied by a heady experience of excitement and euphoria. The relation among the aesthetic illusion, magic, and enthusiasm is illustrated by an analytic case, J. D. Salinger's "The Laughing Man," Woody Allen's Play It Again, Sam, Don Quixote, and the medieval Cult of the Saints.

  13. The Magic of Magic: The Effect of Magic Tricks on Subsequent Engagement with Lecture Material

    ERIC Educational Resources Information Center

    Moss, Simon A.; Irons, Melanie; Boland, Martin

    2017-01-01

    Background and aims: Lecturers often present entertaining videos, or organize a variety of amusing demonstrations, to foster student engagement or to encourage critical analysis. Magic tricks, in particular, have been shown to activate neural circuits that underpin motivation or problem-solving and, therefore, could be beneficial during lectures.…

  14. Magic star puzzle for educational mathematics

    NASA Astrophysics Data System (ADS)

    Gan, Yee Siang; Fong, Wan Heng; Sarmin, Nor Haniza

    2013-04-01

    One of the interesting fields in recreational mathematics is the magic number arrangement. There are different kinds of arrays in the arrangement for a group of numbers. In particular, one of the arrays in magic number arrangement is called magic star. In fact, magic star involves combinatorics that contributes to geometrical analysis and number theory. Hence, magic star is suitable to be introduced as educational mathematics to cultivate interest in different area of mathematics. To obtain the solutions of normal magic stars of order six, the possible sets of numbers for every line in a magic star have been considered. Previously, the calculation for obtaining the solutions has been done manually which is time-consuming. Therefore, a programming code to generate all the fundamental solutions for normal magic star of order six without including the properties of rotation and reflection has been done. In this puzzle, a magic star puzzle is created by using Matlab software, which enables a user to verify the entries for the cells of magic star of order six. Moreover, it is also user-friendly as it provides interactive commands on the inputs given by the user, which enables the user to detect the incorrect inputs. In addition, user can also choose to view all the fundamental solutions as generated by the programming code.

  15. The calculated magnetic, electronic and thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} compound

    SciTech Connect

    Huo, Jin-Rong; Wang, Xiao-Xu; Hu, Yao-Wen; Zhang, Guo-Hua; Cheng, Hai-Xia; Li, Lu; Qian, Ping

    2016-05-15

    The magnetic moment, lattice parameter and atom fraction coordinates for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} are calculated by the first-principles GGA+U method, and the results indicate that the calculated and experimental values are basically accordant when U=2.6 eV. We study the interaction effect and orbital hybridization between Co and Ce atoms. The projected density of states at U=2.6 eV which provided by Co-2c, Ce-2b and Ce-4d sites are contrasted with else U values. Meanwhile the electron density of states for different sites and the distance between various atoms are exhibited. In addition, the thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} are evaluated by using a series of interatomic pair potentials. - Graphical abstract: Change of the total magnetic moment for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} along with the value of U. There is a sharply decline of the curve at U=2.6 eV and, at the moment, the total magnetic moment of the compound have a good agreement with the experimental data. - Highlights: • We research of quaternary rare earth and transition metal compounds. • We perform the calculation of magnetic moment and electronic structure by GGA+U method. • The orbital hybridization between Co and Ce atoms is displayed and analyzed. • Show the plot of projected density of states for different sites more clearly. • Calculate the thermodynamic property of rare-earth transition metal compound.

  16. Magic Carpet Shows Its Colors

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The upper left image in this display is from the panoramic camera on the Mars Exploration Rover Spirit, showing the 'Magic Carpet' region near the rover at Gusev Crater, Mars, on Sol 7, the seventh martian day of its journey (Jan. 10, 2004). The lower image, also from the panoramic camera, is a monochrome (single filter) image of a rock in the 'Magic Carpet' area. Note that colored portions of the rock correlate with extracted spectra shown in the plot to the side. Four different types of materials are shown: the rock itself, the soil in front of the rock, some brighter soil on top of the rock, and some dust that has collected in small recesses on the rock face ('spots'). Each color on the spectra matches a line on the graph, showing how the panoramic camera's different colored filters are used to broadly assess the varying mineral compositions of martian rocks and soils.

  17. Towards a science of magic.

    PubMed

    Kuhn, Gustav; Amlani, Alym A; Rensink, Ronald A

    2008-09-01

    It is argued here that cognitive science currently neglects an important source of insight into the human mind: the effects created by magicians. Over the centuries, magicians have learned how to perform acts that are perceived as defying the laws of nature, and that induce a strong sense of wonder. This article argues that the time has come to examine the scientific bases behind such phenomena, and to create a science of magic linked to relevant areas of cognitive science. Concrete examples are taken from three areas of magic: the ability to control attention, to distort perception, and to influence choice. It is shown how such knowledge can help develop new tools and indicate new avenues of research into human perception and cognition.

  18. Empirical Calculations of {sup 29}Si NMR Chemical Shielding Tensors: A Partial Charge Model Investigation of Hydrolysis in Organically Modified Alkoxy Silanes

    SciTech Connect

    Alam, Todd M.; Henry, Marc

    1999-08-05

    Organically modified alkoxy silanes play an important role in tailoring different properties of silica produced by the sol-gel method. Changes in the size and functionality of the organic group allows control of both physical and chemical properties of the resulting gel, with the kinetics of the polymerization process playing an important role in the design of new siloxane materials. High resolution {sup 29}Si NMR has proven to be valuable tool for monitoring the polymerization reaction, and has been used to investigate a variety of organically modified alkoxy silane systems.

  19. Witnessing the elimination of magic wands.

    PubMed

    Blom, Stefan; Huisman, Marieke

    This paper discusses static verification of programs that have been specified using separation logic with magic wands. Magic wands are used to specify incomplete resources in separation logic, i.e., if missing resources are provided, a magic wand allows one to exchange these for the completed resources. One of the applications of the magic wand operator is to describe loop invariants for algorithms that traverse a data structure, such as the imperative version of the tree delete problem (Challenge 3 from the VerifyThis@FM2012 Program Verification Competition), which is the motivating example for our work. Most separation logic-based static verification tools do not provide support for magic wands, possibly because validity of formulas containing the magic wand is, by itself, undecidable. To avoid this problem, in our approach the program annotator has to provide a witness for the magic wand, thus circumventing undecidability due to the use of magic wands. A witness is an object that encodes both instructions for the permission exchange that is specified by the magic wand and the extra resources needed during that exchange. We show how this witness information is used to encode a specification with magic wands as a specification without magic wands. Concretely, this approach is used in the VerCors tool set: annotated Java programs are encoded as Chalice programs. Chalice then further translates the program to BoogiePL, where appropriate proof obligations are generated. Besides our encoding of magic wands, we also discuss the encoding of other aspects of annotated Java programs into Chalice, and in particular, the encoding of abstract predicates with permission parameters. We illustrate our approach on the tree delete algorithm, and on the verification of an iterator of a linked list.

  20. The Other Side of Magic.

    PubMed

    Ekroll, Vebjørn; Sayim, Bilge; Wagemans, Johan

    2017-01-01

    When magicians perform spectacles that seem to defy the laws of nature, they do so by manipulating psychological reality. Hence, the principles underlying the art of conjuring are potentially of interest to psychological science. Here, we argue that perceptual and cognitive principles governing how humans experience hidden things and reason about them play a central role in many magic tricks. Different from tricks based on many other forms of misdirection, which require considerable skill on the part of the magician, many elements of these tricks are essentially self-working because they rely on automatic perceptual and cognitive processes. Since these processes are not directly observable, even experienced magicians may be oblivious to their central role in creating strong magical experiences and tricks that are almost impossible to debunk, even after repeated presentations. We delineate how insights from perceptual psychology provide a framework for understanding why these tricks work so well. Conversely, we argue that studying magic tricks that work much better than one intuitively would believe provides a promising heuristic for charting unexplored aspects of perception and cognition.

  1. Structure of SiO[sub 2] on Al[sub 2]O[sub 3] monolayer catalysts: Investigation by infrared spectroscopy and [sup 29]Si MAS NMR

    SciTech Connect

    Sheng, T.C. ); Lang, S.; Morrow, B.A. ); Gay, I.D. )

    1994-07-01

    Infrared spectroscopy and [sup 29]Si MAS NMR are used to probe the structure of SiO[sub 2] on Al[sub 2]O[sub 3] catalysts prepared by chemical vapor deposition of Si(OCH[sub 3])[sub 4][center dot]SiO[sub 2] loadings from about 0.2-2.5 statistical monolayers are studied. Infrared shows a gradual disappearance of AlOH vibrations as the SiO[sub 2] loading is increased. A population of inaccessible AlOH is also observed. The Si-O-X asymmetric stretching frequency shows a continuous variation with SiO[sub 2] content, consistent with X varying from Al at low levels to Si at high levels of silica. [sup 29]Si NMR shows composite peaks at all SiO[sub 2] levels. At the lowest level most intensity is concentrated in the -80 to -85 ppm range, corresponding to Si with attached -OAl groups. At the highest silica levels, the spectrum can be deconvoluted into peaks at -108, -100, and -92 ppm. These correspond to Si(OSi)[sub 4], Si(OSi)[sub 3]OH, and mixtures of Si(OSi)[sub 2](OH)[sub 2] with -OAl-containing species. A model is proposed for build up of the silica layer on these catalysts. Random deposition of silica on any available surface is shown to give a semiquantitative account of the experimental results. 31 refs., 6 fig., 2 tabs.

  2. Atomic structure and dehydration mechanism of amorphous silica: Insights from 29Si and 1H solid-state MAS NMR study of SiO2 nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Na; Lee, Sung Keun

    2013-11-01

    Detailed knowledge of the atomic structure of hydrous species on surface of amorphous silica and the effect of temperature and particle size on their atomic configurations are essential to understand the nature of fluids-amorphous silicates interactions and the dehydration processes in the amorphous oxides. Here, we report the 29Si, 1H MAS, and 1H-29Si heteronuclear correlation (HetCor) NMR spectra of 7 nm and 14 nm amorphous silica nanoparticles—a model system for natural amorphous silica—where previously unknown details of changes in their atomic structures with varying dehydration temperature and particle size are revealed. Diverse hydroxyl groups with varying atomic configurations and molecular water apparently show distinct dehydration trends. The dehydration (i.e., removal of water) of amorphous silica nanoparticles mostly results in the increase of isolated silanol by removing water molecules from hydrogen-bonded silanols associated water molecules. With further increase in dehydration temperature, the intensity of isolated silanol peak decreases above ˜873 K, suggesting that the condensation of isolated silanol may occur mainly above ˜873 K. The entire dehydration (and dehydroxylation) process completes at ˜1473 K. Both the water (i.e., physisorbed water and hydrogen-bonded water) and hydrogen-bonded silanol species show a dramatic change in the slope of intensity variation at ˜873 K, indicating that most of silanols is hydrogen-bonded to water rather than to other silanols. The fraction of hydrogen-bonded proton species is also much smaller in 14 nm amorphous silica nanoparticles than in 7 nm amorphous silica nanoparticles mainly due to the presences of larger fractions of water and hydrogen-bonded silanol species. 29Si NMR results show that with increasing dehydration temperature, the fraction of Q4 species apparently increases at the expense of Q2 and Q3 species. The fractions of Q2 and Q3 structures in 7 nm amorphous silica nanoparticles are

  3. High-Frequency (13)C and (29)Si NMR Chemical Shifts in Diamagnetic Low-Valence Compounds of Tl(I) and Pb(II): Decisive Role of Relativistic Effects.

    PubMed

    Vícha, Jan; Marek, Radek; Straka, Michal

    2016-02-15

    The (13)C and (29)Si NMR signals of ligand atoms directly bonded to Tl(I) or Pb(II) heavy-element centers are predicted to resonate at very high frequencies, up to 400 ppm for (13)C and over 1000 ppm for (29)Si, outside the typical experimental NMR chemical-shift ranges for a given type of nuclei. The large (13)C and (29)Si NMR chemical shifts are ascribed to sizable relativistic spin-orbit effects, which can amount to more than 200 ppm for (13)C and more than 1000 ppm for (29)Si, values unexpected for diamagnetic compounds of the main group elements. The origin of the vast spin-orbit contributions to the (13)C and (29)Si NMR shifts is traced to the highly efficient 6p → 6p* metal-based orbital magnetic couplings and related to the 6p orbital-based bonding together with the low-energy gaps between the occupied and virtual orbital subspaces in the subvalent Tl(I) and Pb(II) compounds. New NMR spectral regions for these compounds are suggested based on the fully relativistic density functional theory calculations in the Dirac-Coulomb framework carefully calibrated on the experimentally known NMR data for Tl(I) and Pb(II) complexes.

  4. On the Magic Square and Inverse

    ERIC Educational Resources Information Center

    Elzaidi, S. M.

    2005-01-01

    In this note, we give a method for finding the inverse of a three by three magic square matrix without using the usual methods for finding the inverse of a matrix. Also we give a method for finding the inverse of a three by three magic square matrix whose entries are also matrices. By using these ideas, we can construct large matrices whose…

  5. The Role of Statistics in Management Magic

    ERIC Educational Resources Information Center

    Stivers, Richard

    2004-01-01

    Technology and magic both represent the human will to power - to dominate nature and ultimately humans. In a technological civilization, magic imitates technology. Modern management often entails psychological techniques (the human relations approach) and organizational techniques (the scientific approach). The heart of the latter is statistical…

  6. Cancer, unproven therapies, and magic.

    PubMed

    Wein, S

    2000-09-01

    Commonly used by cancer patients, unproven therapies are treatments that the practitioner claims can alter the disease process although there is no proof to support the claim. The reasons for the popularity of unproven therapies fall into two categories--practical considerations and fundamental mechanisms. Research has implicated the following practical factors: a pragmatic search for relief of symptoms, expression of a philosophical view, a need to reestablish a sense of control in life, and dissatisfaction with conventional medicine. Fundamental mechanisms include traditional magic, the heroic individual, and a delusional pattern of thinking. Underpinning and generating these factors is the fear of death. Particularly in patients with cancer, this is not only a fear of nonexistence, but of loneliness, the unknown, pain, loss of control, and emptiness. The popularity of unproven therapies poses a challenge to the medical system at large, and oncologists, psycho-oncologists, and palliative-care physicians, in particular. The essence of the challenge is to understand the reasons for the use of unproven therapies, to analyze our own behavior, and conclude what if anything our response should be. Unproven therapies (as with magic, a sense of heroism, and delusional thinking) fulfill the function of resolving the inexplicable and the psychologically painful--i.e., relieving the anxiety associated with cancer.

  7. Spatial distribution of organic functional groups supported on mesoporous silica nanoparticles: A study by conventional and DNP-enhanced 29Si solid-state NMR

    DOE PAGES

    Kobayashi, Takeshi; Singappuli-Arachchige, Dilini; Wang, Zhuoran; ...

    2016-12-23

    Solid-state NMR spectroscopy, both conventional and dynamic nuclear polarization (DNP)-enhanced, was employed to study the spatial distribution of organic functional groups attached to the surface of mesoporous silica nanoparticles via co-condensation and grafting. The most revealing information was provided by DNP-enhanced two-dimensional 29Si–29Si correlation measurements, which unambiguously showed that post-synthesis grafting leads to a more homogeneous dispersion of propyl and mercaptopropyl functionalities than co-condensation. Furthermore, during the anhydrous grafting process, the organosilane precursors do not self-condense and are unlikely to bond to the silica surface in close proximity (less than 4 Å) due to the limited availability of suitably arrangedmore » hydroxyl groups.« less

  8. Magic wavelengths for terahertz clock transitions

    SciTech Connect

    Zhou Xiaoji; Xu Xia; Chen Xuzong; Chen Jingbiao

    2010-01-15

    Magic wavelengths for laser trapping of boson isotopes of alkaline-earth metal atoms Sr, Ca, and Mg are investigated while considering terahertz clock transitions between the {sup 3}P{sub 0}, {sup 3}P{sub 1}, and {sup 3}P{sub 2} metastable triplet states. Our calculation shows that magic wavelengths for laser trapping do exist. This result is important because those metastable states have already been used to make accurate clocks in the terahertz frequency domain. Detailed discussions for magic wavelengths for terahertz clock transitions are given in this article.

  9. Magic wavelengths for terahertz clock transitions

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoji; Xu, Xia; Chen, Xuzong; Chen, Jingbiao

    2010-01-01

    Magic wavelengths for laser trapping of boson isotopes of alkaline-earth metal atoms Sr, Ca, and Mg are investigated while considering terahertz clock transitions between the 3P0, 3P1, and 3P2 metastable triplet states. Our calculation shows that magic wavelengths for laser trapping do exist. This result is important because those metastable states have already been used to make accurate clocks in the terahertz frequency domain. Detailed discussions for magic wavelengths for terahertz clock transitions are given in this article.

  10. The magic of relay mirrors

    NASA Astrophysics Data System (ADS)

    Duff, Edward A.; Washburn, Donald C.

    2004-09-01

    Laser weapon systems would be significantly enhanced with the addition of high altitude or space-borne relay mirrors. Such mirrors, operating alone with a directed energy source, or many in a series fashion, can be shown to effectively move the laser source to the last, so-called fighting mirror. This "magically" reduces the range to target and offers to enhance the performance of directed energy systems like the Airborne Laser and even ground-based or ship-based lasers. Recent development of high altitude airships will be shown to provide stationary positions for such relay mirrors thereby enabling many new and important applications for laser weapons. The technical challenges to achieve this capability are discussed.

  11. Insurance, risk, and magical thinking.

    PubMed

    Tykocinski, Orit E

    2008-10-01

    The possession of an insurance policy may not only affect the severity of a potential loss but also its perceived probability. Intuitively, people may feel that if they are insured nothing bad is likely to happen, but if they do not have insurance they are at greater peril. In Experiment 1, respondents who were reminded of their medical insurance felt they were less likely to suffer health problems in the future compared to people who were not reminded of their medical insurance. In Experiment 2a, participants who were unable to purchase travel insurance judged the probability of travel-related calamities higher compared to those who were insured. These results were replicated in Experiment 3a in a simulation of car accident insurance. The findings are explained in terms of intuitive magical thinking, specifically, the negative affective consequences of "tempting fate" and the sense of safety afforded by the notion of "being covered."

  12. [Magical and religious healing in Byzantium].

    PubMed

    Józsa, László

    2010-01-01

    Religious and magical ways of healing have been known and practiced since the very beginning of human history. In the present article, the Byzantine philosophical, cultural, historical and "methodological" aspects of this way of healing are discussed. The article outlines the development of magic healing in Byzantium from the 4th to the 15th century. During this period magical therapy included the cult of patron saints--listed by the author--and pleading for divine intervention as well. The activity of "anargyroi" and the use of magical objects and amulets is also discussed in detail. Exorcism was also a part of religious therapy both against psychical and somatical diseases. In early Christianity, and especially in Byzantium the devil or other demons were also supposed to cause various somatical or psychical illnesses by "intrusion" or "internalisation," i.e. by possession or obsession of their victims.

  13. Magical thinking in narratives of adolescent cutters.

    PubMed

    Gregory, Robert J; Mustata, Georgian T

    2012-08-01

    Adolescents sometimes cut themselves to relieve distress; however, the mechanism is unknown. Previous studies have linked self-injury to deficits in processing emotions symbolically through language. To investigate expressive language of adolescent cutters, the authors analyzed 100 narratives posted on the Internet. Most narratives (n = 66) displayed idiosyncratic use of language indicating poor differentiation between the real and the symbolic, such as blood substituting for negative emotions, which can then be released from the self; or emotional pain magically transforming into physical pain, which can then be managed. This kind of magical thinking correlated with cutting to relieve distress, to see blood, and to feel pain, but negatively correlated with complex representation of people, understanding social causality, and self-esteem. The results suggest that magical thinking represents a pre-symbolic mental state that processes and organizes distressing emotions through body schema. Magical thinking thus provides a plausible mechanism for why cutting works.

  14. Working wonders? investigating insight with magic tricks.

    PubMed

    Danek, Amory H; Fraps, Thomas; von Müller, Albrecht; Grothe, Benedikt; Ollinger, Michael

    2014-02-01

    We propose a new approach to differentiate between insight and noninsight problem solving, by introducing magic tricks as problem solving domain. We argue that magic tricks are ideally suited to investigate representational change, the key mechanism that yields sudden insight into the solution of a problem, because in order to gain insight into the magicians' secret method, observers must overcome implicit constraints and thus change their problem representation. In Experiment 1, 50 participants were exposed to 34 different magic tricks, asking them to find out how the trick was accomplished. Upon solving a trick, participants indicated if they had reached the solution either with or without insight. Insight was reported in 41.1% of solutions. The new task domain revealed differences in solution accuracy, time course and solution confidence with insight solutions being more likely to be true, reached earlier, and obtaining higher confidence ratings. In Experiment 2, we explored which role self-imposed constraints actually play in magic tricks. 62 participants were presented with 12 magic tricks. One group received verbal cues, providing solution relevant information without giving the solution away. The control group received no informative cue. Experiment 2 showed that participants' constraints were suggestible to verbal cues, resulting in higher solution rates. Thus, magic tricks provide more detailed information about the differences between insightful and noninsightful problem solving, and the underlying mechanisms that are necessary to have an insight.

  15. The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barceló, M.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Bitossi, M.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Cecchi, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Corti, D.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Dettlaff, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fidalgo, D.; Fink, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Haberer, W.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Illa, J. M.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lemus, J. L.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorca, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Negrello, M.; Neustroev, V.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schlammer, J.; Schmidl, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Tejedor, L. A.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Wetteskind, H.; Will, M.; Zanin, R.

    2016-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is ∼ 50 GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectrum above 220 GeV is (0.66 ± 0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the σ of a 2-dimensional Gaussian distribution, at those energies is ≲ 0.07°, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in the following components: < 15% in energy scale, 11%-18% in flux normalization and ± 0.15 for the energy spectrum power-law slope.

  16. Structure and disorder in iron-bearing sodium silicate glasses and melts: High-resolution 29Si and 17O solid-state NMR study

    NASA Astrophysics Data System (ADS)

    Kim, H.; Lee, S.

    2012-12-01

    Understanding of the effect of iron content on the structure (Si coordination environment and the degree of polymerization) of iron-bearing silicate melts and glasses is essential for studying their macroscopic properties and diverse geological processes in Earth's interior. Although the recent advances in high-resolution solid-state NMR techniques provide detailed structural information of a diverse iron-free oxide glasses with varying composition (e.g., Lee, P. Natl. Acad. Sci. USA., 2011, 108, 6847; Lee and Sung, Chem. Geol., 2008, 256, 326; Park and Lee, Geochim. Cosmochim. Acta, 2012, 80, 125; Lee et al., Phys. Rev., 103, 095501, 2009), their application to iron-bearing silicate glasses has a limited usefulness in resolving atomic configurations due to the effect of paramagnetic cation (i.e., Fe) on the NMR spectra. Here, we report the first ^{29}Si and ^{17}O NMR spectra for sodium-iron silicate glasses with varying iron content (Na_{2}O-Fe_{2}O_{3}-SiO_{2} glasses, up to 34.60 wt% Fe_{2}O_{3}), revealing previously unknown details of iron-induced changes in structure and disorder. While signal intensity decreases and peak width increases exponentially with increasing iron content [=Fe_{2}O_{3}/(Na_{2}O+Fe_{2}O_{3})], ^{29}Si MAS NMR spectra for sodium-iron silicate glasses present the slight peak shift and an asymmetrical peak broadening toward higher Q^{n} species with increasing iron content. This result implies an increase in the degree of polymerization with increasing iron content. Additionally, ^{29}Si spin-relaxation time (T_{1}) for the glasses decreases with increasing of iron content by several orders of magnitude. ^{17}O 3QMAS NMR spectra for the glasses show well-resolved non-bridging oxygen (NBO, Na-O-Si) and bridging oxygen (BO, Si-O-Si) even at relatively high iron content, providing the first direct experimental estimation of the degree of polymerization. In sodium-iron silicate glasses, the fraction of NBO decreases with increasing iron

  17. Metal Carbonation of Forsterite in Supercritical CO2 and H2O Using Solid State 29Si, 13C NMR Spectroscop

    SciTech Connect

    Kwak, Ja Hun; Hu, Jian Z.; Hoyt, David W.; Sears, Jesse A.; Wang, Chong M.; Rosso, Kevin M.; Felmy, Andrew R.

