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Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents (OSTI)

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

1986-01-01T23:59:59.000Z

2

Edward Purcell and Nuclear Magnetic Resonance (NMR)  

Office of Scientific and Technical Information (OSTI)

a large audience of physicists. Purcell's stunning introductory textbook on Electricity and Magnetism has educated and inspired a generation of physicists, who refer to it...

3

I. I. Rabi, Nuclear Magnetic Resonance (NMR), and Radar  

NLE Websites -- All DOE Office Websites (Extended Search)

I. I. Rabi, Nuclear Magnetic Resonance (NMR), and Radar I. I. Rabi, Nuclear Magnetic Resonance (NMR), and Radar Resources with Additional Information I.I. Rabi Courtesy of Brookhaven National Laboratory 'Isidor Isaac Rabi [was] a pioneer in exploring the atom and a major force in 20th-century physics.'1 He won the 1944 Nobel Prize in Physics "for his resonance method for recording the magnetic properties of atomic nuclei". 'His work in turn made possible the precise measurements necessary for the development of the atomic clock, the laser and the diagnostic scanning of the human body by nuclear magnetic resonance. '1 In 1929, Dr. Rabi started working at Columbia University, where he conducted molecular beam research. However, 'Rabi did not relish the task of coaxing from a departmental chairman or dean even the relatively modest funds needed for molecular beam equipment.'2 When Harold Urey, a professor at Columbia, won the 1934 Nobel Prize in Chemistry for his discovery of deuterium, he also received 'an award from the Carnegie Foundation of about $8,000 to assist his research. Urey had no immediate need of this munificence'2 and gave part of it to Dr. Rabi 'so he could continue his research. By 1937 that research had led him to the technique for which he won his Nobel Prize. '1

4

Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents (OSTI)

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

1984-01-01T23:59:59.000Z

5

Two Phase Flow Measurements by Nuclear Magnetic Resonance (NMR)  

SciTech Connect

In concentrated suspensions, there is a tendency for the solid phase to migrate from regions of high shear rate to regions of low shear (Leighton & Acrivos, 1987). In the early years that our effort was funded by the DOE Division of Basic Energy Science, quantitative measurement of this process in neutrally buoyant suspensions was a major focus (Abbott, et al., 1991; Altobelli, et al., 1991). Much of this work was used to improve multi-phase numerical models at Sandia National Laboratories. Later, our collaborators at Sandia and the University of New Mexico incorporated body forces into their numerical models of suspension flow (Rao, Mondy, Sun, et al., 2002). We developed experiments that allow us to study flows driven by buoyancy, to characterize these flows in well-known and useful engineering terms (Altobelli and Mondy, 2002) and to begin to explore the less well-understood area of flows with multiple solid phases (Beyea, Altobelli, et al., 2003). We also studied flows that combine the effects of shear and buoyancy, and flows of suspensions made from non-Newtonian liquids (Rao, Mondy, Baer, et al, 2002). We were able to demonstrate the usefulness of proton NMR imaging of liquid phase concentration and velocity and produced quantitative data not obtainable by other methods. Fluids flowing through porous solids are important in geophysics and in chemical processing. NMR techniques have been widely used to study liquid flow in porous media. We pioneered the extension of these studies to gas flows (Koptyug, et al, 2000, 2000, 2001, 2002). This extension allows us to investigate a wider range of Peclet numbers, and to gather data on problems of interest in catalysis. We devised two kinds of NMR experiments for three-phase systems. Both experiments employ two NMR visible phases and one phase that gives no NMR signal. The earlier method depends on the two visible phases differing in a NMR relaxation property. The second method (Beyea, Altobelli, et al., 2003) uses two different nuclei, protons and 19F. It also uses two different types of NMR image formation, a conventional spin-echo and a single-point method. The single-point method is notable for being useful for imaging materials which are much more rigid than can usually be studied by NMR imaging. We use it to image “low density” polyethylene (LDPE) plastic in this application. We have reduced the imaging time for this three-phase imaging method to less than 10 s per pair of profiles by using new hardware. Directly measuring the solid LDPE signal was a novel feature for multi-phase flow studies. We also used thermally polarized gas NMR (as opposed to hyper-polarized gas) which produces low signal to noise ratios because gas densities are on the order of 1000 times smaller than liquid densities. However since we used multi-atom molecules that have short T1's and operated at elevated pressures we could overcome some of the losses. Thermally polarized gases have advantages over hyperpolarized gases in the ease of preparation, and in maintaining a well-defined polarization. In these studies (Codd and Altobelli, 2003), we used stimulated echo sequences to successfully obtain propagators of gas in bead packs out to observation times of 300 ms. Zarraga, et al. (2000) used laser-sheet profilometry to investigate normal stress differences in concentrated suspensions. Recently we developed an NMR imaging analog for comparison with numerical work that is being performed by Rekha Rao at Sandia National Laboratories (Rao, Mondy, Sun, et al, 2002). A neutrally buoyant suspension of 100 mm PMMA spheres in a Newtonian liquid was sheared in a vertical Couette apparatus inside the magnet. The outer cylinder rotates and the inner cylinder is fixed. At these low rotation rates, the free-surface of the Newtonian liquid shows no measurable deformation, but the suspension clearly shows its non-Newtonian character.

Altobelli, Stephen A; Fukushima, Eiichi

2006-08-14T23:59:59.000Z

6

Methyl quantum tunneling and nitrogen-14 NQR NMR studies using a SQUID magnetic resonance spectrometer  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) techniques have been very successful in obtaining molecular conformation and dynamics information. Unfortunately, standard NMR and NQR spectrometers are unable to adequately detect resonances below a few megahertz due to the frequency dependent sensitivity of their Faraday coil detectors. For this reason a new spectrometer with a dc SQUID (Superconducting Quantum Interference Device) detector, which has no such frequency dependence, has been developed. Previously, this spectrometer was used to observe {sup 11}B and {sup 27}Al NQR resonances. The scope of this study was increased to include {sup 23}Na, {sup 51}V, and {sup 55}Mn NQR transitions. Also, a technique was presented to observe {sup 14}N NQR resonances through cross relaxation of the nitrogen polarization to adjacent proton spins. When the proton Zeeman splitting matches one nitrogen quadrupoler transition the remaining two {sup 14}N transitions can be detected by sweeping a saturating rf field through resonance. Additionally, simultaneous excitation of two nitrogen resonances provides signal enhancement which helps to connect transitions from the same site. In this way, nitrogen-14 resonances were observed in several amino acids and polypeptides. This spectrometer has also been useful in the direct detection of methyl quantum tunneling splittings at 4.2 K. Tunneling, frequencies of a homologous series of carboxylic acids were measured and for solids with equivalent crystal structures, an exponential correlation between the tunneling frequency and the enthalpy of fusion is observed. This correlation provides information about the contribution of intermolecular interactions to the energy barrier for methyl rotation.

Black, B.E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1993-07-01T23:59:59.000Z

7

Evaluation Of Automated Low-Field Nuclear Magnetic Resonance (NMR) Relaxometry For Analysis Of Silicone Polymers  

Science Conference Proceedings (OSTI)

Screening studies and Design of Experiments (DoE) were performed to evaluate measurement variation of a new, non-destructive Nuclear Magnetic Resonance (NMR) test system designed to assess age-induced degradation of Outer Pressure Pads (OPP). The test method and results from 54,275 measurements are described. A reduction in measurement error was obtained after metal support struts were replaced with plastic support struts adjacent to the front position of the test chamber. However, remaining interference and a lack of detecting any age-related degradation prevent the use of the NMR system as a non-destructive surveillance test for OPPs. A cursory evaluation of the system with cellular silicone samples obtained more uniform results with increased error as measurements approached the sample’s edge.

M. H. Wilson

2009-10-02T23:59:59.000Z

8

Magnetic Resonance Facility (Fact Sheet)  

DOE Green Energy (OSTI)

This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

Not Available

2012-03-01T23:59:59.000Z

9

Nuclear Magnetic Resonance Laboratory  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance Laboratory. ... A 600 MHz Nuclear Magnetic Resonance Spectrometer. Analytical Data Compilation Reference Materials. ...

2012-10-01T23:59:59.000Z

10

Toxicometabolomics approach to urinary biomarkers for mercuric chloride (HgCl{sub 2})-induced nephrotoxicity using proton nuclear magnetic resonance ({sup 1}H NMR) in rats  

Science Conference Proceedings (OSTI)

The primary objective of this study was to determine and characterize surrogate biomarkers that can predict nephrotoxicity induced by mercuric chloride (HgCl{sub 2}) using urinary proton nuclear magnetic resonance ({sup 1}H NMR) spectral data. A procedure for {sup 1}H NMR urinalysis using pattern recognition was proposed to evaluate nephrotoxicity induced by HgCl{sub 2} in Sprague-Dawley rats. HgCl{sub 2} at 0.1 or 0.75 mg/kg was administered intraperitoneally (i.p.), and urine was collected every 24 h for 6 days. Animals (n = 6 per group) were sacrificed 3 or 6 days post-dosing in order to perform clinical blood chemistry tests and histopathologic examinations. Urinary {sup 1}H NMR spectroscopy revealed apparent differential clustering between the control and HgCl{sub 2} treatment groups as evidenced by principal component analysis (PCA) and partial least square (PLS)-discriminant analysis (DA). Time- and dose-dependent separation of HgCl{sub 2}-treated animals from controls was observed by PCA of {sup 1}H NMR spectral data. In HgCl{sub 2}-treated rats, the concentrations of endogenous urinary metabolites of glucose, acetate, alanine, lactate, succinate, and ethanol were significantly increased, whereas the concentrations of 2-oxoglutarate, allantoin, citrate, formate, taurine, and hippurate were significantly decreased. These endogenous metabolites were selected as putative biomarkers for HgCl{sub 2}-induced nephrotoxicity. A dose response was observed in concentrations of lactate, acetate, succinate, and ethanol, where severe disruption of the concentrations of 2-oxoglutarate, citrate, formate, glucose, and taurine was observed at the higher dose (0.75 mg/kg) of HgCl{sub 2}. Correlation of urinary {sup 1}H NMR PLS-DA data with renal histopathologic changes suggests that {sup 1}H NMR urinalysis can be used to predict or screen for HgCl{sub 2}-induced nephrotoxicity{sub .}

Kim, Kyu-Bong, E-mail: kyubong@inje.ac.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Department of Pharmaceutical Engineering, Inje University, Obang-dong, Gimhae, Gyungnam 621-749 (Korea, Republic of); Um, So Young, E-mail: syum@kfda.go.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Chung, Myeon Woo, E-mail: mwchung@kfda.go.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Jung, Seung Chul, E-mail: ipipe4@nate.co [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Oh, Ji Seon, E-mail: aquajs24@nate.co [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Kim, Seon Hwa, E-mail: hwa2003@kfda.go.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Na, Han Sung, E-mail: nhk1515@korea.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of); Lee, Byung Mu, E-mail: bmlee@skku.ed [College of Pharmacy, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Choi, Ki Hwan, E-mail: hyokwa11@korea.k [Korea Food and Drug Administration, 5-Nokbun-dong, Eunpyung-gu, Seoul 122-704 (Korea, Republic of)

2010-12-01T23:59:59.000Z

11

2-3 High Field Magnetic Resonance Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

HFMRF Overview HFMRF Overview High Field Magnetic Resonance Facility A significant portion of research conducted in the High Field Magnetic Resonance Facility (HFMRF) focuses on developing a fundamental, molecular-level understanding of biochemi- cal and biological systems and their response to environmental effects. A secondary focus is in materials science and catalysis and the chemical mechanisms and processes that operate in these areas. Resident and matrixed research staff within this facility offer expertise in the areas of structural biology, solid-state materials characterization, and magnetic resonance imaging (MRI) techniques. Instrumentation & Capabilities NMR * 900-MHz NMR (operational in 2004) * 800-MHz NMR * 750-MHz NMR * 600-MHz NMR (2 systems)

12

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

This invention relates to the field of nuclear magnetic resonance imaging and nuclear magnetic resonance spectroscopy, also known simply as magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). MRI and MRS are particularly useful in medical research and diagnosis. MRI may be used in addition to x-ray imaging. This invention concerns a family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 2 figs.

Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

1989-01-24T23:59:59.000Z

13

An ant colony optimization approach for solving the nuclear magnetic resonance structure based assignment problem  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance (NMR) Spectroscopy is an important technique that allows determining protein structure in solution. An important problem in protein structure determination using NMR spectroscopy is the mapping of peaks to corresponding amino ... Keywords: ant colony optimization, backbone resonance assignments, n15-labeled, nmr

Jeyhun Aslanov; Bülent Çatay; Mehmet Serkan Apaydin

2013-07-01T23:59:59.000Z

14

Microfluidic gas flow profiling using remote detection NMR  

E-Print Network (OSTI)

using remote detection NMR Christian Hilty* † , Eringas mixture containing 0.3% NMR active 129 Xe (1% Xe atNuclear Magnetic Resonance (NMR) to obtain spatially and

Hilty, Christian; McDonnell, Erin; Granwehr, Josef; Pierce, Kimberly; Han, Song-I Han; Pines, Alexander

2005-01-01T23:59:59.000Z

15

GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS  

Science Conference Proceedings (OSTI)

Proton nuclear magnetic resonance (NMR) is used in the Earth Sciences as a means of obtaining information about the molecular-scale environment of fluids in porous geological materials. Laboratory experiments were conducted to advance our fundamental understanding of the link between the NMR response and the geochemical properties of geological materials. In the first part of this research project, we studied the impact of both the surface-area-to-volume ratio (S/V) of the pore space and the surface relaxivity on the NMR response of fluids in sand-clay mixtures. This study highlighted the way in which these two parameters control our ability to use NMR measurements to detect and quantify fluid saturation in multiphase saturated systems. The second part of the project was designed to explore the way in which the mineralogic form of iron, as opposed to simply the concentration of iron, affects the surface relaxation rate and, more generally, the NMR response of porous materials. We found that the magnitude of the surface relaxation rate was different for the various iron-oxide minerals because of changes in both the surface-area-to-volume ratio of the pore space, and the surface relaxivity. Of particular significance from this study was the finding of an anomalously large surface relaxivity of magnetite compared to that of the other iron minerals. Differences in the NMR response of iron minerals were seen in column experiments during the reaction of ferrihydrite-coated quartz sand with aqueous Fe(II) solutions to form goethite, lepidocrocite and magnetite; indicating the potential use of NMR as a means of monitoring geochemical reactions. The final part of the research project investigated the impact of heterogeneity, at the pore-scale, on the NMR response. This work highlighted the way in which the geochemistry, by controlling the surface relaxivity, has a significant impact on the link between NMR data and the microgeometry of the pore space.

Rosemary Knight

2008-08-25T23:59:59.000Z

16

Nuclear magnetic resonance offers new insights into Pu 239  

NLE Websites -- All DOE Office Websites (Extended Search)

Nuclear magnetic resonance offers new insights into Pu 239 Nuclear magnetic resonance offers new insights into Pu 239 Nuclear magnetic resonance offers new insights into Pu 239 Fingerprint of element found by LANL/Japanese team. May 29, 2012 How would the detonation of a nuclear energy source afffect an incoming asteroid? Georgios Koutroulakis and H. Yasuoka in the condensed-matter NMR lab at Los Alamos National Laboratory after having observed the magnetic resonance signal of Pu 239 for the first time. Get Expertise Scientist Eric Bauer Condensed Matter & Magnet Science Email Professor Hiroshi Yasuoka Japan Atomic Energy Agency "This discovery of the plutonium 239 magnetic resonance promises to revolutionize our understanding of plutonium solid state physics, chemistry, biology and materials science."

17

Low field magnetic resonance imaging  

DOE Patents (OSTI)

A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

Pines, Alexander (Berkeley, CA); Sakellariou, Dimitrios (Billancourt, FR); Meriles, Carlos A. (Fort Lee, NJ); Trabesinger, Andreas H. (London, GB)

2010-07-13T23:59:59.000Z

18

High Field Magnetic Resonance Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

HFMRF Overview HFMRF Overview Section 2-3-1 High Field Magnetic Resonance Facility The High Field Magnetic Resonance Facility (HFMRF) focuses a significant portion of its research on developing a fundamental, molecular-level understanding of biochemical and biological systems and their response to environmental effects. A secondary focus is materials science, including catalysis and chemical mechanisms and processes. Staff and science consultants within this facility offer expertise in the areas of structural biology, solid-state materials characterization, and magnetic resonance imaging (MRI) techniques. Research activities in the HFMRF include: * structure determination of large molecular assemblies such as protein-DNA (normal and damaged DNA) and protein-RNA complexes

19

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

Smith, Paul H. (Los Alamos, NM); Brainard, James R. (Los Alamos, NM); Jarvinen, Gordon D. (Los Alamos, NM); Ryan, Robert R. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

20

Nuclear magnetic resonance contrast agents  

DOE Patents (OSTI)

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

1997-12-30T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

NMR analogues of the quantum Zeno effect  

E-Print Network (OSTI)

We describe Nuclear Magnetic Resonance (NMR) demonstrations of the quantum Zeno effect, and discuss briefly how these are related to similar phenomena in more conventional NMR experiments.

Li Xiao; Jonathan A. Jones

2005-06-28T23:59:59.000Z

22

Nuclear Magnetic Resonance Implementation of a Quantum Clock Synchronization Algorithm  

E-Print Network (OSTI)

The quantum clock synchronization algorithm proposed by I. L. Chuang (Phys. Rev. Lett, 85, 2006(2000)) has been implemented in a three qubit nuclear magnetic resonance quantum system. The effective-pure state is prepared by the spatial averaging approach. The time difference between two separated clocks can be determined by reading out directly through the NMR spectra.

Jingfu Zhang; Guilu Long; Zhiwei Deng; Wenzhang Liu; Zhiheng Lu

2004-06-27T23:59:59.000Z

23

Suspension stirrer for NMR spectroscopy  

DOE Patents (OSTI)

This invention relates to nuclear magnetic resonance (NMR) spectroscopy and, more particularly, to the application of NMR spectroscopy to cell culture samples. A perfusion treatment system maintains microenvironmental conditions about cell spheroids during nuclear magnetic resonance (NMR) examination. A non-magnetic stirring assembly is inserted within a conventional NMR tube to continuously and uniformly supply a perfusate adjacent the spheroids. The perfusate is circulated during the spheroid stirring to maintain known perfusion conditions and eliminate artifacts from the NMR data. 4 figs.

Freyer, J.P; Coulter, J.R.

1990-12-02T23:59:59.000Z

24

Ex-Situ High Resolution NMR and MRI - Lawrence Berkeley ...  

Alexander Pines and colleagues have opened the way to high resolution ex situ nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

25

Magnetic resonance as a channel of directed transmission of electromagnetic energy in animate nature  

E-Print Network (OSTI)

The phenomenon of magnetic resonance (either NMR or ESR) is a responce of atomic (molecular) system to the external electromagnetic effect. Electrons and nuclei, which possess magnetic moment, are the "magnetic antennas" in the biosystem "human being". They are able to receive (radiate) electromagnetic energy selectively in coordinates $H$ (magnetic field), $\

E. Ya. Fursa

2002-12-09T23:59:59.000Z

26

'NMR on a Chip' Features NIST Magnetic Mini-Sensor  

Science Conference Proceedings (OSTI)

... of Standards and Technology (NIST) can detect nuclear magnetic resonance ... NIST Mini-Sensor May Have Biomedical and Security Applications”). ...

2011-07-19T23:59:59.000Z

27

An Improved Nuclear Vector Replacement Algorithm for Nuclear Magnetic Resonance Assignment  

E-Print Network (OSTI)

An Improved Nuclear Vector Replacement Algorithm for Nuclear Magnetic Resonance Assignment to the Nuclear Vector Replacement (NVR) algorithm [24] for high-throughput Nuclear Magnetic Resonance (NMR% accu- racy) on the same test suite examined in [24], and runs in O(n5/2 log (cn)) time where n

28

Magnetic resonance apparatus  

SciTech Connect

Means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial component of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.

Jackson, Jasper A. (Los Alamos, NM); Cooper, Richard K. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

29

Magnetic resonance apparatus  

DOE Patents (OSTI)

The patent consists of means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial correspondent of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.

Jackson, J.A.; Cooper, R.K.

1980-10-10T23:59:59.000Z

30

Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials  

DOE Patents (OSTI)

An ultra-low magnetic field NMR system can non-invasively examine containers. Database matching techniques can then identify hazardous materials within the containers. Ultra-low field NMR systems are ideal for this purpose because they do not require large powerful magnets and because they can examine materials enclosed in conductive shells such as lead shells. The NMR examination technique can be combined with ultra-low field NMR imaging, where an NMR image is obtained and analyzed to identify target volumes. Spatial sensitivity encoding can also be used to identify target volumes. After the target volumes are identified the NMR measurement technique can be used to identify their contents.

Kraus, Robert H. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Volegov, Petr L. (Los Alamos, NM)

2010-03-30T23:59:59.000Z

31

NMR Characterization of Partially Deuterated ?-Glycine  

E-Print Network (OSTI)

1. The wide-line 2 H NMR spectrum (A) of the deuterium-NMR Characterization of Partially Deuterated -Glycine R. E.magnetic resonance (NMR) spectroscopy is an established

Taylor, Robert E; Chim, Nicholas; Dybowski, Cecil

2006-01-01T23:59:59.000Z

32

Magnetic Resonance Connectome Automated Pipeline  

E-Print Network (OSTI)

This manuscript presents a novel, tightly integrated pipeline for estimating a connectome, which is a comprehensive description of the neural circuits in the brain. The pipeline utilizes magnetic resonance imaging (MRI) data to produce a high-level estimate of the structural connectivity in the human brain. The Magnetic Resonance Connectome Automated Pipeline (MRCAP) is efficient and its modular construction allows researchers to modify algorithms to meet their specific requirements. The pipeline has been validated and over 200 connectomes have been processed and analyzed to date. This tool enables the prediction and assessment of various cognitive covariates, and this research is applicable to a variety of domains and applications. MRCAP will enable MR connectomes to be rapidly generated to ultimately help spur discoveries about the structure and function of the human brain.

Gray, William R; Vogelstein, Joshua T; Landman, Bennett A; Prince, Jerry L; Vogelstein, R Jacob

2011-01-01T23:59:59.000Z

33

Nuclear magnetic resonance studies of macroscopic morphology and dynamics  

Science Conference Proceedings (OSTI)

Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample`s density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques.

Barrall, G.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Materials Science Div.

1995-09-01T23:59:59.000Z

34

NMR system and method having a permanent magnet providing a rotating magnetic field  

DOE Patents (OSTI)

Disclosed herein are systems and methods for generating a rotating magnetic field. The rotating magnetic field can be used to obtain rotating-field NMR spectra, such as magic angle spinning spectra, without having to physically rotate the sample. This result allows magic angle spinning NMR to be conducted on biological samples such as live animals, including humans.

Schlueter, Ross D [Berkeley, CA; Budinger, Thomas F [Berkeley, CA

2009-05-19T23:59:59.000Z

35

High-Temperature Superconducting Magnets for NMR and MRI: R&D Activities at the MIT Francis Bitter Magnet Laboratory  

E-Print Network (OSTI)

This paper describes the NMR/MRI magnets that are currently being developed at the MIT Francis Bitter Magnet Laboratory: 1) a 1.3 GHz NMR magnet; 2) a compact NMR magnet assembled from YBCO annuli; and 3) a persistent-mode, ...

Iwasa, Yukikazu

36

C-13 NMR 68 Chem 355 Jasperse C-13 NMR  

E-Print Network (OSTI)

C-13 NMR 68 Chem 355 Jasperse C-13 NMR I. Introduction to Spectroscopy Spectroscopy involves. In organic chemistry, the most important type of spectroscopy is "NMR" ("Nuclear Magnetic Resonance" spectroscopy). NMR spectroscopy is routinely used for chemical analysis, whether to identify the structure

Jasperse, Craig P.

37

Wireless Energy Transfer Using Magnetic Resonance  

Science Conference Proceedings (OSTI)

In 1899, Nikola Tesla, who had devised a type of resonant transformer called the Tesla coil, achieved a major breakthrough in his work by transmitting 100 million volts of electric power wirelessly over a distance of 26 miles to light up a bank of 200 ... Keywords: wireless energy transfer, near field, evanescent wave, magnetic resonance, self-resonance

Rohan Bhutkar; Sahil Sapre

2009-12-01T23:59:59.000Z

38

Fundamental investigations of supported monometallic and bimetallic catalysts by proton magnetic resonance spectroscopy  

DOE Green Energy (OSTI)

Proton magnetic resonance spectroscopy, or nuclear magnetic resonance (NMR) of hydrogen, has been applied to investigate silica-supported Group VIII monometallic and Group VIII-Group IB bimetallic catalysts and alumina- and silica-supported platinum-rhenium bimetallic catalysts. Two adsorbed states of hydrogen, i.e., irreversible and reversible hydrogen, on the surfaces of monometallic Ru, Pt, and Cu particles and bimetallic Ru-Group Ib, Pt-Group Ib, and Pt-Re particles were observed directly via proton NMR. The same amounts of the irreversible hydrogen adsorbed on pure Ru catalysts were measured by both proton NMR and the volumetric technique. The electronic environments on surfaces of monometallic catalysts are sensitive to changes in metal dispersion, state of adsorbed hydrogen, and residual chlorine. Surface compositions for the Ru--Cu and Pt--Cu bimetallic catalysts were determined by NMR of adsorbed hydrogen. 297 refs., 96 figs., 19 tabs.

Wu, Xi.

1990-09-21T23:59:59.000Z

39

Experimental Test of Complementarity by Nuclear Magnetic Resonance Techniques  

E-Print Network (OSTI)

We have tested complementarity for the ensemble-averaged spin states of nuclei $^{13}$C in the molecule of $^{13}$CHCl$_{3}$ by the use of the spin states of another nuclei $^{1}$H as the path marker. It turns out that the wave-particle duality holds when one merely measures the probability density of quantum states, and that the wave- and particle-like behavior is simultaneously observed with the help of measuring populations and coherence in a single nuclear magnetic resonance(NMR) experiment. Effects of path-marking schemes and causes of the appearance and disappearance of the wave behavior are analysed.

Xiwen Zhu; Ximing Fang; Xinhua Peng; Mang Feng; Kelin Gao; Fei Du

2000-11-22T23:59:59.000Z

40

Plutonium less mysterious with nuclear magnetic resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Plutonium less mysterious with nuclear magnetic resonance Plutonium less mysterious with nuclear magnetic resonance Plutonium less mysterious with nuclear magnetic resonance For more than 50 years, chemists and physicists have been searching for the plutonium-239 magnetic resonance signal. May 21, 2012 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Introduction to NMR Spectroscopy and Physics. C-13 NMR in more detail than "Summary" 83 Chem 355 Jasperse C-13 NMR  

E-Print Network (OSTI)

Introduction to NMR Spectroscopy and Physics. C-13 NMR in more detail than "Summary" 83 Chem 355 Jasperse C-13 NMR I. Introduction to Spectroscopy Spectroscopy involves gaining information from, the most important type of spectroscopy is "NMR" ("Nuclear Magnetic Resonance" spectroscopy). NMR

Jasperse, Craig P.

42

Cranial anatomy and detection of ischemic stroke in the cat by nuclear magnetic resonance imaging  

SciTech Connect

Proton nuclear magnetic resonance (NMR) images of cat heads were obtained using a small, experimental imaging system. As a prelude to the study of experimental ischemic brain infarction, the normal cat head was imaged for identification of anatomical features. Images of one cat which had undergone ligation of the middle cerebral artery three weeks previously showed brain changes associated with chronic ischemic stroke and compared favorably with findings on computed tomography (CT). The NMR images have millimetric spatial resolution. NMR parameters inherent in the tissues provide intensity variations and are sufficiently sensitive to yield contrast resolution surpassing that of CT.

Buonanno, F.S.; Pykett, I.L.; Kistler, J.P.; Vielma, J.; Brady, T.J.; Hinshaw, W.S.; Goldman, M.R.; Newhouse, J.H.; Pohost, G.M.

1982-04-01T23:59:59.000Z

43

A new inversion method for (T2, D) 2D NMR logging and fluid typing  

Science Conference Proceedings (OSTI)

One-dimensional nuclear magnetic resonance (1D NMR) logging technology has some significant limitations in fluid typing. However, not only can two-dimensional nuclear magnetic resonance (2D NMR) provide some accurate porosity parameters, but it can also ... Keywords: Diffusion coefficient (D), Fluid typing, Transverse relaxation time (T2), Two-dimensional NMR (2D NMR) logging

Maojin Tan; Youlong Zou; Cancan Zhou

2013-02-01T23:59:59.000Z

44

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Non-medical Uses of Computed Tomography (CT) Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

45

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance  

Office of Scientific and Technical Information (OSTI)

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

46

Monitoring Temperature Changes in Capillary Electrophoresis with Nanoliter-Volume NMR  

E-Print Network (OSTI)

Monitoring Temperature Changes in Capillary Electrophoresis with Nanoliter-Volume NMR Thermometry 61801 Nanoliter-volume proton nuclear magnetic resonance (NMR) spectroscopy is used to monitor. Additionally, NMR thermometry allows nonequilibrium temperatures in analyte bands to be monitored during

Andrews, Anne M.

47

Advances in NMR Methodology  

E-Print Network (OSTI)

NMR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .of classical diffusion in NMR studies of water in biologicalmicrocoil-based microfluidic NMR probes. Journal of Magnetic

Trease, David Richard

2010-01-01T23:59:59.000Z

48

Distinguishing Carbonate Reservoir Pore Facies with Nuclear Magnetic Resonance Measurements  

Science Conference Proceedings (OSTI)

Characterization of carbonate rocks may involve identifying the important pore types which are present. In the past, this task has required detailed petrographic analysis of many core samples. Here, we describe a method which uses nuclear magnetic resonance (NMR) measurements to reduce the amount of petrographic analysis needed for porosity typing of carbonate reservoir rocks.For a rock sample which has been measured with NMR, our method decomposes the log(T{sub 2}) spectrum into at most three Gaussian-shaped components and gives a set of nine parameters. Two characteristic quantities having geological significance are extracted from the nine parameters. Values of the two quantities are compared with a reference set, established from samples having both NMR and petrographic evaluations of porosity types. We use a Bayesian approach to the classification of the dominant porosity type.Tests of our method on 103 samples show a correct prediction in 60 to 90 percent of the samples. The lower success rate was obtained for samples with five porosity types from three fields; the higher success rate obtained with samples with three porosity types from one well. The use of geologically significant quantities extracted from the decomposition gives comparable success rate to those obtained using a standard, non-geological approach such as canonical variates.

Genty, Coralie [ExxonMobil Production Company (United States); Jensen, Jerry L. [University of Calgary, Department of Chemical and Petroleum Engineering (Canada)], E-mail: jjensen@ucalgary.ca; Ahr, Wayne M. [Texas A and M University, Department of Geology and Geophysics (United States)

2007-03-15T23:59:59.000Z

49

Nuclear magnetic resonance imaging and analysis for determination of porous media properties  

E-Print Network (OSTI)

Advanced nuclear magnetic resonance (NMR) imaging methodologies have been developed to determine porous media properties associated with fluid flow processes. This dissertation presents the development of NMR experimental and analysis methodologies, called NMR probes, particularly for determination of porosity, permeability, and pore-size distributions of porous media while the developed methodologies can be used for other properties. The NMR relaxation distribution can provide various information about porous systems having NMR active nuclei. The determination of the distribution from NMR relaxation data is an ill-posed inverse problem that requires special care, but conventionally the problem has been solved by ad-hoc methods. We have developed a new method based on sound statistical theory that suitably implements smoothness and equality/inequality constraints. This method is used for determination of porosity distributions. A Carr-Purcell-Meiboom-Gill (CPMG) NMR experiment is designed to measure spatially resolved NMR relaxation data. The determined relaxation distribution provides the estimate of intrinsic magnetization which, in turn, is scaled to porosity. A pulsed-field-gradient stimulated-echo (PFGSTE) NMR velocity imaging experiment is designed to measure the superficial average velocity at each volume element. This experiment measures velocity number distributions as opposed to the average phase shift, which is conventionally measured, to suitably quantify the velocities within heterogeneous porous media. The permeability distributions are determined by solving the inverse problem formulated in terms of flow models and the velocity data. We present new experimental designs associated with flow conditions to enhance the accuracy of the estimates. Efforts have been put forth to further improve the accuracy by introducing and evaluating global optimization methods. The NMR relaxation distribution can be scaled to a pore-size distribution once the surface relaxivity is known. We have developed a new method, which avoids limitations on the range of time for which data may be used, to determine surface relaxivity by the PFGSTE NMR diffusion experiment.

Uh, Jinsoo

2005-12-01T23:59:59.000Z

50

NMR in rotating magnetic fields: Magic angle field spinning  

E-Print Network (OSTI)

to High- Resolution ex Situ NMR Spectroscopy”, Science, 293,A. Pines, “High- resolution NMR of biological tissues usingP. Mansfield and P. G. Morris, “NMR Imaging in Biomedicine”,

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

2004-01-01T23:59:59.000Z

51

NMR Quantum Information Processing  

E-Print Network (OSTI)

Nuclear Magnetic Resonance (NMR) has provided a valuable experimental testbed for quantum information processing (QIP). Here, we briefly review the use of nuclear spins as qubits, and discuss the current status of NMR-QIP. Advances in the techniques available for control are described along with the various implementations of quantum algorithms and quantum simulations that have been performed using NMR. The recent application of NMR control techniques to other quantum computing systems are reviewed before concluding with a description of the efforts currently underway to transition to solid state NMR systems that hold promise for scalable architectures.

Chandrasekhar Ramanathan; Nicolas Boulant; Zhiying Chen; David G. Cory; Isaac Chuang; Matthias Steffen

2004-08-26T23:59:59.000Z

52

Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects  

SciTech Connect

Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an encoding module for the recently developed NMR remote detection experiment. The feasibility of using hyperpolarized xenon-129 gas as a sensor is discussed. This work also reports the use of an optical atomic magnetometer to detect the nuclear magnetization of Xe-129 gas, which has potential applicability as a detection module for NMR remote detection experiments.

Urban, Jeffry Todd

2004-12-21T23:59:59.000Z

53

THz Dynamic Nuclear Polarization NMR  

E-Print Network (OSTI)

Dynamic nuclear polarization (DNP) increases the sensitivity of nuclear magnetic resonance (NMR) spectroscopy by using high frequency microwaves to transfer the polarization of the electrons to the nuclear spins. The ...

Nanni, Emilio Alessandro

54

Study of hydrogen in coals, polymers, oxides, and muscle water by nuclear magnetic resonance; extension of solid-state high-resolution techniques. [Hydrogen molybdenum bronze  

DOE Green Energy (OSTI)

Nuclear magnetic resonance (NMR) spectroscopy has been an important analytical and physical research tool for several decades. One area of NMR which has undergone considerable development in recent years is high resolution NMR of solids. In particular, high resolution solid state /sup 13/C NMR spectra exhibiting features similar to those observed in liquids are currently achievable using sophisticated pulse techniques. The work described in this thesis develops analogous methods for high resolution /sup 1/H NMR of rigid solids. Applications include characterization of hydrogen aromaticities in fossil fuels, and studies of hydrogen in oxides and bound water in muscle.

Ryan, L.M.

1981-10-01T23:59:59.000Z

55

Point sensitive NMR imaging system using a magnetic field configuration with a spatial minimum  

DOE Patents (OSTI)

A point-sensitive NMR imaging system (10) in which a main solenoid coil (11) produces a relatively strong and substantially uniform magnetic field and a pair of perturbing coils (PZ1 and PZ2) powered by current in the same direction superimposes a pair of relatively weak perturbing fields on the main field to produce a resultant point of minimum field strength at a desired location in a direction along the Z-axis. Two other pairs of perturbing coils (PX1, PX2; PY1, PY2) superimpose relatively weak field gradients on the main field in directions along the X- and Y-axes to locate the minimum field point at a desired location in a plane normal to the Z-axes. An RF generator (22) irradiates a tissue specimen in the field with radio frequency energy so that desired nuclei in a small volume at the point of minimum field strength will resonate.

Eberhard, Philippe H. (El Cerrito, CA)

1985-01-01T23:59:59.000Z

56

INTRODUCTION PART I 11 Introduction Part I Solid State NMR  

E-Print Network (OSTI)

10 PART I #12;INTRODUCTION ­ PART I 11 Introduction Part I ­ Solid State NMR OVERVIEW Nuclear magnetic resonance (NMR) spectroscopy can provide atomic-resolution structures of biological molecules. The exact resonance frequency depends on the chemical environment of each spins, as a result the NMR

Watts, Anthony

57

Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet.  

E-Print Network (OSTI)

Nuclear Magnetic Resonance: Portable and integrated Lead: P. Poulichet. Permanent members: L. Rousseau, A. Fakri. Associated researchers: C. Delabie, A. Exertier. Portable Nuclear Magnetic Resonance : our work in the field of nuclear magneto resonance is focused on the design and the realization

Baudoin, Geneviève

58

Nuclear magnetic resonance experiments with dc SQUID amplifiers  

Science Conference Proceedings (OSTI)

The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

Heaney, M.B. (California Univ., Berkeley, CA (USA). Dept. of Physics Lawrence Berkeley Lab., CA (USA))

1990-11-01T23:59:59.000Z

59

Magnetic resonance studies on ZnO nanocrystals  

Science Conference Proceedings (OSTI)

ZnO nanocrystals with diameters ranging from 4 to 50 nm were prepared via a wet chemical method and post-growth annealing treatments. The electron paramagnetic resonance (EPR) spectra of the nanocrystals show the resonance of electron centers with g-value ... Keywords: K ? P theory, ZnO nanocrystal, electronic paramagnetic resonance (EPR), magnetic resonance

H. Zhou; A. Hofstaetter; D. M. Hofmann; B. K. Meyer

2003-05-01T23:59:59.000Z

60

Novel nuclear magnetic resonance techniques for studying biological molecules  

E-Print Network (OSTI)

parameters by solid-state nuclear magnetic resonance." J.and R. V. Pound. "Nuclear audiofrequency spectroscopy byresonant heating of the nuclear spin system." Phys. Rev. ,

Laws, David D.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Magnetic moment of Ag-104(m) and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei  

E-Print Network (OSTI)

Nuclear magnetic resonance (NMR/ON) measurements with beta- and gamma-ray detection have been performed on oriented Ag-104(g,m) nuclei with the NICOLE He-3-He-4 dilution refrigerator setup at ISOLDE/CERN. For Ag-104(g) (I-pi = 5(+)) the gamma-NMR/ON resonance signal was found at nu = 266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (< 1 K) is found to be vertical bar B-hf(AgFe)vertical bar = 44.709(35) T. A detailed analysis of other relevant data available in the literature yields three more values for this hyperfine field. Averaging all four values yields a new and precise value for the hyperfine field of Ag in Fe; that is, vertical bar B-hf(AgFe)vertical bar = 44.692(30) T. For Ag-104(m) (I-pi = 2(+)), the anisotropy of the beta particles provided the NMR/ON resonance signal at nu = 627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the magnetic moment mu(Ag-104m) = +3.691(3) mu(N), which is significantly more precise than previous results. The magnetic moments of the even-A Ag102 -110 isotopes are discussed in view of the competition between the (pi g(9/2))(7/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) and the (pi g(9/2))(9/2+)(-3)(nu d(5/2)nu g(7/2))(5/2+) configurations. The magnetic moments of the ground and isomeric states of Ag-104 can be explained by an almost complete mixing of these two configurations.

V. V. Golovko; I. S. Kraev; T. Phalet; B. Delaure; M. Beck; V. Yu. Kozlov; S. Coeck; F. Wauters; P. Herzog; Ch. Tramm; D. Zakoucky; D. Venos; D. Srnka; M. Honusek; U. Koester; N. Severijns

2010-06-30T23:59:59.000Z

62

NMR Characterization  

NLE Websites -- All DOE Office Websites (Extended Search)

NMR NMR Characterization of C3H and HCT Down-Regulated Alfalfa Lignin Yunqiao Pu & Fang Chen & Angela Ziebell & Brian H. Davison & Arthur J. Ragauskas Published online: 20 October 2009 # Springer Science + Business Media, LLC. 2009 Abstract Independent down-regulation of genes encoding p-coumarate 3-hydroxylase (C3H) and hydroxycinnamoyl CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) has been previously shown to reduce the recalcitrance of alfalfa and thereby improve the release of fermentable sugars during enzymatic hydrolysis. In this study, ball-milled lignins were isolated from wild-type control, C3H, and HCT gene down-regulated alfalfa plants. One- and two-dimensional nuclear magnetic resonance (NMR) techniques were utilized to determine structural changes in the ball-milled alfalfa lignins resulting from this genetic engineering.

63

Liquid-State NMR and Scalar Couplings in Microtesla Magnetic Fields  

ference in free energy of solvation between the ... K. S. Richardson, Mechanism and Theory in Organic Chemistry ... We obtained nuclear magnetic resonance ...

64

900-MHz NMR: Accelerating Scientific Discovery  

NLE Websites -- All DOE Office Websites (Extended Search)

00-MHz NMR: Accelerating Scientific 00-MHz NMR: Accelerating Scientific Discovery Scientific Innovation Through Integration 900-MHz NMR: Accelerating Scientific Discovery 900-MHz NMR: Accelerating Scientific Discovery Introduction When the U.S. Department of Energy's (DOE's) Office of Biological and Environmental Research approved the development and purchase of the world's first 900-MHz NMR (nuclear magnetic resonance) spectrometer in 1992, the highest magnetic field available was 750 MHz. DOE's decision and the ultimate success of its 900-MHz NMR spectrometer, which recently saw its five-year anniversary of operation at EMSL, catalyzed the development of a new generation of ultrahigh-field NMR spectrometers worldwide. Building new technology Building the magnet for the 900-MHz NMR spectrometer brought engineering challenges. Can the

65

Squid detected NMR and MRI at ultralow fields  

DOE Patents (OSTI)

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Clarke, John (Berkeley, CA); McDermott, Robert (Louisville, CO); Pines, Alexander (Berkeley, CA); Trabesinger, Andreas Heinz (CH-8006 Zurich, CH)

2007-05-15T23:59:59.000Z

66

Squid detected NMR and MRI at ultralow fields  

DOE Patents (OSTI)

Nuclear magnetic resonance (NMR) signals are detected in microtesla fields. Prepolarization in millitesla fields is followed by detection with an untuned dc superconducting quantum interference device (SQUID) magnetometer. Because the sensitivity of the SQUID is frequency independent, both signal-to-noise ratio (SNR) and spectral resolution are enhanced by detecting the NMR signal in extremely low magnetic fields, where the NMR lines become very narrow even for grossly inhomogeneous measurement fields. MRI in ultralow magnetic field is based on the NMR at ultralow fields. Gradient magnetic fields are applied, and images are constructed from the detected NMR signals.

Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA); McDermott, Robert F. (Monona, WI); Trabesinger, Andreas H. (London, GB)

2008-12-16T23:59:59.000Z

67

A nuclear magnetic resonance probe of group IV clathrates  

E-Print Network (OSTI)

The clathrates feature large cages of silicon, germanium, or tin, with guest atoms in the cage centers. The group IV clathrates are interesting because of their thermoelectric efficiency, and their glasslike thermal conductivity at low temperatures. Clathrates show a variety of properties, and the motion of cage center atoms is not well understood. In Sr8Ga16Ge30, we found that the slow atomic motion in the order 10-5 s is present in this system, which is much slower than what would be expected for standard atomic dynamics. NMR studies of Sr8Ga16Ge30 showed that Knight shift and T1 results are consistent with low density metallic behavior. The lineshapes exhibit changes consistent with motional narrowing at low temperatures, and this indicates unusually slow hopping rates. To further investigate this behavior, we made a series of measurements using the Carr-Purcell-Meiboom-Gill NMR sequence. Fitting the results to a hopping model yielded an activation energy of 4.6 K. We can understand all of our observations in terms of non-resonant atomic tunneling between asymmetric sites within the cages, in the presence of disorder. For Ba8Ga16Ge30, the relaxation behavior (T1) deviates from the Korringa relation, and the Knight shift and linewidth change with temperature. Those results could be explained by carrier freezout, and the development of a dilute set of magnetic moments due to these localized carriers. For Ba8Ga16Ge30 samples made from Ga flux, we observed different T1 and Knight shift behavior as compared to n type material. This is due to the differences in carrier type among these different samples. The p type sample has a smaller Knight shift and a slower relaxation rate than n type samples made with the stoichiometric ratio, which is consistent with a change in orbital symmetry between the conduction and valence bands. WDS study for Ba8Al10Ge36 showed the existence of vacancies in the Al-deficient samples, which results in some degree of ordering of Al occupation on the framework sites. In Al NMR measurements on Ba8AlxGe40-x with x = 12 to 16, we found that T1 of all Al samples follows the Korringa relation. The broadening of the single NMR central peak of Ba8Al16Ge30 is due to the inhomogeneous Knight shifts for occupation of different framework sites. For Ba8Al12Ge34 and Ba8Al13Ge33, we observed two peaks, and NMR results show that they are from distinct Al sites, while for each peak, the inhomogeneous broadening is much smaller. The difference in lineshapes we attributed to the existence of vacancies which we detected in the Al-deficient materials, and we assign one of the two Al peaks to Al adjacent to a vacancy.

Gou, Weiping

2008-08-01T23:59:59.000Z

68

SQUID-Detected NMR and MRI at Ultralow Magnetic Fields  

By combining the use of supersensitive magnetic field detecting Superconducting QUantum Interference Devices (SQUIDS) with ...

69

Direct imaging of neural currents using ultra-low field magnetic resonance techniques  

DOE Patents (OSTI)

Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

Volegov, Petr L. (Los Alamos, NM); Matlashov, Andrei N. (Los Alamos, NM); Mosher, John C. (Los Alamos, NM); Espy, Michelle A. (Los Alamos, NM); Kraus, Jr., Robert H. (Los Alamos, NM)

2009-08-11T23:59:59.000Z

70

NMR Detection with Multiple Solenoidal Microcoils for Continuous-Flow Capillary Electrophoresis  

E-Print Network (OSTI)

NMR Detection with Multiple Solenoidal Microcoils for Continuous-Flow Capillary Electrophoresis of Illinois, Urbana, Illinois 61801 Nuclear magnetic resonance (NMR) spectroscopy repre- sents a promising on-line detector for capillary electro- phoresis (CE). The inherent poor sensitivity of NMR mandates the use of NMR

Andrews, Anne M.

71

The new -NMR facility at TRIUMF and applications in semiconductors  

E-Print Network (OSTI)

The new -NMR facility at TRIUMF and applications in semiconductors K.H. Chow a, Z. Salman b R facililty for conducting beta-detected nuclear magnetic resonance (-NMR) investigations of condensed matter facility are described, and some preliminary results on 8Li+ in GaAs are presented. Key words: -NMR

Baartman, Richard Abram

72

Speedup of quantum state transfer by three- qubit interactions: Implementation by nuclear magnetic resonance  

E-Print Network (OSTI)

Universal quantum information processing requires single-qubit rotations and two-qubit interactions as minimal resources. A possible step beyond this minimal scheme is the use of three-qubit interactions. We consider such three-qubit interactions and show how they can reduce the time required for a quantum state transfer in an XY spin chain. For the experimental implementation, we use liquid-state nuclear magnetic resonance (NMR), where three-qubit interactions can be implemented by sequences of radio-frequency pulses.

Jingfu Zhang; Xinhua Peng; Dieter Suter

2005-12-25T23:59:59.000Z

73

Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report  

SciTech Connect

The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

1994-04-01T23:59:59.000Z

74

Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials  

DOE Patents (OSTI)

Method comprising obtaining an NMR measurement from a sample wherein an ultra-low field NMR system probes the sample and produces the NMR measurement and wherein a sampling temperature, prepolarizing field, and measurement field are known; detecting the NMR measurement by means of inductive coils; analyzing the NMR measurement to obtain at least one measurement feature wherein the measurement feature comprises T1, T2, T1.rho., or the frequency dependence thereof; and, searching for the at least one measurement feature within a database comprising NMR reference data for at least one material to determine if the sample comprises a material of interest.

Matlashov, Andrei Nikolaevich; Urbaitis, Algis V.; Savukov, Igor Mykhaylovich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry

2013-03-05T23:59:59.000Z

75

The Determination of Deuterium and Tritium in Effluent Wastewater by Pulsed Nuclear Magnetic Resonance Spectroscopy  

SciTech Connect

A pulsed nuclear magnetic resonance (NMR) procedure was developed for the quantitative determination of deuterium and tritium in radioactive, effluent, wastewater to aid in the design of an efficient combined electrolytic/catalytic exchange system for the recovery of these hydrogen isotopes. The deuterium and tritium NMR signals were observed at 9.210 and 45.7 MHz, respectively. Ten different effluent water samples were analyzed for deuterium and tritium to establish base-line data for the preparation of standard reference samples. The hydrogen isotope concentrations ranged from 0.11 to 2.40 g deuterium and from 2.0 to 21.0 mg tritium per liter of processed sample. The standard deviation of the hydrogen isotope determinations is +- 0.017 g deuterium and +- 0.06 mg tritium per liter of processed effluent water. In the future, the effectiveness of specially prepared and analyzed (calorimetry) effluent samples as tritium standards will be investigated.

Attalla, A.; Birkbeck, J. C.

1985-04-01T23:59:59.000Z

76

Imaging agents for in vivo magnetic resonance and scintigraphic imaging  

DOE Patents (OSTI)

Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided.

Engelstad, Barry L. (Orinda, CA); Raymond, Kenneth N. (Berkeley, CA); Huberty, John P. (Corte Madera, CA); White, David L. (Oakland, CA)

1991-01-01T23:59:59.000Z

77

Target-specific contrast agents for magnetic resonance microscopy  

E-Print Network (OSTI)

High-resolution ex vivo magnetic resonance microscopy (MRM) can be used to delineate prominent architectonic features in the human brain, but increased contrast is required to visualize more subtle distinctions. The goal ...

Hepler Blackwell, Megan Leticia

2007-01-01T23:59:59.000Z

78

Imaging agents for in vivo magnetic resonance and scintigraphic imaging  

DOE Patents (OSTI)

Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided. No Drawings

Engelstad, B.L.; Raymond, K.N.; Huberty, J.P.; White, D.L.

1991-04-23T23:59:59.000Z

79

Simulation of a Heisenberg XY- chain and realization of a perfect state transfer algorithm using liquid nuclear magnetic resonance  

E-Print Network (OSTI)

The three- spin chain with Heisenberg XY- interaction is simulated in a three- qubit nuclear magnetic resonance (NMR) quantum computer. The evolution caused by the XY- interaction is decomposed into a series of single- spin rotations and the $J$- coupling evolutions between the neighboring spins. The perfect state transfer (PST) algorithm proposed by M. Christandl et al [Phys. Rev. Lett, 92, 187902(2004)] is realized in the XY- chain.

Jingfu Zhang; Gui Lu Long; Wei Zhang; Zhiwei Deng; Wenzhang Liu; Zhiheng Lu

2005-03-25T23:59:59.000Z

80

Novel Detection Schemes of Nuclear Magnetic Resonance and Magnetic ...  

of peaks through a network of coupled spins. The power of NMR is in its ability to ... a signi?cant loss in sensitivity due to the very small volume of analyte on ...

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients  

SciTech Connect

Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

1994-12-01T23:59:59.000Z

82

Method for nuclear magnetic resonance imaging  

DOE Patents (OSTI)

A method for in vivo NMR imaging of the blood vessels and organs of a patient characterized by using a dark dye-like imaging substance consisting essentially of a stable, high-purity concentration of D/sub 2/O in a solution with water.

Kehayias, J.J.; Joel, D.D.; Adams, W.H.; Stein, H.L.

1988-05-26T23:59:59.000Z

83

Advanced characterization of physical properties of coals with different coal structures by nuclear magnetic resonance and X-ray computed tomography  

Science Conference Proceedings (OSTI)

In order to understand the correlation between coal structure and physical property of coal, samples with different coal structures were collected from the Late Permian period coal seams in the Laochang area, Yunnan Province, China. A set of experiments ... Keywords: Adsorption capacities, Coal structure, Nuclear magnetic resonance (NMR), Seepage capacities, X-ray computed tomography (X-CT)

Song Li; Dazhen Tang; Hao Xu; Zi Yang

2012-11-01T23:59:59.000Z

84

NMR and SR study of magnetic dilution in the triangular Heisenberg antiferromagnet This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network (OSTI)

NMR and SR study of magnetic dilution in the triangular Heisenberg antiferromagnet NaCrO 2 Collections Journals About Contact us My IOPscience #12;NMR and µSR study of magnetic dilution with isotropic interactions [1]. We examine by NMR and µSR the effect of substitution of non magnetic Ga3+ ions

Paris-Sud 11, Université de

85

Spin microscope based on optically detected magnetic resonance  

DOE Patents (OSTI)

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

2010-07-13T23:59:59.000Z

86

Spin microscope based on optically detected magnetic resonance  

Science Conference Proceedings (OSTI)

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

2009-10-27T23:59:59.000Z

87

Spin microscope based on optically detected magnetic resonance  

SciTech Connect

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

2010-06-29T23:59:59.000Z

88

Spin microscope based on optically detected magnetic resonance  

DOE Patents (OSTI)

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of impaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

2009-11-10T23:59:59.000Z

89

Spin microscope based on optically detected magnetic resonance  

SciTech Connect

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Berman, Gennady P. (Los Alamos, NM); Chernobrod, Boris M. (Los Alamos, NM)

2007-12-11T23:59:59.000Z

90

Compact orthogonal NMR field sensor  

DOE Patents (OSTI)

A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

Gerald, II, Rex E. (Brookfield, IL); Rathke, Jerome W. (Homer Glen, IL)

2009-02-03T23:59:59.000Z

91

Development of Nuclear Magnetic Resonance Pulse Sequences and Probes to Study Biomacromolecules  

DOE Green Energy (OSTI)

The determination of the three dimensional structures at high resolution of biomolecules, such as proteins and nucleic acids, enables us to understand their function at the molecular level. At the present time, there are only two methods available for determining such structures, nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction. Compared to well-established X-ray diffraction techniques, NMR methodology is relatively new and has many areas in which improvement can still be attained. In this project, we focused on the development of new NMR probes and pulse sequences that were tailored to tackle specific problems that are not adequately addressed by current technology. Probes are the hardware that contain the radio frequency (RF) circuitry used to both excite and detect the NMR signals. Pulse sequences are composed of a series of RF pulses and delays, which are applied to the sample held within the magnetic field by the probe, so as to manipulate the nuclear spins. Typically, a probe is developed for a specific set of nuclei and types of experiments and the pulse sequences are then written to use the probe in an optimal manner. In addition, the inter-development of instrumentation and methods are determined by the specific biological question to be examined. Thus our efforts focused on addressing an area of importance in NMR Structural Biology namely more effective ways to use the phosphorus ({sup 31}P) nucleus. Phosphorus is a very important biological element that is strategically located in nucleic acids, where it imparts negative charge and flexibility to RNA and DNA. It is also a component of the cellular membrane and thus interacts with membrane proteins. It is used in mechanisms to signal, activate or deactivate enzymes; and participates in energy storage and release. However, the phosphorus nucleus exhibits certain properties, such as poor spectral dispersion, low sensitivity of detection, and fast relaxation, which limit its effective use in NMR studies of biomolecules. Our unique combination of expertise at LLNL allowed us to tackle each of the negative features of {sup 31}P-NMR in a three-pronged, concerted effort. The nature of our work necessitated an interdependent, multidisciplinary approach that required knowledge of spin physics (pulse sequences), engineering (probes), and structural biology (sample preparation and structure determination).

Cosman, M; Krishnan, V V; Maxwell, R

2001-02-26T23:59:59.000Z

92

Preprint -January 2011 To be published in Journal of Physics: Conference Series An active feedback scheme for low field NMR  

E-Print Network (OSTI)

scheme for low field NMR experiments Emmanuel Baudin1, Kajum Safiullin1, Steven W. Morgan1,2 and Pierre-Jean Nacher1 Abstract. In low field nuclear magnetic resonance (NMR) it is desirable to combine proper the sample and the detection coil is needed for NMR with highly magnetized samples and a large bandwidth

Paris-Sud XI, Université de

93

Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz  

Science Conference Proceedings (OSTI)

A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect {sup 27}Al NQR signals in ruby (Al{sub 2}O{sub 3}[Cr{sup 3+}]) at 359 and 714 kHz. {copyright} {ital 1996 American Institute of Physics.}

TonThat, D.M.; Clarke, J. [Department of Physics, University of , California (United States)]|[Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1996-08-01T23:59:59.000Z

94

Protein MAS NMR methodology and structural analysis of protein assemblies  

E-Print Network (OSTI)

Methodological developments and applications of solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy, with particular emphasis on the analysis of protein structure, are described in this thesis. ...

Bayro, Marvin J

2010-01-01T23:59:59.000Z

95

FURMAN NMR SAFETY INFORMATION Standard safety guidelines have been put in place for work around the high-field magnets, and all users  

E-Print Network (OSTI)

FURMAN NMR SAFETY INFORMATION Standard safety guidelines have been put in place for work around and serious personal injury, including death. NMR Magnetic Field Strength · Remember: The magnetic field is ALWAYS on. · Don't enter the NMR room if you have a pacemaker, implanted pacemaker leads or any other

96

Using NMR to study full intact wine bottles A.J. Weekley, P. Bruins, M. Sisto, and M.P. Augustine*  

E-Print Network (OSTI)

Using NMR to study full intact wine bottles A.J. Weekley, P. Bruins, M. Sisto, and M.P. Augustine 2002; revised 19 November 2002 Abstract A nuclear magnetic resonance (NMR) probe and spectrometer Sauvignons with high resolution 1 H NMR spectroscopy. Selected examples of full bottle 13 C NMR spectra

Augustine, Mathew P.

97

RESEARCH Open Access H low field nuclear magnetic resonance  

E-Print Network (OSTI)

magnetic resonance, Biodiesel, Biodiesel physical properties, Chemometrics, Laplace inversion of biodiesel Paula Berman1 , Adi Leshem1 , Oren Etziony1 , Ofer Levi2 , Yisrael Parmet2 , Michael Saunders3 and Zeev Wiesman1* Abstract Background: Biodiesel production has increased dramatically over the last

Stanford University

98

Proposed Detection of Dynamically Oriented Nuclei by Acoustic Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

It is proposed that acoustic nuclear magnetic resonance be used to detect steady?state nuclear orientation achieved by the Jeffries Abragam effect. This is a new scheme for double magnetic resonance (ADMR) in contrast with conventional DMR

Mary Duns Scotus Breitbart; W. A. Barker

1967-01-01T23:59:59.000Z

99

Real-Time 2D NMR Identification of Analytes Undergoing Continuous Chromatographic Separation  

E-Print Network (OSTI)

Real-Time 2D NMR Identification of Analytes Undergoing Continuous Chromatographic Separation Boaz of multidimensional nuclear magnetic resonance (NMR) spectra within a single scan. A promising application opened up, with the real-time acquisition of a series of 2D 1 H NMR spectra arising from a mixture of compounds subject

Frydman, Lucio

100

PhD Project: NMR Advanced Methodologies to investigate water diffusion in colloids and  

E-Print Network (OSTI)

PhD Project: NMR Advanced Methodologies to investigate water diffusion in colloids and biological lengthscales. Nuclear Magnetic Resonance (NMR) is capable of investigating the diffusion of molecules in fluids and the information obtainable with the conventional DTI. Another NMR branch where diffusion issues can be improved

Roma "La Sapienza", Università di

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

2006 Nature Publishing Group Optical detection of liquid-state NMR  

E-Print Network (OSTI)

© 2006 Nature Publishing Group Optical detection of liquid-state NMR I. M. Savukov1 , S.-K. Lee1 & M. V. Romalis1 Nuclear magnetic resonance (NMR) in liquids and solids is primarily detected field itself provides only limited spatial or structural information about the sample. Most NMR

Romalis, Mike

102

Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

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.

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

2013-01-01T23:59:59.000Z

103

Rapid determination of sugar content in biomass hydrolysates using nuclear magnetic resonance spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biofuels and Environmental Biotechnology Biotechnology and Bioengineering Biofuels and Environmental Biotechnology Biotechnology and Bioengineering DOI 10.1002/bit.24741 Rapid determination of sugar content in biomass hydrolysates using nuclear magnetic resonance spectroscopy † Erica Gjersing*, Renee M. Happs, Robert W. Sykes, Crissa Doeppke, and Mark F. Davis National Bioenergy Center, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401 *Address correspondence to: Erica.Gjersing@nrel.gov; phone: 303-384-7984; fax: 303-384- 6363 Key Words: hydrolysate, Partial Least Squares, 1H NMR, PLS regression † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to

104

Optically Detected Magnetic Resonance Studies on ?-conjugated semiconductor systems  

Science Conference Proceedings (OSTI)

Optically Detected Magnetic Resonance (ODMR) techniques were used to investigate the dynamics of excitons and charge carriers in ?-conjugated organic semiconductors. Degradation behavior of the negative spin-1/2 electroluminescence-detected magnetic resonance (ELDMR) was observed in Alq3 devices. The increase in the resonance amplitude implies an increasing bipolaron formation during degradation, which might be the result of growth of charge traps in the device. The same behavior of the negative spin-1/2 ELDMR was observed in 2wt% Rubrene doped Tris(8-hydroxyquinolinato)aluminium (Alq3) devices. However, with increasing injection current, a positive spin-1/2 ELDMR, together with positive spin 1 triplet powder patterns at {delta}m{sub S}={+-}1 and {delta}m{sub S}={+-}2, emerges. Due to the similarities in the frequency dependences of single and double modulated ELDMR and the photoluminescence-detected magnetic resonance (PLDMR) results in poly[2-methoxy-5-(2 -ethyl-hexyloxy)-1,4-phenyl ene vinylene] (MEH-PPV) films, the mechanism for this positive spin-1/2 ELDMR was assigned to enhanced triplet-polaron quenching under resonance conditions. The ELDMR in rubrene doped Alq3 devices provides a path to investigate charge distribution in the device under operational conditions. Combining the results of several devices with different carrier blocking properties and the results from transient EL, it was concluded trions not only exist near buffer layer but also exist in the electron transport layer. This TPQ model can also be used to explain the positive spin-1/2 PLDMR in poly(3-hexylthiophene) (P3HT) films at low temperature and in MEH-PPV films at various temperatures up to room temperature. Through quantitative analysis, TE-polaron quenching (TPQ) model is shown having the ability to explain most behaviors of the positive spin-1/2 resonance. Photocurrent detected magnetic resonance (PCDMR) studies on MEH-PPV devices revealed a novel transient resonance signal. The signal may originate from the higher concentration of deep traps near cathode. A quantitative analysis based on this assumption was carried out and found to be consistent with the experimental results.

Chen, Ying

2011-12-06T23:59:59.000Z

105

Homometallic and Heterometallic Antiferromagnetic Rings: Magnetic Properties Studied by Nuclear Magnetic Resonance  

SciTech Connect

The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr{sub 8} antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr{sup 3+} ion with diamagnetic Cd{sup 2+} (Cr{sub 7}Cd) and with Ni{sup 2+} (Cr{sub 7}Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both {sup 53}Cr-NMR and {sup 19}F-NMR. We have determined the order of magnitude of the transferred hyperfine coupling constant {sup 19}F - M{sup +} where M{sup +} = Cr{sup 3+}, Ni{sup 2+} in the different rings. This latter result gives useful information about the overlapping of the electronic wavefunctions involved in the coordinative bond.

Casadei, Cecilia

2012-05-09T23:59:59.000Z

106

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Allan M. Cormack, Computerized Axial Tomography (CAT) Allan M. Cormack, Computerized Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) Resources with Additional Information magnetic resonance imaging system Computed axial tomography, commonly known as CAT scanning, was introduced in 1972. During a CAT scan, a large coil of x-ray tubes rotates around the patient's body, taking x-rays from all angles. A computer integrates all of these x-rays into a single, three-dimensional image on a television screen. The data can be saved on the computer. Allan M. Cormack, a high energy physicist at Tufts University, shared the 1979 Nobel Prize in Physiology and Medicine for his key work in developing the methods for CAT scanners. At the time of development, these methods were widely regarded as the most significant advance in medical radiography since the 1895 discovery of x-rays.

107

Observation of the uranium 235 nuclear magnetic resonance signal (*)  

E-Print Network (OSTI)

L-1017 Observation of the uranium 235 nuclear magnetic resonance signal (*) H. Le Bail, C. Chachaty signal de résonance magnétique nucléaire de l'isotope 235 de l'uranium est présentée. Elle a été effectuée sur l'hexafluorure d'uranium pur, à l'état liquide à 380 K. Le rapport gyromagnétique mesuré est

Paris-Sud XI, Université de

108

Attainable entanglement of unitary transformed thermal states in liquid-state nuclear magnetic resonance with the chemical shift  

E-Print Network (OSTI)

Recently, Yu, Brown, and Chuang [Phys. Rev. A {\\bf 71}, 032341 (2005)] investigated the entanglement attainable from unitary transformed thermal states in liquid-state nuclear magnetic resonance (NMR). Their research gave an insight into the role of the entanglement in a liquid-state NMR quantum computer. Moreover, they attempted to reveal the role of mixed-state entanglement in quantum computing. However, they assumed that the Zeeman energy of each nuclear spin which corresponds to a qubit takes a common value for all; there is no chemical shift. In this paper, we research a model with the chemical shifts and analytically derive the physical parameter region where unitary transformed thermal states are entangled, by the positive partial transposition (PPT) criterion with respect to any bipartition. We examine the effect of the chemical shifts on the boundary between the separability and the nonseparability, and find it is negligible.

Yukihiro Ota; Shuji Mikami; Motoyuki Yoshida; Ichiro Ohba

2006-12-19T23:59:59.000Z

109

Integrated microchip incorporating atomic magnetometer and microfluidic channel for NMR and MRI  

DOE Patents (OSTI)

An integral microfluidic device includes an alkali vapor cell and microfluidic channel, which can be used to detect magnetism for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Small magnetic fields in the vicinity of the vapor cell can be measured by optically polarizing and probing the spin precession in the small magnetic field. This can then be used to detect the magnetic field of in encoded analyte in the adjacent microfluidic channel. The magnetism in the microfluidic channel can be modulated by applying an appropriate series of radio or audio frequency pulses upstream from the microfluidic chip (the remote detection modality) to yield a sensitive means of detecting NMR and MRI.

Ledbetter, Micah P. (Oakland, CA); Savukov, Igor M. (Los Alamos, NM); Budker, Dmitry (El Cerrito, CA); Shah, Vishal K. (Plainsboro, NJ); Knappe, Svenja (Boulder, CO); Kitching, John (Boulder, CO); Michalak, David J. (Berkeley, CA); Xu, Shoujun (Houston, TX); Pines, Alexander (Berkeley, CA)

2011-08-09T23:59:59.000Z

110

Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance  

Science Conference Proceedings (OSTI)

Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

Kong, Zueqian

2010-03-15T23:59:59.000Z

111

NMR Study of the Magnetic and Metal-Insulator Transitions in Na0:5CoO2: A Nesting Scenario J. Bobroff,1  

E-Print Network (OSTI)

NMR Study of the Magnetic and Metal-Insulator Transitions in Na0:5CoO2: A Nesting Scenario J, France (Received 22 July 2005; published 13 March 2006) Co and Na NMR are used to probe the local have performed a 59Co and 23Na NMR study which allows us to differentiate the two Co sites and to give

Paris-Sud 11, Université de

112

Magnetic motion capture system using LC resonant magnetic marker composed of Ni-Zn ferrite core  

SciTech Connect

We have proposed a magnetic motion capture system using an LC resonant magnetic marker. The proposed system is composed of an exciting coil, an LC marker, and a 5x5-matrix search coil array (25 search coils). The LC marker is small and has a minimal circuit with no battery and can be driven wirelessly by the action of electromagnetic induction. It consists of a Ni-Zn ferrite core (3 mm{phi}x10 mm) with a wound coil and a chip capacitor, forming an LC series circuit with a resonant frequency of 186 kHz. The relative position accuracy of the system is less than 1 mm within the area of 100 mm{sup 3} up to 150 mm from the search coil array. Compared with dc magnetic systems, the proposed system is applicable for precision motion capture in optically isolated spaces without magnetic shielding because the system is not greatly influenced by earth field noise.

Hashi, S.; Toyoda, M.; Ohya, M.; Okazaki, Y.; Yabukami, S.; Ishiyama, K.; Arai, K. I. [Department of Materials Science and Technology, Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan); Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

2006-04-15T23:59:59.000Z

113

Methods for magnetic resonance analysis using magic angle technique  

DOE Patents (OSTI)

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.

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

2011-11-22T23:59:59.000Z

114

NMR study of water distribution inside tomato cells: Effects of water stress Maja Musse*, Mireille Cambert, Franois Mariette  

E-Print Network (OSTI)

NMR study of water distribution inside tomato cells: Effects of water stress Maja Musse*, Mireille nuclear magnetic resonance (NMR) Relaxometry. Two kinds of experiment were performed in order to investigate the correlation between multi-exponential NMR relaxation and the subcellular compartments

Paris-Sud XI, Université de

115

Na NMR Evidence for Charge Order and Anomalous Magnetism in NaxCoO2 I. R. Mukhamedshin,1,* H. Alloul,1,  

E-Print Network (OSTI)

23 Na NMR Evidence for Charge Order and Anomalous Magnetism in NaxCoO2 I. R. Mukhamedshin,1,* H are studied by 23Na NMR and SQUID magnetometry. In nominal 0:50 x 0:70 solid state reacted samples,6] with the magnetic prop- erties. In a pioneering work, two 59Co NMR signals attributed to nonmagnetic Co3 sites were

Paris-Sud 11, Université de

116

Study of gas flow dynamics in porous and granular media with laser-polarized ¹²?Xe NMR  

E-Print Network (OSTI)

This thesis presents Nuclear Magnetic Resonance (NMR) studies of gas flow dynamics in porous and granular media by using laser-polarized ¹²?Xe . Two different physical processes, the gas transport in porous rock cores and ...

Wang, Ruopeng, 1972-

2005-01-01T23:59:59.000Z

117

Development of new parameters for structure determination and dynamic investigations on biomacromolecules by NMR  

E-Print Network (OSTI)

Nuclear magnetic resonance (NMR) spectroscopy is unique in the content of structural as well as dynamic information that it can provide at atomic resolution. The aim of this PhD-thesis was to contribute to the understanding ...

Duchardt, Elke, 1975-

2005-01-01T23:59:59.000Z

118

Capillary toroid cavity detector for high pressure NMR  

DOE Patents (OSTI)

A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity contains an elongated central conductor extending within the toroid cavity. The toroid cavity and central conductor generate an RF magnetic field for NMR analysis. A flow-through capillary sample container is located within the toroid cavity adjacent to the central conductor to subject a sample material flowing through the capillary to a static magnetic field and to enable NMR spectra to be recorded of the material in the capillary under a temperature and high pressure environment.

Gerald, II, Rex E. (Brookfield, IL); Chen, Michael J. (Downers Grove, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Honer Glen, IL); ter Horst, Marc (Chapel Hill, NC)

2007-09-11T23:59:59.000Z

119

Magnetic Resonance Imaging at Princeton, UofV, and UNH | U.S...  

Office of Science (SC) Website

Magnetic Resonance Imaging at Princeton, UofV, and UNH Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff...

120

Magnetic Fields1 Increasingly, instruments that generate large static magnetic fields (e.g., NMR spectrometers,  

E-Print Network (OSTI)

been issued by the International Commission on Non-ionizing Radiation (ICNIRP, 2009), which internal shielding, which reduces the strength of the magnetic field outside of the instrument. Strong, the hazards associated with cryogenic liquids are of concern, as well. The health effects of exposure

Shull, Kenneth R.

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Low-noise pulsed pre-polarization magnet system for ultra-low field NMR  

DOE Green Energy (OSTI)

A liquid cooled, pulsed electromagnet of solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system has been designed, fabricated and successfully operated. The magnet design minimizes Johnson noise, minimizes the hydrogen signal and incorporates minimal metal and no ferromagnetic materials. In addition, an acoustically quiet cooling system permitting 50% duty cycle operation was achieved by designing for single-phase, laminar flow, forced convection cooling. Winding, conductor splicing and epoxy impregnation techniques were successfully developed to produce a coil winding body with integral cooling passageways and adequate structural integrity. Issues of material compatibility, housing, coolant flow system and heat rejection system design will be discussed. Additionally, this pulsed electromagnet design has been extended to produce a boiling liquid cooled version in a paired solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system. This pair of liquid nitrogen cooled coils is currently being tested and commissioned. Issues of material compatibility, thermal insulation, thermal contraction, housing and coolant flow design are discussed.

Sims, James R [Los Alamos National Laboratory; Schilling, Josef B [Los Alamos National Laboratory; Swenson, Charles A [Los Alamos National Laboratory; Gardner, David L [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Ammerman, Curti N [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

122

Method of using a nuclear magnetic resonance spectroscopy standard  

DOE Patents (OSTI)

(CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy, wherein the resonance peaks of either .sup.1 H, .sup.13 C, .sup.15 N, or .sup.29 Si may be used as a reference.

Spicer, Leonard D. (Salt Lake City, UT); Bennett, Dennis W. (Clemson, SC); Davis, Jon F. (Salt Lake City, UT)

1985-01-01T23:59:59.000Z

123

Discovery of metabolite features for the modelling and analysis of high-resolution NMR spectra  

Science Conference Proceedings (OSTI)

This study presents three feature selection methods for identifying the metabolite features in nuclear magnetic resonance spectra that contribute to the distinction of samples among varying nutritional conditions. Principal component analysis, Fisher ... Keywords: NMR spectra, OSC, bioinformatics, classification, data mining, feature selection, metabolite features, metabolomics, multivariate statistical analysis, nuclear magnetic resonance, orthogonal signal correction

Hyun-Woo Cho; Seoung Bum Kim; Myong K. Jeong; Youngja Park; Nana Gletsu Miller; Thomas R. Ziegler; Dean P. Jones

2008-06-01T23:59:59.000Z

124

In Situ NMR Analysis of Fluids Contained in Sedimentary Rock Thomas M. de Swiet,* Marco Tomaselli,* Martin D. Hurlimann, and Alexander Pines*  

E-Print Network (OSTI)

In Situ NMR Analysis of Fluids Contained in Sedimentary Rock Thomas M. de Swiet,* Marco Tomaselli of pore fluids may be obtained in situ by magic angle spinning (MAS) nuclear magnetic resonance (NMR), which is normally used for solid samples. 1 H MAS­NMR spectra of water and crude oil in Berea sandstone

Pines, Alexander

125

A Solid-State NMR Method for Solution of Zeolite Crystal Darren H. Brouwer, Richard J. Darton, Russell E. Morris, and Malcolm H. Levitt*,  

E-Print Network (OSTI)

A Solid-State NMR Method for Solution of Zeolite Crystal Structures Darren H. Brouwer, Richard J crystal structures that combines powder XRD and nuclear magnetic resonance (NMR) spectroscopy in which NMR, which probes the distance-dependent dipolar interactions between naturally abundant 29 Si nuclei

Levitt, Malcolm H.

126

Spectroscopic imaging through magnetic resonance for brain tumour diagnostics: Recent achievements, dilemmas and potential solutions via advances in signal processing  

Science Conference Proceedings (OSTI)

In the very recent period Magnetic Resonance Spectroscopy (MRS) and Spectroscopic Imaging (MRSI) have become key diagnostic modalities for neuro-oncology. MRS and MRSI are now applied extensively for initial detection of brain tumours, for histopathologic ... Keywords: biomedical imaging, brain tumours, magnetic resonance spectroscopic imaging, magnetic resonance spectroscopy, metastatic disease

Karen Belki?; Dževad Belki?

2004-04-01T23:59:59.000Z

127

New Methodology For Use in Rotating Field Nuclear Magnetic Resonance  

E-Print Network (OSTI)

MHz and the permanent magnet’s motor’s mechanical rotationa stepping motor held away from the magnet, a pulley system,permanent magnet mechanically is rotated with a motor while

Jachmann, Rebecca C.

2007-01-01T23:59:59.000Z

128

NMR/MRI with hyperpolarized gas and high Tc SQUID  

DOE Patents (OSTI)

A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

Schlenga, Klaus (Eggenstein, DE); de Souza, Ricardo E. (Recife, BR); Wong-Foy, Annjoe (Berkeley, CA); Clarke, John (Berkeley, CA); Pines, Alexander (Berkeley, CA)

2000-01-01T23:59:59.000Z

129

Nuclear quadrupole resonances in compact vapor cells: the crossover from the NMR to the NQR interaction regimes  

E-Print Network (OSTI)

We present the first experimental study that maps the transformation of nuclear quadrupole resonances from the pure nuclear quadrupole regime to the quadrupole-perturbed Zeeman regime. The transformation presents an interesting quantum-mechanical problem, since the quantization axis changes from being aligned along the axis of the electric-field gradient tensor to being aligned along the magnetic field. We achieve large nuclear quadrupole shifts for I = 3/2 131-Xe by using a 1 mm^3 cubic cell with walls of different materials. When the magnetic and quadrupolar interactions are of comparable size, perturbation theory is not suitable for calculating the transition energies. Rather than use perturbation theory, we compare our data to theoretical calculations using a Liouvillian approach and find excellent agreement.

E. A. Donley; J. L. Long; T. C. Liebisch; E. R. Hodby; T. A. Fisher; J. Kitching

2008-10-21T23:59:59.000Z

130

NMR Study in the Iron-Selenide Rb0:74Fe1:6Se2: Determination of the Superconducting Phase as Iron Vacancy-Free Rb0:3Fe2Se2  

E-Print Network (OSTI)

NMR Study in the Iron-Selenide Rb0:74Fe1:6Se2: Determination of the Superconducting Phase as Iron magnetic resonance (NMR) experiments on Rb0:74Fe1:6Se2 reveal clearly distinct spectra originating from a majority antiferromagnetic (AF) and a minority metallic-superconducting (SC) phase. The very narrow NMR

Paris-Sud 11, Université de

131

Optical and magneto-optical properties of one-dimensional magnetized coupled resonator plasma photonic crystals  

Science Conference Proceedings (OSTI)

In this paper, the optical and magneto-optical properties of one-dimensional magnetized coupled resonator plasma photonic crystals have been investigated. We use transfer matrix method to solve our magnetized coupled resonator plasma photonic crystals consist of dielectric and magnetized plasma layers. The results of the change in the optical and magneto-optical properties of structure as a result of the alteration in the structural properties such as thickness, plasma frequency and collision frequency, plasma filling factor, number of resonators and dielectric constant of dielectric layers and external magnetic field have been reported. The main feature of this structure is a good magneto-optical rotation that takes place at the defect modes and the edge of photonic band gap of our proposed optical magnetized plasma waveguide. Our outcomes demonstrate the potential applications of the device for tunable and adjustable filters or reflectors and active magneto-optic in microwave devices under structural parameter and external magnetic field.

Hamidi, S. M. [Laser and Plasma Research Institute, G. C., Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

2012-01-15T23:59:59.000Z

132

Magnetic resonance imaging of solvent transport in polymer networks  

SciTech Connect

The spectroscopic technique of magnetic resonance imaging (MRI) has recently provided a new window into transport of solvents in polymer networks. Diffusion of solvent as a rate-controlling phenomenon is paramount to understanding transport in many important industrial and biological processes, such as upgrading fossil fuels, film casting and coating, development of photoresists, design of drug-delivery systems, development of solvent resistant polymers, etc. By MRI mapping the migration of solvent molecules through various polymer specimens, researchers Robert Botto and George Cody of Argonne National Laboratory, with support from the Division of Chemical Sciences at DOE, were able to characterize and distinguish between different modes of transport behavior associated with fundamentally different types of polymer systems. The method was applied to rubbers, glassy polymers, and coals. In polymers shown to undergo a glass transition from a rigid to rubbery state, a sharply defined solvent front was observed that propagated through specimens in the manner of a constant velocity shock wave. This behavior was contrasted with a smooth solvent concentration gradient found in polymer systems where no glass transition was observed. The results of this analysis have formed the basis of a new model of anomalous transport in polymeric solids and are helping to ascertain fundamental information on the molecular architectures of these materials.

Botto, R.E.; Cody, G.D.

1995-02-01T23:59:59.000Z

133

A nuclear magnetic resonance probe of Fe-Al and Al20V2Eu intermetallics  

E-Print Network (OSTI)

Al-rich Fe-Al systems (FeAl2, Fe2 Al5 and Fe4Al13) and Al20V2Eu have complicated structures with quasicrystal-like features making these materials potentially of interest for magnetic behavior. However, there is not much work on these materials. To study the variety of magnetic properties, we use NMR, magnetic susceptibility, specific heat and other methods in this work. The microscopic electronic and magnetic properties of the Al-rich Fe-Al system and Al20V2Eu have been studied via 27Al NMR at temperatures between 4 and 500 K. The results of spin lattice relaxation rates reveal a pseudogap in Fe4Al13 and Fe2Al5 around the Fermi-level in the density of states. Besides, a square well gap with a width of 2 meV and center at Fermi energy was detected by specific heat measurements in Fe2Al5. Both Fe4 Al13 and Fe2Al5 are non-magnetic systems with dilute magnetic defects, while FeAl2 is a concentrated local magnetic moment system. In Al20V2Eu, a crossover was observed in NMR, magnetization and transport measurements. Above 40 K, Eu(2+) local magnetic moments dominate; below 40 K, a transition to a Kondo regime is observed, where the Kondo effect leads to the reduction of localized moments due to the formation of a spin-compensated Kondo cloud. With increasing magnetic field, f electrons participate more and more in excitations near the Fermi level and a heavy-Fermion state was observed through specific heat measurements at high magnetic field.

Chi, Ji

2007-08-01T23:59:59.000Z

134

Deuterium incorporation in biomass cell wall components by NMR analysis  

SciTech Connect

A commercially available deuterated kale sample was analyzed for deuterium incorporation by ionic liquid solution 2H and 1H nuclear magnetic resonance (NMR). This protocol was found to effectively measure the percent deuterium incorporation at 33%, comparable to the 31% value determined by combustion. The solution NMR technique also suggested by a qualitative analysis that deuterium is preferentially incorporated into the carbohydrate components of the kale sample.

Foston, Marcus B [ORNL; McGaughey, Joseph [ORNL; O'Neill, Hugh Michael [ORNL; Evans, Barbara R [ORNL; Ragauskas, Arthur J [ORNL

2012-01-01T23:59:59.000Z

135

HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2006  

E-Print Network (OSTI)

This team taught, multidisciplinary course covers the fundamentals of magnetic resonance imaging relevant to the conduct and interpretation of human brain mapping studies. The challenges inherent in advancing our knowledge ...

Gollub, Randy L.

136

Bounds on the entanglability of thermal states in liquid-state nuclear magnetic resonance  

E-Print Network (OSTI)

Theorists have recently shown that the states used in current nuclear magnetic resonance (NMIR) quantum computing experiments are not entangled. Yet it is widely believed that entanglement is a necessary resource in the ...

Yu, Terri M. (Terri Mak), 1981-

2003-01-01T23:59:59.000Z

137

Multimodal neuroimaging with simultaneous electroencephalogram and high-field functional magnetic resonance imaging  

E-Print Network (OSTI)

Simultaneous recording of electroencephalogram (EEG) and functional magnetic resonance imaging (tMRI) is an important emerging tool in functional neuroimaging with the potential to reveal new mechanisms for brain function ...

Purdon, Patrick L. (Patrick Lee), 1974-

2005-01-01T23:59:59.000Z

138

Microfluidically Cryo-Cooled Planar Coils for Magnetic Resonance Imaging  

E-Print Network (OSTI)

High signal-to-noise ratio (SNR) is typically required for higher resolution and faster speed in magnetic resonance imaging (MRI). Planar microcoils as receiver probes in MRI systems offer the potential to be configured into array elements for fast imaging as well as to enable the imaging of extremely small objects. Microcoils, however, are thermal noise dominant and suffer limited SNR. Cryo-cooling for the microcoils can reduce the thermal noise, however conventional cryostats are not optimum for the microcoils because they typically use a thick vacuum gap to keep samples to be imaged to near room temperature during cryo-cooling. This vacuum gap is typically larger than the most sensitive region of the microcoils that defines the imaging depth, which is approximately the same as the diameters of the microcoils. Here microfluidic technology is utilized to locally cryo-cool the microcoils and minimize the thermal isolation gap so that the imaging surface is within the imaging depth of the microcoils. The first system consists of a planar microcoil with microfluidically cryo-cooling channels, a thin N2 gap and an imaging. The microcoil was locally cryo-cooled while maintaining the sample above 8°C. MR images using a 4.7 Tesla MRI system shows an average SNR enhancement of 1.47 fold. Second, the system has been further developed into a cryo-cooled microcoil system with inductive coupling to cryo-cool both the microcoil and the on-chip microfabricated resonating capacitor to further improve the Q improvement. Here inductive coupling was used to eliminate the physical connection between the microcoil and the tuning network so that a single cryocooling microfluidic channel could enclose both the microcoil and the capacitor with minimum loss in cooling capacity. Q improvement was 2.6 fold compared to a conventional microcoil with high-Q varactors and transmission line connection. Microfluidically tunable capacitors with the 653% tunability and Q of 1.3 fold higher compared to a conventional varactor have been developed and demonstrated as matching/tuning networks as a proof of concept. These developed microfluidically cryo-cooling system and tunable capacitors for improving SNR will potentially allow MR microcoils to have high-resolution images over small samples.