    2010-03-11

    Ex situ solid state NMR was used for the first time to study fundamental mineral carbonation processes and reaction extent relevant to geologic carbon sequestration (GCS) using a model silicate mineral forsterite (Mg2SiO4)+supercriticalCO2 with and without H2O. Run conditions were 80 C and 96 atm. 29Si NMR clearly shows that in the absence of CO2, the role of H2O is to hydrolyze surface Mg-O-Si bonds to produce dissolved Mg2+, and mono- and oligomeric hydroxylated silica species. Surface hydrolysis products contain only Q0 (Si(OH)4) and Q1(Si(OH)3OSi) species. An equilibrium between Q0, Q1 and Mg2+ with a saturated concentration equivalent to less than 3.2% of the Mg2SiO4 conversion is obtained at a reaction time of up to 7 days. Using scCO2 without H2O, no reaction is observed within 7 days. Using both scCO2 and H2O, the surface reaction products for silica are mainly Q3 (SiOH(OSi)3) species accompanied by a lesser amount of Q2 (Si(OH)2(OSi)2) and Q4 (Si(OSi)4). However, no Q0 and Q1 were detected, indicating the carbonic acid formation/deprotonation and magnesite (MgCO3) precipitation reactions are faster than the forsterite hydrolysis process. Thus it can be concluded that the Mg2SiO4 hydrolysis process is the rate limiting step of the overall mineral carbonation process. 29Si NMR combined with XRD, TEM, SAED and EDX further reveal that the reaction is a surface reaction with the Mg2SiO4 crystallite in the core and with condensed Q2-Q4 species forming amorphous surface layers. 13C MAS NMR identified a possible reaction intermediate as (MgCO3)4-Mg(OH)2-5H2O. However, at long reaction times only crystallite magnesite MgCO3 products are observed.

  18. Entropy and the Magic Flute

    NASA Astrophysics Data System (ADS)

    Morowitz, Harold J.

    1996-10-01

    Harold Morowitz has long been highly regarded both as an eminent scientist and as an accomplished science writer. The essays in The Wine of Life , his first collection, were hailed by C.P. Snow as "some of the wisest, wittiest and best informed I have ever read," and Carl Sagan called them "a delight to read." In later volumes he established a reputation for a wide-ranging intellect, an ability to see unexpected connections and draw striking parallels, and a talent for communicating scientific ideas with optimism and wit. With Entropy and the Magic Flute , Morowitz once again offers an appealing mix of brief reflections on everything from litmus paper to the hippopotamus to the sociology of Palo Alto coffee shops. Many of these pieces are appreciations of scientists that Morowitz holds in high regard, while others focus on health issues, such as America's obsession with cheese toppings. There is also a fascinating piece on the American Type Culture Collection, a zoo or warehouse for microbes that houses some 11,800 strains of bacteria, and over 3,000 specimens of protozoa, algae, plasmids, and oncogenes. Here then are over forty light, graceful essays in which one of our wisest experimental biologists comments on issues of science, technology, society, philosophy, and the arts.

  19. The Magnetics Information Consortium (MagIC)

    NASA Astrophysics Data System (ADS)

    Johnson, C.; Constable, C.; Tauxe, L.; Koppers, A.; Banerjee, S.; Jackson, M.; Solheid, P.

    2003-12-01

    The Magnetics Information Consortium (MagIC) is a multi-user facility to establish and maintain a state-of-the-art relational database and digital archive for rock and paleomagnetic data. The goal of MagIC is to make such data generally available and to provide an information technology infrastructure for these and other research-oriented databases run by the international community. As its name implies, MagIC will not be restricted to paleomagnetic or rock magnetic data only, although MagIC will focus on these kinds of information during its setup phase. MagIC will be hosted under EarthRef.org at http://earthref.org/MAGIC/ where two "integrated" web portals will be developed, one for paleomagnetism (currently functional as a prototype that can be explored via the http://earthref.org/databases/PMAG/ link) and one for rock magnetism. The MagIC database will store all measurements and their derived properties for studies of paleomagnetic directions (inclination, declination) and their intensities, and for rock magnetic experiments (hysteresis, remanence, susceptibility, anisotropy). Ultimately, this database will allow researchers to study "on the internet" and to download important data sets that display paleo-secular variations in the intensity of the Earth's magnetic field over geological time, or that display magnetic data in typical Zijderveld, hysteresis/FORC and various magnetization/remanence diagrams. The MagIC database is completely integrated in the EarthRef.org relational database structure and thus benefits significantly from already-existing common database components, such as the EarthRef Reference Database (ERR) and Address Book (ERAB). The ERR allows researchers to find complete sets of literature resources as used in GERM (Geochemical Earth Reference Model), REM (Reference Earth Model) and MagIC. The ERAB contains addresses for all contributors to the EarthRef.org databases, and also for those who participated in data collection, archiving and

  20. Substitution of [4]Al in layer silicates: Calculation of the Al-Si configurational entropy according to 29Si NMR Spectra

    NASA Astrophysics Data System (ADS)

    Vinograd, Victor L.

    1995-03-01

    A new constructive statistical method was used to simulate the Al-Si distributions in tetrahedral layer of mica according to short range and long range order restrictions and to calculate values of configurational entropy which correspond to simulated distributions. The simulations and the calculated entropy values were constrained by the existing 29Si NMR data for natural and synthetic mica samples. The results of simulation confirm previous conclusions on the importance of short range order restrictions such as Al-avoidance and homogeneous dispersion of charges (HDC) in the tetrahedral layer. The results suggest, however, that the Al-Si distribution in mica closely follows the HDC restriction only for the samples with the Al/(Si+Al) ratios in the range of 0.11 0.3. At higher values of the ratio (0.3 0.37) the degree of the HDC-type ordering decreases towards pure Al-avoidance. In the range of 0.37 0.5 two alternative models namely the HDC model and the model with partial long range order can be used to explain the observed NMR intensities.

  1. 29Si-NMR study of magnetic anisotropy and hyperfine interactions in the uranium-bsed ferromagnet UNiSi2

    SciTech Connect

    Sakai, Hironori; Baek, Seung H; Bauer, Eric D; Ronning, Filip; Thompson, J D

    2009-01-01

    UNiSi{sub 2} orders ferromagnetically below T{sub Curie} = 95 K. This material crystallizes in the orthorhombic CeNiSi{sub 2}-type structure. The uranium atoms form double-layers, which are stacked along the crystallographic b axis (the longest axis). From magnetization measurement the easy (hard) magnetization axis is found to be the c axis (b axis). {sup 29}Si-NMR measurements have been performed in the paramagnetic state. In UNiSi{sub 2}, two crystallographic Si sites exist with orthorhombic local symmetry. The Knight shifts on each Si site have been estimated from the spectra of random and oriented powders. The transferred hyperfine couplings have been also derived. It is found that the transferred hyperfine coupling constants on each Si site are nearly isotropic, and that their Knight shift anisotropy comes from that of the bulk susceptibility. The nuclear-spin lattice relaxation rate 1/T{sub 1} shows temperature-independent behavior, which indicates the existence of localized 5f electron.

  2. Origins of magic: review of genetic and epigenetic effects

    PubMed Central

    2007-01-01

    Objective To assess the evidence for a genetic basis to magic. Design Literature review. Setting Harry Potter novels of J K Rowling. Participants Muggles, witches, wizards, and squibs. Interventions Limited. Main outcome measures Family and twin studies, magical ability, and specific magical skills. Results Magic shows strong evidence of heritability, with familial aggregation and concordance in twins. Evidence suggests magical ability to be a quantitative trait. Specific magical skills, notably being able to speak to snakes, predict the future, and change hair colour, all seem heritable. Conclusions A multilocus model with a dominant gene for magic might exist, controlled epistatically by one or more loci, possibly recessive in nature. Magical enhancers regulating gene expressionmay be involved, combined with mutations at specific genes implicated in speech and hair colour such as FOXP2 and MCR1. PMID:18156238

  3. A Simple Parameterization of 3 x 3 Magic Squares

    ERIC Educational Resources Information Center

    Trenkler, Gotz; Schmidt, Karsten; Trenkler, Dietrich

    2012-01-01

    In this article a new parameterization of magic squares of order three is presented. This parameterization permits an easy computation of their inverses, eigenvalues, eigenvectors and adjoints. Some attention is paid to the Luoshu, one of the oldest magic squares.

  4. The Use of Magic in Teaching Organizational Behavior.

    ERIC Educational Resources Information Center

    Dobson, Joseph J.; Krell, Terence C.

    1999-01-01

    Explains how magic tricks create an Anger-Wonder-Envy response; provides instructions for performing tricks; and explains their relevance to organizational behavior; as in magic, behaviors and events often happened without understandable explanations. (SK)

  5. The Moore-Penrose Inverse of Block Magic Rectangles

    ERIC Educational Resources Information Center

    Hakopian, Y. R.; Eloyan, A. N.

    2007-01-01

    As is known, a semi-magic square is an "n x n" matrix having the sum of entries in each row and each column equal to a constant. This note generalizes this notion and introduce a special class of block matrices called "block magic rectangles." It is proved that the Moore-Penrose inverse of a block magic rectangle is also a block magic rectangle.

  6. Stability of magic planar Ag clusters

    NASA Astrophysics Data System (ADS)

    Chiu, Y. P.; Ou, Y. S.; Chang, Y. R.; Wei, C. M.; Chang, C. S.; Tsong, Tien T.

    2007-03-01

    The spontaneous assembly of atoms and molecules in a system has attracted many research interests and created numerous potential applications. Utilizing the periodic pattern found on the Pb quantum islands, which are grown on the Si(111) surface, we have recently discovered that self-organized Ag planar clusters formed on these templates exhibit enhanced stability at some particular sizes [1]. Existence of the magic atom numbers in these clusters is mainly attributed to the electronic confinement effect. Here, we further explore the strength of these magic clusters subject to the temperature rise and oxygen exposure. Detailed calculations based on ab initio density functional theory have also been performed. The results help establish the relation between the physical and chemical stability of a magic Ag cluster and its size and shape. Ref:[1] Ya-Ping Chiu, Li-Wei Huang, Ching-Ming Wei, Chia-Seng Chang, and Tien-Tzou Tsong, Phys. Rev. Lett. 97, 165504 (2006).

  7. Atmospheric monitoring in MAGIC and data corrections

    NASA Astrophysics Data System (ADS)

    Fruck, Christian; Gaug, Markus

    2015-03-01

    A method for analyzing returns of a custom-made "micro"-LIDAR system, operated alongside the two MAGIC telescopes is presented. This method allows for calculating the transmission through the atmospheric boundary layer as well as thin cloud layers. This is achieved by applying exponential fits to regions of the back-scattering signal that are dominated by Rayleigh scattering. Making this real-time transmission information available for the MAGIC data stream allows to apply atmospheric corrections later on in the analysis. Such corrections allow for extending the effective observation time of MAGIC by including data taken under adverse atmospheric conditions. In the future they will help reducing the systematic uncertainties of energy and flux.

  8. On dimensional reduction of magical supergravity theories

    NASA Astrophysics Data System (ADS)

    Kan, Naoto; Mizoguchi, Shun'ya

    2016-11-01

    We prove, by a direct dimensional reduction and an explicit construction of the group manifold, that the nonlinear sigma model of the dimensionally reduced three-dimensional A = R magical supergravity is F 4 (+ 4) / (USp (6) × SU (2)). This serves as a basis for the solution generating technique in this supergravity as well as allows to give the Lie algebraic characterizations to some of the parameters and functions in the original D = 5 Lagrangian. Generalizations to other magical supergravities are also discussed.

  9. Au40: A Large Tetrahedral Magic Cluster

    SciTech Connect

    Jiang, Deen; Walter, Michael

    2011-01-01

    40 is a magic number for tetrahedral symmetry predicted in both nuclear physics and the electronic jellium model. We show that Au{sub 40} could be such a magic cluster from density functional theory-based basin hopping for global minimization. The putative global minimum found for Au{sub 40} has a twisted pyramid structure, reminiscent of the famous tetrahedral Au{sub 20}, and a sizable HOMO-LUMO gap of 0.69 eV, indicating its molecular nature. Analysis of the electronic states reveals that the gap is related to shell closings of the metallic electrons in a tetrahedrally distorted effective potential.

  10. Carbonation of C–S–H and C–A–S–H samples studied by {sup 13}C, {sup 27}Al and {sup 29}Si MAS NMR spectroscopy

    SciTech Connect

    Sevelsted, Tine F.; Skibsted, Jørgen

    2015-05-15

    Synthesized calcium silicate hydrate (C–S–H) samples with Ca/Si ratios of 0.66, 1.0, and 1.5 have been exposed to atmospheric CO{sub 2} at room temperature and high relative humidity and studied after one to 12 weeks. {sup 29}Si NMR reveals that the decomposition of C–S–H caused by carbonation involves two steps and that the decomposition rate decreases with increasing Ca/Si ratio. The first step is a gradual decalcification of the C–S–H where calcium is removed from the interlayer and defect sites in the silicate chains until Ca/Si = 0.67 is reached, ideally corresponding to infinite silicate chains. In the seconds step, calcium from the principal layers is consumed, resulting in the final decomposition of the C–S–H and the formation of an amorphous silica phase composed of Q{sup 3} and Q{sup 4} silicate tetrahedra. The amount of solid carbonates and of carbonate ions in a hydrous environment increases with increasing Ca/Si ratio for the C–S–H, as shown by {sup 13}C NMR. For C–A–S–H samples with Ca/Si = 1.0 and 1.5, {sup 27}Al NMR demonstrates that all aluminium sites associated with the C–S–H are consumed during the carbonation reactions and incorporated mainly as tetrahedral Al(–OSi){sub 4} units in the amorphous silica phase. A small amount of penta-coordinated Al sites has also been identified in the silica phase.

  11. A comparison of various algorithms to extract Magic Formula tyre model coefficients for vehicle dynamics simulations

    NASA Astrophysics Data System (ADS)

    Vijay Alagappan, A.; Narasimha Rao, K. V.; Krishna Kumar, R.

    2015-02-01

    Tyre models are a prerequisite for any vehicle dynamics simulation. Tyre models range from the simplest mathematical models that consider only the cornering stiffness to a complex set of formulae. Among all the steady-state tyre models that are in use today, the Magic Formula tyre model is unique and most popular. Though the Magic Formula tyre model is widely used, obtaining the model coefficients from either the experimental or the simulation data is not straightforward due to its nonlinear nature and the presence of a large number of coefficients. A common procedure used for this extraction is the least-squares minimisation that requires considerable experience for initial guesses. Various researchers have tried different algorithms, namely, gradient and Newton-based methods, differential evolution, artificial neural networks, etc. The issues involved in all these algorithms are setting bounds or constraints, sensitivity of the parameters, the features of the input data such as the number of points, noisy data, experimental procedure used such as slip angle sweep or tyre measurement (TIME) procedure, etc. The extracted Magic Formula coefficients are affected by these variants. This paper highlights the issues that are commonly encountered in obtaining these coefficients with different algorithms, namely, least-squares minimisation using trust region algorithms, Nelder-Mead simplex, pattern search, differential evolution, particle swarm optimisation, cuckoo search, etc. A key observation is that not all the algorithms give the same Magic Formula coefficients for a given data. The nature of the input data and the type of the algorithm decide the set of the Magic Formula tyre model coefficients.

  12. Magic, Morals and Health: Plus 40 Years

    ERIC Educational Resources Information Center

    Young, Michael; Valois, Robert F.

    2010-01-01

    In the article "Magic, Morals and Health" the reader is treated to Dr. Warren Johnson's thoughts about health and society, and the role of health educators. If one stays with Dr. Johnson's train of thought, one will find Dr. Johnson is concerned that: (1) A large segment of society tends to base at least some of their beliefs about health on…

  13. The deconstruction of magic: rereading, rethinking Erickson.

    PubMed

    Sparks, J A

    2000-01-01

    This article examines the case history writings of Milton Erickson as literary texts. A deconstructive analysis reveals that the modernist assumption of therapist as magical healer disguises the role clients play in their own change. Hypothetically constructed case transcripts contrasted with excerpts from Erickson (see Rossi, 1980) illustrate how the inclusion of client voice enriches understanding of therapeutic change.

  14. Finding the Magic Step by Step.

    ERIC Educational Resources Information Center

    Maidenberg, Claudia

    2000-01-01

    Staff at the Cucamonga (California) School District discovered no magic key to improving mediocre student performance in their schools. Academic gains became evident only after implementing several steady-improvement strategies in teaching, instructional technologies, learning focus, libraries, remedial reading, and summer school. (MLH)

  15. The Magic Moment: Creating Color Harmony

    ERIC Educational Resources Information Center

    Bartges, Dan

    2009-01-01

    If there is a truly magic moment in art class, it must be when a student--of any age--attains a working knowledge of color's core principles. At that point, she or he becomes able to consistently create color harmony in any painting, regardless of the subject matter. From then on, that student gains greater confidence, can paint better pictures…

  16. Imagination and the Magic of Libraries.

    ERIC Educational Resources Information Center

    The Bookmark, 1990

    1990-01-01

    This issue of "The Bookmark" presents 20 articles focusing on the theme that libraries foster imagination. The articles are: (1) "Imagination and the Magic of Libraries" (Elizabeth S. Manion); (2) "Powerful Partners--Discovery and Democracy, An Interview with Cynthia Jenkins" (Anne E. Simon); (3) "Fostering Imagination in Children" (Susan Lehr);…

  17. It's Not Magic! Research on Developing Expertise

    ERIC Educational Resources Information Center

    Peskin, Joan

    2011-01-01

    In the past two decades, a large body of research has examined the differences between novices and experts in subject areas ranging from physics to poetry. Yet research on developing expertise has found no "magic bullet" in becoming an expert and has concluded that innate talent plays a less prominent role than previously imagined.…

  18. Word Magic: Poetry as a Shared Adventure.

    ERIC Educational Resources Information Center

    McVitty, Walter, Ed.

    Written by teachers and poets, this book offers insights into the nature of poetry and the ways in which children can be taught to enjoy reading and writing poetry. The book contains the following articles: "Poetry and the Magic of Words," by Colin Thiele; "Poetry and the Child," by Charles Causley; "A Verse Along the…

  19. Promoting Reasoning through the Magic V Task

    ERIC Educational Resources Information Center

    Bragg, Leicha A.; Widjaja, Wanty; Loong, Esther Yook-Kin; Vale, Colleen; Herbert, Sandra

    2015-01-01

    Reasoning in mathematics plays a critical role in developing mathematical understandings. In this article, Bragg, Loong, Widjaja, Vale & Herbert explore an adaptation of the Magic V Task and how it was used in several classrooms to promote and develop reasoning skills.

  20. Constraints on Children's Judgments of Magical Causality

    ERIC Educational Resources Information Center

    Woolley, Jacqueline D.; Browne, Cheryl A.; Boerger, Elizabeth A.

    2006-01-01

    In 3 studies we addressed the operation of constraints on children's causal judgments. Our primary focus was whether children's beliefs about magical causality, specifically wishing, are constrained by features that govern the attribution of ordinary causality. In Experiment 1, children witnessed situations in which a confederate's wish appeared…

  1. What Is So Magic about Harry?

    ERIC Educational Resources Information Center

    Nelson, Cole; Nelson, Brooke

    2000-01-01

    Presents the comments of an 11-year-old and his mother regarding what is so magical about the Harry Potter series of books. Notes the child enjoyed the fantasy aspects and the animals in the books; and the mother appreciates the sheer fun of reading the books and that the characters show sensitivity and caring for each other. (RS)

  2. The Magic Is in the Students

    ERIC Educational Resources Information Center

    Beaudoin, Nelson

    2008-01-01

    Educators who search for ways to engage students often forget that the magic is really inside them--not educators themselves, as Keith Harvie's poem "Wizard" illustrates. After more than three decades of trying to improve the students' educational experience in the schools where the author has worked, he has come to believe that the…

  3. Magical thinking and memory: distinctiveness effect for tv commercials with magical content.

    PubMed

    Subbotsky, Eugene; Mathews, Jayne

    2011-10-01

    The aim of this study was to examine whether memorizing advertised products of television advertisements with magical effects (i.e., talking animals, inanimate objects which turn into humans, objects that appear from thin air or instantly turn into other objects) is easier than memorizing products of advertisements without such effects, by testing immediate and delayed retention. Adolescents and adults viewed two films containing television advertisements and were asked to recall and recognize the films' characters, events, and advertised products. Film 1 included magical effects, but Film 2 did not. On a free-recall test, no differences in the number of items recalled were noted for the two films. On the immediate recognition test, adolescents, but not adults, showed significantly better recognition for the magical than the nonmagical film. When this test was repeated two weeks later, results were reversed: adults, but not adolescents, recognized a significantly larger number of items from the magical film than the nonmagical one. These results are interpreted to accentuate the role of magical thinking in cognitive processes.

  4. Investigation on Qiong yao shen shu (Qiongyao's Magical Book).

    PubMed

    Huang, L

    1999-01-01

    Written in about the period of late Yuan to early Ming dynasties, Qiongyao's Magical Book is attributed to a Taoist who was also conversant with acupunture art. By investigation, it is found that there are, at least, three books carrying the same title of Qiongyao's Magical Book, including a 3 volume Qiongyao's Magical Book now lost; a 3 - volume Qiongyao's Magical Book of Discovery (also called The Acupuncture Classic of Qiongyao the Immortal printed in the Ming dynasty, which is entirely different from the previous one and is an apocrypha; and a 4 - volume Qiongyao's Magical Book printed in the Qing dynasty also called Qiongyao's Great Collections of Magical Books wiich is a mixture of authentic and apocryphal texts in which 2 medical books irrelevant to the original are attached to the end of volume 3, with supplements by later writers intermingled in other volumes.

  5. Watching films with magical content facilitates creativity in children.

    PubMed

    Subbotsky, Eugene; Hysted, Claire; Jones, Nicola

    2010-08-01

    Two experiments examined the possible link between magical thinking and creativity in preschool children. In Exp. 1, 4- and 6-yr.-old children were shown a film with either a magical or nonmagical theme. Results indicated that the mean scores of children shown the magical film was significantly higher than that of children watching the nonmagical film on the majority of subsequent creativity tests for both age groups. This trend was also found for 6-yr.-olds' drawings of impossible items. In Exp. 2, Exp. 1 was replicated successfully with 6- and 8-yr.-old children. Exposing children to a film with a magical theme did not affect their beliefs about magic. The results were interpreted to accentuate the role of magical thinking in children's cognitive development. Classroom implications of the results were also discussed.

  6. Dynamic polarizabilities and magic wavelengths for dysprosium

    SciTech Connect

    Dzuba, V. A.; Flambaum, V. V.; Lev, Benjamin L.

    2011-03-15

    We theoretically study dynamic scalar polarizabilities of the ground and select long-lived excited states of dysprosium, a highly magnetic atom recently laser cooled and trapped. We demonstrate that there is a set of magic wavelengths of the unpolarized lattice laser field for each pair of states, which includes the ground state and one of these excited states. At these wavelengths, the energy shift due to laser field is the same for both states, which can be useful for resolved sideband cooling on narrow transitions and precision spectroscopy. We present an analytical formula that, near resonances, allows for the determination of approximate values of the magic wavelengths without calculating the dynamic polarizabilities of the excited states.

  7. MAGIC: Model and Graphic Information Converter

    NASA Technical Reports Server (NTRS)

    Herbert, W. C.

    2009-01-01

    MAGIC is a software tool capable of converting highly detailed 3D models from an open, standard format, VRML 2.0/97, into the proprietary DTS file format used by the Torque Game Engine from GarageGames. MAGIC is used to convert 3D simulations from authoritative sources into the data needed to run the simulations in NASA's Distributed Observer Network. The Distributed Observer Network (DON) is a simulation presentation tool built by NASA to facilitate the simulation sharing requirements of the Data Presentation and Visualization effort within the Constellation Program. DON is built on top of the Torque Game Engine (TGE) and has chosen TGE's Dynamix Three Space (DTS) file format to represent 3D objects within simulations.

  8. Unifying Gate Synthesis and Magic State Distillation

    NASA Astrophysics Data System (ADS)

    Campbell, Earl T.; Howard, Mark

    2017-02-01

    The leading paradigm for performing a computation on quantum memories can be encapsulated as distill-then-synthesize. Initially, one performs several rounds of distillation to create high-fidelity magic states that provide one good T gate, an essential quantum logic gate. Subsequently, gate synthesis intersperses many T gates with Clifford gates to realize a desired circuit. We introduce a unified framework that implements one round of distillation and multiquibit gate synthesis in a single step. Typically, our method uses the same number of T gates as conventional synthesis but with the added benefit of quadratic error suppression. Because of this, one less round of magic state distillation needs to be performed, leading to significant resource savings.

  9. On the magical supergravities in six dimensions

    NASA Astrophysics Data System (ADS)

    Günaydin, M.; Samtleben, H.; Sezgin, E.

    2011-07-01

    Magical supergravities are a very special class of supergravity theories whose symmetries and matter content in various dimensions correspond to symmetries and underlying algebraic structures of the remarkable geometries of the Magic Square of Freudenthal, Rozenfeld and Tits. These symmetry groups include the exceptional groups and some of their special subgroups. In this paper, we study the general gaugings of these theories in six dimensions which lead to new couplings between vector and tensor fields. We show that in the absence of hypermultiplet couplings the gauge group is uniquely determined by a maximal set of commuting translations within the isometry group SO(n,1) of the tensor multiplet sector. Moreover, we find that in general the gauge algebra allows for central charges that may have nontrivial action on the hypermultiplet scalars. We determine the new minimal couplings, Yukawa couplings and the scalar potential.

  10. Collaboration in the Magic Tree House

    ERIC Educational Resources Information Center

    Berner, Jane; Minser, Sabrina; Presser, Helen Burkart

    2008-01-01

    The Magic Tree House series is a collection of books by Mary Pope Osborne, each built around a time and place of high interest to young children, with an underlying story that makes children want to read the next book in the series to find out what is going to happen. Here, the authors describe the development of a two-week reading program for…

  11. Immunoconjugates: Magic Bullets for Cancer Therapy?

    NASA Technical Reports Server (NTRS)

    Passeri, Daniel R.; Spiegel, Jack

    1993-01-01

    Conjugating cytotoxic agents to antibodies allows for site-specific delivery of the agent to tumor cells and should provide increased efficacy and reduced non-specific toxicity. These site-specific cytotoxic agents are known as immunoconjugates or 'magic bullets' and have demonstrated great promise as therapeutic agents for cancer and other diseases. The historical developments and future potential of this new approach to cancer therapy are reviewed.

  12. Mathematical Construction of Magic Squares Utilizing Base-N Arithmetic

    ERIC Educational Resources Information Center

    O'Brien, Thomas D.

    2006-01-01

    Magic squares have been of interest as a source of recreation for over 4,500 years. A magic square consists of a square array of n[squared] positive and distinct integers arranged so that the sum of any column, row, or main diagonal is the same. In particular, an array of consecutive integers from 1 to n[squared] forming an nxn magic square is…

  13. Compact Magic-T using microstrip-slotline transitions

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor); Doiron, Terence (Inventor); Moseley, Samuel H. (Inventor)

    2010-01-01

    The design of a compact low-loss Magic-T is described. The planar Magic-T incorporates a compact microstrip-slotline tee junction and small microstrip-slotline transition area to reduce slotline radiation. The Magic-T produces broadband in-phase and out-of-phase power combiner/divider responses, has low in-band insertion loss, and small in-band phase and amplitude imbalance.

  14. The application of psychoanalytic principles to the study of "magic".

    PubMed

    Rudan, Vlasta; Tripković, Mara; Vidas, Mercedes

    2003-06-01

    In this paper Freud's work on animism and magic is elaborated. Those two subjects are presented mainly in his work "Totem and Taboo" (1913). The true motives, which lead primitive man to practice magic are, according to Freud, human whishes and his immense belief in their power. Importance attached to wishes and to the will has been extended from them to all those psychical acts, which are subjected to will. A general overvaluation has thus come about of all mental processes. Things become less important than ideas of things. Relations, which hold between the ideas of things, are equally hold between the things. The principle of governing magic or the technique of animistic way of thinking is one of the 'omnipotence of thoughts'. The overvaluation of psychic acts could be brought into relation with narcissism and megalomania, a belief in the thaumaturgic force of words and a technique for dealing with the external world--'magic'--which appears to be a logical application of these grandiose premises. Recent psychoanalytic authors dealing with the problem of magic emphasize that magic survived culturally to the present days and even in adults who are otherwise intellectually and scientifically 'modern'. Their explanations for that derive from Ferenczi's and especially Róheim's work that pointed out that magic facilitates adaptive and realistically effective endeavors. Balter pointed out that magic employs ego functioning, and conversely ego functioning includes magic.

  15. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  16. The MAGIC meteoric smoke particle sampler

    NASA Astrophysics Data System (ADS)

    Hedin, Jonas; Giovane, Frank; Waldemarsson, Tomas; Gumbel, Jörg; Blum, Jürgen; Stroud, Rhonda M.; Marlin, Layne; Moser, John; Siskind, David E.; Jansson, Kjell; Saunders, Russell W.; Summers, Michael E.; Reissaus, Philipp; Stegman, Jacek; Plane, John M. C.; Horányi, Mihály

    2014-10-01

    Between a few tons to several hundred tons of meteoric material enters the Earth's atmosphere each day, and most of this material is ablated and vaporized in the 70-120 km altitude region. The subsequent chemical conversion, re-condensation and coagulation of this evaporated material are thought to form nanometre sized meteoric smoke particles (MSPs). These smoke particles are then subject to further coagulation, sedimentation and global transport by the mesospheric circulation. MSPs have been proposed as a key player in the formation and evolution of ice particle layers around the mesopause region, i.e. noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE). MSPs have also been implicated in mesospheric heterogeneous chemistry to influence the mesospheric odd oxygen/odd hydrogen (Ox/HOx) chemistry, to play an important role in the mesospheric charge balance, and to be a significant component of stratospheric aerosol and enhance the depletion of O3. Despite their apparent importance, little is known about the properties of MSPs and none of the hypotheses can be verified without direct evidence of the existence, altitude and size distribution, shape and elemental composition. The aim of the MAGIC project (Mesospheric Aerosol - Genesis, Interaction and Composition) was to develop an instrument and analysis techniques to sample for the first time MSPs in the mesosphere and return them to the ground for detailed analysis in the laboratory. MAGIC meteoric smoke particle samplers have been flown on several sounding rocket payloads between 2005 and 2011. Several of these flights concerned non-summer mesosphere conditions when pure MSP populations can be expected. Other flights concerned high latitude summer conditions when MSPs are expected to be contained in ice particles in the upper mesosphere. In this paper we present the MAGIC project and describe the MAGIC MSP sampler, the measurement procedure and laboratory analysis. We also present the attempts to

  17. Tailored slice selection in solid-state MRI by DANTE under magic-echo line narrowing.

    PubMed

    Matsui, Shigeru; Masumoto, Hidefumi; Hashimoto, Takeyuki

    2007-06-01

    We propose a method of slice selection in solid-state MRI by combining DANTE selective excitation with magic-echo (ME) line narrowing. The DANTE RF pulses applied at the ME peaks practically do not interfere with the ME line narrowing in the combined ME DANTE sequence. This allows straightforward tailoring of the slice profile simply by introducing an appropriate modulation, such as a sinc modulation, into the flip angles of the applied DANTE RF pulses. The utility of the method has been demonstrated by preliminary experiments performed on a test sample of adamantane.

  18. What's Magic about Magic Numbers? Chunking and Data Compression in Short-Term Memory

    ERIC Educational Resources Information Center

    Mathy, Fabien; Feldman, Jacob

    2012-01-01

    Short term memory is famously limited in capacity to Miller's (1956) magic number 7 plus or minus 2--or, in many more recent studies, about 4 plus or minus 1 "chunks" of information. But the definition of "chunk" in this context has never been clear, referring only to a set of items that are treated collectively as a single unit. We propose a new…

  19. The Magical Classroom: Exploring Science, Language, and Perception with Children.

    ERIC Educational Resources Information Center

    Strauss, Michael J.

    The science of magic is the subject of this book which also examines how to help children experience and describe the world, how to experiment and ask questions about it, and how to make decisions about what is true and what is not. Background information about the relationship between magic and science and the nature of effects and illusions are…

  20. "Magic" surface clustering of borazines driven by repulsive intermolecular forces.

    PubMed

    Kervyn, Simon; Kalashnyk, Nataliya; Riello, Massimo; Moreton, Ben; Tasseroul, Jonathan; Wouters, Johan; Jones, Tim S; De Vita, Alessandro; Costantini, Giovanni; Bonifazi, Davide

    2013-07-15

    It's a kind of magic: Hydroxy pentaaryl borazine molecules self-assemble into small clusters (see structure) on Cu(111) surfaces, whereas with symmetric hexaaryl borazine molecules large islands are obtained. Simulations indicate that the observed "magic" cluster sizes result from long-range repulsive Coulomb forces arising from the deprotonation of the B-OH groups of the hydroxy pentaaryl borazine.

  1. Magical Mysteries. Texas Reading Club, 1984. A Librarian's Planning Handbook.

    ERIC Educational Resources Information Center

    Oliver, Jim

    Designed to encourage library use by Texas youth, the Texas Reading Club programs usually include a structured reading program and a variety of entertaining literature-related storyhours, puppet shows, films, and other attractive happenings. This handbook for the 1984 theme--"magical mysteries"--focuses on mysteries, magic, and adventure…

  2. Belief in Magic Predicts Children's Selective Trust in Informants

    ERIC Educational Resources Information Center

    Kim, Sunae; Harris, Paul L.

    2014-01-01

    Children are able to distinguish between regular events that can occur in everyday reality and magical events that are ordinarily impossible. How do children respond to a person who brings about magical as compared with ordinary outcomes? In two studies, we tested children's acceptance of informants' claims when the informants had produced either…

  3. Magic Arts Counseling: The Tricks of Illusion as Intervention

    ERIC Educational Resources Information Center

    Levin, David M.

    2006-01-01

    Magic arts counseling is defined as a nontraditional, experiential curriculum utilized for promoting student growth. Applicable research and the history of using magic with students provide the rationale for its employment in educational programming. In an effort to systematically explore its benefits several educational factors and key elements…

  4. Pulling Words Out of a Hat: Magic in ESL Lessons.

    ERIC Educational Resources Information Center

    Friedenberg, Randi D.

    Magic motivates students to talk, and stimulates the affective domain. While watching magic, many people imagine how the effect is accomplished or how they might perform the trick if they were performing. This can be extended into an English lesson by using phrases such as, "If I were a magician, I could..." Total physical response…

  5. Emotional salience, emotional awareness, peculiar beliefs, and magical thinking.

    PubMed

    Berenbaum, Howard; Boden, M Tyler; Baker, John P

    2009-04-01

    Two studies with college student participants (Ns = 271 and 185) tested whether peculiar beliefs and magical thinking were associated with (a) the emotional salience of the stimuli about which individuals may have peculiar beliefs or magical thinking, (b) attention to emotion, and (c) clarity of emotion. Study 1 examined belief that a baseball team was cursed. Study 2 measured magical thinking using a procedure developed by P. Rozin and C. Nemeroff (2002). In both studies, peculiar beliefs and magical thinking were associated with Salience x Attention x Clarity interactions. Among individuals for whom the objects of the belief-magical thinking were highly emotionally salient and who had high levels of attention to emotion, higher levels of emotional clarity were associated with increased peculiar beliefs-magical thinking. In contrast, among individuals for whom the objects of the belief-magical thinking were not emotionally salient and who had high levels of attention to emotion, higher levels of emotional clarity were associated with diminished peculiar beliefs-magical thinking.

  6. Technologies of stage magic: Simulation and dissimulation.

    PubMed

    Smith, Wally

    2015-06-01

    The craft of stage magic is presented in this article as a site to study the interplay of people and technology. The focus is on conjuring in the 19th and early 20th centuries, a time when magicians eagerly appropriated new optical, mechanical and electrical technologies into their acts. Also at this time, a modern style of conjuring emerged, characterized by minimal apparatus and a natural manner of performance. Applying Lucy Suchman's perspective of human-machine reconfigurations, conjuring in this modern style is interpreted as an early form of simulation, coupled with techniques of dissimulation. Magicians simulated the presence of supernational agency for public audiences, while dissimulating the underlying methods and mechanisms. Dissimulation implies that the secret inner workings of apparatus were not simply concealed but were rendered absent. This, in turn, obscured the production of supernatural effects in the translation of agencies within an assembly of performers, assistants, apparatus, apparatus-builders, and so on. How this was achieved is investigated through an analysis of key instructional texts written by and for magicians working in the modern style. Techniques of dissimulation are identified in the design of apparatus for three stage illusions, and in the new naturalness of the performer's manner. To explore the significance of this picture of stage magic, and its reliance on techniques of dissimulation, a parallel is drawn between conjuring and recent performances of computerized life forms, especially those of social robotics. The paper concludes by considering what is revealed about the production of agency in stage magic's peculiar human-machine assemblies.

  7. Can Magic Deception Be Detected at an Unconscious Level?

    PubMed

    Kawakami, Naoaki; Miura, Emi

    2016-12-11

    Magicians present magic tricks that seem to defy the laws of nature, entertaining us by manipulating our attention, perception, and awareness. However, although we are unaware of these manipulations at the level of conscious experience, we may still be aware of them at an unconscious level. We examined whether people can detect a magic deception outside of conscious awareness using an indirect measure. In the present study, we used the Cups and Balls magic trick, which is the transposition of balls between two cups. Participants viewed a video of the magic performance and were required to indicate the position of the ball in a direct self-report measure and completed the Single Category Implicit Association Test as an indirect measure. The results showed that the indirect measure of trick detection had higher accuracy than the direct measure. Our results suggest that while humans cannot consciously detect the magic deception, they do have a sense of what occurred on an unconscious level.

  8. Numerous but rare: an exploration of magic squares.

    PubMed

    Kitajima, Akimasa; Kikuchi, Macoto

    2015-01-01

    How rare are magic squares? So far, the exact number of magic squares of order n is only known for n ≤ 5. For larger squares, we need statistical approaches for estimating the number. For this purpose, we formulated the problem as a combinatorial optimization problem and applied the Multicanonical Monte Carlo method (MMC), which has been developed in the field of computational statistical physics. Among all the possible arrangements of the numbers 1; 2, …, n(2) in an n × n square, the probability of finding a magic square decreases faster than the exponential of n. We estimated the number of magic squares for n ≤ 30. The number of magic squares for n = 30 was estimated to be 6.56(29) × 10(2056) and the corresponding probability is as small as 10(-212). Thus the MMC is effective for counting very rare configurations.

  9. Measurement of Magic Wavelengths for the ^{40}Ca^{+} Clock Transition.

    PubMed

    Liu, Pei-Liang; Huang, Yao; Bian, Wu; Shao, Hu; Guan, Hua; Tang, Yong-Bo; Li, Cheng-Bin; Mitroy, J; Gao, Ke-Lin

    2015-06-05

    We demonstrate experimentally the existence of magic wavelengths and determine the ratio of oscillator strengths for a single trapped ion. For the first time, two magic wavelengths near 396 nm for the ^{40}Ca^{+} clock transition are measured simultaneously with high precision. By tuning the applied laser to an intermediate wavelength between transitions 4s_{1/2}→4p_{1/2} and 4s_{1/2}→4p_{3/2}, the sensitivity of the clock transition Stark shift to the oscillator strengths is greatly enhanced. Furthermore, with the measured magic wavelengths, we determine the ratio of the oscillator strengths with a deviation of less than 0.5%. Our experimental method may be applied to measure magic wavelengths for other ion clock transitions. Promisingly, the measurement of these magic wavelengths paves the way to building all-optical trapped ion clocks.

  10. A Magic Spot in Genome Maintenance.

    PubMed

    Rasouly, Aviram; Pani, Bibhusita; Nudler, Evgeny

    2017-01-01

    Nucleotide excision repair (NER) is the key DNA repair system that eliminates the majority of DNA helix-distorting lesions. RNA polymerase (RNAP) expedites the recognition of DNA damage by NER components via transcription-coupled DNA repair (TCR). In bacteria, a modified nucleotide ppGpp ('magic spot') is a pleiotropic second messenger that mediates the response to nutrient deficiencies by altering the initiation properties of RNAP. In this review, we discuss newly elucidated roles of guanosine 5'-diphosphate 3'-diphosphate (ppGpp) in transcription elongation that couple this alarmone to DNA damage repair and maintenance.

  11. Exceptional supergravity theories and the magic square

    NASA Astrophysics Data System (ADS)

    Günaydin, M.; Sierra, G.; Townsend, P. K.

    1983-12-01

    We derive the magic square of Freudenthal, Rozenfeld, and Tits from the geometry of a special class of N=2 Maxwell-Einstein supergravity theories. We also show that all of these theories are obtainable by truncation of N=8 supergravity theories in various spacetime dimensions d, except for an ``exceptional'' subclass, unique for a given d, which is associated with with the exceptional Jordan algebra of 3 × 3 hermitian octonionic matrices. Laboratoire Propre du Centre National de la Recherche Scientifique, associé à l'Ecole Normale Supérieure et à l'Université de Paris-Sud.

  12. SNLSimMagic v 2.0

    SciTech Connect

    2015-10-21

    This software is an iOS (Apple) Augmented Reality (AR) application that runs on the iPhone and iPad. It is designed to scan in a photograph or graphic and “play” an associated video. This release, SNLSimMagic, was built using Wikitude Augmented Reality (AR) software development kit (SDK) integrated into Apple iOS SDK application and the Cordova libraries. These codes enable the generation of runtime targets using cloud recognition and developer-defined target features which are then accessed by means of a custom application.

  13. An Overview of the MAGIC Project

    DTIC Science & Technology

    1993-12-01

    Fullerdfad wds.wW~m -- mm3miaMi~sf ~W 1. AGERRNCY ORGNE ATONL NAME(Sta ) AND AREPORS(AES 3. RPrTPERI AMND DAEOVGAIZAEO 4.he MIE CorporaTion REPFNDRT...Kansas (KU) In addition, ARPA is funding the MITRE Corporation to help with project coordination. Other MAGIC participants that are contributing...Battle Laboratory, U. S. Army Combined Arms Command (BCBL) "• Digital Equipment Corporation (DEC) ION3 "* Northern Telecom, Inc./Bell Northern Research

  14. ALADIN - a Magic Lamp for the Elderly?

    NASA Astrophysics Data System (ADS)

    Maier, Edith; Kempter, Guido

    Like Aladdin in the medieval oriental folk-tale, the assistive lighting system developed by ALADIN (Ambient Lighting Assistance for an Ageing Population), a research project co-financed by the European Commission, is expected to bring enchantment to people's lives. But this will not be achieved by magic and genies, but by exploiting our knowledge about the impact of lighting. adaptive lighting can contribute considerably to sound sleep and a regular sleep-wake cycle regulated by people's 'inner clock'. This tends to deteriorate with ageing, but is essential to preserve and enhance comfort and wellbeing. And this is the main goal of the assistive ALADIN lighting system.

  15. VHE BL Lacs through the MAGIC glasses

    NASA Astrophysics Data System (ADS)

    Becerra González, Josefa; MAGIC Collaboration

    2015-03-01

    In this contribution an overview of the latest results on the study of BL Lac objects with the MAGIC telescopes at the very high energy (VHE, E>100 GeV) gamma-rays is presented. Three new VHE sources were detected during 2014, two BL Lac objects and the gravitational lensed blazar S3 0218+357. MAGIC detected very fast intra-night variability from IC 310. This detection points to smaller emitting regions than the event horizon, this is hard to be explained in the framework of the current theoretical models. The long term multi wavelength (MWL) study of the BL Lac PKS 1424+240 shows correlation between the radio and optical emission, pointing to a common origin. The MWL SED is not well fitted by a one-zone synchrotron-self Compton (SSC) model, but a two-zone SSC model can explain both, the MWL light curve and the SED. Spectral curvature has been found in the observed VHE spectrum from PG 1553+113. This is the first time that spectral curvature compatible with the EBL absorption is found in an individual object.

  16. Magic in the machine: a computational magician's assistant

    PubMed Central

    Williams, Howard; McOwan, Peter W.

    2014-01-01

    A human magician blends science, psychology, and performance to create a magical effect. In this paper we explore what can be achieved when that human intelligence is replaced or assisted by machine intelligence. Magical effects are all in some form based on hidden mathematical, scientific, or psychological principles; often the parameters controlling these underpinning techniques are hard for a magician to blend to maximize the magical effect required. The complexity is often caused by interacting and often conflicting physical and psychological constraints that need to be optimally balanced. Normally this tuning is done by trial and error, combined with human intuitions. Here we focus on applying Artificial Intelligence methods to the creation and optimization of magic tricks exploiting mathematical principles. We use experimentally derived data about particular perceptual and cognitive features, combined with a model of the underlying mathematical process to provide a psychologically valid metric to allow optimization of magical impact. In the paper we introduce our optimization methodology and describe how it can be flexibly applied to a range of different types of mathematics based tricks. We also provide two case studies as exemplars of the methodology at work: a magical jigsaw, and a mind reading card trick effect. We evaluate each trick created through testing in laboratory and public performances, and further demonstrate the real world efficacy of our approach for professional performers through sales of the tricks in a reputable magic shop in London. PMID:25452736

  17. Diffraction of Neutral Helium Clusters: Evidence for ``Magic Numbers''

    NASA Astrophysics Data System (ADS)

    Brühl, Rüdiger; Guardiola, Rafael; Kalinin, Anton; Kornilov, Oleg; Navarro, Jesús; Savas, Tim; Toennies, J. Peter

    2004-05-01

    The size distributions of neutral 4He clusters in cryogenic jet beams, analyzed by diffraction from a 100nm period transmission grating, reveal magic numbers at N=10 11, 14, 22, 26 27, and 44atoms. Whereas magic numbers in nuclei and clusters are attributed to enhanced stabilities, this is not expected for quantum fluid He clusters on the basis of numerous calculations. These magic numbers occur at threshold sizes for which the quantized excitations calculated with the diffusion Monte Carlo method are stabilized, thereby providing the first experimental confirmation for the energy levels of 4He clusters.

  18. The Royal Society and the decline of magic.

    PubMed

    Hunter, Michael

    2011-06-20

    Whereas some have asserted that the early Royal Society actively sought to discredit magical beliefs, others have seen ideas of this kind as integral to the Society's 'nature' in its early years. This paper argues that, whatever the magical commitments of individual Fellows, the Society's corporate policy simply sidelined such pursuits. Yet, insofar as the result was that magic was excluded by default from the proper realm of scientific enquiry, this attitude was to prove paradoxically influential (although its roots have been retrospectively misconstrued to an extent that is significant in itself).

  19. Doubly Magic Optical Trapping for Cs Atom Hyperfine Clock Transitions

    NASA Astrophysics Data System (ADS)

    Carr, A. W.; Saffman, M.

    2016-10-01

    We analyze doubly magic trapping of Cs hyperfine transitions including previously neglected contributions from the ground state hyperpolarizability and the interaction of the laser light and a static magnetic field. Extensive numerical searches do not reveal any doubly magic trapping conditions for any pair of hyperfine states. However, including the hyperpolarizability reveals light intensity insensitive traps for a wide range of wavelengths at specific intensities. We then investigate the use of bichromatic trapping light fields. Deploying a bichromatic scheme, we demonstrate doubly magic red and blue detuned traps for pairs of states separated by one or two single photon transitions.

  20. Magic neutrino mass matrix and the Bjorken Harrison Scott parameterization

    NASA Astrophysics Data System (ADS)

    Lam, C. S.

    2006-09-01

    Observed neutrino mixing can be described by a tribimaximal MNS matrix. The resulting neutrino mass matrix in the basis of a diagonal charged lepton mass matrix is both 2-3 symmetric and magic. By a magic matrix, I mean one whose row sums and column sums are all identical. I study what happens if 2-3 symmetry is broken but the magic symmetry is kept intact. In that case, the mixing matrix is parameterized by a single complex parameter Ue 3, in a form discussed recently by Bjorken, Harrison, and Scott.