Koo, Chiwan

2013-08-01T23:59:59.000Z

139

Distinguishing carbonate reservoir pore facies with nuclear magnetic resonance as an aid to identify candidates for acid stimulation  

E-Print Network (OSTI)

The determination of reservoir quality and its spatial distribution is a key objective in reservoir characterization. This is especially challenging for carbonates because, due to the effects of diagenesis, quality rarely follows depositional patterns. This study integrates data from thin sections and core analyses with measurements of Nuclear Magnetic Resonance (NMR) T2 relaxation times. It exposes a novel approach to the use of NMR by applying geological and statistical analysis to define relationships between pore characteristics and the T2 data, from which a method to identify pore origin from NMR only is developed. One hundred and three samples taken from eleven wells located in fields of the Middle East, Alabama and Texas were used in the study. Modeling of the T2 spectra, as the sum of three normal components, resulted in the definition of 9 parameters representing the average, the variability and the percentage of total porosity of the specific pore sizes present in the sample. Each specific pore size corresponds to one of the following genetic pore types: intergranular, matrix, dissolution-enhanced, intercrystalline, vuggy and cement-reduced. Among the 9 parameters, two variables were identified as having the highest degree of geological significance that could be used to discriminate between pore categories: �µmax which represents the largest average pore size of all pore types identified in the sample, and Ï�main which represents the size variability of the most abundant pore type. Based on the joint distribution of �µmax and Ï�main computed for each pore category, the probability that an unclassified sample belongs to each of the pore categories, is calculated and the sample is assigned to the category with the highest probability. The accuracy of the method was investigated by comparing NMR predicted pore origin and genetic pore type described from thin section. A result of 89 successful predictions out of 103 samples was obtained. These promising results indicate that T2 time can be a useful identifier of carbonate pore types. Success in this work takes us closer to identifying genetic pore types from NMR logs with minimal calibration against borehole cores and will help predict the spatial distribution of poroperm facies in complex carbonate reservoirs with much improved accuracy.

Genty, Coralie

2006-08-01T23:59:59.000Z

140

Influence of external magnetic and laser radiation fields on Feshbach resonances in collision of atoms  

E-Print Network (OSTI)

We study collision of two atoms with formation of Feshbach resonance at combined interaction with the external magnetic field and laser radiation. In cases of one- and two-photon resonances of laser radiation with two discrete vibrational molecular levels, we show that Feshbach resonances appear at interaction of external magnetic field with dressed states formed via Autler-Townes effect. In addition, in case of one-photon resonance the lower vibrational molecular state is coupled by laser radiation with the continuum of the elastic channel and forms laser-induced Feshbach resonance via both Autler-Townes effect and LICS mechanism. We study the combined process of formation of Feshbach resonances; this enables the control of Feshbach resonance by varying the magnetic field and intensity and frequency of laser radiation. We obtain the cross-sections of elastic and inelastic scattering and show that quenching of resonance occurs at the energy equal to that of the systems ground state. Dependence of the cross-sections on the magnetic field and laser intensity is examined in detail. In all considered cases, the scattering length is obtained depending on the magnetic and laser fields are studied. In the absence of magnetic interaction if the hyperfine substates of the quasibound state in the closed channel and those of individual colliding atoms in the open channel are the same, Feshbach resonances may arise via weak interaction between nuclear and electronic motions, which leads to transitions between electronic states. The obtained results can be employed in new studies of collisions of cold atoms, e.g., of alkali metal atoms and for interpretation of new experiments in BECs.

E. A. Gazazyan; A. D. Gazazyan; V. O. Chaltykyan

2012-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Nuclear Magnetic Resonance Studies of Resorcinol-Formaldehyde Aerogels  

Science Conference Proceedings (OSTI)

In this article we report a detailed study of resorcinol-formaldehyde (RF) aerogels prepared under different processing conditions, [resorcinol]/[catalyst] (R/C) ratios in the starting sol-gel solutions, using continuous flow hyperpolarized 129Xe NMR in combination with solid-state 13C and two-dimensional wide-line separation (2D-WISE) NMR techniques. The degree of polymerization and the mobility of the cross-linking functional groups in RF aerogels are examined and correlated with the R/C ratios. The origin of different adsorption regions is evaluated using both co-adsorption of chloroform and 2D EXSY 129Xe NMR. A hierarchical set of Xe exchange processes in RF aerogels is found using 2D EXSY 129Xe NMR. The exchange of Xe gas follows the sequence (from fastest to slowest): mesopores with free gas, gas in meso- and micro-pores, free gas with micropores, and, finally, among micropore sites. The volume-to-surface-area (Vg/S) ratios for aerogels are measured for the first time without the use of geometric models. The Vg/S parameter, which is related both to the geometry and the interconnectivity of the pore space, has been found to correlate strongly with the R/C ratio and exhibits an unusually large span: an increase in the R/C ratio from 50 to 500 results in about a 5-fold rise in Vg/S.

Moudrakovski, Igor L.; Ratcliffe, C I.; Ripmeester, J A.; Wang, Li Q.; Exarhos, Gregory J.; Baumann, T; Satcher, J H.

2005-06-09T23:59:59.000Z

142

X-ray resonant magnetic scattering study of magnetic stripe domains in a-GdFe thin films  

SciTech Connect

X-ray resonant magnetic scattering (XRMS) has been used to investigate the structure of magnetic stripe domain patterns in thin amorphous GdFe films. Under the influence of a perpendicular magnetic field, the scattered intensity displays a smooth transition from a structure factor of correlated stripes to the form factor of isolated domains. We derive a quite general expression that relates the total scattered intensity of XRMS to the absolute value of the magnetization. Furthermore, we compare our results for the domain period with domain theory. We obtain good agreement for prealigned stripes, but disorder tends to lead to an overestimation of the period measured with XRMS.

Miguel, J.; Peters, J. F.; Toulemonde, O. M.; Goedkoop, J. B. [Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65, 1018 XE, Amsterdam (Netherlands); Dhesi, S. S.; Brookes, N. B. [European Synchrotron Radiation Facility, ESRF, Boite Postale 220, F-38043 Grenoble Cedex (France)

2006-09-01T23:59:59.000Z

143

Electrically detected magnetic resonance in a W-band microwave cavity  

SciTech Connect

We describe a low-temperature sample probe for the electrical detection of magnetic resonance in a resonant W-band (94 GHz) microwave cavity. The advantages of this approach are demonstrated by experiments on silicon field-effect transistors. A comparison with conventional low-frequency measurements at X-band (9.7 GHz) on the same devices reveals an up to 100-fold enhancement of the signal intensity. In addition, resonance lines that are unresolved at X-band are clearly separated in the W-band measurements. Electrically detected magnetic resonance at high magnetic fields and high microwave frequencies is therefore a very sensitive technique for studying electron spins with an enhanced spectral resolution and sensitivity.

Lang, V.; Lo, C. C.; George, R. E.; Lyon, S. A.; Bokor, J.; Schenkel, T.; Ardavan, A.; Morton, J. J. L.

2011-01-14T23:59:59.000Z

144

Quantifying fluid distribution and phase connectivity with a simple 3D cubic pore network model constrained by NMR and MICP data  

Science Conference Proceedings (OSTI)

A computer algorithm is implemented to construct 3D cubic pore networks that simultaneously honor nuclear magnetic resonance (NMR) and mercury injection capillary pressure (MICP) measurements on core samples. The algorithm uses discretized pore-body ... Keywords: Fluid distribution, Invasion percolation, Mercury injection capillary pressure, Nuclear magnetic resonance, Pore network, Relative permeability, Tight-gas sandstone

Chicheng Xu, Carlos Torres-Verdín

2013-12-01T23:59:59.000Z

145

Application of Parallel Imaging to Murine Magnetic Resonance Imaging  

E-Print Network (OSTI)

The use of parallel imaging techniques for image acceleration is now common in clinical magnetic resonance imaging (MRI). There has been limited work, however, in translating the parallel imaging techniques to routine animal imaging. This dissertation describes foundational level work to enable parallel imaging of mice on a 4.7 Tesla/40 cm bore research scanner. Reducing the size of the hardware setup associated with typical parallel imaging was an integral part of achieving the work, as animal scanners are typically small-bore systems. To that end, an array element design is described that inherently decouples from a homogenous transmit field, potentially allowing for elimination of typically necessary active detuning switches. The unbalanced feed of this "dual-plane pair" element also eliminates the need for baluns in this case. The use of the element design in a 10-channel adjustable array coil for mouse imaging is presented, styled as a human cardiac top-bottom half-rack design. The design and construction of the homogenous transmit birdcage coil used is also described, one of the necessary components to eliminating the active detuning networks on the array elements. In addition, the design of a compact, modular multi-channel isolation preamplifier board is described, removing the preamplifiers from the elements and saving space in the bore. Several additions/improvements to existing laboratory infrastructure needed for parallel imaging of live mice are also described, including readying an animal preparation area and developing the ability to maintain isoflurane anesthesia delivery during scanning. In addition, the ability to trigger the MRI scanner to the ECG and respiratory signals from the mouse in order to achieve images free from physiological motion artifacts is described. The imaging results from the compact 10-channel mouse array coils are presented, and the challenges associated with the work are described, including difficulty achieving sample-loss dominance and signal-to-noise ratio (SNR) limitations. In conclusion, in vivo imaging of mice with cardiac and respiratory gating has been demonstrated. Compact array coils tailored for mice have been studied and potential future work and design improvements for our lab in this area are discussed.

Chang, Chieh-Wei 1980-

2012-12-01T23:59:59.000Z

146

Solid-State NMR Studies of Fossil Fuels using One- and Two-Dimensional Methods at High Magnetic Field  

Science Conference Proceedings (OSTI)

We examine the opportunities offered by advancements in solid-state NMR (SSNMR) methods, which increasingly rely on the use of high magnetic fields and fast magic angle spinning (MAS), in the studies of coals and other carbonaceous materials. The sensitivity of one- and two-dimensional experiments tested on several Argonne Premium coal samples is only slightly lower than that of traditional experiments performed at low magnetic fields in large MAS rotors, since higher receptivity per spin and the use of 1H detection of low-gamma nuclei can make up for most of the signal loss due to the small rotor size. The advantages of modern SSNMR methodology in these studies include improved resolution, simplicity of pulse sequences, and the possibility of using J-coupling during mixing.

Althaus, Stacey M.; Mao, Kanmi; Kennedy, Gordon J.; Pruski, Marek

2012-06-24T23:59:59.000Z

147

Resonance enhancement of nonsequential double ionization by a magnetic field  

Science Conference Proceedings (OSTI)

We investigate nonsequential double ionization (NSDI) of helium by using an additional magnetic field parallel to the polarization of the laser pulse. By exploring the ability of a magnetic field for focusing the selected trajectories that contribute to the NSDI, we have found that the yield of NSDI, as a function of the magnetic-field strength, shows different behavior for different laser intensities. As a result, an additional magnetic field provides a way to identify that the NSDI mechanism of laser-assisted collision ionization begins to play an important role as the laser intensity increases.

Li Hongyun [Department of Physics, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Peking University, Beijing 100871 (China); Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Chen Jing; Liu Jie [Center for Nonlinear Studies, Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Jiang Hongbing; Gong Qihuang [Department of Physics, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Peking University, Beijing 100871 (China); Fu Panming; Wang Bingbing [Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yan Zongchao [Department of Physics, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada)

2011-01-15T23:59:59.000Z

148

Using NMR to Validate First-Principles Granular Flow Equations  

E-Print Network (OSTI)

Nuclear magnetic resonance (NMR) experiments are described for two granular-flow systems, the vibrofluidized bed and the gas-fluidized bed. Using pulsed field gradient, magnetic resonance imaging, and hyperpolarized gas NMR, detailed information is obtained for the density and motions of both grains and interstitial gas. For the vibrofluidized bed, the granular temperature profile is measured and compared with a first-principles formulation of granular hydrodynamics. For the gas-fluidized bed, dynamic correlations in the grain density are used to measure the bubble velocity and hyperpolarized xenon gas NMR is used to measure the bubble-emulsion exchange rate. A goal of these measurements is to verify in earth gravity first-principles theories of granular flows, which then can be used to make concrete predictions for granular flows in reduced gravity.

D. Candela; C. Huan; K. Facto; R. Wang; R. W. Mair; R. L. Walsworth

2005-10-23T23:59:59.000Z

149

Footprint structures due to resonant magnetic perturbations in DIII-D  

SciTech Connect

Numerical modeling of the typical footprint structures on the target plates of a divertor tokamak is presented. In the tokamak DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] toroidal mode number n=3 resonant magnetic perturbations are responsible for characteristic footprint stripes. The numerics can resolve substructures within each footprint stripe, which are related to the internal magnetic topology. It is shown that the footprint structures on the inner target plate can be predicted by the unstable manifolds of the separatrix and the q=4 resonant surface. By their intersection with the divertor target plate the unstable manifolds form the footprint boundary and substructures within. Based on the manifold analysis, the boundaries and interior structures of the footprints are explained. A direct connection of all magnetic resonances inside the stochastic plasma volume to the target plates is verified.

Wingen, A.; Spatschek, K. H. [Institut fuer Theoretische Physik, Heinrich-Heine-Universitaet Duesseldorf, D-40225 Duesseldorf (Germany); Evans, T. E. [General Atomics, San Diego, California 92186-5608 (United States)

2009-04-15T23:59:59.000Z

150

Magnetic Resonance Imaging at Princeton, UofV, and UNH | U.S. DOE Office of  

Office of Science (SC) Website

Magnetic Resonance Imaging at Magnetic Resonance Imaging at Princeton, UofV, and UNH Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Magnetic Resonance Imaging at Princeton, UofV, and UNH Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: MRI for hyperpolarized gases Developed at: Princeton, University of Virginia, University of New Hampshire

151

Observation of Magnetic Resonances in Electron Clouds in a Positron Storage Ring  

SciTech Connect

The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, Cherrill M.; Raubenheimer, T.O.; Wang, L.F.; /SLAC

2011-08-24T23:59:59.000Z

152

Toroid cavity/coil NMR multi-detector  

DOE Patents (OSTI)

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

Gerald, II, Rex E. (Brookfield, IL); Meadows, Alexander D. (Indianapolis, IN); Gregar, Joseph S. (Naperville, IL); Rathke, Jerome W. (Homer Glen, IL)

2007-09-18T23:59:59.000Z

153

High-pressure Magic Angle Spinning Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure 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 to include micro-groves at 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 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 penetration loss of pressure for 72 hours. As an application example, in situ 13C 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.

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

2011-10-01T23:59:59.000Z

154

Final Report: Nuclear Magnetic Resonance (NMR) of Catalysis, September 1, 1993 - December 31, 1998  

DOE Green Energy (OSTI)

On going work concerns the mechanisms of methanol conversion to hydrocarbons on zeolite solid acids.

Haw, James F.

1998-12-31T23:59:59.000Z

155

Single-spin measurements for quantum computation using magnetic resonance force microscopy  

SciTech Connect

The quantum theory of a singlespin measurements using a magnetic resonance force microscopy is presented. We use an oscillating cantilever-driven adiabatic reversals technique. The frequency shift of the cantilever vibrations is estimated. We show that the frequency shift causes the formation of the Schroedinger cat state for the cantilever. The interaction between the cantilever and the environment quickly destroys the coherence between the two cantilever trajectories. It is shown that using partial adiabatic reversals one can obtain a significant increase in the frequency shift. We discuss the possibility of sub-magneton spin density detection in molecules using magnetic resonance force microscopy.

Berman, G. P. (Gennady P.); Borgonovi, F.; Rinkevicius, Z.; Tsifrinovich, V. I. (Vladimir I.)

2004-01-01T23:59:59.000Z

156

Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance  

E-Print Network (OSTI)

Quantum ground-state problems are computationally hard problems; for general many-body Hamiltonians, there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10^-5 decimal digit). The ground-state fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wavefunctions than c...

Li, Zhaokai; Chen, Hongwei; Lu, Dawei; Whitfield, James D; Peng, Xinhua; Aspuru-Guzik, Alán; Du, Jiangfeng

2011-01-01T23:59:59.000Z

157

Agentification of Markov model-based segmentation: Application to magnetic resonance brain scans  

Science Conference Proceedings (OSTI)

Objective: Markov random field (MRF) models have been traditionally applied to the task of robust-to-noise image segmentation. Most approaches estimate MRF parameters on the whole image via a global expectation-maximization (EM) procedure. The resulting ... Keywords: Distributed expectation maximization, Magnetic resonance brain scan segmentation, Markov random field, Medical imaging, Multiagents system

Benoit Scherrer; Michel Dojat; Florence Forbes; Catherine Garbay

2009-05-01T23:59:59.000Z

158

Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging  

E-Print Network (OSTI)

- labeled bicarbonate. Nature 2008, 453:940-943. doi:10.1038/nrc2289 Cite this article as: Brindle: Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging. BMC Proceedings 2010 4(Suppl 2):O24. Correspondence...

2010-09-24T23:59:59.000Z

159

Fiber-Optic Stethoscope: A Cardiac Monitoring and Gating System for Magnetic Resonance Microscopy  

E-Print Network (OSTI)

Fiber-Optic Stethoscope: A Cardiac Monitoring and Gating System for Magnetic Resonance Microscopy monitoring and gating purposes. The fiber-optic stethoscope system offers a novel approach to measuring) small enough for use on rats and mice. METHODS Fiber-Optic Stethoscope System Design As shown in the MR

160

Automatic segmentation of non-enhancing brain tumors in magnetic resonance images  

Science Conference Proceedings (OSTI)

Tumor segmentation from magnetic resonance (MR) images may aid in tumor treatment by tracking the progress of tumor growth and/or shrinkage. In this paper we present the first automatic segmentation method which separates non-enhancing brain tumors from ... Keywords: Automatic tissue classification, Fuzzy clustering, Image processing, MRI, Non-enhancing brain tumors

Lynn M Fletcher-Heath; Lawrence O Hall; Dmitry B Goldgof; F.Reed Murtagh

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Segmentation of female pelvic organs in axial magnetic resonance images using coupled geometric deformable models  

Science Conference Proceedings (OSTI)

The segmentation of pelvic structures in magnetic resonance (MR) images of the female pelvic cavity is a challenging task. This paper proposes the use of three novel geometric deformable models to segment the bladder, vagina and rectum in axial MR images. ... Keywords: Bladder, Image segmentation, Imaging appearance, Level set, Prior shape knowledge, Rectum, Vagina

Zhen Ma; Renato M. Natal Jorge; Teresa Mascarenhas; JoãO Manuel R. S. Tavares

2013-05-01T23:59:59.000Z

162

Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects  

SciTech Connect

Topics covered are: anomalous transport and E Ã? B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies.

Alexei Y. Pankin; Arnold H. Kritz

2011-07-19T23:59:59.000Z

163

Effect of Electric and Magnetic Fields on Spin Dynamics in the Resonant Electric Dipole Moment Experiment  

E-Print Network (OSTI)

A buildup of the vertical polarization in the resonant electric dipole moment (EDM) experiment [Y. F. Orlov, W. M. Morse, and Y. K. Semertzidis, Phys. Rev. Lett. 96, 214802 (2006)] is affected by a horizontal electric field in the particle rest frame oscillating at a resonant frequency. This field is defined by the Lorentz transformation of an oscillating longitudinal electric field and a uniform vertical magnetic one. The effect of a longitudinal electric field is significant, while the contribution from a magnetic field caused by forced coherent longitudinal oscillations of particles is dominant. The effect of electric field on the spin dynamics was not taken into account in previous calculations. This effect is considerable and leads to decreasing the EDM effect for the deuteron and increasing it for the proton. The formula for resonance strengths in the EDM experiment has been derived. The spin dynamics has been calculated.

Alexander J. Silenko

2006-04-11T23:59:59.000Z

164

Solving Quantum Ground-State Problems with Nuclear Magnetic Resonance  

E-Print Network (OSTI)

Quantum ground-state problems are computationally hard problems; for general many-body Hamiltonians, there is no classical or quantum algorithm known to be able to solve them efficiently. Nevertheless, if a trial wavefunction approximating the ground state is available, as often happens for many problems in physics and chemistry, a quantum computer could employ this trial wavefunction to project the ground state by means of the phase estimation algorithm (PEA). We performed an experimental realization of this idea by implementing a variational-wavefunction approach to solve the ground-state problem of the Heisenberg spin model with an NMR quantum simulator. Our iterative phase estimation procedure yields a high accuracy for the eigenenergies (to the 10^-5 decimal digit). The ground-state fidelity was distilled to be more than 80%, and the singlet-to-triplet switching near the critical field is reliably captured. This result shows that quantum simulators can better leverage classical trial wavefunctions than classical computers.

Zhaokai Li; Man-Hong Yung; Hongwei Chen; Dawei Lu; James D. Whitfield; Xinhua Peng; Alán Aspuru-Guzik; Jiangfeng Du

2011-06-02T23:59:59.000Z

165

Nuclear Magnetic Resonance Investigation of Dynamics in Poly(Ethylene Oxide) Based Lithium Polyether-ester-sulfonate Ionomers  

SciTech Connect

Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies of both the polymer and lithium ions in the lower ion content samples indicate that the polymer segmental motion and lithium ion hopping motion are correlated even though their respective correlation times differ significantly. A divergent trend is observed for correlation times and activation energies of the highest ion content sample due to the presence of ionic aggregation. Details about the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments.

Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

2012-01-07T23:59:59.000Z

166

89Y NMR probe of Zn induced local magnetism in YBa2(Cu1?yZny ...  

Science Conference Proceedings (OSTI)

a large T-dependent contribution to the 89Y NMR linewidth is evidenced and is ... YBCO6+x samples and 27Al NMR data taken on Al3+ substituted on the Cu ...

167

A quantum description of radiation damping and the free induction signal in magnetic resonance  

Science Conference Proceedings (OSTI)

We apply the methods of cavity quantum electrodynamics (CQED), to obtain a microscopic and fully quantum-mechanical picture of radiation damping in magnetic resonance, and the nascent formation of the free induction signal. Numerical solution of the Tavis-Cummings model - i.e., multiple spins 1/2 coupled to a lossless single-mode cavity - shows in fine detail the transfer of Zeeman energy, via spin coherence, to excite the cavity - represented here by a quantized LC resonator. The case of a single spin is also solved analytically. Although the motion of the Bloch vector is non-classical, we nonetheless show that the quantum mechanical Rabi nutation frequency (as enhanced by cavity coupling and stimulated emission) gives realistic estimates of macroscopic signal strength and the radiation damping constant in nuclear magnetic resonance. We also show how to introduce dissipation: cavity losses by means of a master equation, and relaxation by the phenomenological method of Bloch. The failure to obtain the full Bloch equations (unless semi-classical conditions are imposed on the cavity) is discussed in light of similar issues arising in CQED (and in earlier work in magnetic resonance as well), as are certain problems relative to quantization of the electromagnetic near-field.

Tropp, James [General Electric Healthcare Technologies, 47697 Westinghouse Drive, Fremont, California 94539 (United States)

2013-07-07T23:59:59.000Z

168

DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers  

DOE Patents (OSTI)

A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

1993-01-01T23:59:59.000Z

169

DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers  

DOE Patents (OSTI)

A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced. 7 figures.

Fan, N.Q.; Clarke, J.

1993-10-19T23:59:59.000Z

170

Laser-enhanced NMR spectroscopy: Theoretical considerations  

Science Conference Proceedings (OSTI)

W. S. Warren et al. report that the proton magnetic resonance spectra of chiral molecules are modified slightly by circularly polarized laser light. While it is not unexpected that circularly polarized radiation can influence chiral molecules, the large magnitude of the reported results is surprising. From conservation of parity, and under the conditions of the experiment, the relevant energy shifts per randomly oriented molecule show several simple relations. The chemical shielding of a chiral molecule in right circularly polarized light must be the same as its enantiomer in left circularly polarized light. However, the splitting of nuclear magnetic resonance (NMR) lines in left circular polarization will not necessarily equal that for right circular polarization because of the zero magnetic field term, b[sup 0]I[sub 0]. Direct calculation using the standard Hamiltonian descriptive of the interaction between radiation and matter in a magnetic field shows that for light intensities of 10 W cm[sup [minus]2] the nonchiral chemical shift in the NMR spectrum should yield a value of aI[sub 0] on the order of 10[sup [minus]15] [sigma][sub 0]. The chiral chemical shift, bI[sub 0], is on the order of 10[sup [minus]18] [sigma][sub 0]; for a magnetic field of 10[sup 4] gauss, this intensity-dependent shift corresponds to about 10[sup [minus]15] Hz. The zero magnetic field shift (b[sup 0]I[sub 0]) is about 10[sup [minus]10]Hz. In conclusion, the ordinary manifestation of chirality on light-perturbed chemical shifts is too small to be observed. Shining laser light on a racemic mixture and seeing a single NMR line split into two lines would provide a convincing experimental result. The authors' calculations predict that it will not occur. 3 refs., 1 tab.

Harris, R.A.; Tinoco, I. Jr. (Univ. of California, Berkeley (United States))

1993-02-05T23:59:59.000Z

171

Power Quality Investigation at a Midwest Hospital: Magnetic Resonance Imaging System  

Science Conference Proceedings (OSTI)

Recently, a Midwest hospital contacted its electric utility about malfunctions involving imaging systems including magnetic resonance imaging (MRI) and computed tomography (CT). The MRI system was the primary concern for the hospital. The MRI system was manufactured by a leading imaging system manufacturer and the CT system was manufactured by another leading imaging system manufacturer. To begin investigating the problem, the hospital requested that power-line monitoring be conducted at the facility. Th...

2007-07-26T23:59:59.000Z

172

NMR apparatus for in situ analysis of fuel cells  

Science Conference Proceedings (OSTI)

The subject apparatus is a fuel cell toroid cavity detector for in situ analysis of samples through the use of nuclear magnetic resonance. The toroid cavity detector comprises a gas-tight housing forming a toroid cavity where the housing is exposed to an externally applied magnetic field B.sub.0 and contains fuel cell component samples to be analyzed. An NMR spectrometer is electrically coupled and applies a radiofrequency excitation signal pulse to the detector to produce a radiofrequency magnetic field B.sub.1 in the samples and in the toroid cavity. Embedded coils modulate the static external magnetic field to provide a means for spatial selection of the recorded NMR signals.

Gerald, II, Rex E; Rathke, Jerome W

2012-11-13T23:59:59.000Z

173

Solid state nuclear magnetic resonance methodology and applications to structure determination of peptides, proteins and amyloid fibrils  

E-Print Network (OSTI)

Several methodological developments and applications of multidimensional solid-state nuclear magnetic resonance to biomolecular structure determination are presented. Studies are performed in uniformly 3C, 15N isotope ...

Jaroniec, Christopher P

2003-01-01T23:59:59.000Z

174

Minute Effects of Sex on the Aging Brain: A Multisample Magnetic Resonance Imaging Study of Healthy Aging and Alzheimer's Disease  

E-Print Network (OSTI)

Age is associated with substantial macrostructural brain changes. While some recent magnetic resonance imaging studies have reported larger age effects in men than women, others find no sex differences. As brain morphometry ...

Fjell, Anders M.

175

Whole-heart magnetic resonance coronary angiography with multiple breath-holds and automatic breathing-level tracking  

Science Conference Proceedings (OSTI)

Whole-heart (WH) magnetic resonance coronary angiography (MRCA) studies are usually performed during free breathing while monitoring the position of the diaphragm with real-time motion correction. However

Shigehide Kuhara; Ayako Ninomiya; Tomohisa Okada; Shotaro Kanao; Toshikazu Kamae; Kaori Togashi

2010-01-01T23:59:59.000Z

176

Atomic magnetic gradiometer for room temperature high sensitivity magnetic field detection  

DOE Patents (OSTI)

A laser-based atomic magnetometer (LBAM) apparatus measures magnetic fields, comprising: a plurality of polarization detector cells to detect magnetic fields; a laser source optically coupled to the polarization detector cells; and a signal detector that measures the laser source after being coupled to the polarization detector cells, which may be alkali cells. A single polarization cell may be used for nuclear magnetic resonance (NMR) by prepolarizing the nuclear spins of an analyte, encoding spectroscopic and/or spatial information, and detecting NMR signals from the analyte with a laser-based atomic magnetometer to form NMR spectra and/or magnetic resonance images (MRI). There is no need of a magnetic field or cryogenics in the detection step, as it is detected through the LBAM.

Xu,Shoujun (Berkeley, CA); Lowery, Thomas L. (Belmont, MA); Budker, Dmitry (El Cerrito, CA); Yashchuk, Valeriy V. (Richmond, CA); Wemmer, David E. (Berkeley, CA); Pines, Alexander (Berkeley, CA)

2009-08-11T23:59:59.000Z

177

Studies of electrolyte penetration in carbon anodes by NMR techniques.  

DOE Green Energy (OSTI)

A toroid cavity nuclear magnetic resonance (NMR) detector capable of recording radial concentration profiles, diffusion constants, and displacements of charge carriers was employed to investigate the lithium ion distribution in an electrochemical cell containing a carbonaceous material synthesized from pyrene and pillared clays as inorganic templates. A carbon rod was used in a control experiment to assign the Li{sup +} spectrum and to calibrate the one dimensional radial images.

Sandi, G.

1998-12-09T23:59:59.000Z

178

Chaos at Nonlinear NMR  

E-Print Network (OSTI)

The hodographs of magnetization of nonlinear nuclear magnetic resonance are investigated in the conditions of resonance on the unshifted frequency. It is shown that, depending on the value of amplitude of the variable field and value of frequency shift, topologically different hodographs separated from each other by separatrix are obtained.

A. Ugulava; S. Chkhaidze; L. Chotorlishvili; Z. Rostomashvili

2009-02-17T23:59:59.000Z

179

NMR Spectroscopy Protein-NMR  

E-Print Network (OSTI)

Keywords NMR Spectroscopy Protein-NMR Physical Organic Chemistry » Prof. Dr. Stefan Berger The research group of Prof. Dr. Stefan Berger focuses its work on: 1. Protein-NMR for the genera- tion of Protein-Structures. This includes application of all mod- ern 3D NMR pulse sequences for fully 15 N and 13

Schüler, Axel

180

NMR of thin layers using a meanderline surface coil  

DOE Patents (OSTI)

A miniature meanderline sensor coil which extends the capabilities of nuclear magnetic resonance (NMR) to provide analysis of thin planar samples and surface layer geometries. The sensor coil allows standard NMR techniques to be used to examine thin planar (or curved) layers, extending NMRs utility to many problems of modern interest. This technique can be used to examine contact layers, non-destructively depth profile into films, or image multiple layers in a 3-dimensional sense. It lends itself to high resolution NMR techniques of magic angle spinning and thus can be used to examine the bonding and electronic structure in layered materials or to observe the chemistry associated with aging coatings. Coupling this sensor coil technology with an arrangement of small magnets will produce a penetrator probe for remote in-situ chemical analysis of groundwater or contaminant sediments. Alternatively, the sensor coil can be further miniaturized to provide sub-micron depth resolution within thin films or to orthoscopically examine living tissue. This thin-layer NMR technique using a stationary meanderline coil in a series-resonant circuit has been demonstrated and it has been determined that the flat meanderline geometry has about he same detection sensitivity as a solenoidal coil, but is specifically tailored to examine planar material layers, while avoiding signals from the bulk.

Cowgill, Donald F. (San Ramon, CA)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Polarization transfer NMR imaging  

DOE Patents (OSTI)

A nuclear magnetic resonance (NMR) image is obtained with spatial information modulated by chemical information. The modulation is obtained through polarization transfer from a first element representing the desired chemical, or functional, information, which is covalently bonded and spin-spin coupled with a second element effective to provide the imaging data. First and second rf pulses are provided at first and second frequencies for exciting the imaging and functional elements, with imaging gradients applied therebetween to spatially separate the nuclei response for imaging. The second rf pulse is applied at a time after the first pulse which is the inverse of the spin coupling constant to select the transfer element nuclei which are spin coupled to the functional element nuclei for imaging. In a particular application, compounds such as glucose, lactate, or lactose, can be labeled with .sup.13 C and metabolic processes involving the compounds can be imaged with the sensitivity of .sup.1 H and the selectivity of .sup.13 C.

Sillerud, Laurel O. (Los Alamos, NM); van Hulsteyn, David B. (Santa Fe, NM)

1990-01-01T23:59:59.000Z

182

Redox-dependent structure change and hyperfine nuclear magnetic resonance shifts in cytochrome c  

SciTech Connect

Proton nuclear magnetic resonance assignments for reduced and oxidized equine cytochrome c show that many individual protons exhibit different chemical shifts in the two protein forms, reflecting diamagnetic shift effects due to structure change, and in addition contact and pseudocontact shifts that occur only in the paramagnetic oxidized form. To evaluate the chemical shift differences for structure change, the authors removed the pseudocontact shift contribution by a calculation based on knowledge of the electron spin g tensor. The g-tensor calculation, when repeated using only 12 available C{sub {alpha}}H proton resonances for cytochrom c from tuna, proved to be remarkably stable. The derived g tensor was then used together with spatial coordinates for the oxidized form to calculate the pseudocontact shift contribution to proton resonances at 400 identifiable sites throughout the protein, so that the redox-dependent chemical shift discrepancy, could be evaluated. Large residual changes in chemical shift define the Fermi contact shifts, where are found as expected to be limited to the immediate covalent structure of the heme and its ligands and to be asymmetrically distributed over the heme. The chemical shift discrepancies observed appear in the main to reflect structure-dependent diamagnetic shifts rather than hyperfine effects due to displacements in the pseudocontact shift field. Although 51 protons in 29 different residues exhibit significant chemical shift changes, the general impressions one of small structural adjustments to redox-dependent strain rather than sizeable structural displacements or rearrangements.

Feng, Yiquing; Roder, H.; Englander, S.W. (Univ. of Pennsylvania, Philadelphia (USA))

1990-04-10T23:59:59.000Z

183

Raftery Group NMR Probe Development Program The Raftery group has made a number of developments in NMR probes for analytical NMR applications.  

E-Print Network (OSTI)

Raftery Group NMR Probe Development Program The Raftery group has made a number of developments in NMR probes for analytical NMR applications. Shown below are some of the advances made over the past several years. Dual Volume Double Resonance Microcoil NMR Probe Dual Coil probe has the upper coil

Raftery, Dan

184

Nuclear-electronic spin systems, magnetic resonance, and quantum information processing  

E-Print Network (OSTI)

A promising platform for quantum information processing is that of silicon impurities, where the quantum states are manipulated by magnetic resonance. Such systems, in abstraction, can be considered as a nucleus of arbitrary spin coupled to an electron of spin one-half via an isotropic hyperfine interaction. We therefore refer to them as "nuclear-electronic spin systems". The traditional example, being subject to intensive experimental studies, is that of phosphorus doped silicon (Si:P) which couples a spin one-half electron to a nucleus of the same spin, with a hyperfine strength of 117.5 MHz. More recently, bismuth doped silicon (Si:Bi) has been suggested as an alternative instantiation of nuclear-electronic spin systems, differing from Si:P by its larger nuclear spin and hyperfine strength of 9/2 and 1.4754 GHz respectively. The aim of this thesis has been to develop a model that is capable of predicting the magnetic resonance properties of nuclear-electronic spin systems. The theoretical predictions of this model have been tested against experimental data collected on Si:Bi at 4.044 GHz, and have proven quite successful. Furthermore, the larger nuclear spin and hyperfine strength of Si:Bi, compared with that of Si:P, are predicted to offer advantages for quantum information processing. Most notable amongst these is that magnetic field-dependent two-dimensional decoherence free subspaces, called optimal working points, have been identified to exist in Si:Bi, but not Si:P.

M. H. Mohammady

2013-04-30T23:59:59.000Z

185

High Temperature, Large Sample Volume, Constant Flow Magic Angle Spinning NMR Probe for a 11  

NLE Websites -- All DOE Office Websites (Extended Search)

High Temperature, Large Sample Volume, Constant Flow Magic Angle Spinning NMR Probe for a High Temperature, Large Sample Volume, Constant Flow Magic Angle Spinning NMR Probe for a 11.7 T Magnetic Field for In Situ Catalytic Reaction Characterization Project start date: April 1, 2007 EMSL Lead Investigator: Joseph Ford, EMSL High Field Magnetic Resonance Facility Co-investigators: Jian Zhi Hu, Macromolecular Structure and Dynamics, Biological Science Division, FCSD Jesse Sears and David W. Hoyt, EMSL High Field Magnetic Resonance Facility Detailed understanding of the mechanisms involved in a catalytic reaction requires identification of the nature of the active sites and the temporal evolution of reaction intermediates. Although optical methods such as UV-visible and infrared (IR) spectroscopies can be used for some types of reactions, these do not

186

Diffusion-Weighted Magnetic Resonance Imaging in Monitoring Rectal Cancer Response to Neoadjuvant Chemoradiotherapy  

SciTech Connect

Purpose: To prospectively monitor the response in patients with locally advanced nonmucinous rectal cancer after chemoradiotherapy (CRT) using diffusion-weighted magnetic resonance imaging. The histopathologic finding was the reference standard. Methods and Materials: The institutional review board approved the present study. A total of 62 patients (43 men and 19 women; mean age, 64 years; range, 28-83) provided informed consent. T{sub 2}- and diffusion-weighted magnetic resonance imaging scans (b value, 0 and 1,000 mm{sup 2}/s) were acquired before, during (mean 12 days), and 6-8 weeks after CRT. We compared the median apparent diffusion coefficients (ADCs) between responders and nonresponders and examined the associations with the Mandard tumor regression grade (TRG). The postoperative nodal status (ypN) was evaluated. The Mann-Whitney/Wilcoxon two-sample test was used to evaluate the relationships among the pretherapy ADCs, extramural vascular invasion, early percentage of increases in ADCs, and preoperative ADCs. Results: Low pretreatment ADCs (<1.0 Multiplication-Sign 10{sup -3}mm{sup 2}/s) were correlated with TRG 4 scores (p = .0011) and associated to extramural vascular invasion with ypN+ (85.7% positive predictive value for ypN+). During treatment, the mean percentage of increase in tumor ADC was significantly greater in the responders than in the nonresponders (p < .0001) and a >23% ADC increase had a 96.3% negative predictive value for TRG 4. In 9 of 16 complete responders, CRT-related tumor downsizing prevented ADC evaluations. The preoperative ADCs were significantly different (p = .0012) between the patients with and without downstaging (preoperative ADC {>=}1.4 Multiplication-Sign 10{sup -3}mm{sup 2}/s showed a positive and negative predictive value of 78.9% and 61.8%, respectively, for response assessment). The TRG 1 and TRG 2-4 groups were not significantly different. Conclusion: Diffusion-weighted magnetic resonance imaging seems to be a promising tool for monitoring the response to CRT.

Barbaro, Brunella, E-mail: bbarbaro@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Vitale, Renata; Valentini, Vincenzo; Illuminati, Sonia [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Vecchio, Fabio M. [Department of Pathology, Catholic University School of Medicine, Rome (Italy); Rizzo, Gianluca [Department of Surgery, Catholic University School of Medicine, Rome (Italy); Gambacorta, Maria Antonietta [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy); Coco, Claudio; Crucitti, Antonio; Persiani, Roberto; Sofo, Luigi [Department of Surgery, Catholic University School of Medicine, Rome (Italy); Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Catholic University School of Medicine, Rome (Italy)

2012-06-01T23:59:59.000Z

187

Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device  

Science Conference Proceedings (OSTI)

Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J

2008-10-29T23:59:59.000Z

188

Destabilization of the trapped electron mode by magnetic curvature drift resonances  

SciTech Connect

Electron curvature drift resonances, ignored in earlier work on the trapped-electron modes, are found to exert a strong destabilizing influence in the lower collision frequency range of these instabilities. Effects arising from ion temperature gradients, shear, and finite ion gyroradius are included with these vector nebla-drifts in the analysis, and the resultant eigenvalue equation is solved by numerical procedures rather than the commonly used perturbation techniques. For typical tokamak parameters the maximum growth rates are found to be increased over earlier estimates by roughly a factor of 4, and requirements on magnetic shear strength for stabilization are likewise more severe and very difficult to satisfy. For inverted density profiles, this new destabilizing effect is rendered ineffective, with the result that the modes can be stabilized for achievable values of shear provided the temperature gradients are not too severe. Estimates of the particle and thermal energy transport are given for both normal and inverted profiles. (auth)

Adam, J.C.; Tang, W.M.; Rutherford, P.H.

1975-12-01T23:59:59.000Z

189

Three path interference using nuclear magnetic resonance: a test of the consistency of Born's rule  

E-Print Network (OSTI)

The Born rule is at the foundation of quantum mechanics and transforms our classical way of understanding probabilities by predicting that interference occurs between pairs of independent paths of a single object. One consequence of the Born rule is that three way (or three paths) quantum interference does not exist. In order to test the consistency of the Born rule, we examine detection probabilities in three path intereference using an ensemble of spin-1/2 quantum registers in liquid state nuclear magnetic resonance (LSNMR). As a measure of the consistency, we evaluate the ratio of three way interference to two way interference. Our experiment bounded the ratio to the order of $10^{-3} \\pm 10^{-3}$, and hence it is consistent with Born's rule.