  1. MAGIC: Marine ARM GPCI Investigation of Clouds

    SciTech Connect

    Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

    2012-10-03

    The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

  2. (29)Si, (47)Ti, (49)Ti and (195)Pt solid state MAS NMR spectroscopic investigations of ternary silicides TPtSi, germanides TPtGe (T = Ti, Zr, Hf) and stannide TiPtSn.

    PubMed

    Benndorf, Christopher; Eckert, Hellmut; Pöttgen, Rainer

    2016-05-10

    Eight ternary tetrelides TPtX (T = Ti, Zr, Hf; X = Si, Ge, Sn) were synthesized from the elements by arc-melting and subsequent annealing. TiPtSi, ZrPtSi, ZrPtGe, HfPtSi and HfPtGe crystallize with the orthorhombic TiNiSi type structure, in the space group Pnma. The structures of HfPtSi (a = 654.44(9), b = 387.97(6), c = 750.0(1) pm, wR2 = 0.0592, 411 F(2) values, 20 variables) and HfPtGe (a = 660.36(7), b = 395.18(4), c = 763.05(8) pm, wR2 = 0.0495, 430 F(2) values, 20 variables) were refined from single crystal X-ray diffractometer data. TiPtSn adopts the cubic MgAgAs type. TiPtGe is dimorphic with a TiNiSi type high-temperature modification which transforms to cubic LT-TiPtGe (MgAgAs type). All phases were investigated by high resolution (29)Si, (47)Ti, (49)Ti and (195)Pt solid state MAS NMR spectroscopy. In the cubic compounds, the (47/49)Ti NMR signals are easily detected owing to the absence of quadrupolar broadening effects. The (195)Pt resonances of the orthorhombic compounds are characterized by strongly negative isotropic Knight shifts and large Knight shift anisotropies, whereas positive isotropic Knight shifts and no anisotropies are observed for the cubic compounds. These results indicate that the phase transition in TiPtGe is associated with dramatic changes in the electronic properties. Within each group of isotypic compounds the isotropic (29)Si, (47/49)Ti and (195)Pt Knight shifts show systematic dependences on the transition metal or tetrel atomic number, suggesting that the numerical values are influenced by the electronegativities of the metallic (or metalloid) neighbours.

  3. MAGIC Telescope Observations of Gamma-Ray Bursts

    SciTech Connect

    Garczarczyk, M.; Becerra-Gonzalez, J.; Gaug, M.; Antonelli, A.; Carosi, A.; La Barbera, A.; Spiro, S.; Bastieri, D.; Covino, S.; Dominguez, A.; Longo, F.; Scapin, V.

    2010-10-15

    MAGIC is built to perform observations of prompt and early afterglow emission from Gamma-Ray Bursts (GRBs) above 25 GeV. The instrument is designed to have the lowest possible energy threshold among the ground based {gamma}-ray detectors and the fastest reaction time to alerts distributed over the GRB Coordinates Network (GCN). The MAGIC-I telescope observed 57 GRBs during the first six years. In no cases Very High Energy (VHE){gamma}-ray emission above the threshold energy could be detected. The telescope has undergone several major improvements in sensitivity and repositioning performance. The biggest improvement in sensitivity was achieved with the installation of the second MAGIC-II telescope. Since more than one year both telescopes are observing in stereo mode. MAGIC are the only telescopes fast and sensitive enough to extend the observational energy range of satellite detectors, while GRB prompt and early afterglow emission is still ongoing.

  4. Magic of Play: How It Inspires & Aids Early Development

    MedlinePlus

    ... the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- to ... preschool years, was dubbed "the magic years" by child development expert Selma Fraiberg, PhD, in 1959 when she ...

  5. MAGIC: A Tool for Combining, Interpolating, and Processing Magnetograms

    NASA Technical Reports Server (NTRS)

    Allred, Joel

    2012-01-01

    Transients in the solar coronal magnetic field are ultimately the source of space weather. Models which seek to track the evolution of the coronal field require magnetogram images to be used as boundary conditions. These magnetograms are obtained by numerous instruments with different cadences and resolutions. A tool is required which allows modelers to fmd all available data and use them to craft accurate and physically consistent boundary conditions for their models. We have developed a software tool, MAGIC (MAGnetogram Interpolation and Composition), to perform exactly this function. MAGIC can manage the acquisition of magneto gram data, cast it into a source-independent format, and then perform the necessary spatial and temporal interpolation to provide magnetic field values as requested onto model-defined grids. MAGIC has the ability to patch magneto grams from different sources together providing a more complete picture of the Sun's field than is possible from single magneto grams. In doing this, care must be taken so as not to introduce nonphysical current densities along the seam between magnetograms. We have designed a method which minimizes these spurious current densities. MAGIC also includes a number of post-processing tools which can provide additional information to models. For example, MAGIC includes an interface to the DA VE4VM tool which derives surface flow velocities from the time evolution of surface magnetic field. MAGIC has been developed as an application of the KAMELEON data formatting toolkit which has been developed by the CCMC.

  6. Children's and adults' reactions to magical and ordinary suggestion: are suggestibility and magical thinking psychologically close relatives?

    PubMed

    Subbotsky, Eugene

    2007-11-01

    In Experiment 1, 6- and 9-year-old children and adults were asked to imagine various types of objects. The experimenter then attempted to change the image of those objects in participants' minds by either suggesting that the objects may change against the participants' will, or by asking participants to change the objects as a favor to the experimenter. Two types of suggestive causation were employed: Magical-suggestion (a magic spell was cast with the aim of changing the imagined objects) and ordinary-suggestion (participants were told that the objects in their minds could alter against their will). Ordinary-suggestion was as effective as magical-suggestion in changing the participants' imagined objects. For adults, a direct request for compliance produced a stronger effect than did magical suggestion. This effect was not found in children. In Experiment 2, the two types of suggestion were tested on an alternative type of imagined objects. Adult participants were asked to imagine their futures. It was then proposed that (a) a magic spell could be cast on their futures with the aim of changing them either for the worse or for the better (magical-suggestion), or (b) changing a numerical pattern on a computer screen could change their futures (ordinary-suggestion). All participants denied that changing a numerical pattern on a computer screen could affect their lives, yet in their actions they demonstrated an element of belief in this possibility. As in Experiment 1, in Experiment 2 ordinary suggestion was as effective as magical suggestion. The hypothesis of an historic contiguity between magical causality and ordinary suggestion is discussed.

  7. Magic - Marine Arm Gpci Investigation of Clouds

    NASA Astrophysics Data System (ADS)

    Lewis, E. R.; Wiscombe, W. J.; Albrecht, B. A.; Bland, G.; Flagg, C. N.; Klein, S. A.; Kollias, P.; Mace, G. G.; Reynolds, M.; Schwartz, S. E.; Siebesma, P.; Teixeira, J.; Wood, R.; Zhang, M.

    2012-12-01

    MAGIC, the Marine ARM (Atmospheric Radiation Measurement program) GPCI Investigation of Clouds, will deploy the Second ARM Mobile Facility (AMF2) aboard the Horizon Lines cargo container ship M/V Spirit traversing the route between Los Angeles, CA and Honolulu, HI from October, 2012 through September, 2013 (except from a few months in the middle of this time period when the ship will be in dry dock). During this time AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be Intensive Observational Periods (IOPs), one in January, 2013 and one in July, 2013 during which more detailed measurements of the atmospheric structure will be made. Clouds remain a major source of uncertainty in climate projections. In this context, subtropical marine boundary layer (MBL) clouds play a key role in cloud-climate feedbacks that are not well understood yet play a large role in biases both in seasonal coupled model forecasts and annual mean climate forecasts. In particular, current climate models do not accurately represent the transition from the stratocumulus (Sc) regime, with its high albedo and large impact on the global radiative balance of Earth, to shallow trade-wind cumulus (Cu), which play a fundamental role in global surface evaporation and also albedo. Climate models do not yet adequately parameterize the small-scale physical processes associated with turbulence, convection, and radiation in these clouds. Part of this inability results from lack of accurate data on these clouds and the conditions responsible for their properties, including aerosol properties, radiation, and atmospheric and oceanographic conditions. The primary objectives of MAGIC are to improve the representation of the Sc-to-Cu transition in climate models by characterizing the essential properties of this transition, and to produce the observed

  8. Contextuality supplies the 'magic' for quantum computation.

    PubMed

    Howard, Mark; Wallman, Joel; Veitch, Victor; Emerson, Joseph

    2014-06-19

    Quantum computers promise dramatic advantages over their classical counterparts, but the source of the power in quantum computing has remained elusive. Here we prove a remarkable equivalence between the onset of contextuality and the possibility of universal quantum computation via 'magic state' distillation, which is the leading model for experimentally realizing a fault-tolerant quantum computer. This is a conceptually satisfying link, because contextuality, which precludes a simple 'hidden variable' model of quantum mechanics, provides one of the fundamental characterizations of uniquely quantum phenomena. Furthermore, this connection suggests a unifying paradigm for the resources of quantum information: the non-locality of quantum theory is a particular kind of contextuality, and non-locality is already known to be a critical resource for achieving advantages with quantum communication. In addition to clarifying these fundamental issues, this work advances the resource framework for quantum computation, which has a number of practical applications, such as characterizing the efficiency and trade-offs between distinct theoretical and experimental schemes for achieving robust quantum computation, and putting bounds on the overhead cost for the classical simulation of quantum algorithms.

  9. Effect of iron content on the structure and disorder of iron-bearing sodium silicate glasses: A high-resolution 29Si and 17O solid-state NMR study

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Im; Sur, Jung Chul; Lee, Sung Keun

    2016-01-01

    Despite its geochemical importance and implications for the properties of natural magmatic melts, understanding the detailed structure of iron-bearing silicate glasses remains among the outstanding problems in geochemistry. This is mainly because solid-state NMR techniques, one of the most versatile experimental methods to probe the structure of oxide glasses, cannot be fully utilized for exploring the structural details of iron-bearing glasses as the unpaired electrons in Fe induce strong local magnetic fields that mask the original spectroscopic features (i.e., paramagnetic effect). Here, we report high-resolution 29Si and 17O solid-state NMR spectra of iron-bearing sodium silicate glasses (Na2O-Fe2O3-SiO2, Fe3+/ΣFe = 0.89 ± 0.04, thus containing both ferric and ferrous iron) with varying XFe2O3 [=Fe2O3/(Na2O + Fe2O3)], containing up to 22.9 wt% Fe2O3. This compositional series involves Fe-Na substitution at constant SiO2 contents of 66.7 mol% in the glasses. For both nuclides, the NMR spectra exhibit a decrease in the signal intensities and an increase in the peak widths with increasing iron concentration partly because of the paramagnetic effect. Despite the intrinsic difficulties that result from the pronounced paramagnetic effect, the 29Si and 17O NMR results yield structural details regarding the effect of iron content on Q speciation, spatial distribution of iron, and the extent of polymerization in the iron-bearing silicate glasses. The 29Si NMR spectra show an apparent increase in highly polymerized Q species with increasing XFe2O3 , suggesting an increase in the degree of melt polymerization. The 17O 3QMAS NMR spectra exhibit well-resolved non-bridging oxygen (NBO, Na-O-Si) and bridging oxygen (BO, Si-O-Si) peaks with varying iron concentration. By replacing Na2O with Fe2O3 (and thus with increasing iron content), the fraction of Na-O-Si decreases. Quantitative consideration of this effect confirms that the degree of polymerization is likely to

  10. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    PubMed Central

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Prieto, L. Velilla; Lacy, J. H.

    2016-01-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720 – 790 cm−1. These lines belong to bands v = 1 – 0, 2 – 1, 3 – 2, 4–3, and 5–4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲ 35R⋆(≃ 0″.7). The fits are compatible with an expansion velocity of 1+2.5(r/R⋆ −1) km s−1 between 1 and 5R⋆, 11 km s−1 between 5 and 20R⋆, and 14.5 km s−1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10−6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10−6 at 20R⋆ and to 1.3 × 10−6 at 50R⋆. 28Si32S seems to be rotationally under LTE in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1 – 0 that cannot be found in the lines of bands v = 2 – 1, 3 – 2, 4 – 3, and 5 – 4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates. PMID:26997679

  11. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    NASA Astrophysics Data System (ADS)

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Velilla Prieto, L.; Lacy, J. H.

    2015-10-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720-790 cm-1. These lines belong to bands v = 1-0, 2-1, 3-2, 4-3, and 5-4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲35R⋆ (≃0.7 arcsec). The fits are compatible with an expansion velocity of 1 + 2.5(r/R⋆ - 1) km s-1 between 1 and 5R⋆, 11 km s-1 between 5 and 20R⋆, and 14.5 km s-1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10-6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10-6 at 20R⋆ and to 1.3 × 10-6 at 50R⋆. 28Si32S seems to be rotationally under local thermodynamic equilibrium (LTE) in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1-0 that cannot be found in the lines of bands v = 2-1, 3-2, 4-3, and 5-4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates.

  12. The Local Structural State of Aluminosilicate Garnet Solid Solutions: An Investigation of Grospydite Garnet from the Roberts Victor Kimberlite Using Paramagnetically Shifted 27Al and 29Si MAS NMR Resonances

    NASA Astrophysics Data System (ADS)

    Geiger, C. A.; Palke, A. C.; Stebbins, J. F.

    2014-12-01

    Most rock-forming silicates are substitutional solid solutions. Over the years extensive research has been done to determine their structural and crystal chemical properties. Here, the distribution of cations, or order-disorder behavior, is of central importance. In the case of aluminosilicate garnet solid solutions (X3Al2Si3O12 with X = Mg, Fe2+, Mn2+ and Ca) it has been shown that both synthetic and natural crystals have random long-range X-cation disorder in space group Ia-3d, as given by X-ray single-crystal diffraction measurements. However, the structural state of natural garnets at the local scale is not known. Garnet from a grospydite xenolith from the Roberts Victor kimberlite, South Africa, was studied by 27Al and 29Si MAS NMR spectroscopy. The research thrust was placed on measuring and analyzing paramagnetically shifted resonances to determine the local (short range) structural state of the X-cations in a grossular-rich ternary aluminosilicate garnet solid solution. The garnet crystals are compositionally homogeneous based on microprobe analysis, showing no measurable zoning, and have the formula Grs46.7Prp30.0Alm23.3. The garnet is cubic with the standard garnet space group Ia-3d. The 27Al MAS NMR spectrum shows a very broad asymmetric resonance located between about 100 and -50 ppm. It consists of a number of individual overlapping paramagnetically shifted resonances, which are difficult to analyze quantitatively. The 29Si MAS NMR spectrum, showing better resolution, has two observable resonances termed S0 and S4. S0 is located between about -60 ppm and -160 ppm and S4 is centered at roughly 95 ppm. Both S0 and S4 are composite resonances in nature containing many overlapping individual peaks. S0 contains information on local cation configurations whereby an isolated SiO4 group in the garnet structure does not have an edge-shared Fe2+-containing dodecahedron. S4 involves local configurations where there is one edge-shared dodecahedron containing Fe2

  13. Does magical thinking produce neutralising behaviour? An experimental investigation.

    PubMed

    Bocci, Laura; Gordon, P Kenneth

    2007-08-01

    Magical thinking is of relevance to obsessive compulsive disorder (OCD), and has been most widely investigated in relation to the cognitive bias known as thought-action fusion (TAF). This is seen as playing a role in the formation of fears about responsibility for harm. We suggest that magical thinking may also characterise some types of neutralising behaviour, which arise in response to those fears, and are a hallmark of the disorder. In an experimental study of 51 undergraduate students, we assessed whether the use of neutralising behaviours in response to an induction of fears of increasing likelihood for harm is related to a propensity for magical thinking. The 75.5% of participants demonstrated at least one form of neutralising behaviour in response to a TAF-induction task. Neutralising was associated with stronger and more persistent responses to the task, and with questionnaire measures of magical ideation. Those who neutralised did not report higher levels of OCD symptoms. It appears that neutralising is a common response in circumstances that provoke a sense of responsibility for harm. Its occurrence may be linked to magical thinking, however, the results from this experimental investigation suggested that this process may not be specific to OCD.

  14. A framework for using magic to study the mind

    PubMed Central

    Rensink, Ronald A.; Kuhn, Gustav

    2015-01-01

    Over the centuries, magicians have developed extensive knowledge about the manipulation of the human mind—knowledge that has been largely ignored by psychology. It has recently been argued that this knowledge could help improve our understanding of human cognition and consciousness. But how might this be done? And how much could it ultimately contribute to the exploration of the human mind? We propose here a framework outlining how knowledge about magic can be used to help us understand the human mind. Various approaches—both old and new—are surveyed, in terms of four different levels. The first focuses on the methods in magic, using these to suggest new approaches to existing issues in psychology. The second focuses on the effects that magic can produce, such as the sense of wonder induced by seeing an apparently impossible event. Third is the consideration of magic tricks—methods and effects together—as phenomena of scientific interest in their own right. Finally, there is the organization of knowledge about magic into an informative whole, including the possibility of a science centered around the experience of wonder. PMID:25698983

  15. A framework for using magic to study the mind.

    PubMed

    Rensink, Ronald A; Kuhn, Gustav

    2014-01-01

    Over the centuries, magicians have developed extensive knowledge about the manipulation of the human mind-knowledge that has been largely ignored by psychology. It has recently been argued that this knowledge could help improve our understanding of human cognition and consciousness. But how might this be done? And how much could it ultimately contribute to the exploration of the human mind? We propose here a framework outlining how knowledge about magic can be used to help us understand the human mind. Various approaches-both old and new-are surveyed, in terms of four different levels. The first focuses on the methods in magic, using these to suggest new approaches to existing issues in psychology. The second focuses on the effects that magic can produce, such as the sense of wonder induced by seeing an apparently impossible event. Third is the consideration of magic tricks-methods and effects together-as phenomena of scientific interest in their own right. Finally, there is the organization of knowledge about magic into an informative whole, including the possibility of a science centered around the experience of wonder.

  16. Protein residue linking in a single spectrum for magic-angle spinning NMR assignment.

    PubMed

    Andreas, Loren B; Stanek, Jan; Le Marchand, Tanguy; Bertarello, Andrea; Cala-De Paepe, Diane; Lalli, Daniela; Krejčíková, Magdaléna; Doyen, Camille; Öster, Carl; Knott, Benno; Wegner, Sebastian; Engelke, Frank; Felli, Isabella C; Pierattelli, Roberta; Dixon, Nicholas E; Emsley, Lyndon; Herrmann, Torsten; Pintacuda, Guido

    2015-07-01

    Here we introduce a new pulse sequence for resonance assignment that halves the number of data sets required for sequential linking by directly correlating sequential amide resonances in a single diagonal-free spectrum. The method is demonstrated with both microcrystalline and sedimented deuterated proteins spinning at 60 and 111 kHz, and a fully protonated microcrystalline protein spinning at 111 kHz, with as little as 0.5 mg protein sample. We find that amide signals have a low chance of ambiguous linkage, which is further improved by linking in both forward and backward directions. The spectra obtained are amenable to automated resonance assignment using general-purpose software such as UNIO-MATCH.

  17. Coherence Transfer in Dipolar-Coupled Homonuclear Spin Systems in Solids Rotating at the Magic Angle

    NASA Astrophysics Data System (ADS)

    Weintraub, O.; Vega, S.; Hoelger, C.; Limbach, H. H.

    Two routes for the exploitation of the t-SEDRA pulse scheme, which induces coherence transfer in dipolar-coupled homonuclear spin systems in rotating samples, are demonstrated and discussed. This sequence is utilized to deduce intramolecular connectivities by creating an initial coherence of one spin only, applying the t-SEDRA sequence, and monitoring the signal enhancement of the coupled spin. Probing the signal amplitude variations of the two spins and comparing them to simulations can also yield molecular distances. Using 2D spectroscopy, t-SEDRA can also be utilized to establish spin correlations. In this case, the t-SEDRA sequence is applied during the mixing time of a 2D dipolar-correlation experiment. These two approaches are demonstrated by performing 15N CPMAS NMR experiments on a 15N-doubly labeled sample of 3(5)-methyl-5(3)-phenylpyrazole.

  18. Protein fold determined by paramagnetic magic-angle spinning solid-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Sengupta, Ishita; Nadaud, Philippe S.; Helmus, Jonathan J.; Schwieters, Charles D.; Jaroniec, Christopher P.

    2012-05-01

    Biomacromolecules that are challenging for the usual structural techniques can be studied with atomic resolution by solid-state NMR spectroscopy. However, the paucity of distance restraints >5 Å, traditionally derived from measurements of magnetic dipole-dipole couplings between protein nuclei, is a major bottleneck that hampers such structure elucidation efforts. Here, we describe a general approach that enables the rapid determination of global protein fold in the solid phase via measurements of nuclear paramagnetic relaxation enhancements (PREs) in several analogues of the protein of interest containing covalently attached paramagnetic tags, without the use of conventional internuclear distance restraints. The method is demonstrated using six cysteine-EDTA-Cu2+ mutants of the 56-residue B1 immunoglobulin-binding domain of protein G, for which ~230 longitudinal backbone 15N PREs corresponding to distances of ~10-20 Å were obtained. The mean protein fold determined in this manner agrees with the X-ray structure with a backbone atom root-mean-square deviation of 1.8 Å.

  19. High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics

    DTIC Science & Technology

    2015-11-01

    PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Director, ECBC, ATTN: RDCB-DRT-T, APG, MD 21010-5424  Leidos, Inc., P.O. Box 68, Gunpowder, MD 21010...0068     8. PERFORMING ORGANIZATION REPORT NUMBER ECBC-TR-1326 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR...HD Reactive polymer GD  16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE

  20. Dynamics of Reassembled Thioredoxin Studied by Magic Angle Spinning NMR: Snapshots from Different Timescales

    PubMed Central

    Yang, Jun; Tasayco, Maria Luisa; Polenova, Tatyana

    2014-01-01

    Solid-state NMR spectroscopy can be used to probe internal protein dynamics in the absence of the overall molecular tumbling. In this study, we report 15N backbone dynamics in differentially enriched 1-73(U-13C, 15N)/74-108(U-15N) reassembled thioredoxin on multiple timescales using a series of 2D and 3D MAS NMR experiments probing the backbone amide 15N longitudinal relaxation, 1H-15N dipolar order parameters, 15N chemical shift anisotropy (CSA), and signal intensities in the temperature-dependent and 1H T2′ -filtered NCA experiments. The spin-lattice relaxation rates R1(R1 = 1/T1) were observed in the range from 0.012 to 0.64 s-1 indicating large site-to-site variations in dynamics on pico- to nanosecond time scales. The 1H-15N dipolar order parameters, , and 15N CSA anisotropies, δσ reveal the backbone mobilities in reassembled thioredoxin, as reflected in the average = 0.89 ± 0.06 and δσ = 92.3 ± 5.2 ppm, respectively. From the aggregate of experimental data from different dynamics methods, some degree of correlation between the motions on the different time scales has been suggested. Analysis of the dynamics parameters derived from these solid-state NMR experiments indicates higher mobilities for the residues constituting irregular secondary structure elements than for those located in the α-helices and β-sheets, with no apparent systematic differences in dynamics between the α-helical and β-sheet residues. Remarkably, the dipolar order parameters derived from the solid-state NMR measurements and the corresponding solution NMR generalized order parameters display similar qualitative trends as a function of the residue number. The comparison of the solid-state dynamics parameters to the crystallographic B-factors has identified the contribution of static disorder to the B-factors. The combination of longitudinal relaxation, dipolar order parameter, and CSA line shape analyses employed in this study provides snapshots of dynamics and a new insight on the correlation of these motions on multiple time scales. PMID:19736935

  1. Pf1 bacteriophage hydration by magic angle spinning solid-state NMR

    SciTech Connect

    Sergeyev, Ivan V.; Bahri, Salima; McDermott, Ann E.; Day, Loren A.

    2014-12-14

    High resolution two- and three-dimensional heteronuclear correlation spectroscopy ({sup 1}H–{sup 13}C, {sup 1}H–{sup 15}N, and {sup 1}H–{sup 13}C–{sup 13}C HETCOR) has provided a detailed characterization of the internal and external hydration water of the Pf1 virion. This long and slender virion (2000 nm × 7 nm) contains highly stretched DNA within a capsid of small protein subunits, each only 46 amino acid residues. HETCOR cross-peaks have been unambiguously assigned to 25 amino acids, including most external residues 1–21 as well as residues 39–40 and 43–46 deep inside the virion. In addition, the deoxyribose rings of the DNA near the virion axis are in contact with water. The sets of cross-peaks to the DNA and to all 25 amino acid residues were from the same hydration water {sup 1}H resonance; some of the assigned residues do not have exchangeable side-chain protons. A mapping of the contacts onto structural models indicates the presence of water “tunnels” through a highly hydrophobic region of the capsid. The present results significantly extend and modify results from a lower resolution study, and yield a comprehensive hydration surface map of Pf1. In addition, the internal water could be distinguished from external hydration water by means of paramagnetic relaxation enhancement. The internal water population may serve as a conveniently localized magnetization reservoir for structural studies.

  2. Pf1 bacteriophage hydration by magic angle spinning solid-state NMR

    NASA Astrophysics Data System (ADS)

    Sergeyev, Ivan V.; Bahri, Salima; Day, Loren A.; McDermott, Ann E.

    2014-12-01

    High resolution two- and three-dimensional heteronuclear correlation spectroscopy (1H-13C, 1H-15N, and 1H-13C-13C HETCOR) has provided a detailed characterization of the internal and external hydration water of the Pf1 virion. This long and slender virion (2000 nm × 7 nm) contains highly stretched DNA within a capsid of small protein subunits, each only 46 amino acid residues. HETCOR cross-peaks have been unambiguously assigned to 25 amino acids, including most external residues 1-21 as well as residues 39-40 and 43-46 deep inside the virion. In addition, the deoxyribose rings of the DNA near the virion axis are in contact with water. The sets of cross-peaks to the DNA and to all 25 amino acid residues were from the same hydration water 1H resonance; some of the assigned residues do not have exchangeable side-chain protons. A mapping of the contacts onto structural models indicates the presence of water "tunnels" through a highly hydrophobic region of the capsid. The present results significantly extend and modify results from a lower resolution study, and yield a comprehensive hydration surface map of Pf1. In addition, the internal water could be distinguished from external hydration water by means of paramagnetic relaxation enhancement. The internal water population may serve as a conveniently localized magnetization reservoir for structural studies.

  3. Quadrupolar magic angle spinning NMR spectra fitted using the Pearson IV function.

    PubMed

    Mironenko, Roman M; Belskaya, Olga B; Talsi, Valentin P; Likholobov, Vladimir A

    2014-01-01

    The Pearson IV function was used to fit the asymmetric solid-state (27)Al NMR spectra of alumina based catalysts. A high convergence (correlation coefficient is no less than 0.997) between experimental and simulated spectra was achieved. The decomposition of the (27)Al NMR spectra of zinc/aluminum mixed oxides with different Zn/Al molar ratio revealed an increased fraction (6-9%) of pentacoordinated aluminum atoms in these oxides as compared to γ-Al2O3. As the Zn/Al ratio is raised, the fraction of [AlO6] octahedral units decreases, while the fraction of [AlO4] tetrahedra increases.

  4. IN SITU MAGIC ANGLE SPINNING NMR FOR STUDYING GEOLOGICAL CO(2) SEQUESTRATION

    SciTech Connect

    Hoyt, David W.; Turcu, Romulus VF; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Kwak, Ja Hun; Felmy, Andrew R.; Hu, Jian Z.

    2011-03-27

    Geological carbon sequestration (GCS) is one of the most promising ways of mitigating atmospheric greenhouse gases (1-3). Mineral carbonation reactions are potentially important to the long-term sealing effectiveness of caprock but remain poorly predictable, particularly in low-water supercritical CO2 (scCO2)-dominated environments where the chemistry has not been adequately explored. In situ probes that provide molecular-level information is desirable for investigating mechanisms and rates of GCS mineral carbonation reactions. 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, or a supercritical state, or a mixture thereof (4,5). 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 rotor (6,7), where non-metal materials must be used. In this work, we report development of a unique high pressure MAS NMR capability, and its application to mineral carbonation chemistry in scCO2 under geologically relevant temperatures and pressures.

  5. 77 FR 70432 - Magic Valley Pipeline, L.P.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ... Energy Regulatory Commission Magic Valley Pipeline, L.P.; Notice of Filing Take notice that on November 15, 2012, Magic Valley Pipeline, L.P. (Magic Valley) filed to revise its Statement of Operating... free). For TTY, call (202) 502-8659. Comment Date: 5:00 p.m. Eastern Time on Tuesday, November 27,...

  6. Magical Ideation, Creativity, Handedness, and Cerebral Asymmetries: A Combined Behavioural and fMRI Study

    ERIC Educational Resources Information Center

    Badzakova-Trajkov, Gjurgjica; Haberling, Isabelle S.; Corballis, Michael C.

    2011-01-01

    Magical ideation has been shown to be related to measures of hand preference, in which those with mixed handedness exhibit higher levels of magical ideation than those with either consistent left- or right-handedness. It is unclear whether the relation between magical ideation and hand preference is the result of a bias in questionnaire-taking…

  7. 77 FR 74182 - Magic Valley Pipeline, L.P.; Notice of Petition for Rate Approval

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Magic Valley Pipeline, L.P.; Notice of Petition for Rate Approval Take notice that on November 30, 2012, Magic Valley Pipeline, L.P. (Magic Valley) filed a petition for...

  8. Polar and singular value decomposition of 3×3 magic squares

    NASA Astrophysics Data System (ADS)

    Trenkler, Götz; Schmidt, Karsten; Trenkler, Dietrich

    2013-07-01

    In this note, we find polar as well as singular value decompositions of a 3×3 magic square, i.e. a 3×3 matrix M with real elements where each row, column and diagonal adds up to the magic sum s of the magic square.

  9. The role of magical thinking in forecasting the future.

    PubMed

    Stavrova, Olga; Meckel, Andrea

    2017-02-01

    This article explores the role of magical thinking in the subjective probabilities of future chance events. In five experiments, we show that individuals tend to predict a more lucky future (reflected in probability judgements of lucky and unfortunate chance events) for someone who happened to purchase a product associated with a highly moral person than for someone who unknowingly purchased a product associated with a highly immoral person. In the former case, positive events were considered more likely than negative events, whereas in the latter case, the difference in the likelihood judgement of positive and negative events disappeared or even reversed. Our results indicate that this effect is unlikely to be driven by participants' immanent justice beliefs, the availability heuristic, or experimenter demand. Finally, we show that individuals rely more heavily on magical thinking when their need for control is threatened, thus suggesting that lack of control represents a factor in driving magical thinking in making predictions about the future.

  10. Magic Wavelength for the Hydrogen 1S-2S Transition

    NASA Astrophysics Data System (ADS)

    Kawasaki, Akio

    2016-05-01

    The state of the art precision measurement of the transition frequencies of neutral atoms is performed with atoms trapped by the magic wavelength optical lattice that cancels the ac Stark shift of the transitions. Trapping with magic wavelength lattice is also expected to improve the precision of the hydrogen 1S-2S transition frequency, which so far has been measured only with the atomic beam. In this talk, I discuss the magic wavelength for the hydrogen 1S-2S transition, and the possibility of implementing the optical lattice trapping for hydrogen. Optical trapping of hydrogen also opens the way to perform magnetic field free spectroscopy of antihydrogen for the test of CPT theorem.

  11. Magic supergravities, N=8 and black hole composites

    NASA Astrophysics Data System (ADS)

    Ferrara, Sergio; Gimon, Eric G.; Kallosh, Renata

    2006-12-01

    We present explicit U-duality invariants for the R, C, Q, O (real, complex, quaternionic, and octonionic) magic supergravities in four and five dimensions using complex forms with a reality condition. From these invariants we derive an explicit entropy function and corresponding stabilization equations which we use to exhibit stationary multicenter 1/2 Bogomol’nyi-Prasad-Sommerfield (BPS) solutions of these N=2 d=4 theories, starting with the octonionic one with E7(-25) duality symmetry. We generalize to stationary 1/8 BPS multicenter solutions of N=8, d=4 supergravity, using the consistent truncation to the quaternionic magic N=2 supergravity. We present a general solution of non-BPS attractor equations of the STU truncation of magic models. We finish with a discussion of the BPS-non-BPS relations and attractors in N=2 versus N=5, 6, 8.

  12. Marine Ice Nuclei Collections – MAGIC (MAGIC-IN) Final Campaign Summary

    SciTech Connect

    DeMott, Paul J.; Hill, Thomas C. J.

    2016-02-01

    This campaign augmented measurements obtained via deployment of the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Mobile Facility (AMF) in the Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign. The measurements, comprised of shipboard aerosol collections obtained during the five legs of the summer 2013 cruises, were sent for offline processing to measure ice nucleating particle (INP) number concentrations. The forty-three sample periods each represented, nominally, 24-hour segments during outbound and inbound transits of the Horizon Spirit. The samples were collected at locations between Los Angeles and Hawaii. Eight samples have been analyzed for immersion freezing temperature spectra thus far, using funding from other grants. Remaining samples are being frozen until support for further processing is obtained. Future analyses will investigate the inorganic/organic proportions of ice nuclei, in addition to determining the genetic composition of the overall biological community associated with INPs. Resulting correlations will be compared with other archived aerosol quantities, meteorological and ocean data (e.g., temperature, wind speed, sea surface temperature, etc…) and satellite ocean color products. These findings will ultimately aid in parameterizing oceanic (e.g., sea spray) INP emissions in regional and global scale models, when illustrating aerosol connections to cloud phases and properties. Independent future analyses of frozen filter samples, as proposed by collaborating investigators at the time of this report, will include single particle analyses of marine boundary layer aerosol compositions and morphology. The MAGIC-IN data are considered representative of the oligotrophic, low Chlorophyll-a (with the exception of near-shore) ocean regions, which exist along the MAGIC transect. Current analyses suggest that INP numbers in the marine boundary layer over this region are typically low, compared to existing

  13. A comparison of Magic and FORTE ionosphere measurements

    NASA Astrophysics Data System (ADS)

    Minter, C. F.; Robertson, D. S.; Spencer, P. S. J.; Jacobson, A. R.; Fuller-Rowell, T. J.; Araujo-Pradere, E. A.; Moses, R. W.

    2007-06-01

    To date, no formal validation of the new ionosphere nowcast system, United States-Total Electron Content (US-TEC), at the Space Environment Center in Boulder, Colorado, has been published. This paper therefore lays part of the validation groundwork by comparing solutions from Magic, the analysis version of US-TEC, with total electron content (TEC) data from the Fast Onboard Recording of Transient Events (FORTE) satellite. The Magic system uses ground-based GPS observations to reproduce a four-dimensional model of the electron density in the ionosphere. From this model, the TEC between any two points at any time can be obtained. The FORTE satellite, on the other hand, detects the arrival time versus frequency of a broadband signal from a transmitter at Los Alamos. The FORTE-observed group delay provides the TEC along the line of sight between the transmitter and the satellite. These FORTE line-of-sight observations can be compared with TEC values over the same lines of sight in the Magic model. A root-mean-square error (RMSE) calculation statistically compares 178 lines of sight. The RMSE indicates a statistical error of 2.87 total electron content units (1 TECU = 1016 el/m2) between FORTE and Magic, using the current operational GPS station list in US-TEC. How much FORTE and Magic individually contribute to this error remains indeterminable, although the errors are expected to be unique to either system and uncorrelated. Individual contributions of each method to the RMSE are estimated by eliminating observations most affected by raypath bending in FORTE and by varying the number of stations in Magic.

  14. The H-super(anti)magic decompositions of antiprism graphs

    NASA Astrophysics Data System (ADS)

    Hendy

    2016-02-01

    Let H and G be two simple graphs. The concept of an H-magic decomposition of G arises from the combination between graph decompositions and graph labeling. A family 𝔹 = {G1, G2, …, Gt } of subgraphs of G is an H-decomposition of G, if all subgraphs are isomorphic to graph H, E(Gi) ∩ E(G j) = Ø for i ≠ j, and ∪i=1t E (Gi)=E (G ) . The graph G is said to be H-magic, if there exists a bijection f : V (G) ∪ E(G) → {1, 2,…, |V (G) ∪ E(G)|} such that the sum of labels of all edges and vertices of each copy of H in a decomposition is constant. The graph G is said to be (a, d)H-anti magic, if there exists a bijection f : V (G) ∪ E(G) → {1, 2, …, |V (G) ∪ E(G)|} such that the sum of labels of all edges and vertices of each copy of H in a decomposition is element of {a, a + d, a + 2d,…, a + (k - 1)d}. In this paper we show that the Antiprism graph, An, for n ≥ 3 are H- decomposable, where H isomorf with sun graph, S(Cn), 3-cycle with a pendant, L, and path with length two, P2. Also we show that for n ≥ 3, the Antiprism graph An, has super magic S(Cn)-decompositions, super edge magic L-decompositions and super edge magic P2-decompositions. In addition we show that for n ≥ 3, the Antiprism graph An, has super antimagic (8n2 + 2n, 4n2)- S(Cn)- decompositions.

  15. Compact Low-Loss Planar Magic-T

    NASA Technical Reports Server (NTRS)

    U-yen, Kongpop; Wollack, Edward J.; Doiron, Terence; Moseley, Sameul H.

    2008-01-01

    This design allows broadband power combining with high isolation between the H port and E port, and achieves a lower insertion loss than any other broadband planar magic-T. Passive micro wave/millimeter-wave signal power is combined both in-phase and out-of-phase at the ports, with the phase error being less than 1 , which is limited by port impedance. The in-phase signal combiner consists of two quarter-wavelength-long transmission lines combined at the microstrip line junction. The out-of-phase signal combiner consists of two half-wavelength-long transmission lines combined in series. Structural symmetry creates a virtual ground plane at the combining junction, and the combined signal is converted from microstrip line to slotline. Optimum realizable characteristic impedances are used so that the magic-T provides broadband response with low return loss. The magic-T is used in microwave and millimeter-wave frequencies, with the operating bandwidth being approximately 100 percent. The minimum isolation obtainable is 32 dB from port E to port H. The magic-T VSWR is less than 1.1 in the operating band. Operating temperature is mainly dependent on the variation in the dielectric constant of the substrate. Using crystallized substrate, the invention can operate in an extremely broad range of temperatures (from 0 to 400 K). It has a very high reliability because it has no moving parts and requires no maintenance, though it is desirable that the magic-T operate in a low-humidity environment. Fabrication of this design is very simple, using only two metallized layers. No bond wires, via holes, or air bridges are required. Additionally, this magic-T can operate as an individual component without auxiliary components.

  16. Magic Numbers of Atoms in Surface-Supported Planar Clusters

    NASA Astrophysics Data System (ADS)

    Chiu, Ya-Ping; Huang, Li-Wei; Wei, Ching-Ming; Chang, Chia-Seng; Tsong, Tien-Tzou

    2006-10-01

    Surface-supported planar clusters can sprout active research and create numerous applications in the realm of nanotechnology. Exploitation of these clusters will be more extended if their properties on a supported substrate are thoroughly apprehended, and if they can be fabricated in a controllable way. Here we report finding the magic numbers in two-dimensional Ag clusters grown on Pb quantum islands. We demonstrate, with the images and energy spectra of atomic precision, the transition from electronic origin to a geometric one within the same system. Applying the magic nature, we can also produce a large array of planar clusters with well-defined sizes and shapes.

  17. Attention and awareness in stage magic: turning tricks into research.

    PubMed

    Macknik, Stephen L; King, Mac; Randi, James; Robbins, Apollo; Teller; Thompson, John; Martinez-Conde, Susana

    2008-11-01

    Just as vision scientists study visual art and illusions to elucidate the workings of the visual system, so too can cognitive scientists study cognitive illusions to elucidate the underpinnings of cognition. Magic shows are a manifestation of accomplished magic performers' deep intuition for and understanding of human attention and awareness. By studying magicians and their techniques, neuroscientists can learn powerful methods to manipulate attention and awareness in the laboratory. Such methods could be exploited to directly study the behavioural and neural basis of consciousness itself, for instance through the use of brain imaging and other neural recording techniques.

  18. MAGIC (Mobile Autonomous Generic Instrument Carrier): Environment Specification & Requirements Assessment

    NASA Astrophysics Data System (ADS)

    Wagenbach, S.; Biele, J.; Ho, T.-M.; Lange, C.; Ulamec, S.; Witte, L.; Zoest, T. V.

    2011-10-01

    This paper presents first results of the DLR MAGIC (Mobile Autonomous Generic Instrument Carrier) study. MAGIC, a small robotic landing system that can autonomously relocate and upright, shall allow carrying variable suites of innovative instrumentation (up to a limit of ca. 3kg) for in-situ exploration to a broad, but defined, range of small bodies (such as asteroids, Near Earth Objects (NEO) and small moons). The instrumentation delivered shall allow studying the body's physical properties, internal, surface and subsurface structure and its chemical composition, thus being a complement to any rendezvous or sample return missions to small bodies.

  19. 'Magic coins' and 'magic squares': the discovery of astrological sigils in the Oldenburg Letters.

    PubMed

    Roos, Anna Marie

    2008-09-20

    Enclosed in a 1673 letter to Henry Oldenburg were two drawings of a series of astrological sigils, coins and amulets from the collection of Strasbourg mathematician Julius Reichelt (1637-1719). As portrayals of particular medieval and early modern sigils are relatively rare, this paper will analyse the role of these medals in medieval and early modern medicine, the logic behind their perceived efficacy, and their significance in early modern astrological and cabalistic practice. I shall also demonstrate their change in status in the late seventeenth century from potent magical healing amulets tied to the mysteries of the heavens to objects kept in a cabinet for curiosos. The evolving perception of the purpose of sigils mirrored changing early modem beliefs in the occult influences of the heavens upon the body and the natural world, as well as the growing interests among virtuosi in collecting, numismatics and antiquities.

  20. Solid-state 13C NMR study of banana liquid crystals - 3: Alkyl-tail-group packing environments of an acute-angle bent-core molecule in the hexagonal columnar and cubic phases

    NASA Astrophysics Data System (ADS)

    Kurosu, Hiromichi; Endo, Yumi; Kimura, Saori; Hashimoto, Tomoko; Harada, Motoi; Lee, Eun-Woo; Sone, Masato; Watanabe, Junji; Kang, Sungmin

    2016-02-01

    Solid-state 13C nuclear magnetic resonance (NMR) measurements were performed on the hexagonal columnar and cubic phases of an acute-angle banana-shaped molecule, N(1,7)-S30. In the hexagonal columnar phase, three peaks appear at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that the two alkyl tails have different packing structures, and one of the tails has two different conformations within a single molecule. Combined cross-polarization/magic-angle spinning and pulse saturation transfer/magic-angle spinning measurements show that one of the alkyl chains is located inside and the other is located outside the columnar structure. In the cubic phase, pulse saturation transfer/magic-angle spinning measurement shows that only one peak appears at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that both of the alkyl chains are located outside the cubic structure.

  1. The crystallization of hectorite clays as monitored by small angle X-ray scattering and NMR

    SciTech Connect

    Carrado, K. A.; Xu, L.; Seifert, S.; Gregory, D.; Song, K.; Botto, R. E.

    1999-12-13

    The authors have probed the 48-hr crystallization of a magnesium silicate clay called hectorite. Small angle X-ray scattering (SAXS) at the Advanced Photon Source using aliquots ex situ has revealed that data is consistent with ex situ XRD, TGA, AFM, and IR data in that all these techniques see clay crystallite beginning to form in the first few hours of reaction. Tetraethylammonium (TEA) ions are used to aid crystallization and become incorporated as the exchange cations within the interlayers. {sup 13}C NMR shows that 80% of the final TEA loading is accomplished in the first 10 hrs. {sup 29}Si NMR displays a visible clay silicate peak after just 1 hr. In addition, the first in situ study of clay crystallization of any kind was performed by in situ SAXS. Results are consistent with the ex situ data as well as showing the sensitivity of SAXS to sol gel reactions occurring on the order of minutes.

  2. Application of a Resource Theory for Magic States to Fault-Tolerant Quantum Computing.

    PubMed

    Howard, Mark; Campbell, Earl

    2017-03-03

    Motivated by their necessity for most fault-tolerant quantum computation schemes, we formulate a resource theory for magic states. First, we show that robustness of magic is a well-behaved magic monotone that operationally quantifies the classical simulation overhead for a Gottesman-Knill-type scheme using ancillary magic states. Our framework subsequently finds immediate application in the task of synthesizing non-Clifford gates using magic states. When magic states are interspersed with Clifford gates, Pauli measurements, and stabilizer ancillas-the most general synthesis scenario-then the class of synthesizable unitaries is hard to characterize. Our techniques can place nontrivial lower bounds on the number of magic states required for implementing a given target unitary. Guided by these results, we have found new and optimal examples of such synthesis.

  3. Islands of stability and quasi-magic numbers for super- and ultra-heavy nuclei

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Ellithi, A. Y.; Adel, A.; Anwer, Hisham

    2016-12-01

    In the framework of Strutinsky’s approach, we calculated the shell and the residual pairing correction energies for 5569 even-even nuclei in the range 72 ⩽ Z ⩽ 282 and 96 ⩽ N ⩽ 540. Quasi-magic numbers and deformed islands of stability that reside in a range defined by Green’s formula and the two-neutrons drip line are introduced. We present 36 quasi-magic proton and 53 quasi-magic neutron magic numbers that contribute to the formation of 133 deformed islands of stability along the N-Z space. The quasi-magic proton and neutron magic numbers volatile as the mass number increases and other magic numbers take over. Consequently, the deformed islands of stability fail to exhibit a pattern along the search space covered.

  4. Application of a Resource Theory for Magic States to Fault-Tolerant Quantum Computing

    NASA Astrophysics Data System (ADS)

    Howard, Mark; Campbell, Earl

    2017-03-01

    Motivated by their necessity for most fault-tolerant quantum computation schemes, we formulate a resource theory for magic states. First, we show that robustness of magic is a well-behaved magic monotone that operationally quantifies the classical simulation overhead for a Gottesman-Knill-type scheme using ancillary magic states. Our framework subsequently finds immediate application in the task of synthesizing non-Clifford gates using magic states. When magic states are interspersed with Clifford gates, Pauli measurements, and stabilizer ancillas—the most general synthesis scenario—then the class of synthesizable unitaries is hard to characterize. Our techniques can place nontrivial lower bounds on the number of magic states required for implementing a given target unitary. Guided by these results, we have found new and optimal examples of such synthesis.

  5. Magic from Social Networks that Talk to Management: Four Cases

    ERIC Educational Resources Information Center

    Sugarman, Barry

    2010-01-01

    Purpose: The purpose of this paper is to understand how social networks can help to produce the "magic" of extraordinary results for organizations. Design/methodology/approach: In this exploratory study four cases (from published reports) are compared in order to illustrate different management approaches to utilizing the power of networks.…

  6. "Octagon Magic": Andre Norton and Revitalizing the Girls' Book.

    ERIC Educational Resources Information Center

    Dressel, Janice Hartwick; Molson, Francis J.

    1996-01-01

    Argues that Andre Norton's "Octagon Magic" is neither a conventional girls' book, nor a witch tale, nor a time fantasy but rather a unique coming-of-age story best understood within the context of theorists such as Carol Gilligan, Mary Belenk, and Jean Baker Miller. (TB)

  7. Sleight of hand: magic, therapy and motor performance.

    PubMed

    Harte, Daniel; Spencer, Kevin

    2014-01-01

    Finding creative therapeutic activities to help patients regain range of motion and strength in fun ways are keys aspects to many rehabilitation programs. These authors examine the use of magic tricks as a way to enhance a hand therapy program - Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.

  8. "Pear Blossom's Magic: A Cinderella Story." Standards of Learning Connections.

    ERIC Educational Resources Information Center

    Brookshire, Cathy A.