Daniel K. Park; Osama Moussa; Raymond Laflamme

2012-07-10T23:59:59.000Z

190

Models of Chemical Structure and Dynamics via Nuclear Magnetic Resonance and Ab Initio Computational Chemistry  

E-Print Network (OSTI)

Resolution NMR Theory and Chemical Application ; 3rd ed. ,Methods. In Encyclopedia of Chemical Physics and PhysicalGROUPS ON THE PHYSICAL AND CHEMICAL BEHAVIOR OF CINCHONA

Lai, Jinfeng

2009-01-01T23:59:59.000Z

191

Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials and organisms  

E-Print Network (OSTI)

r I- t of silica aerogels by Xe-129 NMR spectroscopy andcatalysts, ceramics, aerogels, food products, and antiquatedxenon penetration within an aerogel sample as a function of

Goodson, B.M.

2010-01-01T23:59:59.000Z

192

Nuclear magnetic resonance wide-line study of hydrogen in the yttrium-yttrium dihydride system  

DOE Green Energy (OSTI)

The /sup 1/H nuclear magnetic resonance was studied in the yttrium-hydrogen system YH/sub x/ in the composition range 0.20 less than or equal to x less than or equal to 1.98 and temperature range 77 K less than or equal to T less than or equal to 490/sup 0/K. Both ..cap alpha..- and ..beta..-phases of YH/sub x/ were investigated in polycrystalline (powdered) specimens. Rigid lattice proton resonance second moments were obtained for both ..cap alpha..- and ..beta..-phase samples. Analysis of the second moment for ..cap alpha..-YH/sub x/ (..cap alpha..-phase) indicates that the hydrogen resides in both the tetrahedral and octahedral interstitial sites of the hcp Y lattice. Second moment values for ..beta..-YH/sub x/ (..beta..-phase) indicate that a sizeable fraction of the octahedral interstitial sites in the fcc yttrium metal lattice are occupied by hydrogen, while a nonnegligible fraction of the tetrahedral interstitial sites are vacant. For example, in YH/sub 1.98/, 28% of the octahedral sites are occupied, while 15% of the tetrahedral sites are vacant. The results for ..beta..-YH/sub x/ also indicate that as the H concentration increases, the probability of H occupation of octahedral sites increases.

Anderson, D.L.

1980-03-01T23:59:59.000Z

193

EMSL Research and Capability Development Proposals Cryogenic NMR and Advanced Electronic Structure Theory as a Unique EMSL Capability  

NLE Websites -- All DOE Office Websites (Extended Search)

Temperature dependence of the on-resonance portion Temperature dependence of the on-resonance portion of the 55 Mn-NMR spectrum of a Mn(IV,IV) dimer acquired at 9.4 T. EMSL Research and Capability Development Proposals Cryogenic NMR and Advanced Electronic Structure Theory as a Unique EMSL Capability for Complex Systems: Application to the Photosynthetic Energy Conversion Systems Project start date: April 1, 2010 EMSL Lead Investigator: Ping Yang Molecular Science Computing Group, EMSL, PNNL Co-investigator: Andrew S. Lipton Cell Biology & Biochemistry, FCSD, PNNL Collaborator: K.V. Lakshmi Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute The goal of this proposal is to demonstrate a unique capability to be enabled at EMSL-the integration of leading-edge cryogenic nuclear magnetic resonance (NMR) measurements and advanced electronic

194

Dynamics of lipid bilayers from comparative analysis of 2 nuclear magnetic resonance relaxation data as a function  

E-Print Network (OSTI)

to the predominant mechanisms of nuclear spin relax- ation in lipid bilayers. To critically test various dDynamics of lipid bilayers from comparative analysis of 2 H and 13 C nuclear magnetic resonance September 1997 Analysis of the nuclear spin relaxation rates of lipid membranes provides a powerful means

Brown, Michael F.

195

Search for magnetic dipole strength and giant spin-flip resonances in heavy nuclei. [120 to 200 MeV  

SciTech Connect

A description is given of the use of high-resolution (n,n) scattering and the (p,n) reaction as tools to investigate highly excited states, with emphasis on information pertaining to magnetic dipole strength and giant spin-flip resonances in heavy nuclei. It is shown how the ability to determine uniquely the spins and parities of resonances observed in neutron scattering has been instrumental to an understanding of the distribution of M1 strength in /sup 207/ /sup 208/Pb. Some recent results of (p,n) studies with intermediate energy protons are discussed. Energy systematics of the giant Gamow-Teller (GT) resonance as well as new ..delta..l = ..delta..S = 1 resonance with J/sup ..pi../ = (1,2)/sup -/ are presented. It is shown how the (p,n) reaction might be useful in locating M1 strength in heavy nuclei. 20 figures.

Horen, D.J.

1980-01-01T23:59:59.000Z

196

Apparatus for preparing a solution of a hyperpolarized noble gas for NMR and MRI analysis  

DOE Patents (OSTI)

The present invention relates generally to nuclear magnetic resonance (NMR) techniques for both spectroscopy and imaging. More particularly, the present invention relates to methods in which hyperpolarized noble gases (e.g., Xe and He) are used to enhance and improve NMR and MRI. Additionally, the hyperpolarized gas solutions of the invention are useful both in vitro and in vivo to study the dynamics or structure of a system. When used with biological systems, either in vivo or in vitro, it is within the scope of the invention to target the hyperpolarized gas and deliver it to specific regions within the system.

Pines, Alexander (Berkeley, CA); Budinger, Thomas (Berkeley, CA); Navon, Gil (Ramat Gan, IL); Song, Yi-Qiao (Berkeley, CA); Appelt, Stephan (Waiblingen, DE); Bifone, Angelo (Rome, IT); Taylor, Rebecca (Berkeley, CA); Goodson, Boyd (Berkeley, CA); Seydoux, Roberto (Berkeley, CA); Room, Toomas (Albany, CA); Pietrass, Tanja (Socorro, NM)

2008-06-10T23:59:59.000Z

197

Fe K-edge X-ray resonant magnetic scattering from Ba(Fe1?xCox)2As2 superconductors  

SciTech Connect

We present an X-ray resonant magnetic scattering study at the Fe-K absorption edge of the BaFe2As2 compound. The energy spectrum of the resonant scattering, together with our calculation using the full-potential linear-augmented plane wave method with a local density functional suggests that the observed resonant scattering arises from electric dipole (E1) transitions. We discuss the role of Fe K-edge X-ray resonant magnetic scattering in understanding the relationship between the structure and the antiferromagnetic transition in the doped Ba(Fe1?xCox)2As2 superconductors.

Kim, Min Gyu; Kreyssig, Andreas; Lee, Yongbin; McQueeney, Robert J.; Harmon, Bruce N.; Goldman, Alan I.

2012-06-15T23:59:59.000Z

198

Ultra-low field magnetic resonance using optically pumped noble gases and SQUID detection  

E-Print Network (OSTI)

7780 Gradient Amplifiers TTL I l co Gradient Coils I FigureMacNMR version 4.5.9. One TTL line from the Aries was usedas mentioned in Chapter 3). One TTL line was used to gate a

Wong-Foy, Annjoe G.

2010-01-01T23:59:59.000Z

199

Lithium-7 nuclear magnetic resonance investigation of lithium insertion in hard carbon  

Science Conference Proceedings (OSTI)

Lithium battery anodes based on disordered, hard carbon were prepared by low-temperature (1,000 C) pyrolysis of cotton cloth. Samples were lithiated in an electrochemical cell. The Li insertion (potential vs. capacity) curve exhibits two different regions: a sloping one, from 1.1 to 0.1 V (vs Li/Li{sup +}) denoted as the high-voltage region (HVR), and a plateau between 0.1 and zero V, denoted as the low-voltage plateau (LVP). Lithium-7 high-resolution (magic angle spinning) nuclear magnetic resonance measurements in fully lithiated samples reveal three main features: a broad line at ca. 50 ppm, a relatively sharp line at 17 ppm, with a shoulder at about zero ppm (all shifts relative to aqueous LiCl). The 50 ppm component is attributed to Li intercalated between turbostratically disordered graphene planes and is associated with the LVP part of the potential curve. The 17 ppm signal arises from a Li site which resides in amorphous hydrogen-containing regions of the carbon and is correlated with the HVR part of the curve. The zero ppm component is attributed to the irreversible portion of the Li (up to {approximately} 20% of the total) which constitutes the solid electrolyte interphase on the surface of the carbon grains formed by electrochemical reduction of the electrolyte. These spectral assignments were verified by running other samples which were electrochemically delithiated to varying degrees.

Dai, Y.; Wang, Y.; Greenbaum, S.G. [City Univ. of New York, NY (United States). Dept. of Physics; Eshkenazi, V.; Peled, E. [Tel Aviv Univ., IL (United States). School of Chemistry

1998-04-01T23:59:59.000Z

200

Respiratory motion of the heart: Implications for magnetic resonance coronary angiography  

Science Conference Proceedings (OSTI)

Magnetic resonance(MR) coronary imaging is susceptible to artifacts caused by motion of the heart. The purpose of this thesis was to study the respiratory motion of the coronary arteries and to use the results to develop strategies for improved MRimaging. The first section of the thesis describes a MR motion correction technique for objects undergoing a 3D affine transformation. The remainder of the thesis focuses on measuring the respiratory motion of the heart from free breathing x-ray angiograms. Stereo reconstruction methods are used to generate 3D models of the arteries from biplane angiograms. A method for tracking the motion of the arteries in a sequence of biplane images is presented next. The algorithm uses 3D regularizing constraints on the length changes of the arteries and on the spatial regularity of their motion. The algorithm was validated using a deforming vascular phantom. RMS 3D distance errors were measured between centerline models tracked in the x-ray images and gold-standard models derived from a gated 3D MR acquisition. The mean error was 0.69±0.06? mm for four different orientations of the x-ray system. The motion field recovered from free breathing angiograms is a combination of the cardiac contraction and respiratory motion of the heart. A cardiac respiratory parametric model is formulated to decompose the field into independent cardiac and respiratory components. Results are presented for ten patients imaged during spontaneous tidal breathing. For all patients

Guy Shechter

2004-01-01T23:59:59.000Z

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201

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

DOE Patents (OSTI)

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.

Hu, Jian Zhi (Richland, WA); Sears, Jr., Jesse A. (Kennewick, WA); Hoyt, David W. (Richland, WA); Wind, Robert A. (Kennewick, WA)

2009-05-19T23:59:59.000Z

202

Resolving the Impact of Biological Processes on Water Transport in Unsaturated Porous Media Through Nuclear Magnetic Resonance Micro-Imaging  

DOE Green Energy (OSTI)

The magnetic resonance microscopy (MRM) work at Montana State University has extended the imaging of a single biofilm in a 1 mm capillary reactor to correlate T2 magnetic relaxation maps displaying biofilm structure with the corresponding velocity patterns in three dimensions in a Staphylococcus epidermidis biofilm fouled square capillary. A square duct geometry is chosen to provide correlation with existing experiments and simulations, as research bioreactors tend to be of square or rectangular cross section for optical or microelectrode access. The spatially resolved velocity data provide details on the impact of biofilm induced advection on mass transport from the bulk fluid to the biofilm and through the capillary bioreactor.

Seymour, Joseph D.

2005-06-01T23:59:59.000Z

203

Automated sample preparation station for studying self-diffusion in porous solids with NMR spectroscopy  

Science Conference Proceedings (OSTI)

In studies of gas diffusion in porous solids with nuclear magnetic resonance (NMR) spectroscopy the sample preparation procedure becomes very important. An apparatus is presented here that pretreats the sample ex situ and accurately sets the desired pressure and temperature within the NMR tube prior to its introduction in the spectrometer. The gas manifold that supplies the NMR tube is also connected to a microbalance containing another portion of the same sample, which is kept at the same temperature as the sample in the NMR tube. This arrangement permits the simultaneous measurement of the adsorption loading on the sample, which is required for the interpretation of the NMR diffusion experiments. Furthermore, to ensure a good seal of the NMR tube, a hybrid valve design composed of titanium, a Teflon registered seat, and Kalrez registered O-rings is utilized. A computer controlled algorithm ensures the accuracy and reproducibility of all the procedures, enabling the NMR diffusion experiments to be performed at well controlled conditions of pressure, temperature, and amount of gas adsorbed on the porous sample.

Hedin, Niklas; DeMartin, Gregory J.; Reyes, Sebastian C. [Corporate Strategic Research, ExxonMobil Research and Engineering Company, 1545 Route 22 East, Annandale, New Jersey 08801 (United States)

2006-03-15T23:59:59.000Z

204

Radiation-Induced Damage to Microstructure of Parotid Gland: Evaluation Using High-Resolution Magnetic Resonance Imaging  

SciTech Connect

Purpose: To elucidate the radiation-induced damage to the microstructure of the parotid gland using high-resolution magnetic resonance imaging. Methods and Materials: High-resolution magnetic resonance imaging of the parotid gland was performed before radiotherapy (RT) and during the RT period or {<=}3 weeks after RT completion for 12 head-and-neck cancer patients using a 1.5-T scanner with a microscopy coil. The maximal cross-sectional area of the gland was evaluated, and changes in the internal architecture of the gland were assessed both visually and quantitatively. Results: Magnetic resonance images were obtained at a median parotid gland dose of 36 Gy (range, 11-64). According to the quantitative analysis, the maximal cross-sectional area of the gland was reduced, the width of the main duct was narrowed, and the intensity ratio of the main duct lumen to background was significantly decreased after RT (p <.0001). According to the visual assessment, the width of the main duct tended to narrow and the contrast of the duct lumen tended to be decreased, but no significant differences were noted. The visibility of the duct branches was unclear in 10 patients (p = .039), and the septum became dense in 11 patients (p = .006) after RT. Conclusion: High-resolution magnetic resonance imaging is a noninvasive method of evaluating radiation-induced changes to the internal architecture of the parotid gland. Morphologic changes in the irradiated parotid gland were demonstrated during the RT course even when a relatively small dose was delivered to the gland.

Kan, Tomoko, E-mail: tkan@grape.med.tottori-u.ac.j [Department of Radiology, Tottori University Faculty of Medicine, Yonago, Tottori (Japan); Kodani, Kazuhiko; Michimoto, Koichi; Fujii, Shinya; Ogawa, Toshihide [Department of Radiology, Tottori University Faculty of Medicine, Yonago, Tottori (Japan)

2010-07-15T23:59:59.000Z

205

Available Technologies: Remote NMR/MRI Detection  

Low field encoding : High field detection = better sensitivity. APPLICATIONS: Enhanced sensitivity expands the uses of nuclear magnetic resonance ...

206

Simulation of chemical reaction dynamics on an NMR quantum computer  

E-Print Network (OSTI)

Quantum simulation can beat current classical computers with minimally a few tens of qubits and will likely become the first practical use of a quantum computer. One promising application of quantum simulation is to attack challenging quantum chemistry problems. Here we report an experimental demonstration that a small nuclear-magnetic-resonance (NMR) quantum computer is already able to simulate the dynamics of a prototype chemical reaction. The experimental results agree well with classical simulations. We conclude that the quantum simulation of chemical reaction dynamics not computable on current classical computers is feasible in the near future.

Dawei Lu; Nanyang Xu; Ruixue Xu; Hongwei Chen; Jiangbin Gong; Xinhua Peng; Jiangfeng Du

2011-05-21T23:59:59.000Z

207

ADVANCED SOLIDS NMR STUDIES OF COAL STRUCTURE AND CHEMISTRY  

SciTech Connect

This report covers the progress made on the title project for the project period. The study of coal chemical structure is a vital component of research efforts to develop better chemical utilization of coals, and for furthering our basic understanding of coal geochemistry. In this grant we are addressing several structural questions pertaining to coals with advances in state of the art solids NMR methods. The main activity during this granting period was a completion of a detailed comparative analysis of the suite of spectral editing techniques developed in our laboratory for this purpose. The appended report is a manuscript being submitted to the Journal of Magnetic Resonance on this subject.

1997-09-01T23:59:59.000Z

208

NMR CAT scanner: a new look at the brain  

SciTech Connect

Thin-section transverse axial scans of the healthy human brain have been produced by nuclear magnetic resonance, and these are of sufficient quality to be compared to X-ray CAT scans of the same sections. Not unexpectedly, there are marked differences in the contrast shown by various structures within the brain. It seems even at this early stage that NMR CAT scanning could well become a hazard-free and possibly cheaper alternative method, with considerable potential. The precise technique used and its implementation are discussed, and the methods are compared, particularly with a view to future diagnostic use.

Moore, W.S. (Univ. of Nottingham, University Park, England); Holland, G.N.; Kreel, L.

1980-01-01T23:59:59.000Z

209

NMR characterization of thin films  

SciTech Connect

A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

Gerald, II, Rex E. (Brookfield, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Homer Glen, IL); Diaz, Rocio (Chicago, IL); Vukovic, Lela (Westchester, IL)

2008-11-25T23:59:59.000Z

210

Effect of Gold Marker Seeds on Magnetic Resonance Spectroscopy of the Prostate  

SciTech Connect

Purpose: Magnetic resonance stereoscopic imaging (MRSI) of the prostate is an emerging technique that may enhance targeting and assessment in radiotherapy. Current practices in radiotherapy invariably involve image guidance. Gold seed fiducial markers are often used to perform daily prostate localization. If MRSI is to be used in targeting prostate cancer and therapy assessment, the impact of gold seeds on MRSI must be investigated. The purpose of this study was to quantify the effects of gold seeds on the quality of MRSI data acquired in phantom experiments. Methods and Materials: A cylindrical plastic phantom with a spherical cavity 10 centimeters in diameter wss filled with water solution containing choline, creatine, and citrate. A gold seed fiducial marker was put near the center of the phantom mounted on a plastic stem. Spectra were acquired at 1.5 Tesla by use of a clinical MRSI sequence. The ratios of choline + creatine to citrate (CC/Ci) were compared in the presence and absence of gold seeds. Spectra in the vicinity of the gold seed were analyzed. Results: The maximum coefficient of variation of CC/Ci induced by the gold seed was found to be 10% in phantom experiments at 1.5 T. Conclusion: MRSI can be used in prostate radiotherapy in the presence of gold seed markers. Gold seeds cause small effects (in the order of the standard deviation) on the ratio of the metabolite's CC/Ci in the phantom study done on a 1.5-T scanner. It is expected that gold seed markers will have similar negligible effect on spectra from prostate patients. The maximum of 10% of variation in CC/Ci found in the phantom study also sets a limit on the threshold accuracy of CC/Ci values for deciding whether the tissue characterized by a local spectrum is considered malignant and whether it is a candidate for local boost in radiotherapy dose.

Hossain, Murshed, E-mail: Murshed.Hossain@fccc.edu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Schirmer, Timo [Global MR Applied Science Laboratory, GE Healthcare, Munich (Germany); Richardson, Theresa; Chen, Lili; Buyyounouski, Mark K.; Ma Changming [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

2012-05-01T23:59:59.000Z

211

Magnetic Resonance Imaging-Guided Osseous Biopsy in Children With Chronic Recurrent Multifocal Osteomyelitis  

SciTech Connect

Purpose: To report the safety and diagnostic performance of magnetic resonance (MRI)-guided core biopsy of osseous lesions in children with chronic recurrent multifocal osteomyelitis (CRMO) that were visible on MRI but were occult on radiography and computed tomography (CT). Materials and Methods: A retrospective analysis of MRI-guided osseous biopsy performed in seven children (four girls and three boys; mean age 13 years (range 11 to 14) with CRMO was performed. Indication for using MRI guidance was visibility of lesions by MRI only. MRI-guided procedures were performed with 0.2-Tesla (Magnetom Concerto; Siemens, Erlangen, Germany; n = 5) or 1.5-T (Magnetom Espree; Siemens; n = 2) open MRI systems. Core needle biopsy was obtained using an MRI-compatible 4-mm drill system. Conscious sedation or general anesthesia was used. Parameters evaluated were lesion visibility, technical success, procedure time, complications and microbiology, cytology, and histopathology findings. Results: Seven of seven (100%) targeted lesions were successfully visualized and sampled. All obtained specimens were sufficient for histopathological analysis. Length of time of the procedures was 77 min (range 64 to 107). No complications occurred. Histopathology showed no evidence of malignancy, which was confirmed at mean follow-up of 50 months (range 28 to 78). Chronic nonspecific inflammation characteristic for CRMO was present in four of seven (58%) patients, and edema with no inflammatory cells was found in three of seven (42%) patients. There was no evidence of infection in any patient. Conclusion: MRI-guided osseous biopsy is a safe and accurate technique for the diagnosis of pediatric CRMO lesions that are visible on MRI only.

Fritz, Jan, E-mail: jfritz9@jhmi.edu [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Tzaribachev, Nikolay [University Children's Hospital, Eberhard-Karls-University Tuebingen, Division of Pediatric Rheumatology (Germany); Thomas, Christoph [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Wehrmann, Manfred [Eberhard-Karls-University Tuebingen, Department of Pathology (Germany); Horger, Marius S. [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Carrino, John A. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science (United States); Koenig, Claudius W.; Pereira, Philippe L. [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology (Germany)

2012-02-15T23:59:59.000Z

212

Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Metastatic Potential of Melanoma Xenografts  

SciTech Connect

Purpose: Gadolinium diethylene-triamine penta-acetic acid (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been suggested as a useful noninvasive method for characterizing the physiologic microenvironment of tumors. In the present study, we investigated whether Gd-DTPA-based DCE-MRI has the potential to provide biomarkers for hypoxia-associated metastatic dissemination. Methods and Materials: C-10 and D-12 melanoma xenografts were used as experimental tumor models. Pimonidazole was used as a hypoxia marker. A total of 60 tumors were imaged, and parametric images of K{sup trans} (volume transfer constant of Gd-DTPA) and v{sub e} (fractional distribution volume of Gd-DTPA) were produced by pharmacokinetic analysis of the DCE-MRI series. The host mice were killed immediately after DCE-MRI, and the primary tumor and the lungs were resected and prepared for histologic assessment of the fraction of pimonidazole-positive hypoxic tissue and the presence of lung metastases, respectively. Results: Metastases were found in 11 of 26 mice with C-10 tumors and 14 of 34 mice with D-12 tumors. The primary tumors of the metastatic-positive mice had a greater fraction of hypoxic tissue (p = 0.00031, C-10; p < 0.00001, D-12), a lower median K{sup trans} (p = 0.0011, C-10; p < 0.00001, D-12), and a lower median v{sub e} (p = 0.014, C-10; p = 0.016, D-12) than the primary tumors of the metastatic-negative mice. Conclusions: These findings support the clinical attempts to establish DCE-MRI as a method for providing biomarkers for tumor aggressiveness and suggests that primary tumors characterized by low K{sup trans} and low v{sub e} values could have a high probability of hypoxia-associated metastatic spread.

Ovrebo, Kirsti Marie; Ellingsen, Christine; Galappathi, Kanthi [Group of Radiation Biology and Tumor Physiology, Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Rofstad, Einar K., E-mail: einar.k.rofstad@rr-research.no [Group of Radiation Biology and Tumor Physiology, Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway)

2012-05-01T23:59:59.000Z

213

Image-Based Monitoring of Magnetic Resonance-Guided Thermoablative Therapies for Liver Tumors  

SciTech Connect

Minimally invasive treatment options for liver tumor therapy have been increasingly used during the last decade because their benefit has been proven for primary and inoperable secondary liver tumors. Among these, radiofrequency ablation has gained widespread consideration. Optimal image-guidance offers precise anatomical information, helps to position interventional devices, and allows for differentiation between already-treated and remaining tumor tissue. Patient safety and complete ablation of the entire tumor are the overriding objectives of tumor ablation. These may be achieved most elegantly with magnetic resonance (MR)-guided therapy, where monitoring can be performed based on precise soft-tissue imaging and additional components, such as diffusion-weighted imaging and temperature mapping. New MR scanner types and newly developed sequence techniques have enabled MR-guided intervention to move beyond the experimental phase. This article reviews the current role of MR imaging in guiding radiofrequency ablation. Signal characteristics of primary and secondary liver tumors are identified, and signal alteration during therapy is described. Diffusion-weighted imaging (DWI) and temperature mapping as special components of MR therapy monitoring are introduced. Practical information concerning coils, sequence selection, and parameters, as well as sequence gating, is given. In addition, sources of artifacts are identified and techniques to decrease them are introduced, and the characteristic signs of residual tumor in T1-, T2-, and DWI are described. We hope to enable the reader to choose MR sequences that allow optimal therapy monitoring depending on the initial signal characteristics of the tumor as well as its size and location in the liver.

Rempp, Hansjoerg, E-mail: hansjoerg.rempp@med.uni-tuebingen.de; Clasen, Stephan [Eberhard Karls University of Tuebingen, Department of Diagnostic and Interventional Radiology (Germany); Pereira, Philippe L. [SLK-Kliniken, Clinic for Radiology, Nuclear Medicine, and Minimal Invasive Therapies (Germany)

2012-12-15T23:59:59.000Z

214

Method for nuclear magnetic resonance imaging using deuterum as a contrast agent  

DOE Patents (OSTI)

A method for in vivo NMR imaging of the blood vessels and organs of a patient characterized by using a dark dye-like imaging substance consisting essentially of a stable, high-purity concentration of D.sub.2 O in a solution with water.

Kehayias, Joseph J. (Chestnut Hill, MA); Joel, Darrel D. (Setauket, NY); Adams, William H. (Eastport, NY); Stein, Harry L. (Glen Head, NY)

1990-01-01T23:59:59.000Z

215

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution conductivity imaging  

E-Print Network (OSTI)

to a conductor generates a constant magnetic field with flux density jB r . If the current carrying conductor potentials and the magnetic fields produced by the probing current are measured. Surface potentials and the point spread function is not space invariant. On the other hand, magnetic field and electrical current

Eyüboðlu, Murat

216

NMR monitoring of intracellular sodium in dog and rabbit kidney tubules  

SciTech Connect

{sup 23}Na-nuclear magnetic resonance (NMR) was used to monitor intra- and extracellular sodium in suspensions of dog cortical tubules, rabbit cortical tubules, and dog thick ascending limbs. The NMR visibility of the intracellular sodium was determined by comparing the NMR and flame photometry results and by redistributing the sodium ions between the intra- and extracellular compartments using the ionophore nystatin (influx) or sodium substitution for choline in the extracellular fluid (efflux). The intracellular sodium visibility was {approximately}30% for the total sodium and 58% for the transportable sodium. Addition of sodium to sodium-depleted homogenates of dog renal cortex also showed a loss of visibility. The values of the relaxation times T{sub 1} and T{sub 2} were determined but could not be correlated with the visibility measurements. The intracellular sodium concentration in dog cortical tubules incubated in optimal biochemical conditions was estimated at 51 mM was dependent on the extracellular sodium concentration.

Boulanger, Y.; Vinay, P.; Boulanger, M. (Universite de Montreal, Quebec (Canada))

1987-11-01T23:59:59.000Z

217

Quantitative Determination of Chemical Processes by Dynamic Nuclear Polarization Enhanced Nuclear Magnetic Resonance Spectroscopy  

E-Print Network (OSTI)

Dissolution dynamic nuclear polarization (DNP) provides several orders of magnitude of NMR signal enhancement by converting the much larger electron spin polarization to nuclear spin polarization. Polarization occurs at low temperature (1.4K) and is followed by quickly dissolving the sample for room temperature NMR detection. DNP is generally applicable to almost any small molecules and can polarize various nuclei including 1H, 19F and 13C. The large signal from DNP enhancement reduces the limit of detection to micromolar or sub-micromolar concentration in a single scan. Since DNP enhancement often provides the only source for the observable signal, it enables tracking of the polarization flow. Therefore, DNP is ideal for studying chemical processes. Here, quantitative tools are developed to separate kinetics and spin relaxation, as well as to obtain structural information from these measurements. Techniques needed for analyzing DNP polarized sample are different from those used in conventional NMR because a large, yet non-renewable hyperpolarization is available. Using small flip angle pulse excitation, the hyperpolarization can still be divided into multiple scans. Based on this principle, a scheme is presented that allows reconstruction of indirect spectral dimensions similarly to conventional 2D NMR. Additionally, small flip angle pulses can be used to obtain a succession of scans separated in time. A model describing the combined effects of the evolution of a chemical process and of spin-lattice relaxation is shown. Applied to a Diels-Alder reaction, it permitted measuring kinetics along with the effects of auto- and cross-relaxation. DNP polarization of small molecules also shows significant promise for studying protein-ligand interaction. The binding of fluorinated ligands to the protease trypsin was studied through the observation of various NMR parameter changes, such as line width, signal intensity and chemical shift of the ligands. Intermolecular polarization transfer from hyperpolarized ligand to protein can further provide information about the binding pocket of the protein. As an alternative to direct observation of protein signal, a model is presented to describe a two-step intermolecular polarization transfer between competitively binding ligands mediated through the common binding pocket of the protein. The solutions of this model relate the evolution of signal intensities to the intermolecular cross relaxation rates, which depend on individual distances in the binding epitope. In summary, DNP provides incomparable sensitivity, speed and selectivity to NMR. Quantitative models such as those discussed here enable taking full advantage of these benefits for the study of chemical processes.

Zeng, Haifeng

2012-05-01T23:59:59.000Z

218

Tumor Volume Reduction Rate Measured by Magnetic Resonance Volumetry Correlated With Pathologic Tumor Response of Preoperative Chemoradiotherapy for Rectal Cancer  

SciTech Connect

Purpose: To determine whether the tumor volume reduction rate (TVRR) measured using three-dimensional region-of-interest magnetic resonance volumetry correlates with the pathologic tumor response after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. Methods and Materials: The study included 405 patients with locally advanced rectal cancer (cT3-T4) who had undergone preoperative CRT and radical proctectomy. The tumor volume was measured using three-dimensional region-of-interest magnetic resonance volumetry before and after CRT but before surgery. We analyzed the correlation between the TVRR and the pathologic tumor response in terms of downstaging and tumor regression grade (TRG). Downstaging was defined as ypStage 0-I (ypT0-T2N0M0), and the TRG proposed by Dworak et al. was used. Results: The mean TVRR was 65.0% {+-} 22.3%. Downstaging and complete regression occurred in 167 (41.2%) and 58 (14.3%) patients, respectively. The TVRRs according to ypT classification (ypT0-T2 vs. ypT3-T4), ypN classification (ypN0 vs. ypN1-N2), downstaging (ypStage 0-I vs. ypStage II-III), good regression (TRG 3-4 vs. TRG 1-2), and complete regression (TRG 4 vs. TRG 1-3) were all significantly different (p <.05). When the TVRR was categorized into three groups (<60%, 60-80%, and >80%), the rates of ypT0-T2, ypN0, downstaging, and good regression were all significantly greater for patients with a TVRR of {>=}60%, as was the complete regression rate for patients with a TVRR >80% (p <.05). Conclusion: The TVRR measured using three-dimensional region-of-interest magnetic resonance volumetry correlated significantly with the pathologic tumor response in terms of downstaging and TRG after preoperative CRT for locally advanced rectal cancer.

Yeo, Seung-Gu [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Radiation Oncology, Soon Chun Hyang University College of Medicine, Cheonan (Korea, Republic of); Kim, Dae Yong, E-mail: radiopiakim@hanmail.ne [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Kim, Tae Hyun [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Jung, Kyung Hae; Hong, Yong Sang [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Medical Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Chang, Hee Jin; Park, Ji Won [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Lim, Seok-Byung [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Colon and Rectal Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Hyo Seong [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Jeong, Seung-Yong [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2010-09-01T23:59:59.000Z

219

The hydration of reactive cement-in-polymer dispersions studied by nuclear magnetic resonance  

Science Conference Proceedings (OSTI)

The behaviour of two novel cement-in-polymer (c/p) dispersions, namely cement-in-poly(vinyl acetate) and cement-in-poly(vinyl alcohol) upon exposure to water at room temperature was investigated by a combination of various NMR methods. The swelling, cracking, and the water ingress were monitored non-destructively using {sup 1}H single point imaging. The hydration of the cement matrix was investigated using {sup 29}Si NMR whilst {sup 13}C CPMAS NMR spectra allowed the quantification of the kinetics of the hydrolysis reaction of poly(vinyl acetate) into poly(vinyl alcohol). The polymer controls the rate of water ingress and swelling which in turn determines the behaviour of the c/p dispersions upon exposure to water. For the cement-in-poly(vinyl alcohol), the rates of water ingress and swelling are much faster than the hydration of the clinker whilst for the cement-in-poly(vinyl acetate) the slow rates of the two processes allow the formation of a cementious matrix which assures the stability of the sample.

Olaru, A.M. [Institut fuer Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen (Germany); Weichold, O. [DWI an der RWTH Aachen, e. V., Pauwelsstrasse 8, 52056 Aachen (Germany); Adams, A., E-mail: aadams@mc.rwth-aachen.de [Institut fuer Technische und Makromolekulare Chemie, RWTH Aachen University, Templergraben 55, 52056 Aachen (Germany)

2011-11-15T23:59:59.000Z

220

Use of earth field spin echo NMR to search for liquid minerals  

DOE Patents (OSTI)

An instrument for measuring the spatial, qualitative and quantitative parameters of an underground nuclear magnetic resonance (NMR) active liquid mineral deposit, including oil and water. A phased array of excitation and receiver antennas on the surface and/or in a borehole excites the NMR active nuclei in the deposit, and using known techniques from magnetic resonance imaging (MRI), the spatial and quantitative distribution of the deposit can be measured. A surface array may utilize, for example, four large (50-500 diameter) diameter wire loops laid on the ground surface, and a weak (1.5-2.5 kHz) alternating current (AC) field applied, matching the NMR frequency of hydrogen in the rather flat and uniform earth magnetic field. For a short duration (a few seconds) an additional gradient field can be generated, superimposed to the earth field, by applying direct current (DC) to the grid (wire loops), enhancing the position sensitivity of the spin-echo and also suppressing large surface water signals by shifting them to a different frequency. The surface coil excitation can be combined with downhole receivers, which are much more radio-quiet compared to surface receivers, and this combination also enhances the position resolution of the MRI significantly. A downhole receiver module, for example, may have a 5.5 inch diameter and fit in a standard six inch borehole having a one-quarter inch thick stainless steel casing. The receiver module may include more than one receiver units for improved penetration and better position resolution.

Stoeffl, Wolfgang (Livermore, CA)

2001-01-01T23:59:59.000Z

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221

Magnetic Resonance-Based Treatment Planning for Prostate Intensity-Modulated Radiotherapy: Creation of Digitally Reconstructed Radiographs  

SciTech Connect

Purpose: To develop a technique to create magnetic resonance (MR)-based digitally reconstructed radiographs (DRR) for initial patient setup for routine clinical applications of MR-based treatment planning for prostate intensity-modulated radiotherapy. Methods and Materials: Twenty prostate cancer patients' computed tomography (CT) and MR images were used for the study. Computed tomography and MR images were fused. The pelvic bony structures, including femoral heads, pubic rami, ischium, and ischial tuberosity, that are relevant for routine clinical patient setup were manually contoured on axial MR images. The contoured bony structures were then assigned a bulk density of 2.0 g/cm{sup 3}. The MR-based DRRs were generated. The accuracy of the MR-based DDRs was quantitatively evaluated by comparing MR-based DRRs with CT-based DRRs for these patients. For each patient, eight measuring points on both coronal and sagittal DRRs were used for quantitative evaluation. Results: The maximum difference in the mean values of these measurement points was 1.3 {+-} 1.6 mm, and the maximum difference in absolute positions was within 3 mm for the 20 patients investigated. Conclusions: Magnetic resonance-based DRRs are comparable to CT-based DRRs for prostate intensity-modulated radiotherapy and can be used for patient treatment setup when MR-based treatment planning is applied clinically.

Chen, Lili [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)]. E-mail: lili.chen@fccc.edu; Nguyen, Thai-Binh [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Jones, Elan [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Chen Zuoqun [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Luo Wei [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Wang Lu [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Price, Robert A. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Pollack, Alan [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Ma, C.-M. Charlie [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States)

2007-07-01T23:59:59.000Z

222

Magnetic resonance as a structural probe of a uranium (VI) sol-gel process  

DOE Green Energy (OSTI)

NMR investigations on the ORNL process for sol-gel synthesis of microspherical nuclear fuel (UO{sub 2}), has been useful in sorting out the chemical mechanism in the sol-gel steps. {sup 13}C, {sup 15}N, and {sup 1}H NMR studies on the HMTA gelation agent (Hexamethylene tetramine, C{sub 6}H{sub l2}N{sub 4}) has revealed near quantitative stability of this adamantane-like compound in the sol-Gel process, contrary to its historical role as an ammonia source for gelation from the worldwide technical literature. {sub 17}0 NMR of uranyl (UO{sub 2}{sup ++}) hydrolysis fragments produced in colloidal sols has revealed the selective formation of a uranyl trimer, ((UO{sub 2}){sub 3}({mu}{sub 3}-O)({mu}{sub 2}-OH){sub 3}){sup +}, induced by basic hydrolysis with the HMTA gelation agent. Spectroscopic results show that trimer condensation occurs during sol-gel processing leading to layered polyanionic hydrous uranium oxides in which HMTAH{sup +} is occluded as an intercalation'' cation. Subsequent sol-gel processing of microspheres by ammonia washing results in in-situ ion exchange and formation of a layered hydrous ammonium uranate with a proposed structural formula of (NH{sub 4}){sub 2}((UO{sub 2}){sub 8}O{sub 4}(OH){sub 10}) {center dot} 8H{sub 2}0. This compound is the precursor to sintered U0{sub 2} ceramic fuel.

King, C.M.; Thompson, M.C.; Buchanan, B.R. (Westinghouse Savannah River Co., Aiken, SC (United States)); King, R.B. (Georgia Univ., Athens, GA (United States). Dept. of Chemistry); Garber, A.R. (South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry)

1989-01-01T23:59:59.000Z

223

Magnetic resonance as a structural probe of a uranium (VI) sol-gel process  

DOE Green Energy (OSTI)

NMR investigations on the ORNL process for sol-gel synthesis of microspherical nuclear fuel (UO{sub 2}), has been useful in sorting out the chemical mechanism in the sol-gel steps. {sup 13}C, {sup 15}N, and {sup 1}H NMR studies on the HMTA gelation agent (Hexamethylene tetramine, C{sub 6}H{sub l2}N{sub 4}) has revealed near quantitative stability of this adamantane-like compound in the sol-Gel process, contrary to its historical role as an ammonia source for gelation from the worldwide technical literature. {sub 17}0 NMR of uranyl (UO{sub 2}{sup ++}) hydrolysis fragments produced in colloidal sols has revealed the selective formation of a uranyl trimer, [(UO{sub 2}){sub 3}({mu}{sub 3}-O)({mu}{sub 2}-OH){sub 3}]{sup +}, induced by basic hydrolysis with the HMTA gelation agent. Spectroscopic results show that trimer condensation occurs during sol-gel processing leading to layered polyanionic hydrous uranium oxides in which HMTAH{sup +} is occluded as an ``intercalation`` cation. Subsequent sol-gel processing of microspheres by ammonia washing results in in-situ ion exchange and formation of a layered hydrous ammonium uranate with a proposed structural formula of (NH{sub 4}){sub 2}[(UO{sub 2}){sub 8}O{sub 4}(OH){sub 10}] {center_dot} 8H{sub 2}0. This compound is the precursor to sintered U0{sub 2} ceramic fuel.

King, C.M.; Thompson, M.C.; Buchanan, B.R. [Westinghouse Savannah River Co., Aiken, SC (United States); King, R.B. [Georgia Univ., Athens, GA (United States). Dept. of Chemistry; Garber, A.R. [South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry

1989-12-31T23:59:59.000Z

224

Nuclear magnetic flowmeter -- Spectrometer with fiber -optical communication line in cooling systems of atomic energy plants  

Science Conference Proceedings (OSTI)

Fiber-optic communication line for transmitting a signal of nuclear magnetic resonance of liquid medium in the ship's central computer was developed. This fiber-optic communication line allows us to give an NMR signal in digital or analog form without ... Keywords: FOCL transmission coefficient, Fiber optic communication line (FOCL), communication system, optical converter, optical modulator

V. V. Davydov; V. I. Dudkin; A. U. Karseev

2013-04-01T23:59:59.000Z

225

Method of using a nuclear magnetic resonance spectroscopy standard. [SO/sub 2/ in gases by fluorescence  

DOE Patents (OSTI)

(CH/sub 3/)/sub 3/SiNSO is produced by the reaction of ((CH/sub 3/)/sub 3/SI)/sub 2/NH with SO/sub 2/. Also produced in the reaction are ((CH/sub 3/)/sub 3/Si)/sub 2/O and a new solid compound (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/). Both (CH/sub 3/)/sub 3/SiNSO and (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO/sub 2/ pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH/sub 3/)/sub 3/Si)/sub 2/NH, whereby any SO/sub 2/ present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO/sub 2/ in the original gas sample. The solid product (NH/sub 4/)((CH/sub 3/)/sub 3/SiOSO/sub 2/) may be used as a standard in solid state NMR spectroscopy, wherein the resonance peaks of either /sup 1/H, /sup 13/C, /sup 15/N, or /sup 29/Si may be used as a reference.

Spicer, L.D.; Bennett, D.W.; Davis, J.F.

1983-05-09T23:59:59.000Z

226

Investigation of Mechanical Activation on Li-N-H Systems Using 6Li Magic Angle Spinning Nuclear Magnetic Resonance at Ultra-High Field  

SciTech Connect

Abstract The significantly enhanced spectral resolution in the 6Li MAS NMR spectra of Li-N-H systems at ultra-high field of 21.1 tesla is exploited, for the first time, to study the detailed electronic and chemical environmental changes associated with mechanical activation of Li-N-H system using high energy balling milling. Complementary to ultra-high field studies, the hydrogen discharge dynamics are investigated using variable temperature in situ 1H MAS NMR at 7.05 tesla field. The significantly enhanced spectral resolution using ultra-high filed of 21.1 tesla was demonstrated along with several major findings related to mechanical activation, including the upfield shift of the resonances in 6Li MAS spectra induced by ball milling, more efficient mechanical activation with ball milling at liquid nitrogen temperature than with ball milling at room temperature, and greatly enhanced hydrogen discharge exhibited by the liquid nitrogen ball milled samples.

Hu, Jian Zhi; Kwak, Ja Hun; Yang, Zhenguo; Osborn, William; Markmaitree, Tippawan; Shaw, Leonard D.