    Virginia Standards of Learning for Kindergarten through fifth grade are listed in this paper with student activities related to observation of live theatre performances of "Pear Blossom's Magic: A Cinderella Story" written by George Wead. This play toured in Virginia in 1999-2000 and was performed by the high school theater touring…

  9. Response to Alexandra Kertz-Wezel, "The Magic of Music"

    ERIC Educational Resources Information Center

    Gromsko, Joyce Eastlund

    2005-01-01

    In this article, the author responds to the paper by Kertz-Wezel entitled "The Magic of Music." Here, she discusses an approach to music experience she had developed that depends on collaborative music-making, as opposed to the approach by Kertz-Wezel. She describes how her approach, contrary to the individualistic approach espoused by…

  10. Martin Gardner: 100 Years of the Magic of Physics

    ERIC Educational Resources Information Center

    Gillaspy, John D.

    2014-01-01

    2014 marks the 100th anniversary of the birth of Martin Gardner, a man whose writings helped inspire generations of young students to pursue a career in physics and mathematics. From his first to his last, and many in between, Gardner's publications often combined magic and science. A recurring theme was the clever use of physical principles…

  11. Response to Tavin's "The Magical Quality of Aesthetics"

    ERIC Educational Resources Information Center

    Carter, Mary C.

    2009-01-01

    In this commentary, I argue that Kevin Tavin's (2008) use of Lacan's "objet a" in his "Studies in Art Education" commentary "The Magical Quality of Aesthetics" is not a helpful analogy or solution for art education's search for the role of aesthetics. I offer that a pragmatist and dialogic viewpoint may be more useful and, because it describes the…

  12. Ring Falling into a Chain: No Magic--Just Physics

    ERIC Educational Resources Information Center

    Vollmer, Michael; Mollmann, Klaus-Peter

    2011-01-01

    Magic tricks are very popular, and they can and should be used in teaching when the underlying principle is easily explained by physics. Such tricks often fall in the realm of hands-on experiments, which are considered to be potentially very effective in raising interest and motivating students. Unfortunately, many hands-on experiments are easy to…

  13. Pre-School Children's Encounters with "The Magic Flute"

    ERIC Educational Resources Information Center

    Nyland, Berenice; Acker, Aleksandra; Ferris, Jill; Deans, Jan

    2011-01-01

    This article describes a music programme in an Australian early learning centre. Through a repertoire of songs, games and instruments, the children were introduced to music forms, including opera. Mozart's Magic Flute was presented to these children by watching the Metropolitan Opera's latest film performance. Because this opera seized the…

  14. Magnetospheric ';magic' frequencies excited by subsolar magnetosheath jets

    NASA Astrophysics Data System (ADS)

    Archer, M. O.; Hartinger, M.; Horbury, T. S.

    2013-12-01

    Statistical and event studies have shown that magnetospheric ULF waves are often observed at persistent discrete Pc5 frequencies known as ';magic' frequencies [see Menk 2011 for a recent review]. While typically assumed to be global (cavity/waveguide) modes, another interpretation is that of magnetopause surface eigenmodes, which may be excited by localised pressure enhancements in the magnetosheath. To distinguish between these hypotheses, we identify transient jets in the magnetosheath (which occur about 2% of the time, predominantly downstream of the quasi-parallel shock) and statistically investigate the spectral response of the magnetospheric magnetic field at geostationary orbit. The broadband jets do indeed excite waves at the ';magic' frequencies, with both direct and resonant driving. We show that the expected fundamental frequencies of magnetopause surface eigenmodes have two preferential values over a wide range of upstream conditions, corresponding to fast and slow solar wind, and that their harmonics are in good agreement with the ';magic' frequencies. We also show that the waves are largely inconsistent with global (cavity/waveguide) modes outside the plasmasphere. Thus we conclude that the ';magic' frequencies are most likely due to magnetopause surface eigenmodes. Menk, F. W., Magnetospheric ULF waves: A review, in The dynamic magnetosphere, edited by W. Lui and M. Fujimoto, IAGA Special Sopron Book Series, pp. 223-256, Springer-Verlag Berlin, doi:10.1007/978-94-007-0501-2_13, 2011.

  15. Magic Universe - The Oxford Guide to Modern Science

    NASA Astrophysics Data System (ADS)

    Calder, Nigel

    2003-11-01

    As a prolific author, BBC commentator, and magazine editor, Nigel Calder has spent a lifetime spotting and explaining the big discoveries in all branches of science. In Magic Universe , he draws on his vast experience to offer readers a lively, far-reaching look at modern science in all its glory, shedding light on the latest ideas in physics, biology, chemistry, medicine, astronomy, and many other fields. What is truly magical about Magic Universe is Calder's incredible breadth. Migrating birds, light sensors in the human eye, black holes, antimatter, buckyballs and nanotubes--with exhilarating sweep, Calder can range from the strings of a piano to the superstrings of modern physics, from Pythagoras's theory of musical pitch to the most recent ideas about atoms and gravity and a ten-dimensional universe--all in one essay. The great virtue of this wide-ranging style--besides its liveliness and versatility--is that it allows Calder to illuminate how the modern sciences intermingle and cross-fertilize one another. Indeed, whether discussing astronauts or handedness or dinosaurs, Calder manages to tease out hidden connections between disparate fields of study. What is most wondrous about the "magic universe" is that one can begin with stellar dust and finish with life itself. Drawing on interviews with more than 200 researchers, from graduate students to Nobel prize-winners, Magic Universe takes us on a high-spirited tour through the halls of science, one that will enthrall everyone interested in science, whether a young researcher in a high-tech lab or an amateur buff sitting in the comfort of an armchair.

  16. Lithium Ion Mobility in Lithium Phosphidosilicates: Crystal Structure, (7) Li, (29) Si, and (31) P MAS NMR Spectroscopy, and Impedance Spectroscopy of Li8 SiP4 and Li2 SiP2.

    PubMed

    Toffoletti, Lorenzo; Kirchhain, Holger; Landesfeind, Johannes; Klein, Wilhelm; van Wüllen, Leo; Gasteiger, Hubert A; Fässler, Thomas F

    2016-12-05

    The need to improve electrodes and Li-ion conducting materials for rechargeable all-solid-state batteries has drawn enhanced attention to the investigation of lithium-rich compounds. The study of the ternary system Li-Si-P revealed a series of new compounds, two of which, Li8 SiP4 and Li2 SiP2 , are presented. Both phases represent members of a new family of Li ion conductors that display Li ion conductivity in the range from 1.15(7)×10(-6) Scm(-1) at 0 °C to 1.2(2)×10(-4) Scm(-1) at 75 °C (Li8 SiP4 ) and from 6.1(7)×10(-8) Scm(-1) at 0 °C to 6(1)×10(-6) Scm(-1) at 75 °C (Li2 SiP2 ), as determined by impedance measurements. Temperature-dependent solid-state (7) Li NMR spectroscopy revealed low activation energies of about 36 kJ mol(-1) for Li8 SiP4 and about 47 kJ mol(-1) for Li2 SiP2 . Both compounds were structurally characterized by X-ray diffraction analysis (single crystal and powder methods) and by (7) Li, (29) Si, and (31) P MAS NMR spectroscopy. Both phases consist of tetrahedral SiP4 anions and Li counterions. Li8 SiP4 contains isolated SiP4 units surrounded by Li atoms, while Li2 SiP2 comprises a three-dimensional network based on corner-sharing SiP4 tetrahedra, with the Li ions located in cavities and channels.

  17. MAGIC-web: a platform for untargeted and targeted N-linked glycoprotein identification.

    PubMed

    Lih, T Mamie; Choong, Wai-Kok; Chen, Chen-Chun; Cheng, Cheng-Wei; Lin, Hsin-Nan; Chen, Ching-Tai; Chang, Hui-Yin; Hsu, Wen-Lian; Sung, Ting-Yi

    2016-07-08

    MAGIC-web is the first web server, to the best of our knowledge, that performs both untargeted and targeted analyses of mass spectrometry-based glycoproteomics data for site-specific N-linked glycoprotein identification. The first two modules, MAGIC and MAGIC+, are designed for untargeted and targeted analysis, respectively. MAGIC is implemented with our previously proposed novel Y1-ion pattern matching method, which adequately detects Y1- and Y0-ion without prior information of proteins and glycans, and then generates in silico MS(2) spectra that serve as input to a database search engine (e.g. Mascot) to search against a large-scale protein sequence database. On top of that, the newly implemented MAGIC+ allows users to determine glycopeptide sequences using their own protein sequence file. The third module, Reports Integrator, provides the service of combining protein identification results from Mascot and glycan-related information from MAGIC-web to generate a complete site-specific protein-glycan summary report. The last module, Glycan Search, is designed for the users who are interested in finding possible glycan structures with specific numbers and types of monosaccharides. The results from MAGIC, MAGIC+ and Reports Integrator can be downloaded via provided links whereas the annotated spectra and glycan structures can be visualized in the browser. MAGIC-web is accessible from http://ms.iis.sinica.edu.tw/MAGIC-web/index.html.

  18. Preparation and use of 131I magic gel as a dosimeter for targeted radionuclide therapy.

    PubMed

    Courbon, Frédéric; Love, Peter; Chittenden, Sarah; Flux, Glen; Ravel, Patrice; Cook, Gary

    2006-10-01

    Clinical interest in targeted radiotherapy is increasing, but accurate dosimetry studies are difficult to achieve. The aim of this study was to investigate the preparation and use of a "normoxic" polymer gel (with a tissue-equivalent density), known as MAGIC gel, and magnetic resonance imaging (MRI) for nonsealed source dosimetry. MAGIC gel samples were mixed with deionized water (MAGIC95) or a solution of 131I (131I-MAGIC95). By measuring the radioinduced variations of R2 values (relaxivity) of irradiated gels, we analyzed the response of MAGIC95 and MAGIC samples to external photon beam or 131I irradiation (131I-MAGIC95). MRI showed that a homogeneous dose distribution from 131I can be achieved if the MAGIC gel, at a temperature of approximately 35 degrees C, is mixed in 131I solution and the resulting mixture shaken gently for 30 minutes. It is important that the vials are completely filled, as residual air reduces polymerization and causes spontaneous polymerization stripes. Responses of MAGIC95 or MAGIC gels to external photon beam irradiation are similar. The variations of R2 values for 131I-MAGIC95 gel depend on the absorbed dose and not on the duration of the irradiation being reproducible from one batch of gel to another. MAGIC gel responses to 131I or external beam irradiation (EBI) are different. Our preliminary results suggest that radiolabeled "normoxic" polymer can be easily and safely produced. Radiolabeled MAGIC gel may, therefore, be suitable for the creation of phantoms dedicated to nonsealed source dosimetry.

  19. Experimental magic state distillation for fault-tolerant quantum computing.

    PubMed

    Souza, Alexandre M; Zhang, Jingfu; Ryan, Colm A; Laflamme, Raymond

    2011-01-25

    Any physical quantum device for quantum information processing (QIP) is subject to errors in implementation. In order to be reliable and efficient, quantum computers will need error-correcting or error-avoiding methods. Fault-tolerance achieved through quantum error correction will be an integral part of quantum computers. Of the many methods that have been discovered to implement it, a highly successful approach has been to use transversal gates and specific initial states. A critical element for its implementation is the availability of high-fidelity initial states, such as |0〉 and the 'magic state'. Here, we report an experiment, performed in a nuclear magnetic resonance (NMR) quantum processor, showing sufficient quantum control to improve the fidelity of imperfect initial magic states by distilling five of them into one with higher fidelity.

  20. Polymorphism in magic-sized Au144(SR)60 clusters

    PubMed Central

    Jensen, Kirsten M.Ø.; Juhas, Pavol; Tofanelli, Marcus A.; Heinecke, Christine L.; Vaughan, Gavin; Ackerson, Christopher J.; Billinge, Simon J. L.

    2016-01-01

    Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. Here we present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution function analysis of X-ray powder diffraction data. The study reveals structural polymorphism in these archetypal nanoclusters. In addition to confirming the theoretically predicted icosahedral-cored cluster, we also find samples with a truncated decahedral core structure, with some samples exhibiting a coexistence of both cluster structures. Although the clusters are monodisperse in size, structural diversity is apparent. The discovery of polymorphism may open up a new dimension in nanoscale engineering. PMID:27297400

  1. Qutrit Magic State Distillation Tight in Some Directions.

    PubMed

    Dawkins, Hillary; Howard, Mark

    2015-07-17

    Magic state distillation is a crucial component in the leading approaches to implementing universal fault-tolerant quantum computation, with existing protocols for both qubit and higher dimensional systems. Early work focused on determining the region of distillable states for qubit protocols; yet comparatively little is known about which states can be distilled and with what distillable region for d>2. Here we focus on d=3 and present new four-qutrit distillation schemes that improve upon the known distillable region, and achieve distillation tight to the boundary of undistillable states for some classes of state. As a consequence of recent results, this implies that there is a family of quantum states that enable universality if and only if they exhibit contextuality with respect to stabilizer measurements. We also identify a new routine whose fixed point is a magic state with maximal sum negativity; i.e., it is maximally nonstablizer in a specific sense.

  2. Polymorphism in magic-sized Au144(SR)60 clusters

    NASA Astrophysics Data System (ADS)

    Jensen, Kirsten M. Ø.; Juhas, Pavol; Tofanelli, Marcus A.; Heinecke, Christine L.; Vaughan, Gavin; Ackerson, Christopher J.; Billinge, Simon J. L.

    2016-06-01

    Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. Here we present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution function analysis of X-ray powder diffraction data. The study reveals structural polymorphism in these archetypal nanoclusters. In addition to confirming the theoretically predicted icosahedral-cored cluster, we also find samples with a truncated decahedral core structure, with some samples exhibiting a coexistence of both cluster structures. Although the clusters are monodisperse in size, structural diversity is apparent. The discovery of polymorphism may open up a new dimension in nanoscale engineering.

  3. Ghosts, UFOs, and magic: positive affect and the experiential system.

    PubMed

    King, Laura A; Burton, Chad M; Hicks, Joshua A; Drigotas, Stephen M

    2007-05-01

    Three studies examined the potential interactions of the experiential system and positive affect (PA) in predicting superstitious beliefs and sympathetic magic. In Study 1, experientiality and induced positive mood interacted to predict the emergence of belief in videos purporting to show unidentified flying objects or ghosts. In Study 2, naturally occurring PA interacted with experientiality to predict susceptibility to sympathetic magic, specifically difficulty in throwing darts at a picture of a baby (demonstrating the law of similarity). In Study 3, induced mood interacted with experientiality to predict sitting farther away from, and expressing less liking for, a partner who had stepped in excrement (demonstrating the law of contagion). Results are interpreted as indicating that PA promotes experiential processing. Implications for the psychology of nonrational beliefs and behaviors are discussed.

  4. The magic crayon: an object definition and volume calculation testbed

    NASA Astrophysics Data System (ADS)

    Beard, David V.; Faith, R. E.; Eberly, David H.; Pizer, Stephen M.; Kurak, Charles; Johnston, Richard E.

    1993-09-01

    Rapid, accurate definition and volume calculation of anatomical objects is essential for effective CT and MR diagnosis. Absolute volumes often signal abnormalities while relative volumes--such as a change in tumor size--can provide critical information on the effectiveness of radiation therapy. To this end, we have developed the 'magic crayon' (MC) anatomical object visualization, object definition, and volume calculation tool as a follow on to UNC's Image Hierarchy Editor (IHE) and Image Hierarchy Visualizer (IHV). This paper presents the magic crayon system detailing interaction, implementation, and preliminary observer studies. MC has several features: (1) it uses a number of 3D visualization methods to visualize rapidly an anatomical object. (2) MC can serve as a test bed for various object definition algorithms. (3) MC serves as a testbed allowing the comparative evaluation of various volume calculation methods including pixel counting and Dr. David Eberly's divergence method.

  5. Magical Empiricism and 'Exposed Being' in Medicine and Traditional Healing.

    PubMed

    Thornton, Robert

    2015-01-01

    Southern African traditional healers often generalize too broadly from discrete ('accidental') instances of success, partly to recruit a clientele, while biomedicine frequently reasons incorrectly from the general to the specific. Both logics are based on empirical observations, but are inversions of each other; these I characterize as 'magical empiricism.' 'Magic' functions as a metapragmatic discourse to recruit a clientele from a skeptical public that doubts the efficacy of any therapeutic interventions, and it acts in parallel with other practical (and efficacious) healing acts. I introduce the concept of 'exposed beings' to describe locally specific constructions of the person as patient and healer. This helps to explain the existence and enduring appeal of many different medical practices and beliefs in South Africa, but I suggest that 'medical parallelism' rather than 'pluralism' might be more accurate.

  6. Polymorphism in magic-sized Au144(SR)60 clusters

    SciTech Connect

    Jensen, Kirsten M. O.; Juhas, Pavol; Tofanelli, Marcus A.; Heinecke, Christine L.; Vaughan, Gavin; Ackerson, Christopher J.; Billinge, Simon J. L.

    2016-06-14

    Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. We present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution function analysis of X-ray powder diffraction data. Our study reveals structural polymorphism in these archetypal nanoclusters. Additionally, in order to confirm the theoretically predicted icosahedral-cored cluster, we also find samples with a truncated decahedral core structure, with some samples exhibiting a coexistence of both cluster structures. Although the clusters are monodisperse in size, structural diversity is apparent. Finally, the discovery of polymorphism may open up a new dimension in nanoscale engineering.

  7. Polymorphism in magic-sized Au144(SR)60 clusters

    DOE PAGES

    Jensen, Kirsten M. O.; Juhas, Pavol; Tofanelli, Marcus A.; ...

    2016-06-14

    Ultra-small, magic-sized metal nanoclusters represent an important new class of materials with properties between molecules and particles. However, their small size challenges the conventional methods for structure characterization. We present the structure of ultra-stable Au144(SR)60 magic-sized nanoclusters obtained from atomic pair distribution function analysis of X-ray powder diffraction data. Our study reveals structural polymorphism in these archetypal nanoclusters. Additionally, in order to confirm the theoretically predicted icosahedral-cored cluster, we also find samples with a truncated decahedral core structure, with some samples exhibiting a coexistence of both cluster structures. Although the clusters are monodisperse in size, structural diversity is apparent. Finally,more » the discovery of polymorphism may open up a new dimension in nanoscale engineering.« less

  8. Parsivel Disdrometer Support for MAGIC Field Campaign Report

    SciTech Connect

    Kollias, Pavlos; Bartholomew, Mary Jane

    2016-06-01

    In the Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign, the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s second Mobile Facility (AMF2) was deployed on the Horizon Lines cargo ship Spirit traversing a route between Los Angeles, California and Honolulu, Hawaii for one full year. The transect for this deployment was chosen specifically because it crosses the stratocumulus-to-cumulus transition of the North-East Pacific, a region of great climatic interest and a close approximation to the transect used for several focused model intercomparison efforts. The cloud type and cover along this transect vary from low marine stratocumulus with high areal coverage near the California coast to isolated shallow cumulus with much lower areal coverage in the trade wind regime near Hawaii. The low marine stratocumulus decks, with their high albedo, exert a major influence on the shortwave radiation budget in the ocean environment, and thus provide an extremely important forcing of Earth’s climate. The trade cumulus clouds play a large role in the global surface evaporation and also in Earth’s albedo. One of the important science drivers of the MAGIC campaign was to measure the properties of clouds and precipitation, specifically cloud type, fractional coverage, base height, physical thickness, liquid water path (LWP), optical depth, and drizzle and precipitation frequency, amount, and extent. Retrievals of cloud and precipitation properties during the MAGIC campaign relied critically on the calibration of the AMF2 radar systems. For MAGIC this included the KAZR and M-WACR, both fixed zenith-pointing systems, and the 1290 MHz beam steerable wind profiler.

  9. From the Magic of Light to the Destruction of Night

    NASA Astrophysics Data System (ADS)

    Posch, Thomas

    2012-09-01

    Life on the Earth depends on the light from the Sun. Humans generally have a very positive attitude towards light. This paper discusses the 'magic of light' - i.e. our dependence on and even addiction to light - and how it gradually led to the destruction of natural darkness by means of excessive artificial illumination. Furthermore, we develop a theory of the aesthetic value of natural nightscapes, which we illustrate by masterpieces from the history of painting.

  10. Detection Parameters In Magic-LC/FT-IR

    NASA Astrophysics Data System (ADS)

    Ferguson, Glenda K.; de Haseth, James A.

    1989-12-01

    Detection limits using the Monodisperse Aerosol Generation Interface Combining Liquid Chromatography with Fourier transform infrared (MAGIC-LC/FT-IR) spectrometry have been studied. Caffeine and p-nitroaniline samples were deposited from both water and 50:50 methanol:water solutions. Various quantities of solutes were injected and deposited on KBr windows. Infrared spectra were taken and compared with reference spectra obtained from the deposition of a relatively concentrated solution.

  11. The Magic Background of Pearl Harbor. Volume 2. Appendix

    DTIC Science & Technology

    1977-01-01

    on a basis of equality with other nationals and freedom from discrimination . A-3 THE"MAGIC"BACKGROUNDOFP ARLH RBOR...nationals and freedom from discrimination . The present understanding shall be kept as a confidential memorandum between theofthis Trans. 5-14-41 No.9... discrimination as important in the Pacific, and that the United States practices this princi- ple toward the American States, if Japan is willing also to

  12. Perceptual elements in Penn & Teller's "Cups and Balls" magic trick.

    PubMed

    Rieiro, Hector; Martinez-Conde, Susana; Macknik, Stephen L

    2013-01-01

    Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired by the entertainment duo Penn & Teller, conducted with three opaque and subsequently with three transparent cups. Magician Teller used his right hand to load (i.e. introduce surreptitiously) a small ball inside each of two upside-down cups, one at a time, while using his left hand to remove a different ball from the upside-down bottom of the cup. The sleight at the third cup involved one of six manipulations: (a) standard maneuver, (b) standard maneuver without a third ball, (c) ball placed on the table, (d) ball lifted, (e) ball dropped to the floor, and (f) ball stuck to the cup. Seven subjects watched the videos of the performances while reporting, via button press, whenever balls were removed from the cups/table (button "1") or placed inside the cups/on the table (button "2"). Subjects' perception was more accurate with transparent than with opaque cups. Perceptual performance was worse for the conditions where the ball was placed on the table, or stuck to the cup, than for the standard maneuver. The condition in which the ball was lifted displaced the subjects' gaze position the most, whereas the condition in which there was no ball caused the smallest gaze displacement. Training improved the subjects' perceptual performance. Occlusion of the magician's face did not affect the subjects' perception, suggesting that gaze misdirection does not play a strong role in the Cups and Balls illusion. Our results have implications for how to optimize the performance of this classic magic trick, and for the types of hand and object motion that maximize magic misdirection.

  13. {sup 13}C chemical shift anisotropies for carbonate ions in cement minerals and the use of {sup 13}C, {sup 27}Al and {sup 29}Si MAS NMR in studies of Portland cement including limestone additions

    SciTech Connect

    Sevelsted, Tine F.; Herfort, Duncan

    2013-10-15

    {sup 13}C isotropic chemical shifts and chemical shift anisotropy parameters have been determined for a number of inorganic carbonates relevant in cement chemistry from slow-speed {sup 13}C MAS or {sup 13}C({sup 1}H) CP/MAS NMR spectra (9.4 T or 14.1 T) for {sup 13}C in natural abundance. The variation in the {sup 13}C chemical shift parameters is relatively small, raising some doubts that different carbonate species in Portland cement-based materials may not be sufficiently resolved in {sup 13}C MAS NMR spectra. However, it is shown that by combining {sup 13}C MAS and {sup 13}C({sup 1}H) CP/MAS NMR carbonate anions in anhydrous and hydrated phases can be distinguished, thereby providing valuable information about the reactivity of limestone in cement blends. This is illustrated for three cement pastes prepared from an ordinary Portland cement, including 0, 16, and 25 wt.% limestone, and following the hydration for up to one year. For these blends {sup 29}Si MAS NMR reveals that the limestone filler accelerates the hydration for alite and also results in a smaller fraction of tetrahedrally coordinated Al incorporated in the C-S-H phase. The latter result is more clearly observed in {sup 27}Al MAS NMR spectra of the cement–limestone blends and suggests that dissolved aluminate species in the cement–limestone blends readily react with carbonate ions from the limestone filler, forming calcium monocarboaluminate hydrate. -- Highlights: •{sup 13}C chemical shift anisotropies for inorganic carbonates from {sup 13}C MAS NMR. •Narrow {sup 13}C NMR chemical shift range (163–171 ppm) for inorganic carbonates. •Anhydrous and hydrated carbonate species by {sup 13}C MAS and {sup 13}C({sup 1}H) CP/MAS NMR. •Limestone accelerates the hydration for alite in Portland – limestone cements. •Limestone reduces the amount of aluminium incorporated in the C-S-H phase.

  14. Magic state distillation protocols with noisy Clifford gates

    NASA Astrophysics Data System (ADS)

    Brooks, Peter

    2013-03-01

    A promising approach to universal fault-tolerant quantum computation is to implement the non-universal group of Clifford gates, and to achieve universality by adding the ability to prepare high-fidelity copies of certain ``magic states''. By applying state distillation protocols, many noisy copies of a magic state ancilla can be purified into a smaller number of clean copies which are arbitrarily close to the perfect state, using only Clifford operations. In practice, the Clifford gates themselves will be noisy, which can limit the efficiency of state distillation and put a floor on the achievable fidelity with the desired state. Recently, a number of new state distillation protocols have been proposed that have the potential to reduce the required resource overhead. I analyze these protocols and explore the tradeoffs between these different approaches to magic state distillation when noisy Clifford gates are taken into account. Supported in part by IARPA under contract D11PC20165, by NSF under Grant No. PHY-0803371, by DOE under Grant No. DE-FG03-92-ER40701, and by NSA/ARO under Grant No. W911NF-09-1-0442.

  15. SKS splitting beneath the MAGIC FlexArray experiment

    NASA Astrophysics Data System (ADS)

    Aragon, J. C.; Long, M. D.; Benoit, M. H.; Kirby, E.; King, S. D.

    2015-12-01

    The Mid-Atlantic Geophysical Integrative Collaboration (MAGIC) is an EarthScope and GeoPRISMS-funded project that involves a collaborative effort among seismologists, geodynamicists, and geomorphologists to understand the relationships among surface processes, crustal and lithospheric structure, and deep mantle flow beneath eastern North America. The eastern passive continental margin has been modified by multiple episodes of orogenesis and rifting through several cycles of supercontinent assembly and breakup over the past 1.3 billion years of Earth history. The MAGIC Flexible Array broadband seismic deployment began in October 2013, with the main phase of the deployment taking place in October 2014. As of summer 2015 the experiment had 27 stations running; the deployment will demobilize in October 2016. We have investigated splitting of SKS phases measured at MAGIC stations during the early stages of the deployment. As illustrated by this presentation, stations located in the Appalachian Mountains, present fast splitting directions parallel to the strike of the Appalachian range, with delay times of approximately 1 sec. At stations to the east and west of the high topography, we find more complicated splitting patterns, with fast directions that vary over short length scales and a large number of null SKS arrivals over a range of backazimuths. These observations suggest a significant contribution to SKS splitting from anisotropy in the lithospheric upper mantle in our study region.

  16. CdSe magic-sized nuclei, magic-sized nanoclusters and regular nanocrystals: monomer effects on nucleation and growth.

    PubMed

    Yu, Kui

    2012-02-21

    Colloidal semiconductor quantum dots (QDs) have been well appreciated for their potential in nanophotonics with an unprecedented impact in various areas, including light emitting diodes (LEDs) and solar cells. There is an outstanding demand on the control of size and size distribution for the various applications, with rational design supported by fundamental understanding of nucleation and growth. This Research News introduces recent advances in the synthesis of colloidal CdSe magic-sized nuclei (MSN) exhibiting sharp bandgap emission, with a model proposed to illustrate the nature of monomers and their degree of supersaturation (DS) affecting the formation of various CdSe MSN, magic-sized nanoclusters (MSCs), and regular nanocrystals (RNCs). Also, this model addresses tuning the CdSe RNCs into the CdSe MSN with the presence of cadmium acetate (Cd(OAc)2) affecting the nature of the monomers.

  17. Reading Angles in Maps

    ERIC Educational Resources Information Center

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

  18. [The magic universe of cures: the role of magic practices and witchcraft in the universe of 17th century Mato Grosso].

    PubMed

    Sá, Mario

    2009-01-01

    The article analyzes the role of healing agents played by practitioners of magic and witchcraft in Mato Grosso society during the 17th century. It observes that magic and witchcraft were developed as competitors, alternatives or associated with other forms of healing (official and lay). It points out how such roles contributed to the process of subjugating its practitioners, especially Africans, Indians and their descendents, and were appropriated as an opportunity for survival in the colonial slave society. The pastoral visit made by Bruno Pinna in 1785 to Cuiabá and nearby areas served as the principal source of knowledge regarding the practices and practitioners of magic and witchcraft.

  19. Viewing angle changeable display

    NASA Astrophysics Data System (ADS)

    Leng, Jinbi; Huang, Ziqiang; Yang, Wenjun; Chen, Xiaoxi

    2010-10-01

    Viewing angle changeable display can change the display viewing angle as needed: In the public place the display could have a narrow viewing angle for privacy, while in the private place the displays could have a wide viewing angle for the convenience of the operation and better viewing experience. This article propose a novel adjustable optical transmission device to realize the viewing angle changes for LCD by using the principle of guest- host effect of liquid crystal. The major technology is to insert a special equipment between the backlight and the LCD, through which the backlight will display either parallel or scattered features to get an either narrow or wide viewing angle. The equipment is an adjustable transmission cell (ATC) which is actually a black G-H LC cell. This ATC is the main focus of our invention. The ATC consists of a polarizer sheet and a special guest-host liquid crystal device filled with the two-phase dye (called as GH-LC in this report), to achieve the viewing angle change in the LCD. When an electrical field charges to the ATC, only the so-called near-axis lights can pass through the ATC within a relatively small angle, while the other scattered lights are absorbed sequentially by GH-LC and the polarizer sheet. On the other hand, when there is no electrical charge to the ATC, the cell behaves like a normal polarizer; and the scattered light can pass through the cell and polarizer in a normal way. This paper describes the principle and structure of the device, applies the electric field on the sample to observe the electro-optical properties, combine the theoretical and experimental research, getting the viewing angle effects of the display.

  20. Photoelectric angle converter

    NASA Astrophysics Data System (ADS)

    Podzharenko, Volodymyr A.; Kulakov, Pavlo I.

    2001-06-01

    The photo-electric angle transmitter of rotation is offered, at which the output voltage is linear function of entering magnitude. In a transmitter the linear phototransducer is used on the basis of pair photo diode -- operating amplifier, which output voltage is linear function of the area of an illuminated photosensitive stratum, and modulator of a light stream of the special shape, which ensures a linear dependence of this area from an angle of rotation. The transmitter has good frequent properties and can be used for dynamic measurements of an angular velocity and angle of rotation, in systems of exact drives and systems of autocontrol.

  1. Meteorite incidence angles

    NASA Astrophysics Data System (ADS)

    Hughes, D. W.

    1993-06-01

    Think about an asteroid smashing into the surface of the Moon and excavating a crater; or hitting Earth and scattering meteorite fragments over a strewn field. Imagine a fragment of cometary dust burning out in the Earth's atmosphere and producing a meteor. These bodies have paths that are inclined at some angle to the vertical. But what is the predominant value of this angle of incidence, i? How does the number of incident bodies vary as a function of angle i? And how do both these affect the prevalence of non- circular lunar craters and the ellipticity of meteorite strewn fields?

  2. Magic and/as Rhetoric: Outlines of a History of Phantasy.

    ERIC Educational Resources Information Center

    Covino, William A.

    1992-01-01

    Defines magic as a process of inducing belief and creating community rather than as a product of an otherworldly incantation. Provides an historical survey of pre-Enlightenment relationships between magic and rhetoric. Proposes that the rise of current-traditional rhetoric coincides with the destruction and disappearance of the magical…

  3. Most-Perfect Pandiagonal Magic Squares and Their Moore-Penrose Inverse

    ERIC Educational Resources Information Center

    Trenkler, Dietrich; Trenkler, Gotz

    2004-01-01

    In this note 4 x 4 most-perfect pandiagonal magic squares are considered in which rows, columns and the two main, along with the broken, diagonals add up to the same sum. It is shown that the Moore-Penrose inverse of these squares has the same magic property.

  4. Elementary School Teachers' Perceptions toward ICT: The Case of Using Magic Board for Teaching Mathematics

    ERIC Educational Resources Information Center

    Yuan, Yuan; Lee, Chun-Yi

    2012-01-01

    This study aims at investigating elementary school teachers' perceptions toward to the use of ICT. Magic Board, an interactive web-based environment which provides a set of virtual manipulatives for elementary mathematics, is used as the case of ICT. After participating in Magic Board workshops, 250 elementary school teachers in Taiwan responded…

  5. In an ICT-Based Teacher-Education Context: Why Was Our Group "The Magic Group"?

    ERIC Educational Resources Information Center

    Helleve, Ingrid

    2007-01-01

    This article deals with a group of distance learning student teachers, who, after the course was completed, called themselves "The Magic Group". The concept "magic" refers to the reflective and productive learning process the group members experienced, a process far beyond their individual borders. The collaborative process was…

  6. Magic Squares: From Primary Classroom to Postgraduate Research in Ten Simple Exercises

    ERIC Educational Resources Information Center

    Roberts, Tim

    2007-01-01

    It is not often that one can introduce primary school students to a problem at the forefront of mathematics research, and have any expectation of understanding; but with magic squares, one can do exactly that. Magic squares are an ideal tool for the effective illustration of many mathematical concepts. This paper assumes little prior knowledge on…

  7. The Cultural Work of Magical Realism in Three Young Adult Novels

    ERIC Educational Resources Information Center

    Latham, Don

    2007-01-01

    Magical realism as a literary mode is often subversive and transgressive, questioning the values and assumptions of the dominant society that it depicts. Young adult literature, by contrast, is typically thought to serve a socializing function, helping to integrate young readers into adult society. What then is the cultural work of magical realism…

  8. Personal Social Networks and the Cultivation of Expertise in Magic: An Interview Study

    ERIC Educational Resources Information Center

    Rissanen, Olli; Palonen, Tuire; Pitkänen, Petteri; Kuhn, Gustav; Hakkarainen, Kai

    2013-01-01

    The purpose of the present study was to examine expertise in magic by interviewing 16 prominent Finnish magicians who were identified earlier through a social network analysis of 120 Finnish magicians. A semi-structured interview was administered that addressed the participants' histories; their relationship to magic, the nature of their…

  9. Using Magic Board as a Teaching Aid in Third Grader Learning of Area Concepts

    ERIC Educational Resources Information Center

    Chang, Wen-Long; Yuan, Yuan; Lee, Chun-Yi; Chen, Min-Hui; Huang, Wen-Guu

    2013-01-01

    The purpose of this study was to explore the impact of incorporating Magic Board in the instruction of concepts related to area. We adopted a non-equivalent quasi-experimental design and recruited participants from two classes of third-grade students in an elementary school in Taoyuan County, Taiwan. Magic Board was used as a teaching aid in the…

  10. Molecules, magic and forgetful fruit flies: the supernatural science of medical gas research.

    PubMed

    Mychaskiw, George

    2011-09-06

    Medical gas research often involves the study of molecules under extraphysiologic conditions, that is, conditions that do not exist in nature. This "supernatural" nature of medical gas research sometimes produces results that appear to be almost "magic" to those schooled in traditional physiology"Any sufficiently advanced technology is indistinguishable from magic".-Arthur C. Clarke.

  11. Preschoolers' Magical Explanations for Violations of Physical, Social, and Mental Laws

    ERIC Educational Resources Information Center

    Browne, Cheryl A.; Woolley, Jacqueline D.

    2004-01-01

    In 2 experiments we explored young preschoolers' knowledge of constraints on human action by presenting them with violations of different types of law and asking whether the violations required magic. In Experiment 1, children responded that physical violations required magic more than did social violations. In Experiment 2, violations were…

  12. Angles, Time, and Proportion

    ERIC Educational Resources Information Center

    Pagni, David L.

    2005-01-01

    This article describes an investigation making connections between the time on an analog clock and the angle between the minute hand and the hour hand. It was posed by a middle school mathematics teacher. (Contains 8 tables and 6 figures.)

  13. Magic-T Junction using Microstrip/Slotline Transitions

    NASA Technical Reports Server (NTRS)

    U-yen, Kongpop; Wollack, Edward J.; Doiron, Terence

    2008-01-01

    An improved broadband planar magic-T junction that incorporates microstrip/slotline transitions has been developed. In comparison with a prior broadband magic-T junction incorporating microstrip/slotline transitions, this junction offers superior broadband performance. In addition, because this junction is geometrically simpler and its performance is less affected by fabrication tolerances, the benefits of the improved design can be realized at lower fabrication cost. There are potential uses for junctions like this one in commercial microwave communication receivers, radar and polarimeter systems, and industrial microwave instrumentation. A magic-T junction is a four-port waveguide junction consisting of a combination of an H-type and an E-type junction. An E-type junction is so named because it includes a junction arm that extends from a main waveguide in the same direction as that of the electric (E) field in the waveguide. An H-type junction is so named because it includes a junction arm parallel to the magnetic (H) field in a main waveguide. A magic-T junction includes two input ports (here labeled 1 and 2, respectively) and two output ports (here labeled E and H, respectively). In an ideal case, (1) a magic-T junction is lossless, (2) the input signals add (that is, they combine in phase with each other) at port H, and (3) the input signals subtract (that is, they combine in opposite phase) at port E. The prior junction over which the present junction is an improvement affords in-phase-combining characterized by a broadband frequency response, and features a small slotline area to minimize in-band loss. However, with respect to isolation between ports 1 and 2 and return loss at port E, it exhibits narrowband frequency responses. In addition, its performance is sensitive to misalignment of microstrip and slotline components: this sensitivity is attributable to a limited number of quarter-wavelength (lambda/4) transmission-line sections for matching impedances

  14. Characterization of a novel two dimensional diode array the ''magic plate'' as a radiation detector for radiation therapy treatment

    SciTech Connect

    Wong, J. H. D.; Fuduli, I.; Carolan, M.; Petasecca, M.; Lerch, M. L. F.; Perevertaylo, V. L.; Metcalfe, P.; Rosenfeld, A. B.

    2012-05-15

    Purpose: Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the ''magic plate'' (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery. Methods: The prototype MP is an 11 x 11 detector array based on thin (50 {mu}m) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary ''drop-in'' technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response. Results: Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180 deg. Angular dependence was within 3.5% for the gantry angles {+-} 75 deg. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In

  15. Enhancing Pseudo-Telepathy in the Magic Square Game

    PubMed Central

    Pawela, Łukasz; Gawron, Piotr; Puchała, Zbigniew; Sładkowski, Jan

    2013-01-01

    We study the possibility of reversing an action of a quantum channel. Our principal objective is to find a specific channel that reverses as accurately as possible an action of a given quantum channel. To achieve this goal we use semidefinite programming. We show the benefits of our method using the quantum pseudo-telepathy Magic Square game with noise. Our strategy is to move the pseudo-telepathy region to higher noise values. We show that it is possible to reverse the action of a noise channel using semidefinite programming. PMID:23762246

  16. Design of an integrated optical magic T for astronomy applications.

    PubMed

    El-Sabban, S; Khalil, D; Schanen, I; Benech, P

    2000-12-20

    A new integrated optical component is introduced that performs the function of the well-known microwave magic T, i.e., that produces the sum and the difference of the two input optical signals. Two structures are proposed and tested theoretically for this purpose. The first is based on the symmetric Y junction, and the second is based on interference phenomena in a multimode waveguide. The theoretical design is tested with a beam-propagation method simulation, and good performance is obtained. The effects of the geometrical design parameters on the structures' performance (bandwidth, cross talk, and losses) are also investigated.

  17. Enhancing pseudo-telepathy in the magic square game.

    PubMed

    Pawela, Lukasz; Gawron, Piotr; Puchała, Zbigniew; Sładkowski, Jan

    2013-01-01

    We study the possibility of reversing an action of a quantum channel. Our principal objective is to find a specific channel that reverses as accurately as possible an action of a given quantum channel. To achieve this goal we use semidefinite programming. We show the benefits of our method using the quantum pseudo-telepathy Magic Square game with noise. Our strategy is to move the pseudo-telepathy region to higher noise values. We show that it is possible to reverse the action of a noise channel using semidefinite programming.

  18. Magical realism: a cultural intervention for traumatized Hispanic children.

    PubMed

    De Rios, M D

    1997-01-01

    A case study is presented of two Spanish-speaking immigrant children who were run over in an automobile accident and hospitalized, to describe a culturally congruent play-therapy technique. Drawing on the work of Pynoos and Nader, the author argues for an anthropological approach in play therapy to create hyperaroused states for the traumatized child and to use cultural super heroes-what is termed "magical realism." Such an approach can be used with Latin American traumatized children as well as with children from other Third World countries to provide a culturally appropriate intervention to treat the psychological sequelae of trauma.

  19. Bringing magic to the nursing workforce of the future.

    PubMed

    Sorrell, Jeanne M; Cangelosi, Pamela R

    2004-01-01

    How can nursing education respond to the ominous signs of a serious shortage of nurses in the future? One answer to this question is a focus on reclaiming nurses' stories of the "real-world" of nursing practice. In the process of creating a childrens book, The Magic Stethoscope, a group of nurse authors found a new appreciation for the stories of their practice and the need to share these stories with children. The authors hope that these stories will inspire children to consider the exciting career opportunities for the nursing workforce of the future.

  20. [100 years of Dr. Ehrlich's magic bullet (1909-2009)].

    PubMed

    García-Sánchez, José Elías; García, Enrique; Merino, María Lucila

    2010-10-01

    The aim of this article is to pay tribute to Paul Ehrlich and his contributions to science, in particular those related to antimicrobial therapy, at the end of a prodigious decade of celebrations to fête his person and work. The year 2009 marks the centenary of the discovery of the experimental anti-syphilitic activity of Salvarsan and the first clinical studies showing its efficacy against syphilis. This homage is conveyed through the presentation of bibliographic data, mention of his most important scientific achievements based on his original publications, and by analyzing the film Dr. Ehrlich's Magic Bullet (1940) by William Dieterle.

  1. Myths, magic and reality in nursing ethics: a personal perspective.

    PubMed

    Tschudin, V

    1998-01-01

    Ethics, especially in nursing, tends to be surrounded by myths and ideas that have more in common with magic than reality. This article argues from quotes of two medieval men, Thomas Aquinas and Meister Eckhart, that ethical behaviour among nurses is not something difficult or far-fetched, but something immediate, everyday, and often very simple. The more weighty ethical dilemmas are not diminished by this. Aspects of justice, compassion and courage are discussed from the point of view of relationships with clients and colleagues, and the need for (helpful) myths is stressed.

  2. The in-situ generation of silica reinforcement in modified polydimethylsiloxane elastomers

    SciTech Connect

    Prabakar, S; Bates, S.E.; Black, E.P.; Ulibarri, T.A.

    1996-06-01

    Structure and properties of a series of modified polydimethylsiloxane (PDMS) elastomers reinforced by {ital in situ} generated silic particles were investigated. The PDMS elastomer was modified by systematically varying the molecular weight between reactive groups incorporated into the backbone. Tetraethoxysilane (TEOS) and partial hydrolyzate of TEOS were used to generate silic particles. Chemistry and phase structure of the materials were investigated by {sup 29}Si magic angle spinning nuclear magnetic resonance spectroscopy and swelling experiments.

  3. Magic moment? Maternal marriage for children born out of wedlock.

    PubMed

    Gibson-Davis, Christina

    2014-08-01

    To test the existence of the "magic moment" for parental marriage immediately post-birth and to inform policies that preferentially encourage biological over step parent marriage, this study estimates the incidence and stability of maternal marriage for children born out of wedlock. Data came from the National Survey of Family Growth on 5,255 children born non maritally. By age 15, 29 % of children born non maritally experienced a biological-father marriage, and 36 % experienced a stepfather marriage. Stepfather marriages occurred much later in a child's life-one-half occurred after the child turned age 7-and had one-third higher odds of dissolution. Children born to black mothers had qualitatively different maternal marriage experiences than children born to white or Hispanic mothers, with less biological-parent marriage and higher incidences of divorce. Findings support the existence of the magic moment and demonstrate that biological marriages were more enduring than stepfather marriages. Yet relatively few children born out of wedlock experienced stable, biological-parent marriages as envisioned by marriage promotion programs.

  4. Spanish jet: something more than gemstone with magical properties

    SciTech Connect

    Suarez-Ruiz, I.; Iglesias, M.J.

    2007-07-01

    The first reference to the existence of jet in Spain dates back to the 7th century. Due to the magical powers attributed to this stone, it has always been considered a mysterious gem. Spanish jet is now a scarce natural resource. The article gives scientific explanation for the magical properties of Spanish jet. It is a humic coal, black in colour, bright, carves and polishes well and has a remarkably stability on exposure to the air, for centuries. Its composition is almost exclusively organic and FTIR analysis shows a high proportion of aliphatic over condensed aromatic structures. The conventional rank parameters are not applicable as the results are contradictory. Carbon content and rank of organic matter suggest it is a high volatile bituminous coal, which agrees with the reflectance for phlobaphinite, the other maceral of the huminite/vitrinite group in this coal. These contradictory characteristics of Spanish jet are derived from an anomalous high enrichment of hydrogen. During coalification there is an increase in aromaticity which is responsible for the variation in coal rank parameters, carbon content and responsible for the variation in coal rank parameters, carbon content and vitrinite reflectance. The remarkable stability is attributed to the adsorbed hydrocarbons preventing easy access of oxygen. 2 figs.

  5. Magic and tune-out wavelengths for atomic francium

    NASA Astrophysics Data System (ADS)

    Dammalapati, U.; Harada, K.; Sakemi, Y.

    2016-04-01

    The frequency dependent polarizabilities of the francium atom are calculated from the available data of energy levels and transition rates. Magic wavelengths for the state insensitive optical dipole trapping are identified from the calculated light shifts of the 7 s 2S1/2, 7 p 2P1/2,3/2, and 8 s 2S1/2 levels of the 7 s -7 p 2S1/2 2P1/2,3/2 and 7 s -8 s 2S1/2 2S1/2 transitions, respectively. Wavelengths in the ultraviolet, visible, and near infrared region are identified that are suitable for cooling and trapping. Magic wavelengths between the 600-700 nm and 700-1000 nm regions, which are blue and red detuned with the 7 s -7 p and 7 s -8 s transitions, are feasible to implement as lasers with sufficient power are available. In addition, we calculated the tune-out wavelengths where the ac polarizability of the ground 7 s 2S1/2 state in francium is zero. These results are beneficial as laser cooled and trapped francium has been in use for fundamental symmetry investigations like searches for an electron permanent electric dipole moment in an atom and for atomic parity nonconservation.

  6. Magically deceptive biological motion-the French Drop Sleight.

    PubMed

    Phillips, Flip; Natter, Michael B; Egan, Eric J L

    2015-01-01

    Intentional deception, as is common in the performance of magic tricks, can provide valuable insight into the mechanisms of perception and action. Much of the recent investigations into this form of deception revolve around the attention of the observer. Here, we present experiments designed to investigate the contributions of the performer to the act of deception. An experienced magician and a naïve novice performed a classic sleight known as the French Drop. Video recordings of the performance were used to measure the quality of the deception-e.g., if a non-magician observer could discriminate instances where the sleight was performed (a deceptive performance) from those where it was not (a veridical performace). During the performance we recorded the trajectory of the hands and measured muscle activity via EMG to help understand the biomechanical mechanisms of this deception. We show that expertise plays a major role in the quality of the deception and that there are significant variations in the motion and muscular behaviors between successful and unsuccessful performances. Smooth, minimal movements with an exaggerated faux-transfer of muscular tension were characteristic of better deception. This finding is consistent with anecdotal reports and the magic performance literature.

  7. Magically deceptive biological motion—the French Drop Sleight

    PubMed Central

    Phillips, Flip; Natter, Michael B.; Egan, Eric J. L.