2008-07-15T23:59:59.000Z

227

Magnetic-resonance and thermophysical studies of the magnetic phase diagram for a GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4} single crystal  

Science Conference Proceedings (OSTI)

The antiferromagnetic resonance, heat capacity, magnetic properties, and magnetic phase diagram of a GdFe{sub 3}(BO{sub 3}){sub 4} crystal in which some of the iron ions were substituted by diamagnetic gallium ions have been investigated. It has been found that the Neel temperature upon diamagnetic substitution decreased to 17 K compared to 38 K in the unsubstituted crystal. The effective exchange and anisotropy fields for GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4} have been estimated from the field dependences of magnetization and resonance measurements. The magnetic phase diagram of the crystal has been constructed from magnetic and resonance measurements. In GdFe{sub 2.1}Ga{sub 0.9}(BO{sub 3}){sub 4}, there is no spontaneous reorientation and, in the absence of a magnetic field, the crystal remains an easy-axis one in the entire domain of magnetic ordering. The critical field of the reorientation transition to an induced easy-plane state in a magnetic field along the trigonal axis has been found to increase compared to that in the unsubstituted crystal.

Pankrats, A. I.; Petrakovskii, G. A.; Tugarinov, V. I., E-mail: vit@iph.krasn.ru; Kartashev, A. V.; Temerov, V. L. [Russian Academy of Science, Siberian Branch, Kirensky Institute of Physics (Russian Federation)

2011-09-15T23:59:59.000Z

228

C NMR Spectra C NMR Spectra  

E-Print Network (OSTI)

S16 1 H and 13 C NMR Spectra (see p S3) Me N-i-Pr #12;S17 1 H and 13 C NMR Spectra (see p S3) Me NBn #12;S18 1 H and 13 C NMR Spectra (see p S4) NBn #12;S19 1 H and 13 C NMR Spectra (see p S4) NBn Me Me Me #12;S20 1 H and 13 C NMR Spectra (see p S4) N-n-Bu Me Me Me #12;S21 1 H and 13 C NMR Spectra

Collum, David B.

229

Investigation of wettability by NMR microscopy and spin-lattice relaxation  

Science Conference Proceedings (OSTI)

The wettability of reservoir rock has an important impact on the efficiency of oil recovery processes and the distribution of oil and water within the reservoir. One of the potentially useful tools for wettability measurements is nuclear magnetic resonance (NMR) and spin-lattice relaxation. More recently using NMR microscopy NIPER has developed the capability of imaging one- and two-phase fluid systems in reservoir rock at resolutions to 25 microns. Effects seen in the images of fluids within the pore space of rocks near the rock grain surfaces hinted at the possibility of using NMR microscopy to map the wettability variations at grain sites within the pore space. Investigations were begun using NMR microscopy and spin-lattice relaxation time measurements on rock/fluid systems and on well-defined fractional wet model systems to study these effects. Relaxation data has been modelled using the stretched exponential relationship recently introduced. Comparisons of the NMR microscopy results of the model system with the rock results indicate that the observed effects probably do not reflect actual wettability variations within the pore space. The results of the relaxation time measurements reveal that even in the simple model studied, the behavior of two phases is somewhat ambiguous and much more complex and requires more study.

Doughty, D.A.; Tomutsa, Liviu

1993-11-01T23:59:59.000Z

230

LARGE SCALE PRODUCTION, PURIFICATION, AND 65CU SOLID STATE NMR OF AZURIN  

SciTech Connect

This paper details a way to produce azurin with an effi ciency over 10 times greater than previously described and demonstrates the fi rst solid state nuclear magnetic resonance spectrum of 65Cu(I) in a metalloprotein. A synthetic gene for azurin based upon the DNA sequence from Pseudomonas aeruginosa including the periplasmic targeting sequence was subcloned into a T7 overexpression vector to create the plasmid pGS-azurin, which was transformed into BL21 (DE3) competent cells. The leader sequence on the expressed protein causes it to be exported to the periplasmic space of Escherichia coli. Bacteria grown in a fermentation unit were induced to overexpress the azurin, which was subsequently purifi ed through an endosmotic shock procedure followed by high performance liquid chromatography (HPLC). 1,500 mg of azurin were purifi ed per liter of culture. 65Cu(II) was added to apo-azurin and then reduced. The 65Cu metal cofactor in azurin was observed with solid state nuclear magnetic resonance (NMR) to determine any structural variations that accompanied copper reduction. This is the fi rst solid state NMR spectra of a copper(I) metalloprotein. Analysis of the NMR spectra is being used to complement hypotheses set forth by x-ray diffraction and computational calculations of electron transfer mechanisms in azurin.

Gao, A.; Heck, R.W.

2008-01-01T23:59:59.000Z

231

Dynamic T{sub 2}-mapping during magnetic resonance guided high intensity focused ultrasound ablation of bone marrow  

Science Conference Proceedings (OSTI)

Focal bone tumor treatments include amputation, limb-sparing surgical excision with bone reconstruction, and high-dose external-beam radiation therapy. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is an effective non-invasive thermotherapy for palliative management of bone metastases pain. MR thermometry (MRT) measures the proton resonance frequency shift (PRFS) of water molecules and produces accurate (<1 Degree-Sign C) and dynamic (<5s) thermal maps in soft tissues. PRFS-MRT is ineffective in fatty tissues such as yellow bone marrow and, since accurate temperature measurements are required in the bone to ensure adequate thermal dose, MR-HIFU is not indicated for primary bone tumor treatments. Magnetic relaxation times are sensitive to lipid temperature and we hypothesize that bone marrow temperature can be determined accurately by measuring changes in T{sub 2}, since T{sub 2} increases linearly in fat during heating. T{sub 2}-mapping using dual echo times during a dynamic turbo spin-echo pulse sequence enabled rapid measurement of T{sub 2}. Calibration of T{sub 2}-based thermal maps involved heating the marrow in a bovine femur and simultaneously measuring T{sub 2} and temperature with a thermocouple. A positive T{sub 2} temperature dependence in bone marrow of 20 ms/ Degree-Sign C was observed. Dynamic T{sub 2}-mapping should enable accurate temperature monitoring during MR-HIFU treatment of bone marrow and shows promise for improving the safety and reducing the invasiveness of pediatric bone tumor treatments.

Waspe, Adam C.; Looi, Thomas; Mougenot, Charles; Amaral, Joao; Temple, Michael; Sivaloganathan, Siv; Drake, James M. [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada); Philips Healthcare Canada, Markham, ON, L6C 2S3 (Canada); Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada); Department of Applied Mathematics, University of Waterloo, Waterloo, ON, N2L 3G1 (Canada); Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, M5G 1X8 (Canada)

2012-11-28T23:59:59.000Z

232

Fast Magnetic Resonance Imaging via Adaptive Broadband Encoding of the MR Signal Content  

E-Print Network (OSTI)

signal is radiated from the sample and decays over time both via the return of the sample's magnetization decays after sample excitation. Relaxation times of the order of 1sec in human tissue make the process studies where a continu- ous series of images is required, for example in contrast bolus tracking

Edelman, Alan

233

JOURNAL OF MAGNETIC RESONANCE 54, 170-173 ( 1983) The l-l Hard Pulse:A Simple and Effective Method of Water  

E-Print Network (OSTI)

JOURNAL OF MAGNETIC RESONANCE 54, 170- 173 ( 1983) The l-l Hard Pulse:A Simple and Effective Method the long Alexander (I) and 2-l-4 Redfield (2) pulses and the hard time-shared Redfield (3, 4), jump-return (5), and 1-2-1 pulses (6). The hard time-shared pulse sequences have the significant advantage over

Clore, G. Marius

234

Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy  

E-Print Network (OSTI)

Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...

Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

2012-01-01T23:59:59.000Z

235

Coal liquefaction process streams characterization and evaluation. Characterization of coal-derived materials by field desorption mass spectrometry, two-dimensional nuclear magnetic resonance, supercritical fluid extraction, and supercritical fluid chromatography/mass spectrometry  

SciTech Connect

Under contract from the DOE , and in association with CONSOL Inc., Battelle, Pacific Northwest Laboratory (PNL) evaluated four principal and several complementary techniques for the analysis of non-distillable direct coal liquefaction materials in support of process development. Field desorption mass spectrometry (FDMS) and nuclear magnetic resonance (NMR) spectroscopic methods were examined for potential usefulness as techniques to elucidate the chemical structure of residual (nondistillable) direct coal liquefaction derived materials. Supercritical fluid extraction (SFE) and supercritical fluid chromatography/mass spectrometry (SFC/MS) were evaluated for effectiveness in compound-class separation and identification of residual materials. Liquid chromatography (including microcolumn) separation techniques, gas chromatography/mass spectrometry (GC/MS), mass spectrometry/mass spectrometry (MS/MS), and GC/Fourier transform infrared (FTIR) spectroscopy methods were applied to supercritical fluid extracts. The full report authored by the PNL researchers is presented here. The following assessment briefly highlights the major findings of the project, and evaluates the potential of the methods for application to coal liquefaction materials. These results will be incorporated by CONSOL into a general overview of the application of novel analytical techniques to coal-derived materials at the conclusion of CONSOL`s contract.

Campbell, J.A.; Linehan, J.C.; Robins, W.H. [Battelle Pacific Northwest Lab., Richland, WA (United States)

1992-07-01T23:59:59.000Z

236

NMR Study of the Dynamics of ILs with -CH2Si(CH3)3 vs CH2C(CH3)3  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetic Resonance Study of the Dynamics of Imidazolium Ionic Magnetic Resonance Study of the Dynamics of Imidazolium Ionic Liquids with -CH2Si(CH3)3 vs CH2C(CH3)3 Substituents S. H. Chung, R. Lopato, S. G. Greenbaum, H. Shirota, E. W. Castner, Jr. and J. F. Wishart J. Phys. Chem. B 111, 4885-4893 (2007). [Find paper at ACS Publications] or use ACS Articles on Request Abstract: Trimethylsilylmethyl (TMSiM)-substituted imidazolium bis(trifluoromethylsulfonyl)imide (NTf2-), and tetrafluoroborate (BF4-) ionic liquids (ILs) have lower room-temperature viscosities by factors of 1.6 and 7.4, respectively, than isostructural neopentylimidazolium ILs. In an attempt to account for the effects of silicon substitution in imidazolium RTILs and to investigate the ion dynamics, we report nuclear magnetic resonance (NMR) measurements of 1H (I = 1/2) and 19F (I = 1/2)

237

1D Solution NMR Procedure (Bruker AVANCE Machines running TopSpin under WINDOWS XP)  

E-Print Network (OSTI)

1D Solution NMR Procedure (Bruker AVANCE Machines running TopSpin under WINDOWS XP) Jerry Hu, x7914 NMR yourself; Take everything ferromagnetic or vulnerable to magnetic field, such as mechanic watches them somewhere away from magnets; Table of Contents 1D Solution NMR Procedure

Akhmedov, Azer

238

The Next Challenge in X-Ray Science: Control of Resonant Electronic  

NLE Websites -- All DOE Office Websites (Extended Search)

The Next Challenge in X-Ray Science: Control of Resonant Electronic The Next Challenge in X-Ray Science: Control of Resonant Electronic Processes Wednesday, September 11, 2013 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Joachim Stöhr, LCLS My talk will give a historic perspective of the revolutionary science that was enabled by the advent of high power sources of coherent electromagnetic radiation and the implications for future scientific opportunities with x-ray free electron lasers (X-FELs). The historical journey starts with the development of radar microwave sources in the 1940s that fueled the development of nuclear magnetic resonance (NMR) techniques which by now have led to 6 Nobel Prizes. The theoretical description of NMR as coherent processes between nuclear states by Rabi and Bloch also provided the theoretical basis for the optical laser and its applications. Over the last

239

Minimally Invasive Magnetic Resonance Imaging-Guided Free-Hand Aspiration of Symptomatic Nerve Route Compressing Lumbosacral Cysts Using a 1.0-Tesla Open Magnetic Resonance Imaging System  

SciTech Connect

Purpose: To evaluate the feasibility of minimally invasive magnetic resonance imaging (MRI)-guided free-hand aspiration of symptomatic nerve route compressing lumbosacral cysts in a 1.0-Tesla (T) open MRI system using a tailored interactive sequence. Materials and Methods: Eleven patients with MRI-evident symptomatic cysts in the lumbosacral region and possible nerve route compressing character were referred to a 1.0-T open MRI system. For MRI interventional cyst aspiration, an interactive sequence was used, allowing for near real-time position validation of the needle in any desired three-dimensional plane. Results: Seven of 11 cysts in the lumbosacral region were successfully aspirated (average 10.1 mm [SD {+-} 1.9]). After successful cyst aspiration, each patient reported speedy relief of initial symptoms. Average cyst size was 9.6 mm ({+-}2.6 mm). Four cysts (8.8 {+-} 3.8 mm) could not be aspirated. Conclusion: Open MRI systems with tailored interactive sequences have great potential for cyst aspiration in the lumbosacral region. The authors perceive major advantages of the MR-guided cyst aspiration in its minimally invasive character compared to direct and open surgical options along with consecutive less trauma, less stress, and also less side-effects for the patient.

Bucourt, Maximilian de, E-mail: mdb@charite.de; Streitparth, Florian, E-mail: florian.streitparth@charite.de; Collettini, Federico [Charite-University Medicine, Department of Radiology (Germany); Guettler, Felix [Jena University, Department of Radiology (Germany); Rathke, Hendrik; Lorenz, Britta; Rump, Jens; Hamm, Bernd [Charite-University Medicine, Department of Radiology (Germany); Teichgraeber, U. K. [Jena University, Department of Radiology (Germany)

2012-02-15T23:59:59.000Z

240

TIME DOMAIN MULTIPLE QUANTUM NMR  

E-Print Network (OSTI)

Comparison with Single Quantum NMR C. Frequency Selectiveli, A. Bax, "Two Dimensional NMR" , Delft University Press,G. Bodenhausen, Prog. in NMR Spec. A. Pines, D. Wemmer, J.

Weitekamp, D.P.

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

HYDROGEN AND DEUTERIUM NMR OF SOLIDS BY MAGIC ANGLE SPINNING  

DOE Green Energy (OSTI)

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 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. Theoretical and technical aspects are described in the text with comments on the application of the principles to other nuclei of interest.

Eckman, R.R.

1982-10-01T23:59:59.000Z

242

Mobility of organic pollutants in soil components. What role can magic angle spinning NMR play?  

E-Print Network (OSTI)

Mobility of organic pollutants in soil components. What role can magic angle spinning NMR play? C resonance (NMR) spectroscopy on dry samples. We recently demonstrated the potential of the 1 H high resolution magic angle spinning (MAS) NMR technique to study such mechanisms in situ on highly hydrated

Paris-Sud XI, Université de

243

Single-Scan NMR Spectroscopy at Arbitrary Dimensions Yoav Shrot and Lucio Frydman*  

E-Print Network (OSTI)

Single-Scan NMR Spectroscopy at Arbitrary Dimensions Yoav Shrot and Lucio Frydman* Contribution resonance (NMR) provides one of the foremost analytical tools available to elucidate the structure a parametric incrementation of their values throughout independent experiments. Two-dimensional (2D) NMR

Frydman, Lucio

244

Hydrogen and deuterium NMR of solids by magic-angle spinning  

DOE Green Energy (OSTI)

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.

Eckman, R.R.

1982-10-01T23:59:59.000Z

245

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

246

EMSL: Capabilities: NMR and EPR  

NLE Websites -- All DOE Office Websites (Extended Search)

NMR and EPR Additional Information Meet the NMR and EPR Experts Related EMSL User Projects NMR and EPR Tools are Applied to all Science Themes 900-MHz NMR: Accelerating Scientific...

247

Abstract-In this study, imaging of electrical current density in conducting objects, which contain nuclear magnetic resonance  

E-Print Network (OSTI)

at each cycle within the object. The applied current pulse creates a measurable magnetic flux density. The component of magnetic flux density parallel to the main magnetic field accumulates an additional phase with and without the current pulse. Measurement of all three components of magnetic flux density makes

Eyüboðlu, Murat

248

NMR Nomenclature: nuclear spin properties and conventions for chemical shifts (IUPAC Recommendations 2001)  

Science Conference Proceedings (OSTI)

A unified scale is recommended for reporting the NMR chemical shifts of all nuclei relative to the 1H resonance of tetramethylsilane. The unified scale is designed to provide a precise ratio, ?, of the resonance frequency of a ... Keywords: IUPAC, NMR, chemical shift scales, notation, nuclear spin properties

Robin K. Harris; Edwin D. Becker; Sonia M. Cabral De Menezes; Robin Goodfellow; Pierre Granger

2002-09-01T23:59:59.000Z

249

A Signal-Inducing Bone Cement for Magnetic Resonance Imaging-Guided Spinal Surgery Based on Hydroxyapatite and Polymethylmethacrylate  

Science Conference Proceedings (OSTI)

The aim of this study was to develop a signal-inducing bone cement for magnetic resonance imaging (MRI)-guided cementoplasty of the spine. This MRI cement would allow precise and controlled injection of cement into pathologic lesions of the bone. We mixed conventional polymethylmethacrylate bone cement (PMMA; 5 ml methylmethacrylate and 12 g polymethylmethacrylate) with hydroxyapatite (HA) bone substitute (2-4 ml) and a gadolinium-based contrast agent (CA; 0-60 {mu}l). The contrast-to-noise ratio (CNR) of different CA doses was measured in an open 1.0-Tesla scanner for fast T1W Turbo-Spin-Echo (TSE) and T1W TSE pulse sequences to determine the highest signal. We simulated MRI-guided cementoplasty in cadaveric spines. Compressive strength of the cements was tested. The highest CNR was (1) 87.3 (SD 2.9) in fast T1W TSE for cements with 4 {mu}l CA/ml HA (4 ml) and (2) 60.8 (SD 2.4) in T1W TSE for cements with 1 {mu}l CA/ml HA (4 ml). MRI-guided cementoplasty in cadaveric spine was feasible. Compressive strength decreased with increasing amounts of HA from 46.7 MPa (2 ml HA) to 28.0 MPa (4 ml HA). An MRI-compatible cement based on PMMA, HA, and CA is feasible and clearly visible on MRI images. MRI-guided spinal cementoplasty using this cement would permit direct visualization of the cement, the pathologic process, and the anatomical surroundings.

Wichlas, Florian, E-mail: florian.wichlas@charite.de; Seebauer, Christian J.; Schilling, Rene [University Charite, Center for Musculoskeletal Surgery (Germany); Rump, Jens [University Charite, Department of Radiology (Germany); Chopra, Sascha S. [University Charite, Center for Musculoskeletal Surgery (Germany); Walter, Thula; Teichgraeber, Ulf K. M. [University Charite, Department of Radiology (Germany); Bail, Hermann J. [University Charite, Center for Musculoskeletal Surgery (Germany)

2012-06-15T23:59:59.000Z

250

Magnetic Resonance Lymphography Findings in Patients With Biochemical Recurrence After Prostatectomy and the Relation With the Stephenson Nomogram  

SciTech Connect

Purpose: To estimate the occurrence of positive lymph nodes on magnetic resonance lymphography (MRL) in patients with a prostate-specific antigen (PSA) recurrence after prostatectomy and to investigate the relation between score on the Stephenson nomogram and lymph node involvement on MRL. Methods and Materials: Sixty-five candidates for salvage radiation therapy were referred for an MRL to determine their lymph node status. Clinical and histopathologic features were recorded. For 49 patients, data were complete to calculate the Stephenson nomogram score. Receiver operating characteristic (ROC) analysis was performed to determine how well this nomogram related to the MRL result. Analysis was done for the whole group and separately for patients with a PSA <1.0 ng/mL to determine the situation in candidates for early salvage radiation therapy, and for patients without pathologic lymph nodes at initial lymph node dissection. Results: MRL detected positive lymph nodes in 47 patients. ROC analysis for the Stephenson nomogram yielded an area under the curve (AUC) of 0.78 (95% confidence interval, 0.61-0.93). Of 29 patients with a PSA <1.0 ng/mL, 18 had a positive MRL. Of 37 patients without lymph node involvement at initial lymph node dissection, 25 had a positive MRL. ROC analysis for the Stephenson nomogram showed AUCs of 0.84 and 0.74, respectively, for these latter groups. Conclusion: MRL detected positive lymph nodes in 72% of candidates for salvage radiation therapy, in 62% of candidates for early salvage radiation therapy, and in 68% of initially node-negative patients. The Stephenson nomogram showed a good correlation with the MRL result and may thus be useful for identifying patients with a PSA recurrence who are at high risk for lymph node involvement.

Meijer, Hanneke J.M., E-mail: H.Meijer@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Debats, Oscar A. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Roach, Mack [Department of Radiation Oncology and Urology, University of California San Francisco, San Francisco, California (United States)] [Department of Radiation Oncology and Urology, University of California San Francisco, San Francisco, California (United States); Span, Paul N. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Witjes, J. Alfred [Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kaanders, Johannes H.A.M.; Lin, Emile N.J.Th. van [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Barentsz, Jelle O. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

2012-12-01T23:59:59.000Z

251

NDE methods for green ceramics. [Microradiography, CAT, ultrasonic, NMR  

SciTech Connect

This paper describes a preliminary investigation of radiographic, ultrasonic, and nuclear magnetic resonance (NMR) imaging methods for the nondestructive evaluation of green (unfired) ceramics. Microradiography provides sharper images than ordinary radiographs, and very small defects can be detected. The application of microradiography to ceramics is reviewed, and preliminary experiments with a commercial microradiography unit are described. Computerized axial tomographic (CAT) imaging with x-rays provides images of cross sections of an object and thus eliminates unwanted detail (noise). CAT scanning provides for detection of flaws in the 10 to 100 ..mu..m range. Initial CAT-scanning results for green-state ceramics are presented. Conventional ultrasonic techniques are difficult to use in green ceramics because of their high attenuation, fragility, and couplant-absorbing properties. However, ultrasonic velocity and attenuation data are presented which provide useful information related to density variations and the elastic anisotropy of the green state. The NMR study suggests that areas of high porosity may be detectable if the binder is burned out and replaced with a hydrogen-rich dopant such as water.

Kupperman, D.S.; Ellingson, W.A.; Berger, H.

1984-10-01T23:59:59.000Z

252

Journal of Magnetic Resonance  

Flow Microcoil Remote detection ... 2 Inlet valve Inlet pressure Outlet valve Outlet pressure ... 2. The price of storing the phase in this manner is that each data

253

{sup 13}C and {sup 17}O NMR binding constant studies of uranyl carbonate complexes in near-neutral aqueous solution. Yucca Mountain Project Milestone Report 3351  

SciTech Connect

Valuable structural information, much of it unavailable by other methods, can be obtained about complexes in solution through NMR spectroscopy. From chemical shift and intensity measurements of complexed species, NMR can serve as a species-specific structural probe for molecules in solution and can be used to validate thermodynamic constants used in geochemical modeling. Fourier-transform nuclear magnetic resonance (FT-NMR) spectroscopy has been employed to study the speciation of uranium(VI) ions in aqueous carbonate solutions as a function of pH, ionic strength, carbonate concentration, uranium concentration, and temperature. Carbon-13 and oxygen-17 NMR spectroscopy were used to monitor the fractions, and hence thermodynamic binding constants of two different uranyl species U0{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} and (UO{sub 2}){sub 3}(CO{sub 3}){sub 6}{sup 6{minus}} in aqueous solution. Synthetic buffer solutions were prepared under the ionic strength conditions used in the NMR studies in order to obtain an accurate measure of the hydrogen ion concentration, and a discussion of pH = {minus}log(a{sub H}{sup +}) versus p[H] = {minus}log[H+] is provided. It is shown that for quantitative studies, the quantity p[H] needs to be used. Fourteen uranium(VI) binding constants recommended by the OECD NEA literature review were corrected to the ionic strengths employed in the NMR study using specific ion interaction theory (SIT), and the predicted species distributions were compared with the actual species observed by multinuclear NMR. Agreement between observed and predicted stability fields is excellent. This establishes the utility of multinuclear NMR as a species-specific tool for the study of the actinide carbonate complexation constants, and serves as a means for validating the recommendations provided by the OECD NEA.

Clark, D.L.; Newton, T.W.; Palmer, P.D.; Zwick, B.D.

1995-01-01T23:59:59.000Z

254

Using CamGRID to Calculate Protein Structures from NMR Data  

E-Print Network (OSTI)

Department of Biochemistry University of Cambridge Using CamGRID to Calculate Protein Structures from NMR Data Helen Mott Structural Studies of Signalling Proteins Nuclei with spin (e.g. 1H) align (mostly) with the applied magnetic field... restraints NMR t preparation evolution detection 2D NMR t1 t2...

Mott, Helen

2011-09-09T23:59:59.000Z

255

NMR Laboratory Session #1: Measurement of SpinLattice Relaxation Time T1 and  

E-Print Network (OSTI)

NMR Laboratory Session #1: Measurement of SpinLattice Relaxation Time T1 and SpinSpin Relaxation setup the NMR instrument so that the magnetic field is locked and the software is running remember to make sure the lock on light is on. ) 3. Insert a NMR tube with a large volume of glycerol

Braun, Paul

256

Influence of Water on Diffusion in Imidazolium-Based Ionic Liquids by NMR  

E-Print Network (OSTI)

Influence of Water on Diffusion in Imidazolium-Based Ionic Liquids by NMR Sergey Vasenkov AMRIS - Chemical Engineering, University of Florida In this work we applied a novel pulsed field gradient (PFG) NMR) NMR and high magnetic field gradients (up to 30 T/m). Application of high field allows for an easy

Weston, Ken

257

Organic Light-Emitting Diodes (OLEDs) and Optically-Detected Magnetic Resonance (ODMR) studies on organic materials  

Science Conference Proceedings (OSTI)

Organic semiconductors have evolved rapidly over the last decades and currently are considered as the next-generation technology for many applications, such as organic light-emitting diodes (OLEDs) in flat-panel displays (FPDs) and solid state lighting (SSL), and organic solar cells (OSCs) in clean renewable energy. This dissertation focuses mainly on OLEDs. Although the commercialization of the OLED technology in FPDs is growing and appears to be just around the corner for SSL, there are still several key issues that need to be addressed: (1) the cost of OLEDs is very high, largely due to the costly current manufacturing process; (2) the efficiency of OLEDs needs to be improved. This is vital to the success of OLEDs in the FPD and SSL industries; (3) the lifetime of OLEDs, especially blue OLEDs, is the biggest technical challenge. All these issues raise the demand for new organic materials, new device structures, and continued lower-cost fabrication methods. In an attempt to address these issues, we used solution-processing methods to fabricate highly efficient small molecule OLEDs (SMOLEDs); this approach is costeffective in comparison to the more common thermal vacuum evaporation. We also successfully made efficient indium tin oxide (ITO)-free SMOLEDs to further improve the efficiency of the OLEDs. We employed the spin-dependent optically-detected magnetic resonance (ODMR) technique to study the luminescence quenching processes in OLEDs and organic materials in order to understand the intrinsic degradation mechanisms. We also fabricated polymer LEDs (PLEDs) based on a new electron-accepting blue-emitting polymer and studied the effect of molecular weight on the efficiency of PLEDs. All these studies helped us to better understand the underlying relationship between the organic semiconductor materials and the OLEDs’ performance, and will subsequently assist in further enhancing the efficiency of OLEDs. With strongly improved device performance (in addition to other OLEDs' attributes such as mechanical flexibility and potential low cost), the OLED technology is promising to successfully compete with current technologies, such as LCDs and inorganic LEDs.

Cai, Min

2011-11-30T23:59:59.000Z

258

EMSL: Capabilities: NMR and EPR Experts  

NLE Websites -- All DOE Office Websites (Extended Search)

NMR and EPR Experts Additional Information Meet the NMR and EPR Experts NMR and EPR Tools are Applied to all Science Themes 900-MHz NMR: Accelerating Scientific Discovery...

259

Direct Characterization of Kerogen by X-ray and Solid-State [superscript 13]C Nuclear Magnetic Resonance Methods  

Science Conference Proceedings (OSTI)

A combination of solid-state {sup 13}C NMR, X-ray photoelectron spectroscopy (XPS) and sulfur X-ray absorption near edge structure (S-XANES) techniques are used to characterize organic oxygen, nitrogen, and sulfur species and carbon chemical/structural features in kerogens. The kerogens studied represent a wide range of organic matter types and maturities. A van Krevelen plot based on elemental H/C data and XPS derived O/C data shows the well established pattern for type I, type II, and type III kerogens. The anticipated relationship between the Rock-Eval hydrogen index and H/C is independent of organic matter type. Carbon structural and lattice parameters are derived from solid-state {sup 13}C NMR analysis. As expected, the amount of aromatic carbon, measured by both {sup 13}C NMR and XPS, increases with decreasing H/C. The correlation between aromatic carbon and Rock-Eval T{sub max}, an indicator of maturity, is linear for types II and IIIC kerogens, but each organic matter type follows a different relationship. The average aliphatic carbon chain length (Cn) decreases with an increasing amount of aromatic carbon in a similar manner across all organic matter types. The fraction of aromatic carbons with attachments (FAA) decreases, while the average number of aromatic carbons per cluster (C) increases with an increasing amount of aromatic carbon. FAA values range from 0.2 to 0.4, and C values range from 12 to 20 indicating that kerogens possess on average 2- to 5-ring aromatic carbon units that are highly substituted. There is basic agreement between XPS and {sup 13}C NMR results for the amount and speciation of organic oxygen. XPS results show that the amount of carbon oxygen single bonded species increases and carbonyl-carboxyl species decrease with an increasing amount of aromatic carbon. Patterns for the relative abundances of nitrogen and sulfur species exist regardless of the large differences in the total amount of organic nitrogen and sulfur seen in the kerogens. XPS and S-XANES results indicate that the relative level of aromatic sulfur increases with an increasing amount of aromatic carbon for all kerogens. XPS show that the majority of nitrogen exists as pyrrolic forms in comparable relative abundances in all kerogens studied. The direct characterization results using X-ray and NMR methods for nitrogen, sulfur, oxygen, and carbon chemical structures provide a basis for developing both specific and general average chemical structural models for different organic matter type kerogens.

Kelemen, S. R.; Afeworki, M.; Gorbaty, M.L.; Sansone, M.; Kwiatek, P.J.; Walters, C.C.; Freund, H.; Siskin, M.; Bence, A.E.; Curry, D.J.; Solum, M.; Pugmire, R.J.; Vandenbroucke, M.; Leblond, M.; Behar, F. (ExxonMobil); (ExxonMobil); (IFP); (Utah)

2008-06-12T23:59:59.000Z

260

Direct Characterization of Kerogen By X-Ray And Solid-State **13C Nuclear Magnetic Resonance Methods  

DOE Green Energy (OSTI)

A combination of solid-state {sup 13}C NMR, X-ray photoelectron spectroscopy (XPS) and sulfur X-ray absorption near edge structure (S-XANES) techniques are used to characterize organic oxygen, nitrogen, and sulfur species and carbon chemical/structural features in kerogens. The kerogens studied represent a wide range of organic matter types and maturities. A van Krevelen plot based on elemental H/C data and XPS derived O/C data shows the well established pattern for type I, type II, and type III kerogens. The anticipated relationship between the Rock-Eval hydrogen index and H/C is independent of organic matter type. Carbon structural and lattice parameters are derived from solid-state 13C NMR analysis. As expected, the amount of aromatic carbon, measured by both {sup 13}C NMR and XPS, increases with decreasing H/C. The correlation between aromatic carbon and Rock-Eval Tmax, an indicator of maturity, is linear for types II and IIIC kerogens, but each organic matter type follows a different relationship. The average aliphatic carbon chain length (Cn') decreases with an increasing amount of aromatic carbon in a similar manner across all organic matter types. The fraction of aromatic carbons with attachments (FAA) decreases, while the average number of aromatic carbons per cluster (C) increases with an increasing amount of aromatic carbon. FAA values range from 0.2 to 0.4, and C values range from 12 to 20 indicating that kerogens possess on average 2- to 5-ring aromatic carbon units that are highly substituted. There is basic agreement between XPS and 13C NMR results for the amount and speciation of organic oxygen. XPS results show that the amount of carbon oxygen single bonded species increases and carbonyl-carboxyl species decrease with an increasing amount of aromatic carbon. Patterns for the relative abundances of nitrogen and sulfur species exist regardless of the large differences in the total amount of organic nitrogen and sulfur seen in the kerogens. XPS and S-XANES results indicate that the relative level of aromatic sulfur increases with an increasing amount of aromatic carbon for all kerogens. XPS show that the majority of nitrogen exists as pyrrolic forms in comparable relative abundances in all kerogens studied. The direct characterization results using X-ray and NMR methods for nitrogen, sulfur, oxygen, and carbon chemical structures provide a basis for developing both specific and general average chemical structural models for different organic matter type kerogens.

Keleman, S.R.; Afeworki, M.; Gorbaty, M.L.; Sansone, M.; Kwiatek, P.J.; Walters, C.C.; Freund, H.; Siskin, M.; Bence, A.E.; Curry, D.J.; Solum, M.; Pugmire, R.J.; Vandenbroucke, M.; Leblond, M.; Behar, F.

2007-07-09T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

(129)Xe NMR of Mesoporous Silicas  

DOE Green Energy (OSTI)

The porosities of three mesoporous silica materials were characterized with {sup 129}Xe NMR spectroscopy. The materials were synthesized by a sol-gel process with r = 0, 25, and 70% methanol by weight in an aqueous cetyltrimethylammonium bromide solution. Temperature dependent chemical shifts and spin lattice relaxation times reveal that xenon does not penetrate the pores of the largely disordered (r= 70%) silica. For both r = 0 and 25%, temperature dependent resonances corresponding to physisorbed xenon were observed. An additional resonance for the r = 25% sample was attributed to xenon between the disordered cylindrical pores. 2D NMR exchange experiments corroborate the spin lattice relaxation data which show that xenon is in rapid exchange between the adsorbed and the gas phase.

Anderson, M.T.; Asink, R.A.; Kneller, J.M.; Pietrass, T.

1999-04-23T23:59:59.000Z

262

A Combined 6,7Li NMR and Molecular Dynamics Study of Li Diffusion in Li2TiO3  

SciTech Connect

Understanding lithium diffusion properties in electrode materials is important for designing rechargeable lithium-ion batteries with improved performance. In this work, the lithium dynamics in layered Li2TiO3 were characterized using a combination of 6,7Li nuclear magnetic resonance (NMR) over a wide temperature range (150 to 500 K), and molecular dynamics (MD) simulations. The 7Li static NMR and stimulated echo experiments show slow and partial lithium diffusion in Li2TiO3. The high-field (21.1 T) 6Li magic angle spinning NMR shows a new tetrahedral lithium site along with the three crystallographic octahedral sites in Li2TiO3 sample. MD simulations predict that lithium can occupy a tetrahedral site if two or more vacancies exist in the vicinity, which may result, for example, from the presence of a Ti defect in the LiTi2 layer. 6Li two-dimensional (2D) exchange NMR experiments show evidence of lithium diffusion between the pure Li and LiTi2 layers along the c axis. Although the 2D exchange NMR data is not sensitive to lithium diffusion in the ab plane, MD simulations show that lithium diffusion in the pure Li layer is equally probable. Combining these results, a detailed picture of the lithium diffusion pathways in Li2TiO3 is presented.

Vijayakumar, M.; Kerisit, Sebastien N.; Yang, Zhenguo; Graff, Gordon L.; Liu, Jun; Sears, Jesse A.; Burton, Sarah D.; Rosso, Kevin M.; Hu, Jian Z.

2009-10-27T23:59:59.000Z

263

The Application of Dynamic Nuclear Polarization Enhanced NMR to Non-Equilibrium Systems  

E-Print Network (OSTI)

Nuclear magnetic resonance (NMR) yields remarkably detailed structural information about virtually any molecule. However, its application to non-equilibrium systems is hampered by a lack of sensitivity. To increase the amount of signal that can be obtained from a NMR experiment, various hyperpolarization schemes have been previously introduced. One such technique is dynamic nuclear polarization (DNP), which can enhance NMR sensitivity by several orders of magnitude. The work detailed here focuses on the development of methods utilizing DNP to study non-equilibrium systems such as chemical and biochemical reactions in real-time. To work with hyperpolarized samples, we have designed and constructed a rapid injection and mixing system. This system allows samples to be transported between superconducting magnets used for polarization and for NMR spectroscopy in less than two seconds. Rapid transport is essential for successful use of samples with short spin-lattice relaxation times. For the study of reactions under non-equilibrium conditions, the system provides the additional capability for samples to be mixed with a second, unpolarized reagent. A chromogenic trypsin catalyzed ester hydrolysis reaction was used to validate the DNP-NMR technique as a tool for kinetic analysis. It is shown that the DNP-NMR method agrees with the conventional UV method within the uncertainty of the measurement. Hyperpolarization in this modality presents both challenges and opportunities, each of which motivate the development of new NMR techniques. In addition to the determination of kinetics, DNP-NMR is amenable to mechanistic analysis of a reaction. We have developed a technique based on selective inversion of spin-polarization, which allows for mapping of atoms between reactant and product of a reaction. This scheme was applied to a Grignard reaction, demonstrating applicability to organic reactions. Signal averaging, as it is applied for conventional multi-dimensional correlation spectroscopy cannot always be applied easily when using hyperpolarized sample. For the rapid measurement of heteronuclear correlation spectra, we have developed a technique utilizing the differential scaling of scalar coupling under off-resonance irradiation. Although DNP-NMR yields spectra of outstanding quality even with small quantities of sample, peak intensities are not quantitative. It is nevertheless possible to compare peak multiplets obtained from fractionally isotope labeled samples. Using biosynthetically labeled lipids from E. Coli cells, we showed that the resulting labeling patterns reflect their biosynthetic pathways. As a final case-study employing several of these newly developed methods, the uronate isomerase catalyzed isomerization of glucuronate into fructuronate was studied. The ability to follow the reaction in real-time while directly observing all anomeric forms of the reactant and product permits the independent determination of kinetics for each anomeric form of substrate and product. This study revealed the anomeric specificity of the enzyme.

Bowen, Sean Michael

2011-12-01T23:59:59.000Z

264

Application of NMR Methods to Identify Detection Reagents for Use in the Development of Robust Nanosensors  

SciTech Connect

Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful technique for studying bi-molecular interactions at the atomic scale. Our NMR lab is involved in the identification of small molecules, or ligands that bind to target protein receptors, such as tetanus (TeNT) and botulinum (BoNT) neurotoxins, anthrax proteins and HLA-DR10 receptors on non-Hodgkin's lymphoma cancer cells. Once low affinity binders are identified, they can be linked together to produce multidentate synthetic high affinity ligands (SHALs) that have very high specificity for their target protein receptors. An important nanotechnology application for SHALs is their use in the development of robust chemical sensors or biochips for the detection of pathogen proteins in environmental samples or body fluids. Here, we describe a recently developed NMR competition assay based on transferred nuclear Overhauser effect spectroscopy (trNOESY) that enables the identification of sets of ligands that bind to the same site, or a different site, on the surface of TeNT fragment C (TetC) than a known ''marker'' ligand, doxorubicin. Using this assay, we can identify the optimal pairs of ligands to be linked together for creating detection reagents, as well as estimate the relative binding constants for ligands competing for the same site.

Cosman, M; Krishnan, V V; Balhorn, R

2004-04-29T23:59:59.000Z

265

A unified view of coherent and incoherent dihydrogen exchange in transition metal hydrides by nuclear resonance and inelastic neutron scattering  

SciTech Connect

In this paper a unified view of coherent and incoherent dihydrogen exchange in transition metal hydrides by nuclear magnetic resonance (NMR) and inelastic neutron scattering (INS) is presented. It is shown that both exchange processes coexist i.e. do not transform into each other although they may dominate the spectra in different temperature ranges. This superposition is the consequence of the incorporation of the tunnel frequency J of the coherent process into the nuclear two-spin hamiltonian of hydrogen pairs which allows to treat the problem using the well known density matrix theory of NMR line-shapes developed by Alexander and Binsch. It is shown that this theory can also be used to predict the line-shapes of the rotational tunneling transitions observed in the INS spectra of transition metal dihydrogen complexes and that both NMR and INS spectra depend on similar parameters.

Limbach, H.H.; Ulrich, S.; Buntkowsky, G. [Freie Univ. Berlin (Germany). Inst. fuer Organische Chemie; Sabo-Etienne, S.; Chaudret, B. [Toulouse-3 Univ., 31 (France). Lab. de Chimie de Coordination du C.N.R.S.; Kubas, G.J.; Eckert, J. [Los Alamos National Lab., NM (United States)

1995-08-12T23:59:59.000Z

266

NMR STUDIES OF ORIENTED MOLECULES  

E-Print Network (OSTI)

G. Bodenhausen, Progress in NMR Spec. A. Wokaun and R. R.D. N. Pinder, Progress in NMR Spectroscopy, 10, 1 (1975). D.and R. R. VoId, "Progress in NMR Spectroscopy," 12, 79 A.

Sinton, S.W.

2008-01-01T23:59:59.000Z

267

FOURIER TRANSFORM MULTIPLE QUANTUM NMR  

E-Print Network (OSTI)

TRANSFORM MULTIPLE QUANTUM NMR G. Drobny, A. Pines, S.TRANSFO~~ MULTIPLE QUANTUM NMR G. Drobny, A. Pines, S.

Drobny, G.

2011-01-01T23:59:59.000Z

268

Investigations of the R5(SixGe1-x)4 Intermetallic Compounds by X-Ray Resonant Magnetic Scattering  

SciTech Connect

The XRMS experiment on the Gd{sub 5}Ge{sub 4} system has shown that, below the Neel temperature, T{sub N} = 127 K, the magnetic unit cells is the same as the chemical unit cell. From azimuth scans and the Q dependence of the magnetic scattering, all three Gd sites in the structure were determined to be in the same magnetic space group Pnma. The magnetic moments are aligned along the c-axis and the c-components of the magnetic moments at the three different sites are equal. The ferromagnetic slabs are stacked antiferromagnetically along the b-direction. They found an unusual order parameter curve in Gd{sub 5}Ge{sub 4}. A spin-reorientation transition is a possibility in Gd{sub 5}Ge{sub 4}, which is similar to the Tb{sub 5}Ge{sub 4} case. Tb{sub 5}Ge{sub 4} possesses the same Sm{sub 5}Ge{sub 4}-type crystallographic structure and the same magnetic space group as Gd{sub 5}Ge{sub 4} does. The difference in magnetic structure is that Tb{sub 5}Ge{sub 4} has a canted one but Gd{sub 5}Ge{sub 4} has nearly a collinear one in the low temperature antiferromagnetic phase. The competition between the magneto-crystalline anisotropy and the nearest-neighbor magnetic exchange interactions may allow a 3-dimensional canted antiferromagnetic structure in Tb{sub 5}Ge{sub 4}. The spin-reorientation transition in both Gd{sub 5}Ge{sub 4} and Tb{sub 5}Ge{sub 4} may arise from the competition between the magnetic anisotropy from the spin-orbit coupling of the conduction electrons and the dipolar interactions anisotropy.

Lizhi Tan

2008-08-18T23:59:59.000Z

269

Phase II Trial of Radiosurgery to Magnetic Resonance Spectroscopy-Defined High-Risk Tumor Volumes in Patients With Glioblastoma Multiforme  

SciTech Connect

Purpose: To determine the efficacy of a Gamma Knife stereotactic radiosurgery (SRS) boost to areas of high risk determined by magnetic resonance spectroscopy (MRS) functional imaging in addition to standard radiotherapy for patients with glioblastoma (GBM). Methods and Materials: Thirty-five patients in this prospective Phase II trial underwent surgical resection or biopsy for a GBM followed by SRS directed toward areas of MRS-determined high biological activity within 2 cm of the postoperative enhancing surgical bed. The MRS regions were determined by identifying those voxels within the postoperative T2 magnetic resonance imaging volume that contained an elevated choline/N-acetylaspartate ratio in excess of 2:1. These voxels were marked, digitally fused with the SRS planning magnetic resonance image, targeted with an 8-mm isocenter per voxel, and treated using Radiation Therapy Oncology Group SRS dose guidelines. All patients then received conformal radiotherapy to a total dose of 60 Gy in 2-Gy daily fractions. The primary endpoint was overall survival. Results: The median survival for the entire cohort was 15.8 months. With 75% of recursive partitioning analysis (RPA) Class 3 patients still alive 18 months after treatment, the median survival for RPA Class 3 has not yet been reached. The median survivals for RPA Class 4, 5, and 6 patients were 18.7, 12.5, and 3.9 months, respectively, compared with Radiation Therapy Oncology Group radiotherapy-alone historical control survivals of 11.1, 8.9, and 4.6 months. For the 16 of 35 patients who received concurrent temozolomide in addition to protocol radiotherapeutic treatment, the median survival was 20.8 months, compared with European Organization for Research and Treatment of Cancer historical controls of 14.6 months using radiotherapy and temozolomide. Grade 3/4 toxicities possibly attributable to treatment were 11%. Conclusions: This represents the first prospective trial using selective MRS-targeted functional SRS combined with radiotherapy for patients with GBM. This treatment is feasible, with acceptable toxicity and patient survivals higher than in historical controls. This study can form the basis for a multicenter, randomized trial.

Einstein, Douglas B., E-mail: douglas.einstein@khnetwork.org [Department of Radiation Oncology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Wessels, Barry [Department of Radiation Oncology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Radiation Oncology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Bangert, Barbara [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Fu, Pingfu [Department of Biostatistics, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Biostatistics, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Nelson, A. Dennis [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Cohen, Mark [Department of Pathology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Pathology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Sagar, Stephen [Department of Neurology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Neurology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Lewin, Jonathan [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Radiology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Sloan, Andrew [Department of Neurosurgery, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Neurosurgery, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Zheng Yiran; Williams, Jordonna; Colussi, Valdir; Vinkler, Robert [Department of Radiation Oncology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Radiation Oncology, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States); Maciunas, Robert [Department of Neurosurgery, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)] [Department of Neurosurgery, Case Comprehensive Cancer Center, Case Western Reserve University Kettering, Ohio (United States)

2012-11-01T23:59:59.000Z

270

Integrated, Multi-Scale Characterization of Imbibition and Wettability Phenomena Using Magnetic Resonance and Wide-Band Dielectric Measurements  

SciTech Connect

The petrophysical properties of rocks, particularly their relative permeability and wettability, strongly influence the efficiency and the time-scale of all hydrocarbon recovery processes. However, the quantitative relationships needed to account for the influence of wettability and pore structure on multi-phase flow are not yet available, largely due to the complexity of the phenomena controlling wettability and the difficulty of characterizing rock properties at the relevant length scales. This project brings together several advanced technologies to characterize pore structure and wettability. Grain-scale models are developed that help to better interpret the electric and dielectric response of rocks. These studies allow the computation of realistic configurations of two immiscible fluids as a function of wettability and geologic characteristics. These fluid configurations form a basis for predicting and explaining macroscopic behavior, including the relationship between relative permeability, wettability and laboratory and wireline log measurements of NMR and dielectric response. Dielectric and NMR measurements have been made show that the response of the rocks depends on the wetting and flow properties of the rock. The theoretical models can be used for a better interpretation and inversion of standard well logs to obtain accurate and reliable estimates of fluid saturation and of their producibility. The ultimate benefit of this combined theoretical/empirical approach for reservoir characterization is that rather than reproducing the behavior of any particular sample or set of samples, it can explain and predict trends in behavior that can be applied at a range of length scales, including correlation with wireline logs, seismic, and geologic units and strata. This approach can substantially enhance wireline log interpretation for reservoir characterization and provide better descriptions, at several scales, of crucial reservoir flow properties that govern oil recovery.

Mukul M. Sharma; Steven L. Bryant; Carlos Torres-Verdin; George Hirasaki

2007-09-30T23:59:59.000Z

271

Sequence optimization to reduce velocity offsets in cardiovascular magnetic resonance volume flow quantification - A multi-vendor study  

E-Print Network (OSTI)

of interest may lead to phase-encode wraparound hinder- ing conventional background correction post-processing if still needed. Sequence development might also focus on a more fundamental level of eddy current compensation, such as sequence... and Correcting Gradient Errors in Non-Cartesian Imaging: Are Gradient Errors Linear Time-Invariant (LTI)? Magn Reson Med 2009, 62:1466-1476. 16. Bernstein MA, King KF, Zhou XHJ: Correction Gradients - Eddy Current Compensation. Handbook of MRI pulse sequences...

Rolf, Marijn P; Hofman, Mark B M; Gatehouse, Peter D; Markenroth Bloch, Karin; Heymans, Martijn W; Ebbers, Tino; Graves, Martin J; Totman, John J; Werner, Beat; Rossum, Albert C van; Kilner, Philip J; Heethaar, Rob M

2011-03-09T23:59:59.000Z

272

Design and characterization of 2.45 GHz electron cyclotron resonance plasma source with magnetron magnetic field configuration for high flux of hyperthermal neutral beam  

Science Conference Proceedings (OSTI)

A 2.45 GHz electron cyclotron resonance (ECR) source with a magnetron magnetic field configuration was developed to meet the demand of a hyperthermal neutral beam (HNB) flux on a substrate of more than 1x10{sup 15} cm{sup -2} s{sup -1} for industrial applications. The parameters of the operating pressure, ion density, electron temperature, and distance between the neutralization plate and the substrate for the HNB source are specified in a theoretical analysis. The electron temperature and the ion density are measured to characterize the ECR HNB source using a Langmuir probe and optical emission spectroscopy. The parameters of the ECR HNB source are in good agreement with the theoretically specified parameters.

Kim, Seong Bong [Department of Physics, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of); Convergence Plasma Research Center, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Kim, Dae Chul; Yoo, Suk Jae [Convergence Plasma Research Center, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Namkung, Won; Cho, Moohyun [Department of Physics, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang 790-784 (Korea, Republic of)

2010-08-15T23:59:59.000Z

273

Magnetic Devices and Nanostructures (2005)  

Science Conference Proceedings (OSTI)

... Molecular nanomagnets, which are the smallest well defined magnetic ... moment of a specimen as microwave stimulation causes resonance at ...

2010-10-13T23:59:59.000Z

274

Repetitive resonant railgun power supply  

DOE Patents (OSTI)

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

275

Repetitive resonant railgun power supply  

DOE Patents (OSTI)

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, E.M.; Nunnally, W.C.

1985-06-19T23:59:59.000Z

276

magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

I I Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

277

MaxEnt-Burg Application to Muon-Spin Resonance  

SciTech Connect

Muon-Spin Rotation ({mu}SR) is an experimental technique similar to Nuclear Magnetic Resonance (NMR). {mu}SR data are recorded as a set of time-series histograms of muon-decay events. Both {mu}SR and NMR regularly produce signals that are overlapping, weak and/or broadened in frequency space. These {mu}SR histograms are usually analyzed by curve fitting and Fourier transformations. However, several NMR and {mu}SR groups have developed Maximum Entropy (MaxEnt, ME) applications to improve the sensitivity of the time series analysis. We have focused on the application of the ME-Burg algorithm. The optimal number of autoregression coefficients is between N/3 and N/5 where N is the total number of data points. Selected results for simulated data and real data ME-{mu}SR applications are reported. Most of our {mu}SR work is for cuprate superconductor studies. The strength of the ME-Burg algorithm is fully used, as there is a clear relationship between the muon-spin signal S(i) at any time i and the signals S(i-k) at earlier times. ME-Burg has the major advantage of producing in the frequency transform only structure for which sufficient statistical evidence is present.

Boekema, C.; Browne, M. C. [Department of Physics and Astronomy, San Jose State University, San Jose CA 95192-0106 (United States)

2008-11-06T23:59:59.000Z

278

NMR DOUBLE QUANTUM SPIN DECOUPLING IN SOLIDS  

E-Print Network (OSTI)

M. Mehring, "High Resolution NMR Spectroscopy", Springeret al. , Multiple Quantum NMR, International Summer SchoolLBL-6984 ('. / Preprint NMR OOUBLE QUANTUM SPIN DECOUPLING

Pines, A.

2011-01-01T23:59:59.000Z

279

Reactor-relevant quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields  

Science Conference Proceedings (OSTI)

Results from recent experiments demonstrate that quiescent H-mode (QH-mode) sustained by magnetic torque from non-axisymmetric magnetic fields is a promising operating mode for future burning plasmas. Using magnetic torque from n=3 fields to replace counter-I{sub p} torque from neutral beam injection (NBI), we have achieved long duration, counter-rotating QH-mode operation with NBI torque ranging from counter-I{sub p} to up to co-I{sub p} values of 1-1.3 Nm. This co-I{sub p} torque is 3 to 4 times the scaled torque that ITER will have. These experiments utilized an ITER-relevant lower single-null plasma shape and were done with ITER-relevant values of {nu}{sub ped}{sup *} and {beta}{sub N}{sup ped}. These discharges exhibited confinement quality H{sub 98y2}=1.3, in the range required for ITER. In preliminary experiments using n=3 fields only from a coil outside the toroidal coil, QH-mode plasmas with low q{sub 95}=3.4 have reached fusion gain values of G={beta}{sub N}H{sub 89}/q{sub 95}{sup 2}=0.4, which is the desired value for ITER. Shots with the same coil configuration also operated with net zero NBI torque. The limits on G and co-I{sub p} torque have not yet been established for this coil configuration. QH-mode work to has made significant contact with theory. The importance of edge rotational shear is consistent with peeling-ballooning mode theory. Qualitative and quantitative agreements with the predicted neoclassical toroidal viscosity torque is seen.

Burrell, K. H.; Garofalo, A. M; Osborne, T. H.; Schaffer, M. J.; Snyder, P. B. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Solomon, W. M.; Park, J.-K. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Fenstermacher, M. E. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2012-05-15T23:59:59.000Z

280

A novel contrast agent with rare earth-doped up-conversion luminescence and Gd-DTPA magnetic resonance properties  

SciTech Connect

The magnetic-luminescent multifunctional nanoparticles based on Gd-DTPA and NaYF{sub 4}:Yb, Er were successfully synthesized by the conjugation of activated DTPA and silica-coated/surface-aminolated NaYF{sub 4}:Yb, Er nanoparticles through EDC/NHS coupling chemistry. The as-prepared products were characterized by powder X-ray diffraction, transmission electron microscopy, dynamic light scattering, energy dispersive X-ray analysis, and fourier transform infrared spectrometry. The room-temperature upconversion luminescent spectra and T{sub 1}-weighted maps of the obtained nanoparticles were carried out by 980 nm NIR light excitation and a 3T MR imaging scanner, respectively. The results indicated that the as-synthesized multifunctional nanoparticles with small size, highly solubility in water, and both high MR relaxivities and upconversion luminescence may have potential usage for MR imaging in future. - Graphical abstract: We have synthesized magnetic-luminescent multifunctional nanoparticles based on Gd-DTPA and NaYF4:Yb, Er by the conjugation of activated DTPA and silica-coated/surface-aminolated NaYF4:Yb, Er nanoparticles through EDC/NHS coupling chemistry. Highlights: Black-Right-Pointing-Pointer A novel magnetic-luminescent multifunctional nanoparticles are synthesized. Black-Right-Pointing-Pointer The nanoparticles are highly efficient for luminescence and T{sub 1}-weighted MR imaging. Black-Right-Pointing-Pointer The nanoparticles are small in size and highly solubility in water. Black-Right-Pointing-Pointer The nanoparticles hold great potential usage for future biomedical engineering.

Lu Qing [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Wei Daixu [National Engineering Research Center for Nanotechnology, 28 East Jiang Chuan Rd, Shanghai 200241 (China); Cheng Jiejun [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Xu Jianrong, E-mail: xujianr@hotmail.com [Department of Radiology, Shanghai Renji Hospital, Shanghai Jiao Tong University School of Medicine, 1630 Dong Fang Rd, Shanghai 200127 (China); Zhu Jun, E-mail: yzjzhu@163.com [National Engineering Research Center for Nanotechnology, 28 East Jiang Chuan Rd, Shanghai 200241 (China)

2012-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Novel motor design for rotating anode x-ray tubes operating in the fringe field of a magnetic resonance imaging system  

SciTech Connect

Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors' assembly were also evaluated to determine its stability during acceleration, and a pulse width modulation algorithm was implemented to control the rotation speed of the motor. Results: At a magnetic flux density of 41 mT orthogonal to the axis of rotation (on the lower end of the expected flux density in the MR suite) the maximum speed of the motor was found to be 5150 revolutions per minute (rpm). The acceleration time necessary to reach 3000 rpm was found to be approximately 10 s at 59 mT. The resonance frequency of the assembly with the anode attached was 1310 rpm (21.8 Hz) which is far below the desired operating speeds. Pulse width modulation provides an effective method to control the speed of the motor with a resolution of 100 rpm. Conclusions: The proposed design can serve as a direct replacement to the conventional induction motor used in rotating anode x-ray tubes. It does not suffer from a reduced rotation speed when operating in a MR environment. The presence of chromic steel bearings in the prototype prevented testing at the higher field strengths, and future iterations of the design could eliminate this shortcoming. The prototype assembly demonstrates proof of concept of the authors' design and overcomes one of the major obstacles for a MR compatible rotating anode x-ray tube.

Lillaney, Prasheel; Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States); Shin Mihye [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Hinshaw, Waldo; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Bennett, N. Robert [Department of Radiology, Stanford University, Stanford, California 94305 and Qualcomm MEMS Technologies, San Jose, California 95134 (United States)

2013-02-15T23:59:59.000Z

282

NMR and Transport Studies on Group IV Clathrates and Related Intermetallic Materials  

E-Print Network (OSTI)

Increasing efforts have been put into research about thermoelectric materials for the last few decades, especially recently, faced with the crucial demand for new energy and energy savings. Among the potential candidates for new generation thermoelectric materials are the intermetallic clathrates. Clathrates are cage-structured materials with guest atoms enclosed. Previous studies have shown lower thermal conductivities compared with many other bulk compounds, and it is believed that guest atom vibration modes are the reason for such thermal behaviors. Several models, including the Einstein oscillator and soft potential models, have been used to explain the guest motion. However the characterization of the anharmonic oscillating motion can be a challenge. In this work, Nuclear Magnetic Resonance (NMR), heat capacity and transport measurements have been used to study several clathrate systems, especially the well- known type-I Ba8Ga16Sn30, which has been reported to have one of the lowest thermal conductivities for bulk compounds. In this material the strong anharmonic rattling behavior was investigated and analyzed according to a double well potential model, yielding good agreement with the experimental results. Furthermore, the resistivity and heat capacity results were studied and analyzed according to the influence of the anharmonic contribution. This offered a way to connect the NMR, transport and heat capacity properties, providing an advantageous way to study strongly anharmonic systems. In further work, several related intermetallic materials were examined for their structure, motion and NMR properties. Dynamical and electrical behaviors were investigated by studying the magnetic and quadrupole NMR spin-lattice relaxation. Type-VIII Ba8Ga16Sn30 exhibits an enhanced dynamics-related term at low temperature, but no rattling response as observed for the type-I structure. Type-I Ba8In16Ge30 was compared with the type-I Ba8Ga16Sn30 because their cage structures are similar. No strong anharmonic contribution was found in the NMR T1 behavior of Ba8In16Ge30, however the T2 showed behavior characteristic of atomic motion. In all cases, the magnetic relaxation was used to characterize the electron structures, and n- type Ba8Ga16Ge30 exhibited a spin-lattice relaxation behavior which is characteristic of impurity band structures near the Fermi surface. Also, a series of Ba8CuxGe46-x clathrates were investigated and showed much more insulating like behavior. In related work, the layered BaGa4 and BaGa3Sn have shown interesting NMR spin-spin relaxation behavior that indicates atomic fluctuations. This is similar to the situation found in type-I Ba8In16Ge30. The influence of atomic motion on the NMR and also the atomic structures of these alloys is further discussed in this work.

Zheng, Xiang

2012-08-01T23:59:59.000Z

283

27Al and 1H Solid State NMR Studies Show Evidence of TiAl3 and TiH2 in Ti-doped NaAlH4  

DOE Green Energy (OSTI)

Previous X-ray Diffraction (XRD) and Nuclear Magnetic Resonance (NMR) studies on Ti-doped NaAlH{sub 4} revealed the reaction products of two heavily doped (33.3 at.%) samples that were solvent-mixed and mechanically-milled. This investigation revealed that nano-crystalline or amorphous Al{sub 2}O{sub 3} forms from the possible coordination of aluminum with oxygen atom of the furan ring system from added tetrahydrofuran (THF) in the solvent-mixed sample, and that TiAl{sub 3} forms in mechanically-milled samples. The present paper provides a more sophisticated NMR investigation of the these materials. On heavily doped (33.3 at.%) solvent-mixed samples, {sup 27}Al Magic Angle Spinning (MAS) NMR {sup 27}Al multiple quantum MAS (MQMAS) indicates the presence of an oxide layer of Al{sub 2}O{sub 3} on the surfaces of potentially bulk nanocrystalline Ti, nanocrystalline TiAl{sub 3}, and/or metallic aluminum. The {sup 1}H MAS NMR data also indicate the possible coordination of aluminum with the oxygen atom in the THF. On heavily doped samples that were mechanically milled, {sup 27}Al MAS NMR and static NMR confirms the presence of TiAl{sub 3}. In addition, the {sup 1}H MAS NMR and {sup 1}H spin-lattice relaxation (T{sub 1}) measurements are consistent with the presence of TiH{sub 2}. These results are in agreement with recent XAFS measurements indicating both Al and H within the first few coordination shells of Ti in the doped alanate.

Herberg, J; Maxwell, R; Majzoub, E

2005-05-26T23:59:59.000Z

284

Superconducting Magnet Division | Brookhaven National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

accuracy of these probes is 1 part in 10,000 at 23 of the magnet inner radius. Hall and NMR probes are also available. generic image The photo shows a magnet cold mass being...

285

A functional magnetic resonance imaging study of overt letter verbal fluency using a clustered acquisition sequence: greater anterior cingulate activation with increased task demand  

E-Print Network (OSTI)

Regional cerebral activation during a cognitive task can vary with task demand and task performance. In a functional magnetic resonance imaging study, we examined the effect of manipulating task demand on activation during verbal fluency by using “easy ” and “hard ” letters. A “clustered ” image acquisition sequence allowed overt verbal responses to be made in the absence of scanner noise which facilitated “online” measurement of task performance. Eleven righthanded, healthy male volunteers participated. Twice as many errors were produced with hard as with easy letters (20.8 ? 13.6 and 10.1 ? 10.7 % errors, respectively). For both conditions, the distribution of regional activation was comparable to that reported in studies of covert verbal fluency, but with greater engagement of subcortical areas. The hard condition was associated with greater dorsal anterior cingulate activation than the easy condition. This may reflect the greater demands of the former, particularly in terms of arousal responses with increased task difficulty and the monitoring of potential response errors. © 2002 Elsevier Science (USA)

Cynthia H. Y. Fu; Kevin Morgan; John Suckling; Steve C. R. Williams; Chris Andrew; Goparlen N. Vythelingum; Philip K. Mcguire

2002-01-01T23:59:59.000Z

286

Urinary Tract Effects After Multifocal Nonthermal Irreversible Electroporation of the Kidney: Acute and Chronic Monitoring by Magnetic Resonance Imaging, Intravenous Urography and Urinary Cytology  

Science Conference Proceedings (OSTI)

Purpose: The nonthermal irreversible electroporation (NTIRE) is a novel potential ablation modality for renal masses. The aim of this study was the first evaluation of NTIRE's effects on the renal urine-collecting system using intravenous urography (IVU) and urinary cytology in addition to histology and magnetic resonance imaging (MRI). Methods: Eight percutaneous NTIRE ablations of the renal parenchyma, including the calyxes or pelvis, were performed in three male swine. MRI, IVU, histology, and urinary cytology follow-ups were performed within the first 28 days after treatment. Results: MRI and histological analysis demonstrated a localized necrosis 7 days and a localized scarification of the renal parenchyma with complete destruction 28 days after NTIRE. The urine-collecting system was preserved and showed urothelial regeneration. IVU and MRI showed an unaltered normal morphology of the renal calyxes, pelvis, and ureter. A new urinary cytology phenomenon featured a temporary degeneration by individual vacuolization of detached transitional epithelium cells within the first 3 days after NTIRE. Conclusions: This first urographical, urine-cytological, and MRI evaluation after porcine kidney NTIRE shows multifocal parenchyma destruction while protecting the involved urine-collecting system with regenerated urothelial tissue. NTIRE could be used as a targeted ablation method of centrally located renal masses.

Wendler, Johann Jakob, E-mail: johann.wendler@med.ovgu.de [University of Magdeburg, Department of Urology (Germany); Pech, Maciej [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Porsch, Markus; Janitzky, Andreas [University of Magdeburg, Department of Urology (Germany); Fischbach, Frank [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Buhtz, Peter; Vogler, Klaus [University of Magdeburg, Institute of Pathology (Germany); Huehne, Sarah [University of Magdeburg, Department of Urology (Germany); Borucki, Katrin [University of Magdeburg, Institute of Clinical Chemistry (Germany); Strang, Christof [University of Magdeburg, Department of Anaesthesiology (Germany); Mahnkopf, Dirk [Institute of Medical Technology and Research (Germany); Ricke, Jens [University of Magdeburg, Department of Radiology and Nuclear Medicine (Germany); Liehr, Uwe-Bernd [University of Magdeburg, Department of Urology (Germany)

2012-08-15T23:59:59.000Z

287

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson*  

E-Print Network (OSTI)

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson summarize recent developments of nuclear resonant spectroscopy methods like nuclear resonant inelastic x important information on valence, spin state, and magnetic ordering. Both methods use a nuclear resonant

Jackson, Jennifer M.

288

How to download your NMR data to your computer. Go to http://www.versiontracker.com/dyn/moreinfo/macosx/15693 and download Fugu.  

E-Print Network (OSTI)

How to download your NMR data to your computer. Go to http in the following information. SFTP Server: chem9063.ucdavis.edu Username: nmr Initial Remote Directory: /homeChem". You should now be connected to the nmr server. There are 5 magnets listed in the archive, vnmrj300

Guo, Ting

289

Final Report: Characterization of Hydrogen Adsorption in Carbon-Based Materials by NMR  

Science Conference Proceedings (OSTI)

In support of DOE/EERE's Fuel Cell Technologies Program Hydrogen Sorption Center of Excellence (HSCoE), UNC conducted Nuclear Magnetic Resonance (NMR) measurements that contributed spectroscopic information as well as quantitative analysis of adsorption processes. While NMR based Langmuir isotherms produce reliable H2 capacity measurements, the most astute contribution to the center is provided by information on dihydrogen adsorption on the scale of nanometers, including the molecular dynamics of hydrogen in micropores, and the diffusion of dihydrogen between macro and micro pores. A new method to assess the pore width using H2 as probe of the pore geometry was developed and is based on the variation of the observed chemical shift of adsorbed dihydrogen as function of H2 pressure. Adsorbents designed and synthesized by the Center were assessed for their H2 capacity, the binding energy of the adsorption site, their pore structure and their ability to release H2. Feedback to the materials groups was provided to improve the materials’ properties. To enable in situ NMR measurements as a function of H2 pressure and temperature, a unique, specialized NMR system was designed and built. Pressure can be varied between 10-4 and 107 Pa while the temperature can be controlled between 77K and room temperature. In addition to the 1H investigation of the H2 adsorption process, NMR was implemented to measure the atomic content of substituted elements, e.g. boron in boron substituted graphitic material as well as to determine the local environment and symmetry of these substituted nuclei. The primary findings by UNC are the following: • Boron substituted for carbon in graphitic material in the planar BC3 configuration enhances the binding energy for adsorbed hydrogen. • Arrested kinetics of H2 was observed below 130K in the same boron substituted carbon samples that combine enhanced binding energy with micropore structure. • Hydrogen storage material made from activated PEEK is well suited for hydrogen storage due to its controlled microporous structure and large surface area. • A new porosimetry method for evaluating the pore landscape using H2 as a probe was developed. 1H NMR can probe the nanoscale pore structure of synthesized material and can assess the pore dimension over a range covering 1.2 nm to 2.5 nm, the size that is desired for H2 adsorption. • Analysis of 1H NMR spectra in conjunction with the characterization of the bonding structure of the adsorbent by 13C NMR distinguishes between a heterogeneous and homogeneous pore structure as evidenced by the work on AX21 and activated PEEK. • Most of the sorbents studied are suited to hydrogen storage at low temperature (T < 100K). Of the materials investigated, only boron substituted graphite has the potential to work at higher temperatures if the boron content in the favorable planar BC3 configuration that actively contributes to adsorption can be increased.

Yue Wu; Alfred Kleinhammes

2011-07-11T23:59:59.000Z

290

NMR and EPR  

NLE Websites -- All DOE Office Websites (Extended Search)

systems as wide-ranging as soil organic matter, proteins bound to vesicles or membranes, battery materials, catalysts, and biogeochemical interfaces. In modern nuclear magnetic...

291

In Vivo Near-Infrared Spectroscopy and Magnetic Resonance Imaging Monitoring of Tumor Response to Combretastatin A-4-Phosphate Correlated With Therapeutic Outcome  

Science Conference Proceedings (OSTI)

Purpose: To develop a combination treatment consisting of combretastatin A-4-phosphate (CA4P) with radiation based on tumor oxygenation status. Methods and Materials: In vivo near-infrared spectroscopy (NIRS) and diffusion-weighted (DW) magnetic resonance imaging (MRI) were applied to noninvasively monitor changes in tumor blood oxygenation and necrosis induced by CA4P (30 mg/kg) in rat mammary 13762NF adenocarcinoma, and the evidence was used to optimize combinations of CA4P and radiation treatment (a single dose of 5 Gy). Results: NIRS showed decreasing concentrations of tumor vascular oxyhemoglobin and total hemoglobin during the first 2 h after CA4P treatment, indicating significant reductions in tumor blood oxygenation and perfusion levels (p < 0.001). Twenty-four hours later, in response to oxygen inhalation, significant recovery was observed in tumor vascular and tissue oxygenation according to NIRS and pimonidazole staining results, respectively (p < 0.05). DW MRI revealed significantly increased water diffusion in tumors measured by apparent diffusion coefficient at 24 h (p < 0.05), suggesting that CA4P-induced central necrosis. In concordance with the observed tumor oxygen dynamics, we found that treatment efficacy depended on the timing of the combined therapy. The most significant delay in tumor growth was seen in the group of tumors treated with radiation while the rats breathed oxygen 24 h after CA4P administration. Conclusions: Noninvasive evaluation of tumor oxygen dynamics allowed us to rationally enhance the response of syngeneic rat breast tumors to combined treatment of CA4P with radiation.

Zhao Dawen, E-mail: Dawen.Zhao@UTSouthwestern.ed [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Chang Chenghui [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Kim, Jae G.; Liu Hanli [Joint Program in Biomedical Engineering, University of Texas Arlington and University of Texas Southwestern Medical Center, Arlington, Texas (United States); Mason, Ralph P. [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Joint Program in Biomedical Engineering, University of Texas Arlington and University of Texas Southwestern Medical Center, Arlington, Texas (United States)

2011-06-01T23:59:59.000Z

292

Ga NMR/NQR study of the kagom compound Nd This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network (OSTI)

29 Si NMR and 69,71 Ga NMR/NQR study of the kagomé compound Nd 3 Ga 5 SiO 14 This article has been Contact us My IOPscience #12;29 Si NMR and 69,71 Ga NMR/NQR study of the kagom´e compound Nd3Ga5SiO14.zorko@ijs.si Abstract. We report a comprehensive 29 Si NMR and 69,71 Ga NMR/NQR study of the large- spin magnetically

Paris-Sud 11, Université de

293

Magnetic Nanostructures for post-CMOS Electronics  

Science Conference Proceedings (OSTI)

... Using ferromagnetic resonance spectroscopy, we were able to separate edge behavior from “bulk” behavior in Permalloy magnetic nano-stripes. ...

2012-10-05T23:59:59.000Z

294

NMR implementations of Gauss sums  

E-Print Network (OSTI)

I describe the use of NMR experiments which implement Gauss sums as a method for factoring numbers and discuss whether this approach can be computationally useful.

Jonathan A. Jones

2008-07-10T23:59:59.000Z

295

Near Infrared Microspectroscopy, Fluorescence Microspectroscopy, Infrared Chemical Imaging and High Resolution Nuclear Magnetic Resonance Analysis of Soybean Seeds, Somatic Embryos and Single Cells  

E-Print Network (OSTI)

Novel methodologies are currently being developed and established for the chemical analysis of soybean seeds, embryos and single cells by Fourier Transform Infrared (FT-IR), Fourier Transform Near Infrared (FT-NIR) Microspectroscopy, Fluorescence and High-Resolution NMR (HR-NMR). The first FT-NIR chemical images of biological systems approaching one micron resolution are presented here. Chemical images obtained by FT-NIR and FT-IR Microspectroscopy are presented for oil in soybean seeds and somatic embryos under physiological conditions. FT-NIR spectra of oil and proteins were obtained for volumes as small as two cubic microns. Related, HR-NMR analyses of oil contents in somatic embryos are also presented here with nanoliter precision. Such 400 MHz 1H NMR analyses allowed the selection of mutagenized embryos with higher oil content (e.g. ~20%) compared to non-mutagenized control embryos. Moreover, developmental changes in single soybean seeds and/or somatic embryos may be monitored by FT-NIR with a precision ...

Baianu, I C; Hofmann, N E; Korban, S S; Lozano, P; You, T; AOCS 94th Meeting, Kansas

2002-01-01T23:59:59.000Z

296

Relationships between observed pore and pore-throat geometries, measured porosity and permeability, and indirect measures of pore volume by nuclear magnetic resonance  

E-Print Network (OSTI)

Carbonate reservoirs are a network of pores and connecting pore-throats that contain at least half of the world's oil. Genetic classification of carbonate pores enables one to map the pore types that have greatest influence on reservoir performance. Though NMR logging has been used to estimate pore sizes, it has not been used to identify genetic pore types or to aid in determinations of reservoir quality for different pore assemblages. Five genetic pore types identified in 40 carbonate and 7 sandstone samples were subjected to NMR measurements. Results reveal close correspondence between NMRderived pore volumes and 2-D pore size and shape gleaned from petrographic image analysis. Comparisons of real and synthetic pore shapes showed that shapes of all pore types in the medium size range of 0.02-0.5mm can be reliably compared with synthetic varieties, but such comparisons were unreliable for vuggy pores smaller than 0.5mm. T2 relaxation times for depositional pores exhibit low amplitude, narrow wavelength responses. Moldic pores produced medium amplitude, asymmetrical wavelength responses, and intercrystalline pores show high amplitude, narrow wavelength responses. NMR-derived pore volumes on pores with ferroan dolomite interiors underestimated pore diameter by up to 3 orders of magnitude. Calculated pore-throat sizes from MICP data correlate strongly with measured permeability. Samples with high, intermediate, or low poroperm values displayed characteristic T2 curves confirming that reservoir quality can be estimated from NMR measurements. Future work is expected to show that NMR logging can estimate reservoir quality at field scale and aid in mapping flow units in compartmentalized reservoirs.

Adams, Aaron J.

2005-12-01T23:59:59.000Z

297

Doing Research at An Office of Research Workshop  

E-Print Network (OSTI)

..............................................................................................12 CITI Training Courses............................................................................................................25 Nuclear Magnetic Resonance (NMR) Core Facility

Salama, Khaled

298

1H NMR Relaxation in Urea  

E-Print Network (OSTI)

Acetamide Studied by Deuterium NMR. J. Phys. Chem. 97 (1993)Duer. Solid state 13 C CP MAS NMR study of molecular motionsPulse and Fourier Transform NMR. Introduction to Theory and

Taylor, Robert E; Bacher, Alfred D; Dybowski, C.

2007-01-01T23:59:59.000Z

299

Magnetic resonance imaging in Mexico  

Science Conference Proceedings (OSTI)

MR imaging has experienced an important growth worldwide and in particular in the USA and Japan. This imaging technique has also shown an important rise in the number of MR imagers in Mexico. However

A. O. Rodriguez; R. Rojas; F. A. Barrios

2001-01-01T23:59:59.000Z

300

New Insights into the Crystal and Electronic Structures of Li[subscript 1+x]V[subscript 1?x]O[subscript 2] from Solid State NMR, Pair Distribution Function Analyses, and First Principles Calculations  

Science Conference Proceedings (OSTI)

Pair distribution function (PDF) analyses of synchrotron data obtained for the anode materials Li{sub 1+x}V{sub 1-x}O{sub 2} (0 {le} x {le} 0.1) have been performed to characterize the short to medium range structural ordering. The data show clear evidence for the magnetically-induced distortion of the V sublattice to form trimers, the distortion persisting at even the highest excess Li content considered of x = 0.1. At least three distinct local environments were observed for the stoichiometric material LiVO{sub 2} in {sup 6}Li nuclear magnetic resonance (NMR) spectroscopy, the environments becoming progressively more disordered as the Li content increases. A two-dimensional Li-Li correlation NMR experiment (POST-C7) was used to identify the resonances corresponding to Li within the same layers. NMR spectra were acquired as a function of the state of charge, a distinct environment for Li in Li{sub 2}VO{sub 2} being observed. The results suggest that disorder within the Li layers (in addition to the presence of Li within the V layers as proposed by Armstrong et al. Nat. Mater.2011, 10, 223-229) may aid the insertion of Li into the Li{sub 1+x}V{sub 1-x}O{sub 2} phase. The previously little-studied Li{sub 2}VO{sub 2} phase was also investigated by hybrid density functional theory (DFT) calculations, providing insights into magnetic interactions, spin-lattice coupling, and Li hyperfine parameters.

Pourpoint, Frédérique; Hua, Xiao; Middlemiss, Derek S.; Adamson, Paul; Wang, Da; Bruce, Peter G.; Grey, Clare P. (SBU); (Cambridge); (St Andrews)

2012-10-29T23:59:59.000Z

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301

High Occurrence of Aberrant Lymph Node Spread on Magnetic Resonance Lymphography in Prostate Cancer Patients With a Biochemical Recurrence After Radical Prostatectomy  

SciTech Connect

Purpose: To investigate the pattern of lymph node spread in prostate cancer patients with a biochemical recurrence after radical prostatectomy, eligible for salvage radiotherapy; and to determine whether the clinical target volume (CTV) for elective pelvic irradiation in the primary setting can be applied in the salvage setting for patients with (a high risk of) lymph node metastases. Methods and Materials: The charts of 47 prostate cancer patients with PSA recurrence after prostatectomy who had positive lymph nodes on magnetic resonance lymphography (MRL) were reviewed. Positive lymph nodes were assigned to a lymph node region according to the guidelines of the Radiation Therapy Oncology Group (RTOG) for delineation of the CTV for pelvic irradiation (RTOG-CTV). We defined four lymph node regions for positive nodes outside this RTOG-CTV: the para-aortal, proximal common iliac, pararectal, and paravesical regions. They were referred to as aberrant lymph node regions. For each patient, clinical and pathologic features were recorded, and their association with aberrant lymph drainage was investigated. The distribution of positive lymph nodes was analyzed separately for patients with a prostate-specific antigen (PSA) <1.0 ng/mL. Results: MRL detected positive aberrant lymph nodes in 37 patients (79%). In 20 patients (43%) a positive lymph node was found in the pararectal region. Higher PSA at the time of MRL was associated with the presence of positive lymph nodes in the para-aortic region (2.49 vs. 0.82 ng/mL; p = 0.007) and in the proximal common iliac region (1.95 vs. 0.59 ng/mL; p = 0.009). There were 18 patients with a PSA <1.0 ng/mL. Ten of these patients (61%) had at least one aberrant positive lymph node. Conclusion: Seventy-nine percent of the PSA-recurrent patients had at least one aberrant positive lymph node. Application of the standard RTOG-CTV for pelvic irradiation in the salvage setting therefore seems to be inappropriate.

Meijer, Hanneke J.M., E-mail: H.Meijer@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Lin, Emile N. van [Department of Radiation Oncology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Debats, Oscar A. [Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Witjes, J. Alfred [Department of Urology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Span, Paul N.; Kaanders, Johannes H.A.M. [Department of Radiation Oncology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Barentsz, Jelle O. [Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands)

2012-03-15T23:59:59.000Z

302

Value of Diffusion-Weighted Magnetic Resonance Imaging for Prediction and Early Assessment of Response to Neoadjuvant Radiochemotherapy in Rectal Cancer: Preliminary Results  

Science Conference Proceedings (OSTI)

Purpose: To evaluate diffusion-weighted magnetic resonance imaging (DWI) for response prediction before and response assessment during and early after preoperative radiochemotherapy (RCT) for locally advanced rectal cancer (LARC). Methods and Materials: Twenty patients receiving RCT for LARC underwent MRI including DWI before RCT, after 10-15 fractions and 1 to 2 weeks before surgery. Tumor volume and apparent diffusion coefficient (ADC; b-values: 0-1000 s/mm{sup 2}) were determined at all time points. Pretreatment tumor ADC and volume, tumor ADC change ( Increment ADC), and volume change ( Increment V) between pretreatment and follow-up examinations were compared with histopathologic findings after total mesorectal excision (pathologic complete response [pCR] vs. no pCR, ypT0-2 vs. ypT3-4, T-downstaging or not). The discriminatory capability of pretreatment tumor ADC and volume, Increment ADC, and Increment V for the detection of pCR was compared with receiver operating characteristics analysis. Results: Pretreatment ADC was significantly lower in patients with pCR compared with patients without (in mm{sup 2}/s: 0.94 {+-} 0.12 Multiplication-Sign 10{sup -3} vs. 1.19 {+-} 0.22 Multiplication-Sign 10{sup -3}, p = 0.003), yielding a sensitivity of 100% and specificity of 86% for detection of pCR. The volume reduction during and after RCT was significantly higher in patients with pCR compared with patients without (in %: {Delta}V{sub during}: -62 {+-} 16 vs. -33 {+-} 16, respectively, p = 0.015; and {Delta}V{sub post}: -86 {+-} 12 vs. -60 {+-} 21, p = 0.012), yielding a sensitivity of 83% and specificity of 71% for the {Delta}V{sub during} and, respectively, 83% and 86% for the {Delta}V{sub post}. The Increment ADC during ({Delta}ADC{sub during}) and after RCT ({Delta}ADC{sub post}) showed a significantly higher value in patients with pCR compared with patients without (in %: {Delta}ADC{sub during}: 72 {+-} 14 vs. 16 {+-} 12, p = 0.0006; and {Delta}ADC{sub post}: 88 {+-} 35 vs. 26 {+-} 19, p = 0.0011), yielding a sensitivity and specificity of 100% for the {Delta}ADC{sub during} and, respectively, 100% and 93% for the {Delta}ADC{sub post}. Conclusions: These initial findings indicate that DWI, using pretreatment ADC, {Delta}ADC{sub during}, and {Delta}ADC{sub post} may be useful for prediction and early assessment of pathologic response to preoperative RCT of LARC, with higher accuracy than volumetric measurements.

Lambrecht, Maarten, E-mail: maarten.lambrecht@uzleuven.be [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium); Vandecaveye, Vincent; De Keyzer, Frederik [Department of Radiology, UZ Gasthuisberg, Leuven (Belgium); Roels, Sarah [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium); Penninckx, Freddy [Department of Abdominal Surgery, UZ Gasthuisberg, Leuven (Belgium); Van Cutsem, Eric [Department of Digestive Oncology, UZ Gasthuisberg, Leuven (Belgium); Filip, Claus [Department of Radiology, UZ Gasthuisberg, Leuven (Belgium); Haustermans, Karin [Department of Radiation Oncology, UZ Gasthuisberg, Leuven (Belgium)

2012-02-01T23:59:59.000Z

303

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

SciTech Connect

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.

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

2012-02-21T23:59:59.000Z

304

Computational, electrochemical and {sup 7}Li NMR studies of lithiated disordered carbons electrodes in lithium ion cells.  

DOE Green Energy (OSTI)

Disordered carbons that deliver high reversible capacity in electrochemical cells have been synthesized by using inorganic clays as templates to control the pore size and the surface area. The capacities obtained were much higher than those calculated if the resultant carbon had a graphitic-like structure. Computational chemistry was used to investigate the nature of lithium bonding in a carbon lattice unlike graphite. The lithium intercalated fullerene Li{sub n}-C{sub 60} was used as a model for our (non-graphitic) disordered carbon lattice. A dilithium-C{sub 60} system with a charge and multiplicity of (0,1) and a trilithium-C{sub 60} system with a charge and multiplicity of (0,4) were investigated. The spatial distribution of lithium ions in an electrochemical cell containing this novel disordered carbon material was investigated in situ by Li-7 NMR using an electrochemical cell that was incorporated into a toroid cavity nuclear magnetic resonance (NMR) imager. The concentration of solvated Li{sup +} ions in the carbon anode appears to be larger than in the bulk electrolyte, is substantially lower near the copper/carbon interface, and does not change with cell charging.

Sandi, G.; Gerald, R., II; Scanlon, L. G.; Carrado, K. A.; Winans, R. E.