    2015-01-01

    Intentional deception, as is common in the performance of magic tricks, can provide valuable insight into the mechanisms of perception and action. Much of the recent investigations into this form of deception revolve around the attention of the observer. Here, we present experiments designed to investigate the contributions of the performer to the act of deception. An experienced magician and a naïve novice performed a classic sleight known as the French Drop. Video recordings of the performance were used to measure the quality of the deception—e.g., if a non-magician observer could discriminate instances where the sleight was performed (a deceptive performance) from those where it was not (a veridical performace). During the performance we recorded the trajectory of the hands and measured muscle activity via EMG to help understand the biomechanical mechanisms of this deception. We show that expertise plays a major role in the quality of the deception and that there are significant variations in the motion and muscular behaviors between successful and unsuccessful performances. Smooth, minimal movements with an exaggerated faux-transfer of muscular tension were characteristic of better deception. This finding is consistent with anecdotal reports and the magic performance literature. PMID:25914654

  8. An fMRI investigation of expectation violation in magic tricks.

    PubMed

    Danek, Amory H; Öllinger, Michael; Fraps, Thomas; Grothe, Benedikt; Flanagin, Virginia L

    2015-01-01

    Magic tricks violate the expected causal relationships that form an implicit belief system about what is possible in the world around us. Observing a magic effect seemingly invalidates our implicit assumptions about what action causes which outcome. We aimed at identifying the neural correlates of such expectation violations by contrasting 24 video clips of magic tricks with 24 control clips in which the expected action-outcome relationship is upheld. Using fMRI, we measured the brain activity of 25 normal volunteers while they watched the clips in the scanner. Additionally, we measured the professional magician who had performed the magic tricks under the assumption that, in contrast to naïve observers, the magician himself would not perceive his own magic tricks as an expectation violation. As the main effect of magic - control clips in the normal sample, we found higher activity for magic in the head of the caudate nucleus (CN) bilaterally, the left inferior frontal gyrus and the left anterior insula. As expected, the magician's brain activity substantially differed from these results, with mainly parietal areas (supramarginal gyrus bilaterally) activated, supporting our hypothesis that he did not experience any expectation violation. These findings are in accordance with previous research that has implicated the head of the CN in processing changes in the contingency between action and outcome, even in the absence of reward or feedback.

  9. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  10. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  11. A Compact Low-loss Magic-T using Microstrip-Slotline Transitions

    NASA Technical Reports Server (NTRS)

    U-yen, Kongpop; Wollack, Edward J.; Moseley, Samuel H.; Papapolymerou, John; Laskar, Joy

    2007-01-01

    The design of a compact low-loss magic-T is proposed. The planar magic-T incorporates the compact microstrip-slotline tee junction and small microstrip-slotline transition area to reduce slotline radiation. The experimental results show that the magic-T produces broadband in-phase and out-of-phase power combiner/divider responses, has an average in-band insertion loss of 0.3 dB and small in-band phase and amplitude imbalance of less than plus or minus 1.6 deg. and plus or minus 0.3 dB, respectively.

  12. The use of magical plants by curanderos in the Ecuador highlands

    PubMed Central

    Cavender, Anthony P; Albán, Manuel

    2009-01-01

    Although the use of plants for treating supernaturally caused illnesses (e.g., soul loss, evil wind, witchcraft) has been documented in the Ecuador highlands, so-called magical plants have received much less focused attention than plants used for treating naturalistic disorders. Drawing on interviews done in 2002 and 2003 with 116 curanderos residing in the Ecuador highlands, this paper examines the characteristics of plants identified as magical, how they are used, and how the study of magical plants provides insights into the mindscape of residents of the highlands. PMID:19161618

  13. A Different Angle on Perspective

    ERIC Educational Resources Information Center

    Frantz, Marc

    2012-01-01

    When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

  14. Shortwave Hyperspectral Observations During MAGIC Final Campaign Summary

    SciTech Connect

    McBride, P. J.; Marshak, A.; Yang, W.

    2016-03-01

    The Marine ARM GPCI1 Investigation of Clouds (MAGIC) field campaign was initiated to improve our understanding of low-level marine clouds that have a significant influence on the Earth’s climate. The campaign was conducted using an ARM mobile facility deployed on a commercial ship traveling between Honolulu, Hawaii, and Los Angeles, California, from October 2012 to September 2013. The solar spectral flux radiometer (SSFR) was deployed on July 6, 2013, through the end of the campaign. The SSFR was calibrated and installed by Warren Gore of NASA Ames Research Center, and the data is and will be analyzed by Drs. Alexander Marshak and Weidong Yang of NASA Goddard Space Flight Center, Dr. Samuel LeBlanc of NASA Ames Research Center, Dr. Sebastian Schmidt of the University of Colorado-Boulder, and Dr. Patrick McBride of Atmospheric & Space Technology Research Associates in Boulder, Colorado.

  15. Logistical Support of AirLand Operations: Myth or Magic?

    DTIC Science & Technology

    1992-05-04

    AD-A258 295 111l 1111111 0 i DIll l LOGISTICAL SUPPORT OF AIRLAND OPERATIONS: EETM Y T H R M A G IC S E L E C 2 1 9•DEC2 3 1992• C I A thesis...ng b~ude.. 104f bhn codIeCto~ Of .nfO~maI.Of ,t .~enIal41 (0 a ..rag. I hQ~. ee Nr 9Ow •tQl.Ad,dlflg (be linet foe IOVtw•f~ ,AIIIU(¶I~ r . ,eacbAqIh...inerati,,,: Myth or Magic. Aprroved by: .Theq is Comni tt-t- fTh~airrnan; J ),I i .5 . a rria A.n . T.T! 3:•, J!. Pnwe r . M’. P. A . " ,ý) VoD" Member

  16. Gustave Flaubert, Charles Dickens, and Isaac Pulvermacher's "magic band".

    PubMed

    Waits, Robert K

    2013-01-01

    Around 1850, Isaac L. Pulvermacher (1815-1884) joined the ranks of so-called "galvanists" who had, for nearly a century, been touting the shocks and sparks of electricity as a miracle cure for all ills, including neurological complaints such as palsy and hemiplegia. The famed authors, Gustave Flaubert (1821-1880), in France, and Charles Dickens (1812-1870), in England, although contemporaries, apparently never met or corresponded. But during their lives, they both became aware of Pulvermacher and his patented Hydro-Electric Chains, claimed to impart vigor and cure nearly every complaint. Pulvermacher's chains made a cameo appearance in Madame Bovary (1857), Flaubert's controversial (and most successful) novel. Among Dickens's last letters (1870) was an order for I. L. Pulvermacher and Company's "magic band." Since the Victorian age, electrical and magnetic cures, for better or worse, continue to be products of both the medical profession and quackery.

  17. [Peter of Abano, the 'Conciliator' between magic and science].

    PubMed

    Federici Vescovini, Graziella

    2008-01-01

    Peter of Abano is a personage belonging to history as well as to legend. In this analysis his historical physiognomy of scientist and physician is reconstructed on the basis of a better knowledge of his works in medicine and astronomy (now edited), a discipline, the latest one, in which he excelled in Medieval scientific context (The Lucidator dubitabilium astronomiae (astrologiae) can be read in the critical edition by G. Federici Vescovini, Padova, Esedra, 1992). He opposed extreme position in all fields, by styling himself 'Conciliator' of opposed tendencies. He often reconfirmed a rational concept of medicine and astronomy, which dispelled any demoniac and magic features, against the fanciful legend elaborated during the following centuries.

  18. Magic, science and masculinity: marketing toy chemistry sets.

    PubMed

    Al-Gailani, Salim

    2009-12-01

    At least since the late nineteenth century, toy chemistry sets have featured in standard scripts of the achievement of eminence in science, and they remain important in constructions of scientific identity. Using a selection of these toys manufactured in Britain and the United States, and with particular reference to the two dominant American brands, Gilbert and Chemcraft, this paper suggests that early twentieth-century chemistry sets were rooted in overlapping Victorian traditions of entertainment magic and scientific recreations. As chemistry set marketing copy gradually reoriented towards emphasising scientific modernity, citizenship, discipline and educational value, pre-twentieth-century traditions were subsumed within domestic-and specifically masculine-tropes. These developments in branding strategies point to transformations in both users' engagement with their chemistry sets and the role of scientific toys in domestic play. The chemistry set serves here as a useful tool for measuring cultural change and lay engagement with chemistry.

  19. Magic and artifice in the collection of Athanasius Kircher.

    PubMed

    Waddell, Mark A

    2010-03-01

    Situated at the center of intellectual life in baroque Rome, the museum administered by the Jesuit naturalist Athanasius Kircher (1602-1680) simultaneously instructed and bemused its audiences with an exuberant mix of exotic animals, classical art and technological marvels. Kircher's playful use of spectacle and his irrepressible fondness for "magic" were derided by contemporaries as frivolous wonder-mongering, but the lavish machines at the heart of his museum were more than mere showpieces. Instead, they presented audiences with a compelling vision of the natural world in which the hidden foundations of the universe could be captured and displayed by artifice. Kircher's collection was in itself a vast instrument of revelation, conceived on a grander scale than the telescope of Galileo but rooted all the same in contemporary scientific culture.

  20. Self-reported Magic Eye stereogram skill predicts stereoacuity.

    PubMed

    Wilmer, Jeremy B; Backus, Benjamin T

    2008-01-01

    Autostereograms--commonly known as Magic Eye stereograms (MESs)--are two-dimensional images that support stereoscopic depth perception given an appropriate crossing or uncrossing of the eyes. We find that self-reported MES skill is highly predictive of stereoacuity as measured by a standard clinical test (r142 = 0.45, p < 0.0001; TNO test). Indeed, in our sample of 194 individuals, those who report poor MES skill have a five-fold increased risk of stereo impairment. Those who report poor MES skill also require on average five times greater binocular disparity to perceive stereoscopic depth than those who report good MES skill. Reported MES skill thus carries significant information about stereoacuity.

  1. Magic wavelengths, matrix elements, polarizabilities, and lifetimes of Cs

    NASA Astrophysics Data System (ADS)

    Safronova, M. S.; Safronova, U. I.; Clark, Charles W.

    2016-07-01

    Motivated by recent interest in their applications, we report a systematic study of Cs atomic properties calculated by a high-precision relativistic all-order method. Excitation energies, reduced matrix elements, transition rates, and lifetimes are determined for levels with principal quantum numbers n ≤12 and orbital angular momentum quantum numbers l ≤3 . Recommended values and estimates of uncertainties are provided for a number of electric-dipole transitions and the electric dipole polarizabilities of the n s , n p , and n d states. We also report a calculation of the electric quadrupole polarizability of the ground state. We display the dynamic polarizabilities of the 6 s and 7 p states for optical wavelengths between 1160 and 1800 nm and identify corresponding magic wavelengths for the 6 s -7 p1 /2 and 6 s -7 p3 /2 transitions. The values of relevant matrix elements needed for polarizability calculations at other wavelengths are provided.

  2. Egyptian imprints on Geto-Dacian magical medicine.

    PubMed

    Baran, Dana

    2010-12-01

    Several characteristics of Egyptian culture and civilization could be identified in prehistoric and ancient historic Geto-Dacian territories, belonging to modern Romania (Fig. 1). From early times, magic, religion and philosophy have been part of pre-scientific medicine. Therefore these aspects are to be tackled when speaking of medicine in mythological or legendary ages. Progress of ancient Geto-Dacian medicine was principally ascribed to the interface of local civilizations with ancient Egypt, Greece and Rome. Such connections were well documented and understood in historic times and were mainly based on texts of renowned Greek and Roman historians. Egyptian impact upon Dacia, -the ancient name of today's Romania-, was often explained in terms of indirect Greek- or Roman-mediated influences.The Greek and then the Roman colonies on the Black sea shore, together with later Roman colonies in Dacia Felix, founded in the heart of Transylvania, enabled access for Romania to Mediterranean cultures, including that of Egypt.

  3. Magic and the physical world in thirteenth-century scholasticism.

    PubMed

    Marrone, Steven P

    2009-01-01

    The turn to modern science in the Scientific Revolution of the seventeenth century is typically characterized as dependent on the novel adoption of a mechanical hypothesis for operations in nature. In fact, the Middle Ages saw a partial anticipation of this phenomenon in the scholastic physics of the thirteenth century. More precisely, it was just the two factors, denial of action at a distance and an emphasis on the primary materiality of causation, that constituted this early mechanism--or "protomechanism." The latter's emergence can be seen most clearly where scholastic thinkers-here, William of Auvergne, Thomas Aquinas and Giles of Rome--confronted the theoretical limits of natural cause and effect in their efforts to determine the reality of magic and locate its place in the natural world.

  4. Angles in the Sky?

    NASA Astrophysics Data System (ADS)

    Behr, Bradford

    2005-09-01

    Tycho Brahe lived and worked in the late 1500s before the telescope was invented. He made highly accurate observations of the positions of planets, stars, and comets using large angle-measuring devices of his own design. You can use his techniques to observe the sky as well. For example, the degree, a common unit of measurement in astronomy, can be measured by holding your fist at arm's length up to the sky. Open your fist and observe the distance across the sky covered by the width of your pinky fingernail. That is, roughly, a degree! After some practice, and knowing that one degree equals four minutes, you can measure elapsed time by measuring the angle of the distance that the Moon appears to have moved and multiplying that number by four. You can also figure distances and sizes of things. These are not precise measurements, but rough estimates that can give you a "close-enough" answer.

  5. Contact angle hysteresis explained.

    PubMed

    Gao, Lichao; McCarthy, Thomas J

    2006-07-04

    A view of contact angle hysteresis from the perspectives of the three-phase contact line and of the kinetics of contact line motion is given. Arguments are made that advancing and receding are discrete events that have different activation energies. That hysteresis can be quantified as an activation energy by the changes in interfacial area is argued. That this is an appropriate way of viewing hysteresis is demonstrated with examples.

  6. Laser angle sensor

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.

    1985-01-01

    A laser angle measurement system was designed and fabricated for NASA Langley Research Center. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the model. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. This report includes optical and electrical schematics, system maintenance and operation procedures.

  7. Small Angle Neutron Scattering

    SciTech Connect

    Urban, Volker S

    2012-01-01

    Small Angle Neutron Scattering (SANS) probes structural details at the nanometer scale in a non-destructive way. This article gives an introduction to scientists who have no prior small-angle scattering knowledge, but who seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest. In situ studies of a material s responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is non-destructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis and interpretation of small angle scattering data involves theoretical concepts that are unique to the technique and that are not widely known. This article includes a concise description of the basics, as well as practical know-how that is essential for a successful SANS experiment.

  8. Reasonable magic and the nature of alchemy: Jewish reflections on human embryonic stem cell research.

    PubMed

    Zoloth, Laurie

    2002-03-01

    The controversy about research on human embryonic stem cells both divides and defines us, raising fundamental ethical and religious questions about the nature of the self and the limits of science. This article uses Jewish sources to articulate fundamental concerns about the forbiddenness of knowledge in general and of knowledge thought of as magical creation. Alchemy, and the turning of elements into gold and into substances for longevity, and magic used for the creation of living beings was at stake in various Talmudic texts. Since contemporary discourse calls regenerative science magical, and makes claims about its restorative power, careful reflection on when magic is forbidden and when it is responsible allows a novel understanding of ethical questions in stem cell research.

  9. Scientific Highlights from Observations of Active Galactic Nuclei with the MAGIC Telescope

    SciTech Connect

    Wagner, Robert

    2008-12-24

    Since 2004, the MAGIC {gamma}-ray telescope has newly discovered 6 TeV blazars. The total set of 13 MAGIC-detected active galactic nuclei includes well-studied objects at other wavelengths like Markarian 501 and the giant radio galaxy M 87, but also the distant the flat-spectrum radio quasar 3C 279, and the newly discovered TeV {gamma}-ray emitter S5 0716+71. In addition, also long-term and multi-wavelength studies on well-known TeV blazars and systematic searches for new TeV blazars have been carried out. Here we report selected highlights from recent MAGIC observations of extragalactic TeV {gamma}-ray sources, emphasizing the new physics insights MAGIC was able to contribute.

  10. Western aeronautical test range real-time graphics software package MAGIC

    NASA Technical Reports Server (NTRS)

    Malone, Jacqueline C.; Moore, Archie L.

    1988-01-01

    The master graphics interactive console (MAGIC) software package used on the Western Aeronautical Test Range (WATR) of the NASA Ames Research Center is described. MAGIC is a resident real-time research tool available to flight researchers-scientists in the NASA mission control centers of the WATR at the Dryden Flight Research Facility at Edwards, California. The hardware configuration and capabilities of the real-time software package are also discussed.

  11. Magic as a therapeutic intervention to promote coping in hospitalized pediatric patients.

    PubMed

    Hart, Robyn; Walton, Michael

    2010-01-01

    Magic as a therapeutic intervention is used in an innovative, hospital-based program to address the psychosocial issues children and adolescents often experience as a result of illness and hospitalization. A child life specialist and a magician with an MBA collaborated, blending clinical expertise with business acumen and professional-level magic skills to create the program. The program has two distinct components: (1) magicians using interactive, close-up magic and humor as a technique to promote socialization, enhance self-esteem, and increase opportunities for choice and control, and (2) magicians providing the personal instruction and materials that enable chronically ill and long-term patients to learn and perform magic to promote a sense of empowerment and feelings of mastery. Positive responses from patients, families, and staff to the program at one hospital led to the creation of Open Heart Magic, a non-profit children's foundation that maintains and staffs bedside, interactive therapeutic magic programs in five hospitals in the Chicago metropolitan area.

  12. Wide Angle Movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief movie illustrates the passage of the Moon through the Saturn-bound Cassini spacecraft's wide-angle camera field of view as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. From beginning to end of the sequence, 25 wide-angle images (with a spatial image scale of about 14 miles per pixel (about 23 kilometers)were taken over the course of 7 and 1/2 minutes through a series of narrow and broadband spectral filters and polarizers, ranging from the violet to the near-infrared regions of the spectrum, to calibrate the spectral response of the wide-angle camera. The exposure times range from 5 milliseconds to 1.5 seconds. Two of the exposures were smeared and have been discarded and replaced with nearby images to make a smooth movie sequence. All images were scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is approximately the same in every image. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS)at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  13. Laser angle measurement system

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.; Wilbert, R. E.

    1980-01-01

    The design and fabrication of a laser angle measurement system is described. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the mode. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. Optical and electrical schematics, system maintenance and operation procedures are included, and the results of a demonstration test are given.

  14. Signal loss in 1D magic-angle spinning exchange NMR (CODEX): radio-frequency limitations and intermediate motions.

    PubMed

    Hackel, Christiane; Franz, Cornelius; Achilles, Anja; Saalwächter, Kay; Reichert, Detlef

    2009-08-28

    The popular 1D MAS exchange experiment CODEX suffers limitations due to signal loss during the finite recoupling periods, during which the magnetization evolves in the transverse plane. Here, we address the origins and possible improvements of this problem, aimed at (i) an optimization of the signal-to-noise ratio in the experiments, as well as harnessing intermediate-motion induced signal loss for obtaining approximate information on (ii) correlation times and (iii) potential distributions, where the latter are often found in polymeric systems. First, we show that the intensity of the signal is sensitive to the radiofrequency (rf) parameters of the carbon recoupling and proton decoupling, and care must be taken to gain optimal signal intensity. Optimum conditions are found for recoupling pulses being as short as possible for large chemical shift anisotropy (CSA) values, and approaching a ratio of 3 between the nutation frequencies for protonated carbons, calling for an individual adjustment in each case. Second, we demonstrate that the effect of intermediate motions can be studied semi-quantitatively by combining CODEX data with its constant-time modification CONTRA, which allows for a tuning of the signal loss due to intermediate motions. Third, for the case of samples featuring a distribution of correlation times, we propose a procedure to obtain an estimate of the proportion of molecular segments in the sample for which the CODEX data are representative, i.e., which share of segments moves truly in the slow-motion regime. The procedure involves the combination of CODEX data with a cross-polarisation (CP) reference experiment for an estimate of the full sample magnetization; it is demonstrated on the example of semi-crystalline poly(ethylene oxide).

  15. Pulse-assisted homonuclear dipolar recoupling of half-integer quadrupolar spins in magic-angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Edén, Mattias; Annersten, Hans; Zazzi, Åsa

    2005-07-01

    We demonstrate numerically and experimentally that zero-quantum homonuclear dipolar recoupling techniques employing rotor-synchronized 180° pulses, previously introduced for spin-1/2 applications, are useful also for magnetization transfers between half-integer quadrupolar nuclei in rotating solids. The recoupling sequences are incorporated as mixing periods in two-dimensional experimental protocols, that correlate either single-quantum coherences of coupled spins, or triple-quantum with single-quantum coherences for improving spectral resolution. We present 23Na and 27Al NMR experiments on powders of sodium sulphite [Na 2SO 3], YAG [Y 3Al 5O 12] and a synthetic chlorite mineral [Mg 4.5Al 3Si 2.5O 10(OH) 8].

  16. Fundamental Science Tools for Geologic Carbon Sequestration and Mineral Carbonation Chemistry: In Situ Magic Angle Spinning (MAS) Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Hoyt, D. W.; Turcu, R. V.; Sears, J. A.; Rosso, K. M.; Burton, S. D.; Kwak, J.; Felmy, A. R.; Hu, J.

    2010-12-01

    GCS is one of the most promising ways of mitigating atmospheric greenhouse gases. Mineral carbonation reactions are potentially important to the long-term sealing effectiveness of caprock but remain poorly predictable, particularly reactions occurring in low-water supercritical CO2(scCO2)-dominated environments where the chemistry has not been adequately explored. In situ probes that provide molecular-level information is desirable for investigating mechanisms and rates of GCS mineral carbonation reactions. 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, or 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 rotor. In this work, we report development of a unique high pressure MAS NMR capability, and its application to mineral carbonation chemistry in scCO2 under geologically relevant temperatures and pressures. Our high pressure MAS rotor has successfully maintained scCO2 conditions with minimal leakage over a period of 72 hours. Mineral carbonation reactions of a model magnesium silicate (forsterite) reacted with 96 bars scCO2 containing varying amounts of H2O (both below and above saturation of the scCO2) were investigated at 50○C. Figure 1 shows typical in situ 13C MAS NMR spectra demonstrating that the peaks corresponding to the reactants, intermediates, and the magnesium carbonation products are all observed in a single spectrum. For example, the scCO2 peak is located at 126.1 ppm. Reaction intermediates include the aqueous species HCO3-(160 ppm), partially hydrated/hydroxylated magnesium carbonates(166-168 ppm), and can easily be distinguished from final product magnesite(170 ppm). The new capability and this model mineral carbonation process will be overviewed in light of fundamental geochemical science needs for GCS implementation. Figure 1. 13C MAS NMR spectra of forsterite exposed to scCO2 300% saturated with water at 96 bars and 50°C. MAS rate=2.1 kHz.

  17. Time displacement rotational echo double resonance: Heteronuclear dipolar recoupling with suppression of homonuclear interaction under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Tsai, Tim W. T.; Mou, Yun; Chan, Jerry C. C.

    2012-01-01

    We have developed a novel variant of REDOR which is applicable to multiple-spin systems without proton decoupling. The pulse sequence is constructed based on a systematic time displacement of the pi pulses of the conventional REDOR sequence. This so-called time displacement REDOR (td-REDOR) is insensitive to the effect of homonuclear dipole-dipole interaction when the higher order effects are negligible. The validity of td-REDOR has been verified experimentally by the P-31{C-13} measurements on glyphosate at a spinning frequency of 25 kHz. The experimental dephasing curve is in favorable agreement with the simulation data without considering the homonuclear dipole-dipole interactions.

  18. Variable angle correlation spectroscopy

    SciTech Connect

    Lee, Young Kyo

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

  19. A Note on Angle Construction

    ERIC Educational Resources Information Center

    Francis, Richard L.

    1978-01-01

    The author investigates the construction of angles (using Euclidean tools) through a numerical approach. He calls attention to the surprising impossibility of constructing the conventional units of angle measure--the degree, minute, second, radian, and mil. (MN)

  20. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    SciTech Connect

    Mueller, K.T. California Univ., Berkeley, CA . Dept. of Chemistry)

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.