1998-01-07T23:59:59.000Z

305

Lensless Imaging of Magnetic Nanostructures  

NLE Websites -- All DOE Office Websites (Extended Search)

Wednesday, 28 March 2012 00:00 Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

306

Solid state NMR method development and studies of biological and biomimetic nanocomposites  

Science Conference Proceedings (OSTI)

This thesis describes application and development of advanced solid-state nuclear magnetic resonance techniques for complex materials, in particular organic-inorganic nanocomposites and thermoelectric tellurides. The apatite-collagen interface, essential for understanding the biomineralization process in bone and engineering the interface for controlled bio-mimetic synthesis and optimized mechanical properties, is buried within the nanocomposite of bone. We used multinuclear solid-state NMR to study the composition and structure of the interface. Citrate has been identified as the main organic molecule strongly bound to the apatite surface with a density of 1/(2 nm){sup 2}, covering 1/6 of the total surface area in bovine bone. Citrate provides more carboxylate groups, one of the key functional groups found to affect apatite nucleation and growth, than all the non-collagenous proteins all together in bone; thus we propose that citrate stabilizes apatite crystals at a very small thickness of {approx}3 nm (4 unit cells) to increase bone fracture tolerance. The hypothesis has been confirmed in vitro by adding citrate in the bio-mimetic synthesis of polymerhydroxyapatite nanocomposites. The results have shown that the size of hydroxyapatite nanocrystals decreases as increasing citrate concentration. With citrate concentrations comparable to that in body fluids, similar-sized nanocrystals as in bone have been produced. Besides the dimensions of the apatite crystals, the composition of bone also affects its biofunctional and macroscopic mechanical properties; therefore, our team also extended its effort to enhance the inorganic portion in our bio-mimetic synthesis from originally 15 wt% to current 50 wt% compared to 65 wt% in bovine bone, by using Lysine-Leucine hydroxyapatite nucleating diblock co-polypeptide, which forms a gel at very low concentration. In this thesis, various advanced solid state NMR techniques have been employed to characterize nanocomposites. Meanwhile, we have developed new methods to achieve broadband high resolution NMR and improve the accuracy of inter-nuclear distance measurements involving quadrupolar spins. Broadband high resolution NMR of spin-1/2 nuclei has been accomplished by the adaptation of the magic angle turning (MAT) method to fast magic angle spinning, termed fast MAT, by solving technical problems such as off resonance effects. Fast MAT separates chemical shift anisotropy and isotropic chemical shifts over a spectral range of {approx}1.8 {gamma}B{sub 1} without significant distortions. Fast MAT {sup 125}Te NMR has been applied to study technologically important telluride materials with spectra spreading up to 190 kHz. The signal-to-noise ratio of the spectra is significantly improved by using echo-matched Gaussian filtering in offline data processing. The accuracy of the measured distances between spin-1/2 and quadrupolar nuclei with methods such as SPIDER and REAPDOR has been improved by compensating for the fast longitudinal quadrupolar relaxation on the sub-millisecond with a modified S{sub 0} pulse sequence. Also, the T1Q effect on the spin coherence and its spinning speed dependency has been explored and documented with analytical and numerical simulations as well as experimental measurements.

Hu, Yanyan

2011-02-07T23:59:59.000Z

307

NMR Sample Policy Version: 20 Jul 2006  

E-Print Network (OSTI)

NMR Sample Policy Version: 20 Jul 2006 Task: NMR Sample Preparation Equipment Used: Centrifuge, pH meter, NMR spectrometers, fumehood, fridges, freezers, tube cleaner Location: Rooms G14, G16, G23 and G24 in the Henry Wellcome Building for Biomolecular NMR Spectroscopy, University of Birmingham Hazards

Birmingham, University of

308

NMR STUDIES OF ORIENTED MOLECULES  

E-Print Network (OSTI)

pulse is generated by a TTL controlled r.f. switch. atorModel 100D0898) under TTL control of the pulse programmer.180 MHz NMR spectrometer. TTL control pulses The are input

Sinton, S.W.

2008-01-01T23:59:59.000Z

309

A Microcoil NMR Probe for Coupling Microscale HPLC with On-Line NMR Spectroscopy  

E-Print Network (OSTI)

A Microcoil NMR Probe for Coupling Microscale HPLC with On-Line NMR Spectroscopy Raju Subramanian, Urbana, Illinois 61801 An HPLC NMR system is presented that integrates a commercial microbore HPLC system using a 0.5-mm column with a 500-MHz proton NMR spectrometer using a custom NMR probe with an observe

Andrews, Anne M.

310

Effect of Secondary Echo Signals in Spin-Systems with a Large Inhomogeneous Broadening of NMR Line  

E-Print Network (OSTI)

The possibility of comparatively simple and fast determination of characteristic relaxation parameters T1, T2 and T3 for nuclear spin-systems with strong Larmor and Rabi inhomogeneous broadenings of NMR lines using the secondary echo signal effect was experimentally shown. Resides, this method gives opportunity to obtain a valuable infomation on the inhomogeneous NMR broadening which reflects the character of magnetic field microscopic destribution in such systems, as example, multidomain magnetics and superconductors.

J. G. Chigvinadze; G. I. Mamniashvili; Yu. G. Sharimanov

2003-10-22T23:59:59.000Z

311

Fourier Transform Near Infrared Microspectroscopy, Infrared Chemical Imaging, High-Resolution Nuclear Magnetic Resonance and Fluorescence Microspectroscopy Detection of Single Cancer Cells and Single Viral Particles  

E-Print Network (OSTI)

Single Cancer Cells from Human tumors are being detected and imaged by Fourier Transform Infrared (FT-IR), Fourier Transform Near Infrared (FT-NIR)Hyperspectral Imaging and Fluorescence Correlation Microspectroscopy. The first FT-NIR chemical, microscopic images of biological systems approaching one micron resolution are here reported. Chemical images obtained by FT-NIR and FT-IR Microspectroscopy are also presented for oil in soybean seeds and somatic embryos under physiological conditions. FT-NIR spectra of oil and proteins were obtained for volumes as small as two cubic microns. Related, HR-NMR analyses of oil contents in somatic embryos as well as 99% accurate calibrations are also presented here with nanoliter precision. Such high-resolution, 400 MHz H-1 NMR analyses allowed the selection of mutagenized embryos with higher oil content (e.g. >~20%) compared to the average levels in non-mutagenized control embryos. Moreover, developmental changes in single soybean seeds and/or somatic embryos may be monito...

Baianu,I C; Hofmann, N E; Korban, S S; Lozano, P; You, T

2004-01-01T23:59:59.000Z

312

Apparatus and method for generating a magnetic field by rotation of a charge holding object  

DOE Patents (OSTI)

A device and a method for the production of a magnetic field using a Charge Holding Object that is mechanically rotated. In a preferred embodiment, a Charge Holding Object surrounding a sample rotates and subjects the sample to one or more magnetic fields. The one or more magnetic fields are used by NMR Electronics connected to an NMR Conductor positioned within the Charge Holding Object to perform NMR analysis of the sample.

Gerald, II, Rex E. (Brookfield, IL); Vukovic, Lela (Westchester, IL); Rathke, Jerome W. (Homer Glenn, IL)

2009-10-13T23:59:59.000Z

313

NMR STUDY OF MOLECULAR REFORIENTATION UNDER FIVEFOLD SYMMETRY SOLID PERMETHYLFERROCENE  

E-Print Network (OSTI)

M. Mehring, Vol. 11, NMR Basic Principles and Progress (of the American Chemical Society NMR STUDY OF MOLECULARCalifornia. LBL-10563 NMR STUDY OF MOLECULAR REORIENTATION

Wemmer, D.E.

2013-01-01T23:59:59.000Z

314

Spin coherence transfer in chemical transformations monitored NMR  

E-Print Network (OSTI)

using spatially separated NMR encoding and detection coilsconformational changes. Recently, NMR has also been used inand flow profiles. [9] These NMR techniques directly couple

Anwar, Sabieh M.; Hilty, Christian; Chu, Chester; Bouchard, Louis-S.; Pierce, Kimberly L.; Pines, Alexander

2006-01-01T23:59:59.000Z

315

Probing Asphaltene Aggregation in Native Crude Oils with Low-Field NMR  

SciTech Connect

We show that low-field proton nuclear magnetic resonance (NMR) relaxation and diffusion experiments can be used to study asphaltene aggregation directly in crude oils. Relaxation was found to be multiexponential, reflecting the composition of a complex fluid. Remarkably, the relaxation data for samples with different asphaltene concentrations can be collapsed onto each other by a simple rescaling of the time dimension with a concentration-dependent factor {zeta}, whereas the observed diffusion behavior is unaffected by asphaltene concentration. We interpret this finding in terms of a theoretical model that explains the enhanced relaxation by the transitory entanglement of solvent hydrocarbons within asphaltene clusters and their subsequent slowed motion and diffusion within the cluster. We relate the measured scaling parameters {zeta} to cluster sizes, which we find to be on the order of 2.2-4.4 nm for an effective sphere diameter. These sizes are in agreement with the typical values reported in the literature as well as with the small-angle X-ray scattering (SAXS) experiments performed on our samples.

Zielinski, Lukasz; Saha, Indrajit; Freed, Denise E.; Hrlimann, Martin D.; Liu, Yongsheng (BU-M); (Schlumberger-Doll)

2010-04-13T23:59:59.000Z

316

Investigation of Ti-doped NaAlH4 by solid-state NMR  

DOE Green Energy (OSTI)

In recent years, the development of Ti-doped NaAlH{sub 4} as a hydrogen storage material has gained attention because of its large weight percentage of hydrogen ({approx}5%) compared to traditional interstitial hydrides. The addition of transition-metal dopants, in the form of Ti-halides, such as TiCl{sub 3}, dramatically improves the kinetics of the absorption and desorption of hydrogen from NaAlH{sub 4}. However, the role that Ti plays in enhancing the absorption and desorption of H{sub 2} is still unknown. In the present study, {sup 27}Al, {sup 23}Na, and {sup 1}H MAS (Magic Angle Spinning) NMR (Nuclear Magnetic Resonance) has been performed to understand the titanium speciation in Ti-doped NaAlH{sub 4}. All experiments were performed on a sample of crushed single crystals exposed to Ti during growth, a sample of solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, a reacted sample of solvent-mixed TiCl{sub 3} + {sup 3}NaAlH{sub 4} with THF, and a reacted sample of ball-milled TiCl3 + 3NaAlH{sub 4}. The {sup 27}Al MAS NMR has shown differences in compound formation between solvent-mixed TiCl{sub 3} + 3NaAlH{sub 4} with THF and the mechanically ball-milled TiCl{sub 3} + 3NaAlH{sub 4}. {sup 27}Al MAS NMR of the mechanically ball-milled mixture of fully-reacted TiCl{sub 3} + 3NaAlH{sub 4} showed spectral signatures of TiAl{sub 3} while, the solvent-mixed 4TiCl{sub 3} + 112NaAlH{sub 4}, which is totally reacted, does not show the presences of TiAl{sub 3}, but shows the existence of Al{sub 2}O{sub 3}.

Maxwell, R; Majzoub, E; Herberg, J

2003-11-24T23:59:59.000Z

317

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01T23:59:59.000Z

318

Multiple resonant railgun power supply  

DOE Patents (OSTI)

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, E.M.; Nunnally, W.C.

1985-06-19T23:59:59.000Z

319

Cyclotron Resonances in Electron Cloud Dynamics  

Science Conference Proceedings (OSTI)

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lbstripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

Celata, C. M.; Furman, Miguel A.; Vay, J.-L.; Ng, J. S.T.; Grote, D. P.; Pivi, M. T. F.; Wang, L. F.

2009-04-29T23:59:59.000Z

320

Results from Combined NMR and Electrochemical Impedance ...  

Science Conference Proceedings (OSTI)

Presentation Title, Oxygen-vacancy Transport in Heavily Doped Cubic Zirconia: Results from Combined NMR and Electrochemical Impedance Spectroscopies.

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321

Design and fabrication of a superconducting magnet for an 18 GHz electron cyclotron resonance ion/photon source NFRI-ECRIPS  

Science Conference Proceedings (OSTI)

A superconducting magnet was designed and fabricated for an 18 GHz ECR ion/photon source, which will be installed at National Fusion Research Institute (NFRI) in South Korea. The magnetic system consists of a set of four superconducting coils for axial mirror field and 36 pieces of permanent magnets for hexapolar field. The superconducting coils with a cryocooler (1.5 W - 4.2 K) allow one to reach peak mirror fields of 2.2 T in the injection and those of 1.5 T in the extraction regions on the source axis, and the resultant hexapolar field gives 1.35 T on the plasma chamber wall. The unbalanced magnetic force between the coils and surrounding yoke has been minimized to 16 ton by a coil arrangement and their electrical connection, and then was successfully suspended by 12 strong thermal insulating supports made of large numbers of carbon fibers. In order to block radiative thermal losses, multilayer thermal insulations are covered on the coil windings as well as 40-K aluminum thermal shield. Also new schemes of quench detection and safety system (coil divisions, quench detection coils, and heaters) were employed. For impregnation of the windings a special epoxy has been selected and treated to have a higher breaking strength and a higher thermal conductivity, which enables the superconductors to be uniformly and rapidly cooled down or heated during a quench.

You, H.-J.; Jang, S.-W.; Jung, Y.-H.; Lho, T.-H. [Convergence Plasma Research Center, National Fusion Research Institute, Yusung-gu, Daejeon (Korea, Republic of); Lee, S.-J. [The Theoretical Solutions, JHeng Inc., Seoul (Korea, Republic of)

2012-02-15T23:59:59.000Z

322

Resonant-cavity antenna for plasma heating  

DOE Patents (OSTI)

This invention relates generally to a method and apparatus for transferring energy to a plasma immersed in a magnetic field, and relates particularly to an apparatus for heating a plasma of low atomic number ions to high temperatures by transfer of energy to plasma resonances, particularly the fundamental and harmonics of the ion cyclotron frequency of the plasma ions. This invention transfers energy from an oscillating radio-frequency field to a plasma resonance of a plasma immersed in a magnetic field.

Perkins, F.W. Jr.; Chiu, S.C.; Parks, P.; Rawls, J.M.

1984-01-10T23:59:59.000Z

323

Cyclotron Resonances in Electron Cloud Dynamics  

SciTech Connect

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where lb<< 2pi c/omega c (with lb = bunch length, omega c = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the electron cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor ~;;3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined vertical density"stripes" found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The existence of the resonances has been confirmed in experiments at PEP-II. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations and experimental observations, the reason for the bunch-length dependence, and details of the dynamics are discussed here.

Celata, C. M.; Furman, Miguel A.; Vay, J.-L.; Ng, J. S.T.; Grote, D. P.; Pivi, M. T. F.; Wang, L. F.

2009-04-29T23:59:59.000Z

324

Simulation of ion cyclotron resonance heating through resonant absorption in two-ion species plasma  

DOE Green Energy (OSTI)

Particle simulation of two-ion hybrid cyclotron resonance heating (ICRH) of a magnetized hydrogen plasma with deuteron minority by magnetosonic waves launched from the low magnetic field side is reported. Depending on the minority concentration, partial transmission and partial reflection of the incoming waves off the two-ion hybrid resonance layer occur, in contrast to the mode conversion mainly taking place during incidence from the high field side. Preferential minority heating is observed, as the minority cyclotron resonance is close to the two-ion hybrid resonance layer.

Tajima, T.; Riyopoulos, S.; Demchenko, V.

1987-01-01T23:59:59.000Z

325

C NMR Spectra (see p S10)  

E-Print Network (OSTI)

S31 1 H and 13 C NMR Spectra (see p S10) NHBn Me Ph 10 #12;S32 1 H and 13 C NMR Spectra (see p S10) NHBn Me Ph 11 #12;S33 1 H and 13 C NMR Spectra (see p S11) NH-i-Pr n-Bu NH-i-Pr n-Bu 12 Me Me 13 #12;S34 1 H and 13 C NMR Spectra (see p S11)NH-i-Pr Me Ph 14 #12;S35 1 H and 13 C NMR Spectra (see p S11

Collum, David B.

326

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave-guide resonator structure is designed for use in separating particles of equal momentum but differing in mass, having energies exceeding one billion eiectron volts. The particles referred to are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high energy accelerator. In the resonator a travelling electric wave is produced which travels at the same rate of speed as the unwanted particle which is thus deflected continuously over the length of the resonator. The wanted particle is slightly out of phase with the travelling wave so that over the whole length of the resonator it has a net deflection of substantially zero. The travelling wave is established in a wave guide of rectangular cross section in which stubs are provided to store magnetic wave energy leaving the electric wave energy in the main structure to obtain the desired travelling wave and deflection. The stubs are of such shape and spacing to establish a critical mathemitical relationship. (AEC)

Blewett, J.P.; Kiesling, J.D.

1963-06-11T23:59:59.000Z

327

Two dimensional NMR and NMR relaxation studies of coal structure. Progress report, January 1, 1992--March 31, 1992  

SciTech Connect

This report covers the progress made on the title project for the project period. Four major areas of inquiry are being pursued. Advanced solid state NMR methods are being developed to assay the distribution of the various important functional groups that determine the reactivity of coals. Special attention is being paid to methods that are compatible with the very high magic angle sample spinning rates needed for operation at the high magnetic field strengths available today. Polarization inversion methods utilizing the difference in heat capacities of small groups of spins are particularly promising. Methods combining proton-proton spin diffusion with {sup 13}C CPMAS readout are being developed to determine the connectivity of functional groups in coals in a high sensitivity relay type of experiment. Additional work is aimed at delineating the role of methyl group rotation in the proton NMR relaxation behavior of coals.

Zilm, K.W.

1992-07-01T23:59:59.000Z

328

VOLUME 83, NUMBER 16 P H Y S I C A L R E V I E W L E T T E R S 18 OCTOBER 1999 Probing Porous Media with Gas Diffusion NMR  

E-Print Network (OSTI)

with Gas Diffusion NMR R. W. Mair,1 G. P. Wong,1 D. Hoffmann,1 M. D. Hürlimann,2 S. Patz,3 L. M. Schwartz,2 resonance (GD-NMR) provides a powerful technique for probing the structure of porous media. In random packs of glass beads, using both laser-polarized and thermally polarized xenon gas, we find that GD-NMR can

Walsworth, Ronald L.

329

Cyclotron Resonances in Electron Cloud Dynamics  

SciTech Connect

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l{sub b} << 2{pi}{omega}{sub c}, (l{sub b} = bunch duration, {omega}{sub c} = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor {approx} 3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined density 'stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed.

Celata, C M; Furman, M A; Vay, J L; Grote, D P; Ng, J T; Pivi, M F; Wang, L F

2009-05-05T23:59:59.000Z

330

Optimization of a microwave resonator cavity to perform electron spin resonance measurements on quantum dots  

E-Print Network (OSTI)

This thesis attempts to improve on an ongoing experiment of detecting electron spin resonance (ESR) on AlGaAs/GaAs lateral quantum dots. The experiment is performed in a 2.5 Tesla magnetic field at temperatures around ...

Burger, Anat

2006-01-01T23:59:59.000Z

331

Measurements of magnetic field alignment  

Science Conference Proceedings (OSTI)

The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs.

Kuchnir, M.; Schmidt, E.E.

1987-11-06T23:59:59.000Z

332

The use of solid-state NMR techniques for the analysis of water in coal and the effect of different coal drying techniques on the structure and reactivity of coal. Quarterly report, December 1, 1993--February 28, 1994  

SciTech Connect

The overall objectives of this study are to develop a nuclear magnetic resonance (NMR) method for measuring the water in coal, to measure the changes in coal structure that occur during coal drying, to determine what effect water has on retrograde/condensation reactions, to determine the mechanism by which water may impact coal reactivity toward liquefaction, and to conduct D{sub 2}O exchange studies to ascertain the role of water in coal liquefaction. The objectives for this quarterly report period were (1) to train students in the operation of the coal liquefaction reactor, gas analysis, extraction of the coal residue and coal liquids, and to calculate the percent conversion from the coal liquefaction data; and (2) to implement the changes in the coal liquefaction experimental procedure.

Netzel, D.A.

1994-06-01T23:59:59.000Z

333

Applications of DNP and solid-state NMR for protein structure determination  

E-Print Network (OSTI)

Magic Angle Spinning (MAS) solid state nuclear magnetic resonance (SSNMR) is a developing method for determining the structures and studying the dynamics and functions of biological molecules. This method is particularly ...

Mayrhofer, Rebecca Maria

2010-01-01T23:59:59.000Z

334

Toroids as NMR detectors in metal pressure probes and in flow systems  

DOE Patents (OSTI)

A nuclear magnetic resonance probe to measure the properties of a sample under high pressure conditions. The apparatus employs a free standing, elongated toroidal coil as the RF transmitter and receiver.

Rathke, Jerome W. (Bolingbrook, IL)

1991-01-01T23:59:59.000Z

335

Toroids as NMR detectors in metal pressure probes and in flow systems  

DOE Patents (OSTI)

A nuclear magnetic resonance probe to measure the properties of a sample under high pressure conditions. The apparatus employs a free standing, elongated toroidal coil as the RF transmitter and receiver. 3 figs.

Rathke, J.W.

1990-01-31T23:59:59.000Z

336

NMR Quantum Information Processing with Para-Hydrogen  

E-Print Network (OSTI)

This thesis addresses the problems of initialization and separability in liquid state NMR based quantum information processors. We prepare pure quantum states lying above the entanglement threshold. Our pure state quantum computer derives its purity from the highly polarized nuclear spin states in the para-hydrogen molecule. The thesis begins with a critique of conventional NMR based quantum information processing outlining the major strengths and weaknesses of the technology. We describe the enhanced magnetic ordering of the nuclear spin states in para-hydrogen and an initialization experiment exploiting this effect to achieve pure, entangled states. These states can indeed be used as initial states in implementing quantum algorithms: we describe mplementations of the Deutsch and the Grover quantum algorithms. The "twirl" operation converts a completely arbitrary input state to a Werner singlet. The NMR implementation of this operation is taken up. We also analyze the possibility of sharing the purity of some highly polarized qubits in a quantum computer onto quantum subspaces of arbitrary dimensions, and whether these sharing operations increase or decrease the likelihood of entanglement.

M. S. Anwar

2005-09-07T23:59:59.000Z

337

Cyclotron Resonances in Electron Cloud Dynamics  

Science Conference Proceedings (OSTI)

A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l{sub b} stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed.

Celata, C M; Furman, M A; Vay, J L; Grote, D P; Ng, J T; Pivi, M F; Wang, L F

2009-05-05T23:59:59.000Z

338

RESONATOR PARTICLE SEPARATOR  

DOE Patents (OSTI)

A wave guide resonator structure is described for use in separating particles of equal momentum but differing in mass and having energies exceeding one billion electron volts. The particles are those of sub-atomic size and are generally produced as a result of the bombardment of a target by a beam such as protons produced in a high-energy accelerator. In this wave guide construction, the particles undergo preferential deflection as a result of the presence of an electric field. The boundary conditions established in the resonator are such as to eliminate an interfering magnetic component, and to otherwise phase the electric field to obtain a traveling wave such as one which moves at the same speed as the unwanted particle. The latter undergoes continuous deflection over the whole length of the device and is, therefore, eliminated while the wanted particle is deflected in opposite directions over the length of the resonator and is thus able to enter an exit aperture. (AEC)

Blewett, J.P.

1962-01-01T23:59:59.000Z

339

ELECTRON PARAMAGNETIC RESONANCE ...  

Science Conference Proceedings (OSTI)

ELECTRON PARAMAGNETIC RESONANCE SPECTROELECTROCHEMISTRY OF TRANSITION METAL SOLAR FUELS CATALYSTS. ...

340

Scientific Innovation Through Integration Capabilities Series  

NLE Websites -- All DOE Office Websites (Extended Search)

houses a suite of nuclear magnetic resonance (NMR) spectrometers with frequencies ranging from 300 to 900 MHz. To complement its NMR suite, EMSL also offers a pulsed,...

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

NMR for Equilateral Triangular Geometry under Conditions of Surface Relaxivity - Analytical and Random Walk Solution  

E-Print Network (OSTI)

We consider analytical and numerical solution of NMR relaxation under the condition of surface relaxation in an equilateral triangular geometry. We present an analytical expression for the Green's function in this geometry. We calculate the transverse magnetic relaxation without magnetic gradients present, single-phase, both analytically and numerically. There is a very good match between the analytical and numerical results. We also show that the magnetic signal from an equilateral triangular geometry is qualitatively different from the known solution: plate, cylinder and sphere, in the case of a nonuniform initial magnetization. Non uniform magnetization close to the sharp corners makes the magnetic signal very fast multi exponential. This type of initial configuration fits qualitatively with the experimental results by Song et al.[1]. It should also be noted that the solution presented here can be used to describe absorption of a chemical substance in an equilateral triangular geometry (for a stationary fluid).

J. Finjord; A. Hiorth; U. H. a Lad; S. M. Skjaeveland

2005-08-18T23:59:59.000Z

342

NMR WITH GENERALIZED DYNAMICS OF SPIN AND SPATIAL COORDINATES  

E-Print Network (OSTI)

M. Mehring, High Resolution NMR in Solids, (Springer-Verlag,Res. M. H. Levitt, Prog. in NMR Spect. 18, 61 (1986). A. J.Shaka and J. Keeler, Prog. in NMR Spect. 19, 47 (1987). R.

Lee, C.J.

2010-01-01T23:59:59.000Z

343

NMR structure of hypothetical protein MG354 from Mycoplasma genitalium  

E-Print Network (OSTI)

Bicelle-based liquid crystals for NMR measurement of dipolarbasic pH values. J Biomol NMR 1999;13:187-191. Kraulis PJ.Prot-00430-2004-R1 NMR structure of hypothetical protein

Pelton, Jeffrey G.; Shi, Jianxia; Yokotoa, Hisao; Kim, Rosalind; Wemmer, David E.

2005-01-01T23:59:59.000Z

344

NMR methods to monitor the enzymatic depolymerization of heparin  

E-Print Network (OSTI)

and 5.998 ppm in the 1 H-NMR spectrum downfield of theFund and OTKA MB08A/80066. NMR methods to monitor the010-4132-7 PAPER IN FOREFRONT NMR methods to monitor the

Limtiaco, John F.; Beni, Szabolcs; Jones, Christopher J.; Langeslay, Derek J.; Larive, Cynthia K.

2011-01-01T23:59:59.000Z

345

NMR analysis on microfluidic devices by remote detection  

E-Print Network (OSTI)

hyperpolarized xenon (0.3% of NMR-active 129 Xe in a mixtureNMR analysis on microfluidic devices by remote detectionto perform high-sensitivity NMR imaging and spectroscopic

McDonnell, Erin E.; Han, SongI; Hilty, Christian; Pierce, Kimberly; Pines, Alexander

2005-01-01T23:59:59.000Z

346

NMR STUDIES OF SELECTIVE POPULATION INVERSION AND SPIN CLUSTERING  

E-Print Network (OSTI)

and R.R. Ernst, Prog. NMR Spectrosc. 16, 163 (1983). U.53, a) G. Bodenhausen, Prog. NMR Spectrosc. 14, 137 (1981).TO IN-VIVO NMR AND IMAGING •••••••••. •. •••••••. •••••..••

Baum, J.S.

2010-01-01T23:59:59.000Z

347

STUDY OF CORRELATIONS IN MOLECULAR MOTION BY MULTIPLE QUANTUM NMR  

E-Print Network (OSTI)

VoId and R. R. VoId, Prog. in NMR Spectroscopy, vol. 12. ed.1950). III MULTIPLE QUANTUM NMR SPECTROSCOPY IntroductionThe conventional NMR spectra are usually obtained by a

Tang, J-H.

2008-01-01T23:59:59.000Z

348

NMR quantum gate factorization through canonical cosets  

E-Print Network (OSTI)

The block canonical coset decomposition is developed as a universal algorithmic tool to synthesize n-qubit quantum gates out of experimentally realizable NMR elements. The two-, three-, and four-qubit quantum Fourier transformations are worked out as examples. The proposed decomposition bridges the state of the art numerical analysis with NMR quantum gate synthesis.

Renan Cabrera; Denys I. Bondar; Herschel A. Rabitz

2012-10-29T23:59:59.000Z

349

O NMR study of PryY1yBa2Cu3O6x W. A. MacFarlane,* J. Bobroff, P. Mendels, L. Cyrot, H. Alloul, and N. Blanchard  

E-Print Network (OSTI)

Planar 17 O NMR study of PryY1�yBa2Cu3O6¿x W. A. MacFarlane,* J. Bobroff, P. Mendels, L. Cyrot, H 2002 We report the planar 17 O NMR shift in Pr-substituted YBa2Cu3O6 x , which at x 1 exhibits reduction of Tc . From the temperature-dependent magnetic broadening of the 17 O NMR we conclude that the Pr

Paris-Sud 11, Université de

350

A Complementary Approach from NMR and High-Temperature Raman  

Science Conference Proceedings (OSTI)

Fictive temperature is determined by DSC analysis. Comprehensive modeling of boron-11 MQMAS NMR spectra permits the extraction of the NMR parameters.

351

Nonlinear coupling of nano mechanical resonators to Josephson quantum circuits  

E-Print Network (OSTI)

We propose a technique to couple the position operator of a nano mechanical resonator to a SQUID device by modulating its magnetic flux bias. By tuning the magnetic field properly, either linear or quadratic couplings can be realized, with a discretely adjustable coupling strength. This provides a way to realize coherent nonlinear effects in a nano mechanical resonator by coupling it to a Josephson quantum circuit. As an example, we show how squeezing of the nano mechanical resonator state can be realized with this technique. We also propose a simple method to measure the uncertainty in the position of the nano mechanical resonator without quantum state tomography.

Xingxiang Zhou; Ari Mizel

2006-05-01T23:59:59.000Z

352

expbook.idx - CECM  

E-Print Network (OSTI)

... Stern information measure}}{566} \\indexentry{nuclear magnetic resonance ( NMR)}{566} \\indexentry{Boltzmann-Shannon entropy}{567} \\indexentry{Lambert  ...

353

Daniel W. Bearden  

Science Conference Proceedings (OSTI)

Daniel W. Bearden. Dan's research has focused on nuclear magnetic resonance (NMR) since he started graduate school ...

2012-11-14T23:59:59.000Z

354

Resonant-cavity antenna for plasma heating  

SciTech Connect

Disclosed is a resonant coil cavity wave launcher for energizing a plasma immersed in a magnetic field. Energization includes launching fast Alfven waves to excite ion cyclotron frequency resonances in the plasma. The cavity includes inductive and capacitive reactive members spaced no further than one-quarter wavelength from a first wall confinement chamber of the plasma. The cavity wave launcher is energized by connection to a waveguide or transmission line carrying forward power from a remote radio frequency energy source.

Perkins, Jr., Francis W. (Princeton, NJ); Chiu, Shiu-Chu (San Diego, CA); Parks, Paul (San Diego, CA); Rawls, John M. (Del Mar, CA)

1987-01-01T23:59:59.000Z

355

High-precision evaluation of the magnetic moment of the helion  

SciTech Connect

NMR spectra of samples containing a mixture of hydrogen deuteride HD with pressure of about 80 atm and helium-3 with partial pressure of about 1 atm are analyzed. The ratio of the resonance frequencies of the nuclei, F({sup 3}He)/F(H{sub 2}), is determined to be 0.761786594(2), which is equal to the magnetic moment of the helion (bound in a helium atom) in the units of the magnetic moment of a proton (bound in molecular hydrogen). The uncertainty of two digits in the last place corresponds to a relative error of {delta}[F({sup 3}He)/F(H{sub 2})] = 2.6 Multiplication-Sign 10{sup -9}. The use of the known calculated data on the shielding of nuclei in the helium-3 atom ({sigma}({sup 3}He) = 59924(2) Multiplication-Sign 10{sup -9}) and on the shielding of protons in hydrogen ({sigma}(H{sub 2}) = 26288(2) Multiplication-Sign 10{sup -9}) yields a value of {mu}({sup 3}He)/{mu}{sub p} = -0.761812217(3) for the free magnetic moment of the helion in the units of the proton magnetic moment.

Neronov, Yu. I., E-mail: yineronov@mail.ru; Seregin, N. N. [Mendeleev All-Russia Research Institute of Metrology (Russian Federation)

2012-11-15T23:59:59.000Z

356

The use of a permanent magnet for water content measurements ofwood chips  

Science Conference Proceedings (OSTI)

The Lawrence Berkeley National Laboratory has developed a device that measures the water content of wood chips, pulp and brown stock for the paper industry. This device employs a permanent magnet as the central part of a NMR measurement system. This report describes the magnet and the NMR measurement system. The results of water content measurements in wood chips in a magnetic field of 0.47 T are presented.

Barale, P.J.; Fong, C.G.; Green, M.A.; Luft, P.A.; McInturff,A.D.; Reimer, J.A.; Yahnke, M.

2001-09-20T23:59:59.000Z

357

Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by 1H molecular diffusion NMR and 19F spin diffusion NMR  

E-Print Network (OSTI)

of Technology, Pasadena, CA 91125, USA NMR combined withspin diffusion NMR is useful in studying the drug loadingdiffusion . Spin diffusion . NMR Introduction R f -PEGs (

Mathias, Errol V.; Aponte, Julia; Kornfield, Julia A.; Ba, Yong

2010-01-01T23:59:59.000Z

358

The use of solid-state NMR techniques for the analysis of water in coal and the effect of different coal drying techniques on the structure and reactivity of coal; Quarterly report, September 1--November 30, 1993  

SciTech Connect

For the research program reported here, different methods of drying are being investigated to determine if drying can be accomplished without destroying coal reactivity toward liquefaction. In an effort to understand the mechanism of water for enhancing coal liquefaction yield, the reactions of D{sub 2}O with the molecular constituents of coal during coal liquefaction are being investigated. This study involves the use of solution-state deuterium NMR, as well as, conventional solution-state {sup 1}H and {sup 13}C NMR analyses of the coal, and the coal liquids and residue from a coal liquefaction process. These D{sub 2}O transfer reactions will be conducted on coals which have been dried by various methods and rehydrated using D{sub 2}O and by successive exchange of H{sub 2}O associated with the coals with D{sub 2}O. The drying methods include thermal, microwave, and chemical dehydration of the coal. The overall objectives of this study are to develop a nuclear magnetic resonance (NMR) method for measuring the water in coal, to measure the changes in coal structure that occur during coal drying, to determine what effect water has on retrograde/condensation reactions, to determine the mechanism by which water may impact coal reactivity toward liquefaction, and to conduct D{sub 2}O exchange studies to ascertain the role of water in coal liquefaction. The objectives for this quarterly report period were (1) to measure the volumetric swelling ratio for thermally- and microwave-dried coals and (2) to conduct preliminary experiments concerning the exchange of water in coal with deuterium oxide (D{sub 2}O).

Netzel, D.A.

1993-12-31T23:59:59.000Z

359

900 MHz NMR System User Agreement Version: 20 Jul 2006  

E-Print Network (OSTI)

900 MHz NMR System User Agreement Version: 20 Jul 2006 HWB·NMR operates to facilitate state are encouraged to operate the instruments on their own after authorisation by HWB·NMR staff. It is expected that each person who is approved to be a NMR operator will have, at the minimum: prior experience

Birmingham, University of

360

NMR Advanced methodologies to investigate water diffusion in materials  

E-Print Network (OSTI)

NMR Advanced methodologies to investigate water diffusion in materials and biological systems Ph · Introduction: _Water Diffusion _Experimental technique: NMR · Diffusion NMR: applications to the study glasses · Diffusion NMR in the framework of multi-quantum coherences · Project outline #12;Outlook

Roma "La Sapienza", Università di

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

NMR Detection Using Laser-Polarized Xenon as a DipolarSensor  

Science Conference Proceedings (OSTI)

Hyperpolarized Xe-129 can be used as a sensor to indirectly detect NMR spectra of heteronuclei that are neither covalently bound nor necessarily in direct contact with the Xe atoms, but coupled through long-range intermolecular dipolar couplings. In order to reintroduce long-range dipolar couplings the sample symmetry has to be broken. This can be done either by an asymmetric sample arrangement, or by breaking the symmetry of the spin magnetization with field gradient pulses. Experiments are performed where only a small fraction of the available Xe-129 magnetization is used for each point, so that a single batch of xenon suffices for the point-by-point acquisition of a heteronuclear NMR spectrum. Examples with H-1 as analyte nucleus show that these methods have the potential to obtain spectra with a resolution that is high enough to determine homonuclear J couplings. The applicability of this technique with remote detection is discussed.

Granwehr, Josef; Urban, Jeffry T.; Trabesinger, Andreas H.; Pines, Alexander

2005-02-28T23:59:59.000Z

362

NMR crystallography: The effect of deuteration on high resolution 13 state NMR spectra of a 7-TM protein  

E-Print Network (OSTI)

NMR crystallography: The effect of deuteration on high resolution 13 C solid state NMR spectra, and indirect, 9­17 ppm, dimensions). The measured 13 C NMR line-widths observed for both protonated. Introduction Perdeuteration has been used routinely in solution NMR for 13 C, 15 N labeled protein assignment

Watts, Anthony

363

Tissue oxymetry using magnetic resonance spectroscopy  

E-Print Network (OSTI)

A noninvasive method for in vivo measurement of tissue oxygen concentration has been developed. Several techniques currently used suffer limitations that prevent their practical clinical use. Our method is to use the ...

Liu, Lisa Chiawen

2005-01-01T23:59:59.000Z

364

ARTIFACTS IN MAGNETIC RESONANCE IMAGING FROM ...  

Science Conference Proceedings (OSTI)

... We surmise that the symmetric susceptibility artifact is ... It has two components, the first handling material ... the positive z-axis, the z-component of the ...

365

Radio-frequency quadrupole resonator for linear accelerator  

DOE Patents (OSTI)

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, A.

1982-10-19T23:59:59.000Z

366

Effect of magnetic fluctuations on Raman scattering in {kappa}-(BEDT-TTF){sub 2}Cu(NCS){sub 2}  

Science Conference Proceedings (OSTI)

The temperature dependence of the intensity and frequency of two intense features in the Raman spectrum of {kappa}-(BEDT-TTF){sub 2}Cu(NCS){sub 2} have been measured. The spectra were taken with a Fourier Raman spectrometer equipped with an infrared laser. The two lines are due to a strongly resonant {nu}{sub 9} (A{sub g}) doublet, and a sharp line due to {nu}{sub 60} (B{sub 3g}). The frequencies of these modes are observed to soften below 80 K, in the temperature range where antiferromagnetic spin fluctuations have been observed with NMR, providing evidence of interactions between the phonons and the magnetism. {copyright} {ital 1998} {ital The American Physical Society}

Lin, Y.; Eldridge, J.E. [Physics Department, University of British Columbia, Vancouver, B.C. V6T 1Z1 (Canada); Wang, H.H.; Kini, A.M.; Kelly, M.E.; Williams, J.M.; Schlueter, J. [Chemistry and Materials Science Divisions, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

1998-07-01T23:59:59.000Z

367

Magnetic Resonance of Hyperpolarised Helium-3 at Low Magnetic Fields.  

E-Print Network (OSTI)

??Dans ce travail nous avons étudié le problème du rapport signal à bruit (RSB) en IRM à très bas champ magnétique et exploré des applications… (more)

Safiullin, Kayum

2011-01-01T23:59:59.000Z

368

I. Advances in NMR Signal Processing. II. Spin Dynamics in Quantum Dissipative Systems  

E-Print Network (OSTI)

success rate. Sensitivity enhancement in 43Ca NMR . . . . .projections Resolution enhancement in 25Mg NMR . . . . . . .and G. C. Levy, Prog. NMR Spectrosc. 23, 211 (1991). [14] H.

Lin, Y.-Y.

2010-01-01T23:59:59.000Z

369

EXPERIMENTS ON SELECTIVE EXCITATION OF MULTIPLE-QUANTUM TRANSITIONS IN NMR SPECTROSCOPY  

E-Print Network (OSTI)

M. Mehring, High Resolution NMR Spectroscopy in Solids (sequences for producing quantum NMR spectra. multiple~ InMULTIPLE-QUANTUM TRANSITIONS IN NMR SPECTROSCOPY W.S. Warren

Warren, W.S.

2013-01-01T23:59:59.000Z

370

NMR STUDIES OF LIQUID CRYSTALS AND MOLECULES DISSOLVED IN LIQUID CRYSTAL SOLVENTS  

E-Print Network (OSTI)

Multiple Quantum NMR as a Method for Studying MoleculesUniaxial Phases ..•. •••• 167 The NMR Symmetry Group of aA HIGH FIELD NMR SPECTROMETER Introduction Frequency and

Drobny, G.P.

2010-01-01T23:59:59.000Z

371

Characterization of the nitrate complexes of Pu(IV) using absorption spectroscopy, {sup 15}N NMR, and EXAFS  

Science Conference Proceedings (OSTI)

Nitrate complexes of Pu(IV) are studied in solutions containing nitrate up to 13 molar (M). Three major nitrato complexes are observed and identified using absorption spectroscopy, {sup 15}N nuclear magnetic resonance (NMR), and extended x-ray absorption fine structure (EXAFS) as Pu(NO{sub 3}){sub 2}{sup 2+}, Pu(NO{sub 3}){sub 4}, and Pu(NO{sub 3}){sub 6}{sup 2{minus}}. The possibility that Pu(NO{sub 3}){sub 1}{sup 3+}, Pu(NO{sub 3}){sub 3}{sup 1+} and Pu(NO{sub 3}){sub 5}{sup 1{minus}} are major species in solution is not consistent with these results and an upper limit of 0.10 can be set on the fraction for each of these three nitrate complexes in nitrate containing solutions. Fraction of the three major species in nitric acid over the 1--13 M range were calculated from absorption spectra data. The fraction of Pu(NO{sub 3}){sub 6}{sup 2{minus}} as a function of nitric acid concentration is in good agreement with the literature, whereas the fraction of Pu(NO{sub 3}){sub 2}{sup 2+} and Pu(NO{sub 3}){sub 4} species differ from previous studies. We have modeled the chemical equilibria up to moderate ionic strength ( < 6 molal) using the specific ion interaction theory (SM. Comparison of our experimental observations to literature stability constants that assume the presence of mononitrate species is poor. Stability constant at zero ionic strength for the dinitrato complex is determined to be log({beta}{sub 2}{sup 0})=3.77 {plus_minus} 0.14 (2{sigma}).

Veirs, D.K.; Smith, C.A.; Zwick, B.D.; Marsh, S.F.; Conradson, S.D.

1993-12-01T23:59:59.000Z

372

Solid Fat Content by NMR Laboratory Proficiency Testing Program  

Science Conference Proceedings (OSTI)

Lab Proficiency Testing service for Solid Fat Content by NMR using AOCS Test Method Cd 16-93 to determine solid fat content in Margarine Oil, Vegetable Shortening, Emulsified Shortening Solid Fat Content by NMR Laboratory Proficiency Testing Program Labor

373

Fluid-Rock Characterization and Interactions in NMR Well Logging  

DOE Green Energy (OSTI)

The objective of this project is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. This is the first annual progress report submitted to the DOE. It reports on the work completed during the reporting period even if it may have started before this period. This project is a partnership between Professor George J. Hirasaki at Rice University and Professor Kishore Mohanty at University of Houston. In addition to the DOE, this project is supported by a consortium of oil companies and service companies. The fluid properties characterization has emphasized the departure of live oils from correlations based on dead oils. Also, asphaltic components can result in a difference between the T1 and T2 relaxation time distributions as well as reduce the hydrogen index. The fluid rock characterizations that are reported here are the effects of wettability and internal magnetic field gradients. A pore reconstruction method ha s been developed to recreate three-dimensional porous media from two-dimensional images that reproduce some of their key statistical properties. A Monte Carlo simulation technique has been developed to calculate the magnetization decay in fluid saturated porous media given their pore structure.

Hirasaki, George J.; Mohanty, Kishore, K.

2001-07-13T23:59:59.000Z

374

Available Technologies: Novel Use of NMR with Microfluidic Lab ...  

APPLICATIONS OF TECHNOLOGY: NMR spectroscopy and imaging to determine the chemical composition of a gas or liquid

375

Solid-state NMR imaging system  

DOE Patents (OSTI)

An apparatus for use with a solid-state NMR spectrometer includes a special imaging probe with linear, high-field strength gradient fields and high-power broadband RF coils using a back projection method for data acquisition and image reconstruction, and a real-time pulse programmer adaptable for use by a conventional computer for complex high speed pulse sequences.

Gopalsami, Nachappa (Naperville, IL); Dieckman, Stephen L. (Elmhurst, IL); Ellingson, William A. (Naperville, IL)

1992-01-01T23:59:59.000Z

376

Solid-state NMR imaging system  

DOE Patents (OSTI)

An accessory for use with a solid-state NMR spectrometer includes a special imaging probe with linear, high-field strength gradient fields and high-power broadband RF coils using a back projection method for data acquisition and image reconstruction, and a real-time pulse programmer adaptable for use by a conventional computer for complex high speed pulse sequences.

Gopalsami, N.; Dieckman, S.L.; Ellingson, W.A.

1990-01-01T23:59:59.000Z

377

Solid-state NMR imaging system  

DOE Patents (OSTI)

An accessory for use with a solid-state NMR spectrometer includes a special imaging probe with linear, high-field strength gradient fields and high-power broadband RF coils using a back projection method for data acquisition and image reconstruction, and a real-time pulse programmer adaptable for use by a conventional computer for complex high speed pulse sequences.

Gopalsami, N.; Dieckman, S.L.; Ellingson, W.A.

1990-12-31T23:59:59.000Z

378

PERSPECTIVE Automated protein structure calculation from NMR data  

E-Print Network (OSTI)

PERSPECTIVE Automated protein structure calculation from NMR data Mike P. Williamson � C. Jeremy completely automatic structure determination of small pro- teins of\\15 kDa, from NMR spectra to structure, particu- larly by structural genomics consortia. Keywords NMR structure calculation of proteins Á

Craven, Jeremy

379

STRUCTUREu DITERPENE ELUCIDATION FROM 1 3 C NMR  

E-Print Network (OSTI)

STRUCTUREu DITERPENE ELUCIDATION FROM 1 3 C NMR SPECTRA WITH INDUCTIVE LOGIC PROGRAMMING SASÏ O DZÏ Programming (ILP) to the problem of diterpene structure elucidation from 1 3 C NMR spectra. Diterpenes pharmaceutical e ectors. The interpretation of diterpene 1 3 C NMR spectra normally requires specialists

Dzeroski, Saso

380

Interface between Microbiology and Structural Biology as viewed by NMR  

E-Print Network (OSTI)

1 Interface between Microbiology and Structural Biology as viewed by NMR Muriel DELEPIERRE, Anne NMR spectroscopy is one of two principal experimental techniques used in structural biology. It can and intermolecular interactions. We aim to give an overview of the use of modern high resolution NMR methodology

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Microslot NMR Probe for Metabolomics Studies Hans Georg Krojanski,  

E-Print Network (OSTI)

Microslot NMR Probe for Metabolomics Studies Hans Georg Krojanski, Jo¨ rg Lambert,, Yilmaz Dortmund, Germany A NMR microprobe based on microstrip technology suit- able for investigations of volume-limited samples in the low nanoliter range was designed. NMR spectra of sample quantities in the 100 pmol range

Suter, Dieter

382

Nanomechanical resonance detector  

SciTech Connect

An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

Grossman, Jeffrey C; Zettl, Alexander K

2013-10-29T23:59:59.000Z

383

Applications of highly spin-polarized xenon in NMR  

Science Conference Proceedings (OSTI)

The main goal of the work presented in this thesis is produce highly spin-polarized xenon to create much greater signal intensities (up to 54,000 times greater) so as to allow studies to be made on systems with low surface area and long spin-lattice relaxation times. The spin-exchange optical pumping technique used to create high nuclear spin polarization is described in detail in chapter two. This technique is initially applied to some multiple-pulse optically detected NMR experiments in low magnetic field (50G) that allow the study of quadrupoler interactions with a surface of only a few square centimeters. In chapter three the apparatus used to allow high field {sup 129}Xe NMR studies to be performed with extremely high sensitivity is described and applied to experiments on diamagnetic susceptibility effects in thin ({approximately}2000 layers) films of frozen xenon. Preliminary surface investigations of laser polarized {sup 129}Xe adsorbed an a variety of materials (salts, molecular crystals, amorphous carbon, graphite) are then discussed. A full detailed study of the surface of a particular polymer, poly(acrylic acid), is presented in chapter four which shows the kind of detailed information that can be obtained from this technique. Along with preliminary results for several similar polymers, a summary is given of xenon studies of a novel ultra-high surface area polymer, poly(triarylcarbinol). Finally in chapter five the exciting possibility of transferring the high spin order of the laser polarized xenon has been used to transfer nuclear spin order to {sup 13}CO{sub 2} in a xenon matrix and to protons on poly(triarylcarbinol).

Long, H.W. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1993-09-01T23:59:59.000Z

384

Fast switching NMR system for measurements of ground-state quadrupole moments of short-lived nuclei  

E-Print Network (OSTI)

A beta-ray detecting nuclear quadrupole resonance system has been developed at NSCL/MSU to measure ground-state electric quadrupole moments of short-lived nuclei produced as fast rare isotope beams. This system enables quick and sequential application of multiple transition frequencies over a wide range. Fast switching between variable capacitors in resonance circuits ensures sufficient power delivery to the coil in the beta-ray detecting nuclear magnetic resonance technique. The fast switching technique enhances detection efficiency of resonance signals and is especially useful when the polarization and/or production rate of the nucleus of interest are small and when the nuclear spin is large.

K. Minamisono; R. R. Weerasiri; H. L. Crawford; P. F. Mantica; K. Matsuta; T. Minamisono; J. S. Pinter; J. B. Stoker

2008-02-08T23:59:59.000Z

385

Spectral restoration from low signal-to-noise, distorted NMR signals: application to hyphenated capillary electrophoresis-NMR  

E-Print Network (OSTI)

Spectral restoration from low signal-to-noise, distorted NMR signals: application to hyphenated capillary electrophoresis-NMR Yu Li,a,b Michael E. Lacey,b,c Jonathan V. Sweedler,b,c and Andrew G. Webba; revised 11 February 2003 Abstract In capillary electrophoresis separations coupled to NMR signal detection

Andrews, Anne M.

386

Ultra-low field NMR for detection and characterization of 235 UF6  

SciTech Connect

We have demonstrated the first ultra-low field (ULF) nuclear magnetic resonance measurements of uranium hexafluoride (UF{sub 6}), both depleted and 70% enriched, which is used in the uranium enrichment process. A sensitive non-invasive detection system would have an important role in non-proliferation surveillance. A two-frequency technique was employed to remove the transients induced by rapidly switching off the 50 mT pre-polarization field. A mean transverse relaxation time T{sub 2} of 24 ms was estimated for the un-enriched UF{sub 6} sample measured at a mean temperature of 80 C. Nuclear magnetic resonance at ULF has several advantages including the ability to measure through metal, such as pipes, and simple magnetic field generation hardware. We present here recent data and discuss the potential for non-proliferation monitoring of enrichment and flow velocity.

Espy, Michelle A [Los Alamos National Laboratory; Magnelind, Per E [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Urbaitis, Algis V [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

387

Magnetic chicane for terahertz management  

DOE Patents (OSTI)

The introduction of a magnetic electron beam orbit chicane between the wiggler and the downstream initial bending dipole in an energy recovering Linac alleviates the effects of radiation propagated from the downstream bending dipole that tend to distort the proximate downstream mirror of the optical cavity resonator.

Benson, Stephen (Yorktown, VA); Biallas, George Herman (Yorktown, VA); Douglas, David (Yorktown, VA); Jordan, Kevin Carl (Newport News, VA); Neil, George R. (Williamsburg, VA); Michelle D. Shinn (Newport News, VA); Willams, Gwyn P. (Yorktown, VA)

2010-12-28T23:59:59.000Z

388

An NMR investigation of superconductivity and antiferromagnetism in CaFe2As2 under pressure  

Science Conference Proceedings (OSTI)

We report {sup 75}As NMR measurements in CaFe{sub 2}As{sub 2}, made under applied pressures up to 0.83 CPa produced by a standard clamp pressure cell. Our data reveal phase segregation of paramagnetic (PM) and antiferromagnetic (AFM) phases over a range of pressures, with the AFM phase more than 90% dominant at low temperatures. In situ RF susceptibility measurements indicate the presence of superconductivity. {sup 75}As spin-lattice relaxation experiments indicate that the {sup 75}As nuclei sample the superconductivity while in the magnetically-ordered environment.

Baek, Seung H [Los Alamos National Laboratory; Lee, Han O [Los Alamos National Laboratory; Bauer, E D [Los Alamos National Laboratory; Ronning, F [Los Alamos National Laboratory; Park, T [Los Alamos National Laboratory; Thompson, J D [Los Alamos National Laboratory; Brown, S E [UCLA; Curro, N J [UC DAVIS

2009-01-01T23:59:59.000Z

389

1H-NMR study of the spin dynamics of fine superparamagnetic nanoparticles  

SciTech Connect

We report a broadband 1H-NMR study of the temperature spin dynamics of nearly monodisperse dextran-coated ?-Fe2O3 magnetic nanoparticles. We observed a maximum in T1?1(T) that decreases in amplitude and shifts toward higher temperatures with increasing field. We suggest that this is related to the progressive superparamagnetic spin blocking of the ferrite core. The data can be explained by assuming a single electronic spin-spin correlation time and introducing a field-dependent distribution of anisotropy energy barriers.

Bordonali, L.; Furukawa, Y.; Kraken, M.; Litterst, F.J.; Sangregorio, C.; Casula, M.F.; Lascialfari, A.

2012-05-25T23:59:59.000Z

390

Superconducting Magnets  

NLE Websites -- All DOE Office Websites (Extended Search)

magnet technology has allowed physicists to attain higher energies in circular accelerators. One can obtain higher magnetic fields because there is no resistance in a...

391

Fluid-Rock Characterization and Interactions in NMR Well Logging  

SciTech Connect

The objective of this project was to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity.

Hirasaki, George J.; Mohanty, Kishore K.

2003-02-10T23:59:59.000Z

392

Multinuclear Solid and Liquid State NMR Studies of Battery Materials  

Science Conference Proceedings (OSTI)

NMR can also probe ionic and molecular motion in lithium battery electrolytes with a dynamic range spanning some ten orders of magnitude through relaxation

393

NMR Studies of Molecular Hydrogen in Hydrogenated Amorphous Silicon  

DOE Green Energy (OSTI)

Using NMR, the concentrations of molecular hydrogen have been measured directly in hydrogenated amorphous silicon made by the hot wire chemical vapor deposition (HWCVD) technique.

Su, T.; Chen, S.; Taylor, P. C.; Crandall, R. S.; Mahan, A. H.

2000-01-01T23:59:59.000Z

394

NMR studies of the transcriptional inhibitor I kappa B alpha and its interaction with the transcription factor NF kappa B  

E-Print Network (OSTI)

correction of random coil NMR chemical shifts. J Am Chem Socproteins by multidimensional NMR. Biochemistry Bax, A. ,ensemble interpretation of NMR dipolar couplings without

Cervantes, Carla F.

2010-01-01T23:59:59.000Z

395

Resonant Kicker System Development at SLAC  

DOE Green Energy (OSTI)

The design and installation of the Linear Coherent Light Source [1] at SLAC National Accelerator Laboratory has included the development of a kicker system for selective beam bunch dumping. The kicker is based on an LC resonant topology formed by the 50 uF energy storage capacitor and the 64 uH air core magnet load which has a sinusoidal pulse period of 400us. The maximum magnet current is 500 A. The circuit is weakly damped, allowing most of the magnet energy to be recovered in the energy storage capacitor. The kicker runs at a repetition rate of 120Hz. A PLC-based control system provides remote control and monitoring of the kicker via EPICS protocol. Fast timing and interlock signals are converted by discrete peak-detect and sample-hold circuits into DC signals that can be processed by the PLC. The design and experimental characterization of the system are presented.

Beukers, Tony; Krzaszczak, John; Larrus, Marc; Lira, Antonio de; /SLAC

2009-04-27T23:59:59.000Z

396

NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts  

DOE Green Energy (OSTI)

We have investigated a series of Cu/Co catalysts supported on Titanium Dioxide. This study has sought to examine and compare the nature and effect of the supports Chromia and Titania (Cr[sub 2]O[sub 3], and TiO[sub 2]) on the magnetic character of the Cu-Co-Cr and Cu-Co-TiO[sub 2] catalysts. The magnetization results for Cu/Co, Cu/Co/Cr, Cu/Co/TiO[sub 2] system are presented along with the magnetization data for the unsupported Cu/Co catalysts and data for supported catalysts. Pure cobalt metal has a magnetic moment of 161 emu/g. The measured emu values and the corresponding reduction percentages are given for the various catalysts investigated. The vibration sample magnetometer determines S[sub s], the saturation magnetization, emu per gram of the composite sample. The magnetization values reported are emu per gram of cobalt in the composite. As such the data normally reflects the proportion of cobalt metal that is reduced to metallic form. However, if electronic exchanges occur between cobalt and other elements in the system, the magnetic moment itself differs from the assumed value of 161 emu/g Co then the emu value observed will be the resultant due to the electronic charge density modifications in Co as well as reduction to metallic state. Our earlier NMR studies reveal such electronic structural modifications occur for Cobalt in Cu-Co and Co-TiO[sub 2] systems. The magnetization data in column 3 for Cu-Co-TiO[sub 2] systems unambiguously shows such electron exchanges do occur between cobalt and titania.

Murty, A.N.

1992-01-01T23:59:59.000Z

397

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Regarding Confinement Resonances Regarding Confinement Resonances Print Wednesday, 27 July 2011 00:00 When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

398

Resonant snubber inverter  

DOE Patents (OSTI)

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 14 figs.

Lai, J.S.; Young, R.W. Sr.; Chen, D.; Scudiere, M.B.; Ott, G.W. Jr.; White, C.P.; McKeever, J.W.

1997-06-24T23:59:59.000Z

399

Resonant snubber inverter  

DOE Patents (OSTI)

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Lai, Jih-Sheng (Knoxville, TN); Young, Sr., Robert W. (Oak Ridge, TN); Chen, Daoshen (Knoxville, TN); Scudiere, Matthew B. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN); White, Clifford P. (Knoxville, TN); McKeever, John W. (Oak Ridge, TN)

1997-01-01T23:59:59.000Z

400

XRD and NMR investigation of Ti-compound formation in solution-doping of sodium aluminum hydrides: Solubility of Ti in NaAlH4 crystals grown in THF  

DOE Green Energy (OSTI)

Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using x-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH{sub 4} by this method of exposure. In addition, x-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at. %-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl{sub 3} is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

Majzoub, E H; Herberg, J L; Stumpf, R; Spangler, S; Maxwell, R S

2004-08-26T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

The use of solid-state NMR techniques for the analysis of water in coal and the effect of different coal drying techniques on the structure and reactivity of coal. Quarterly report, June 1--August 31, 1993  

SciTech Connect

One area for improvement in the economics of coal liquefaction is coal drying, particularly for the lower rank coals. However, there is considerable evidence to show that drying has a detrimental effect on the liquefaction behavior of coals. Regarding the liquefaction of coal, there does not appear to have been any systematic study of the methods of coal drying on coal structure and the role water plays in enhancing or lessening coal reactivity toward liquefaction. To conduct this study two coals, the North Dakota Beulah Zap lignite and the Utah Blind Canyon coals were chosen. These coals represent a low and high rank coal, respectively. In addition, the Beulah Zap lignite has a high moisture content whereas the Blind Canyon coal (hvA) bituminous has a very low moisture content. The overall objectives of this study are to develop a nuclear magnetic resonance (NMR) method for measuring the water in coal, to measure the changes in coal structure that occur during coal drying, to determine what effect water has on retrograde/condensation reactions, and to determine the mechanism by which water may impact coal reactivity toward liquefaction. Different methods of drying are being investigated to determine if drying can be accomplished without destroying coal reactivity toward liquefaction. The objectives for this quarterly report period were (1) to measure the volumetric swelling ratio for initial and chemically-dried coals and (2) to conduct preliminary experiments concerning the exchange of water in coal with deuterium oxide (D{sub 2}O).

Netzel, D.A.

1993-11-01T23:59:59.000Z

402

Heteronuclear dipolar couplings, total spin coherence, and bilinear rotations in NMR spectroscopy  

SciTech Connect

In Chapter 1 a variety of different introductory topics are presented. The potential complexity of the nuclear magnetic resonsnace (NMR) spectra of molecules dissolved in liquid crystal solvents serves to motivate the development of multiple quantum (MQ) spectroscopy. The basics of MQ NMR are reviewed in Chapter 2. An experimental search procedure for the optimization of MQ pulse sequences is introduced. Chapter 3 discusses the application of MQ NMR techniques to the measurement of dipolar couplings in heteronuclear spin systems. The advantages of MQ methods in such systems are developed and experimental results for partially oriented (1-/sup 13/C) benzene are presented. Several pulse sequences are introduced which employ a two-step excitation of heteronuclear MQ coherence. A new multiple pulse method, involving the simultaneous irradiation of both rare and abundant spin species, is described. The problem of the broadening of MQ transitions due to magnetic field inhomogeneity is considered in Chapter 4. The method of total spin coherence transfer echo spectroscopy (TSCTES) is presented, with experimets on partially oriented acetaldehyde serving to demonstrate this new technique. TSCTES results in MQ spectra which are sensitive to all chemical shifts and spin-spin couplings and which are free of inhomogeneous broadening. In Chapter 5 the spectroscopy of spin systems of several protons and a /sup 13/C nucleus in the isotropic phase is discussed. The usefulness of the heteronuclear bilinear rotation as a calculational tool is illustrated. Compensated bilinear ..pi.. rotations, which are relatively insensitive to timing parameter missets, are presented. A new technique for homonuclear proton decoupling, Bilinear Rotation Decoupling, is described and its success in weakly coupled systems is demonstrated.

Garbow, J.R.

1983-07-01T23:59:59.000Z

403

High-resolution NMR spectroscopy of biological tissues using projected Magic Angle Spinning  

E-Print Network (OSTI)

High-resolution NMR spectroscopy of biological tissues using486-5744 pines@berkeley.edu NMR spectroscopy of biologicalAbstract: High-resolution NMR spectra of materials subject

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

2005-01-01T23:59:59.000Z

404

NMR studies of p7 protein from hepatitis C virus  

E-Print Network (OSTI)

Heteronuclear Dipolar Solid-State NMR Spectroscopy. J Magn1104 high ?eld solid-state NMR of lossy biological samples.009-0533-y ORIGINAL PAPER NMR studies of p7 protein from

Cook, Gabriel A.; Opella, Stanley J.

2010-01-01T23:59:59.000Z

405

New Probes of Spin Physics and Correlation in Solid-State NMR  

E-Print Network (OSTI)

J. , Two-dimensional Fourier NMR Spectroscopy Ernst, R. R. ;709- 5. INVESTIGATIONS INTO THE NMR STARK EFFECT The century6. CONCLUSION The power of NMR is truly far reaching, as

Kaiser, John Michael

2009-01-01T23:59:59.000Z

406

Alzheimer's amyloid-? and the disordered structural ensemble characterized using molecular dynamics and NMR spectroscopy  

E-Print Network (OSTI)

Hou L et al. (2004) Solution NMR studies of the A beta(1-40)H, Wipf B, Wüthrich K (2001) NMR studies in aqueous solutionconstraints from solid state NMR. Proc Natl Acad Sci USA

Ball, Katherine Aurelia

2013-01-01T23:59:59.000Z

407

Distinguishing multiple chemotaxis Y protein conformations with laser-polarized 129Xe NMR  

E-Print Network (OSTI)

al. 1998. Crystallography & NMR system: A new software suiteand Pelton, J.G. 2000. NMR Structure of Activated CheY. J.hyperpolarized xenon-129 NMR. J. Am. Chem. Soc. 121: 9370–

Lowery, Thomas J.; Doucleff, Michealeen; Ruiz, E. Janette; Rubin, Seth M.; Pines, Alexander; Wemmer, David E.

2005-01-01T23:59:59.000Z

408

STUDY OF LIQUID CRYSTAL CONFORMATION BY MULTIPLE QUANTUM NMR: n-PENTYL CYANOBIPHENYL  

E-Print Network (OSTI)

The proton::. and to of twist NMR spectrum of Proton The toCONFORMATION BY MULTIPLE QUANTUM NMR: n-PENTYL CYANOBIPHENYLCONFORMATION BY MULTIPLE QUANTUM NMR: n~PENTYL CYANOBIPHENYL

Sinton, S.

2013-01-01T23:59:59.000Z

409

Two dimensional NMR Investigations of the dynamic conformations of Phospholipids and liquid crystals  

E-Print Network (OSTI)

I. H. In Phosphorous-31 NMR: Principles and Applications; I.L. B. ; Kalabin, G. A. Prog. in NMR Spect. 1989,21, 293. , IJ Jameson, C. J. In Multinuclear NMR; J. Mason, Ed. ; Plenum

Hong, Mei

2010-01-01T23:59:59.000Z

410

Multiphase imaging of gas flow in a nanoporous material using remote detection NMR  

E-Print Network (OSTI)

D.P. Weitekamp, “Zero field NMR and NQR”, J. Chem. Phys.Amplification of xenon NMR and MRI by remote detection”,of silica aerogels by 129 Xe NMR spectroscopy and imaging”,

Harel, Elad; Granwehr, Josef; Seeley, Juliette A.; Pines, Alex

2005-01-01T23:59:59.000Z

411

NMR Investigations of Surfaces and Interfaces Using Spin-Polarized Xenon  

E-Print Network (OSTI)

Ill Jokisaari, J. Prog, in NMR Spec. 1994, 26,1. Webster, O.Griffin, R. In Experimental NMR Conference; Boston, MA USA,C. P. ; Sinfelt, J. H Prog. NMR Spectrosc. 1990, 22, 401- (

Gaede, H.C.

2010-01-01T23:59:59.000Z

412

NMR Imaging and Rheology Mini-Symposium Date: Friday, September 28th, 2012  

E-Print Network (OSTI)

NMR Imaging and Rheology Mini "Rheological NMR on polymers: flow, mixing, and polymer dynamics" Prof. Ulrich Scheler Leibniz Institute minute intermission 3:40 pm "Diffusion NMR measurements of surfactants in solutions and small- molecules

Ahlers, Guenter

413

Structure and Dynamics of Cholesterol-Containing Polyunsaturated Lipid Membranes Studied by Neutron Diffraction and NMR  

E-Print Network (OSTI)

by Neutron Diffraction and NMR Mihaela Mihailescu • Olivierwas carried out by neutron diffraction, 2 H-NMR and 13C-MAS NMR. Scattering length distribution func- tions of

Mihailescu, Mihaela; Soubias, Olivier; Worcester, David; White, Stephen H.; Gawrisch, Klaus

2011-01-01T23:59:59.000Z

414

NMR structure of the N-terminal domain of the replication initiator protein DnaA  

E-Print Network (OSTI)

Laue, E. D. (1995) J. Biomol. NMR 5, Grzeisek, S. , and Bax,and Bax, A. (1993) J. Biomol. NMR 3, 185-204. Grzesiek, S. ,and Bax, A. (1994) J. Biomol. NMR. 4, 871-878. Page 14 Neri,

Lowery, Thomas J.

2008-01-01T23:59:59.000Z

415

NMR Studies of DNA Oligomerers and Their Interactions with Minor Groove Binding Ligands  

E-Print Network (OSTI)

sites by two- dimensional NMR." J. Am. Chem. Soc. 115, 9900-CCATGAATGG)2 determined by 2D NMR and structural refinementJ.L. (1990b) in Frontiers of NMR in Molecular Biology (D.

Fagan, P.A.

2010-01-01T23:59:59.000Z

416

NMR Detection Using Laser-Polarized Xenon as a Dipolar Sensor  

E-Print Network (OSTI)

Budinger, G. Navon, A. Pines, NMR of laser-polarized xenonEnhancement o˜ of solution NMR and MRI with laser-polarizedA using laser-induced NMR polarization enhancement, J. Am.

Granwehr, Josef; Urban, Jeffry T.; Trabesinger, Andreas H.; Pines, Alexander

2005-01-01T23:59:59.000Z

417

ELECTRON PARAMAGNETIC RESONANCE IN BIOLOGY  

E-Print Network (OSTI)

published in Perspectives in Biology and Medicine. ) 51. D.PARAMAGNETIC RESONANCE IN BIOLOGY G. M. Androes and Melvinparamagnetic resonance in biology is presented, including a

Androes, G.M.; Calvin, Melvin.

2008-01-01T23:59:59.000Z

418

Fluid-Rock Characterization and Interactions in NMR Well Logging  

SciTech Connect

The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

George J. Hirasaki; Kishore K. Mohanty

2005-09-05T23:59:59.000Z

419

Probe for high resolution NMR with sample reorientation  

DOE Patents (OSTI)

An improved NMR probe and method are described which substantially improve the resolution of NMR measurements made on powdered or amorphous or otherwise orientationally disordered samples. The apparatus mechanically varies the orientation of the sample such that the time average of two or more sets of spherical harmonic functions are zero.

Pines, Alexander (Berkeley, CA); Samoson, Ago (Tallinn, SU)

1990-01-01T23:59:59.000Z

420

Probe for high resolution NMR with sample reorientation  

DOE Patents (OSTI)

An improved NMR probe and method are described which substantially improve the resolution of NMR measurements made on powdered or amorphous or otherwise orientationally disordered samples. The apparatus mechanically varies the orientation of the sample such that the time average of two or more sets of spherical harmonic functions are zero. 8 figs.

Pines, A.; Samoson, A.

1990-02-06T23:59:59.000Z

Note: This page contains sample records for the topic "magnetic resonance nmr" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Local structures of polar wurtzites Zn1-xMgxO studied by raman and 67Zn/25Mg NMR spectroscopies and by total neutron scattering  

SciTech Connect

Research in the area of polar semiconductor heterostructures has been growing rapidly, driven in large part by interest in two-dimensional electron gas (2DEG) systems. 2DEGs are known to form at heterojunction interfaces that bear polarization gradients. They can display extremely high electron mobilities, especially at low temperatures, owing to spatial confinement of carrier motions. Recent reports of 2DEG behaviors in Ga{sub 1-x}Al{sub x}N/GaN and Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have great significance for the development of quantum Hall devices and novel high-electron-mobility transistors (HEMTs). 2DEG structures are usually designed by interfacing a polar semiconductor with its less or more polar alloys in an epitaxial manner. Since the quality of the 2DEG depends critically on interface perfection, as well as the polarization gradient at the heterojunction, understanding compositional and structural details of the parent and alloy semiconductors is an important component in 2DEG design and fabrication. Zn{sub 1-x}Mg{sub x}O/ZnO is one of the most promising heterostructure types for studies of 2DEGs, due to the large polarization of ZnO, the relatively small lattice mismatch, and the large conduction band offsets in the Zn{sub 1-x}Mg{sub x}O/ZnO heterointerface. Although 2DEG formation in Zn{sub 1-x}Mg{sub x}O/ZnO heterostructures have been researched for some time, a clear understanding of the alloy structure of Zn{sub 1-x}Mg{sub x}O is currently lacking. Here, we conduct a detailed and more precise study of the local structure of Zn{sub 1-x}Mg{sub x}O alloys using Raman and solid-state nuclear magnetic resonance (NMR), in conjunction with neutron diffraction techniques.

Proffen, Thomas E [Los Alamos National Laboratory; Kim, Yiung- Il [UCSB; Cadars, Sylvian [UCSB; Shayib, Ramzy [UCSB; Feigerle, Charles S [UNIV OF TENNESSEE; Chmelka, Bradley F [UCSB; Seshadri, Ram [UCSB

2008-01-01T23:59:59.000Z

422

Magnetics Publications  

Science Conference Proceedings (OSTI)

... Resonant microwave power absorption and relaxation of the energy levels of ... Kim, ZN Utegulov, JM Shaw, and BT Draine, "Optimization of Arrays of ...

2013-08-18T23:59:59.000Z

423

Spin resonance strength calculations  

SciTech Connect

In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

Courant,E.D.

2008-10-06T23:59:59.000Z

424

Through-bond Correlation Methods for Assigning Protein Resonances with Solid-State NMR Spectroscopy  

E-Print Network (OSTI)

edscon PHASPR 1 to 1.7 usec ;DQF chemical shift correlationd0 : incremented delay (2D) [3 usec] ;l3 : loop for phaseedscon PHASPR 1 to 1.7 usec ;DQF chemical shift correlation

Chen, Lingling

2008-01-01T23:59:59.000Z

425

Fabrication of 3-D cubic unit cells with measured IR resonances.  

Science Conference Proceedings (OSTI)

3-D cubic unit cell arrays containing split ring resonators were fabricated and characterized. The unit cells are {approx}3 orders-of-magnitude smaller than microwave SRR-based metamaterials and exhibit both electrically and magnetically excited resonances for normally incident TEM waves in addition to showing improved isotropic response.

Ellis, A. Robert; Sinclair, Michael B.; Brener, Igal; Wendt, Joel Robert; Burckel, David Bruce; Ginn, James Cleveland, III; Ten Eyck, Gregory A.

2010-03-01T23:59:59.000Z

426

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

427

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

428

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

Regarding Confinement Resonances Print Regarding Confinement Resonances Print When an atom is encapsulated inside a hollow spherical carbon buckyball, the complex is called an "endofullerene." Theoretically, if the atom is an unreactive noble gas like xenon, it should be centered within the cage. If one or more of the atom's electrons are boosted out of the cage by an x-ray photon, the electron waves may be transmitted through or reflected off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but have never been observed. In the first experimental test of this theory, members of an international team led by Ronald Phaneuf, University of Nevada, and working at ALS Beamline 10.0.1 produced and isolated xenon endofullerenes and observed confinement resonances.

429

Regarding Confinement Resonances  

NLE Websites -- All DOE Office Websites (Extended Search)

off the carbon cage, giving rise to an interference effect similar to waves in a water tank. These so-called "confinement resonances" were predicted theoretically a decade ago but...

430

Cylindrical laser resonator  

DOE Patents (OSTI)

The properties of an improved class of lasers is presented. In one configuration of these lasers the radiation propagates radially within the amplifying medium, resulting in high fields and symmetric illumination at the resonator axis. Thus there is a strong focusing of energy at the axis of the resonator. In a second configuration the radiation propagates back and forth in a tubular region of space.

Casperson, Lee W. (Los Angeles, CA)

1976-02-24T23:59:59.000Z

431

Nuclear Resonance Fluorescence for Nuclear Materials Assay  

E-Print Network (OSTI)

Potential of Nuclear Resonance Fluorescence . . . . . . . .2.9.1 Nuclear ThomsonSections . . . . . . . . . . . . . . . Nuclear Resonance

Quiter, Brian Joseph

2010-01-01T23:59:59.000Z

432

Magnetic Storms  

Science Conference Proceedings (OSTI)

... magnetic reversal. As there is no predictive science of geomagnetism, we currently lack even simple forecasts. Our scientific ...

2010-10-05T23:59:59.000Z

433

Magnetic Imaging  

Science Conference Proceedings (OSTI)

... data-storage and permanent magnets with increased energy products, in ... Optimization of future materials, including improved yields, requires an ...

2012-10-02T23:59:59.000Z

434

Magnetic Properties  

Science Conference Proceedings (OSTI)

...Since the discovery of high-temperature superconductors in 1986 (Ref 10), the demonstration of magnetic flux exclusion

435

Effects of Nanoscale Structure on the Magnetism and Transport Properties of Chromium and Chromium-Aluminum Alloys  

E-Print Network (OSTI)

scattering in the electrical resistivity of Cr thin ?lms.Magnetic susceptibility and electrical resistivity of dilutedependence of the electrical resistivity and resonance

Boekelheide, Zoe Austin

2011-01-01T23:59:59.000Z

436

Resonant nonlinear ultrasound spectroscopy  

DOE Patents (OSTI)

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function./.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift .vertline..DELTA..function./.function..sub.0 is determined as a function of applied strain for a component under test, where fo .function..sub.0 the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.

Johnson, Paul A. (Santa Fe, NM); TenCate, James A. (Los Alamos, NM); Guyer, Robert A. (Amherst, MA); Van Den Abeele, Koen E. A. (Sint-Niklaas, BE)

2001-01-01T23:59:59.000Z

437

Solid-State 17O NMR Study of Benzoic Acid Adsorption On Metal Oxide Surfaces  

Science Conference Proceedings (OSTI)

Solid-state 17O NMR spectra of 17O-labeled benzoic and anisic acids are reported and benzoic acid is used to probe the surface of metal oxides. Complexes formed when benzoic acid is dry-mixed with mesoporous silica, and nonporous titania and alumina are characterized. Chemical reactions with silica are not observed. The nature of benzoic acid on silica is a function of the water content of the oxide. The acid disperses in the pores of the silica if the silica is in equilibrium with ambient laboratory humidity. The acid displays high mobility as evidenced by a liquid-like, Lorentzian resonance. Excess benzoic acid remains as the crystalline hydrogen-bonded dimer. Benzoic acid reacts with titania and alumina surfaces in equilibrium with laboratory air to form the corresponding titanium and aluminum benzoates. In both materials the oxygen of the 17O-labeled acid is bound to the metal, showing the reaction proceeds by bond formation between oxygen deficient metal sites and the oxygen of the carboxylic acid. 27Al MAS NMR confirms this mechanism for the reaction on alumina. Dry mixing of benzoic acid with alumina rapidly quenches pentacoordinate aluminum sites, excellent evidence that these sites are confined to the surface of the alumina particles.

Hagaman, Edward {Ed} W [ORNL; Chen, Banghao [ORNL; Jiao, Jian [ORNL; Parsons, Williams [Oak Ridge National Laboratory (ORNL)

2012-01-01T23:59:59.000Z

438

Assembly and magnetic properties of nickel nanoparticles on silicon nanowires  

SciTech Connect

The directed assembly of magnetic Ni nanoparticles at the tips of silicon nanowires is reported. Using electrodeposition Ni shells of thickness from 10 to 100 nm were selectively deposited on Au catalytic seeds at the ends of nanowires. Magnetic characterization confirms a low coercivity ({approx}115 Oe) ferromagnetic behavior at 300 K. This approach to multifunctional magnetic-semiconducting nanostructure assembly could be extended to electrodeposition of other materials on the nanowire ends, opening up novel ways of device integration. Such magnetically functionalized nanowires offer a new approach to developing novel highly localized magnetic probes for high resolution magnetic resonance force microscopy.

Picraux, Samuel T [Los Alamos National Laboratory; Manandhar, Pradeep [Los Alamos National Laboratory; Nazaretski, E [Los Alamos National Laboratory; Thompson, J [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

439

Robustness of quantum discord to sudden death in NMR  

E-Print Network (OSTI)

We investigate the dynamics of entanglement and quantum discord of two qubits in liquid state homonuclear NMR. Applying a phenomenological description for NMR under relaxation process, and taking a group of typical parameters of NMR, we show that when a zero initial state $|00> $ experiences a relaxation process, its entanglement disappears completely after a sequence of so-called sudden deaths and revivals, while the quantum discord retains remarkable values after a sequence of oscillations. That is to say, the quantum discord is more robust than entanglement.

Jianwei Xu; Qihui Chen

2011-06-01T23:59:59.000Z

440

Spin-flip induction of Fano resonance upon electron tunneling through atomic-scale spin structures  

Science Conference Proceedings (OSTI)

The inclusion of inelastic spin-dependent electron scatterings by the potential profiles of a single magnetic impurity and a spin dimer is shown to induce resonance features due to the Fano effect in the transport characteristics of such atomic-scale spin structures. The spin-flip processes leading to a configuration interaction of the system's states play a fundamental role for the realization of Fano resonance and antiresonance. It has been established that applying an external magnetic field and a gate electric field allows the conductive properties of spin structures to be changed radically through the Fano resonance mechanism.

Val'kov, V. V., E-mail: vvv@iph.krasn.ru; Aksenov, S. V., E-mail: asv86@iph.krasn.ru [Russian Academy of Sciences, Siberian Branch, Kirensky Institute of Physics (Russian Federation); Ulanov, E. A. [Siberian State Aerospace University (Russian Federation)

2013-05-15T23:59:59.000Z

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441

Coherent scattering by a spherical medium of resonant atoms  

Science Conference Proceedings (OSTI)

We consider the problem of coherent resonant scattering of electromagnetic waves by a spherical medium of two-level atoms. The frequency dependence of the scattering amplitudes and cross sections reveals a complex structure of narrow peaks and dips. We relate these scattering resonances to the cooperative emission resonances characteristic of a sphere. We find the scattering to show considerable interference between the electric and magnetic multipole contributions, particularly in the lower multipole orders. This interference tends to enhance anisotropies in the differential scattering cross section even for small spheres. For such spheres, the peak values of the resonant contributions of the low-order multipoles to the total scattering cross section can increase with multipole order, in contrast to the usual decrease seen in nonresonant scattering.

Prasad, Sudhakar; Glauber, Roy J. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)

2011-06-15T23:59:59.000Z

442

Method And Apparatus For High Resolution Ex-Situ Nmr Spectroscopy  

DOE Patents (OSTI)

A method and apparatus for ex-situ nuclear magnetic resonance spectroscopy for use on samples outside the physical limits of the magnets in inhomogeneous static and radio-frequency fields. Chemical shift spectra can be resolved with the method using sequences of correlated, composite z-rotation pulses in the presence of spatially matched static and radio frequency field gradients producing nutation echoes. The amplitude of the echoes is modulated by the chemical shift interaction and an inhomogeneity free FID may be recovered by stroboscopically sampling the maxima of the echoes. In an alternative embodiment, full-passage adiabatic pulses are consecutively applied. One embodiment of the apparatus generates a static magnetic field that has a variable saddle point.

Pines, Alexander (Berkeley, CA); Meriles, Carlos A. (El Cerrito, CA); Heise, Henrike (Goettingen, DE); Sakellariou, Dimitrios (Oakland, CA); Moule, Adam (Berkeley, CA)

2004-01-06T23:59:59.000Z

443

ccsd00002995, NMR instabilities and spectral clustering in laser-polarized liquid xenon  

E-Print Network (OSTI)

ccsd­00002995, version 1 ­ 3 Oct 2004 NMR instabilities and spectral clustering in laser in NMR experiments, we have performed low #12;eld NMR on laser-polarized liquid 129 Xe, with nuclear polarization of up to 6%. Contrary to conven- tional NMR results, we #12;nd that instabilities develop after

444

Quantitative NMR analysis of the protein G B1 domain in Xenopus laevis egg extracts  

E-Print Network (OSTI)

Quantitative NMR analysis of the protein G B1 domain in Xenopus laevis egg extracts and intact introduce a eukaryotic cellular system, the Xenopus laevis oocyte, for in-cell NMR analyses of biomolecules of in vivo NMR measurements in this cell type. This approach enables quantitative NMR experiments at defined

Ruderman, Joan

445

Quartz resonator processing system  

DOE Patents (OSTI)

Disclosed is a single chamber ultra-high vacuum processing system for the oduction of hermetically sealed quartz resonators wherein electrode metallization and sealing are carried out along with cleaning and bake-out without any air exposure between the processing steps. The system includes a common vacuum chamber in which is located a rotatable wheel-like member which is adapted to move a plurality of individual component sets of a flat pack resonator unit past discretely located processing stations in said chamber whereupon electrode deposition takes place followed by the placement of ceramic covers over a frame containing a resonator element and then to a sealing stage where a pair of hydraulic rams including heating elements effect a metallized bonding of the covers to the frame.

Peters, Roswell D. M. (Rustburg, VA)

1983-01-01T23:59:59.000Z

446

Solid-State Dynamic Nuclear Polarization at 263 GHz: Spectrometer Design and Experimental Results  

E-Print Network (OSTI)

Dynamic Nuclear Polarization (DNP) experiments transfer polarization from electron spins to nuclear spins with microwave irradiation of the electron spins for enhanced sensitivity in nuclear magnetic resonance (NMR) ...

Rosay, Melanie

447

A Major Advance in Understanding Plutonium | U.S. DOE Office...  

Office of Science (SC) Website

Laboratory, with collaborating scientists from the Japan Atomic Energy Agency, has led to the discovery of the nuclear magnetic resonance (NMR) signature for plutonium, the...

448

Argonne Chemical Sciences & Engineering - People - Support &...  

NLE Websites -- All DOE Office Websites (Extended Search)

e-mail: napora@anl.gov Other Areas Environmental Safety and Health Building Operations Information Systems Nuclear Magnetic Resonance (NMR) Facility Coal Sample Facility April 2011...

449</