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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.


1

MagLab Audio Dictionary: Nuclear Magnetic Resonance (NMR)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nuclear Magnetic Resonance (NMR)? Now Playing: What's Nuclear Magnetic Resonance (NMR)? Enable Javascript and Flash to stream the Magnet Minute Tim Cross Associated Links The NMR...

2

MagLab Audio Dictionary: Nuclear Magnetic Resonance (NMR)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Homogeneity? Now Playing: What's Homogeneity? Enable Javascript and Flash to stream the Magnet Minute Bill Brey Associated Links What's Nuclear Magnetic Resonance (NMR)? What's a...

3

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

4

Nuclear Magnetic Resonance (NMR) is the only logging technique available to estimate pore-size  

E-Print Network [OSTI]

1 ABSTRACT Nuclear Magnetic Resonance (NMR) is the only logging technique available to estimate, Nuclear Magnetic Resonance (NMR) logging has been used to assess a handful of key petrophysical parameters

Torres-Verdín, Carlos

5

Superconducting Magnet Safety Nuclear Magnetic Resonance (NMR) facilities present unique hazards not found in most  

E-Print Network [OSTI]

Superconducting Magnet Safety Nuclear Magnetic Resonance (NMR) facilities present unique hazards or steel reinforced concrete, these ferromagnetic materials may have an effect on the magnetic field environmental temperature control is required (2) Structural support for heavy equipment and vibration control

Maroncelli, Mark

6

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

7

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

8

Characterization of Crude Oil Products Using Data Fusion of Process Raman, Infrared, and Nuclear Magnetic Resonance (NMR) Spectra  

Science Journals Connector (OSTI)

Process Raman, infrared (IR), and nuclear magnetic resonance (NMR) analyses are currently being performed in industrial settings for the monitoring of large scale reactions. These...

Dearing, Thomas I; Thompson, Wesley J; Rechsteiner, Carl E; Marquardt, Brian J

2011-01-01T23:59:59.000Z

9

Study of Brazilian Gasoline Quality Using Hydrogen Nuclear Magnetic Resonance (1H NMR) Spectroscopy and Chemometrics  

E-Print Network [OSTI]

Study of Brazilian Gasoline Quality Using Hydrogen Nuclear Magnetic Resonance (1H NMR) Spectroscopy The identification of gasoline adulteration by organic solvents is not an easy task, because compounds that constitute the solvents are already in gasoline composition. In this work, the use of hydrogen nuclear

Ferreira, Márcia M. C.

10

Advanced Magnetic Resonance Workshop Report | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetic Resonance Workshop Report Advanced Magnetic Resonance Workshop Report NMR and EPR Workshop: Mueller KT, Washton NM, Pruski M, Lipton AS. 2013. "Science Drivers and...

11

Magnetic Resonance Imaging in Soil Science  

Science Journals Connector (OSTI)

Magnetic resonance imaging is based upon the physical effect of nuclear magnetic resonance (NMR) of spin bearing atomic...1991; Blmich, 2000...). The most important NMR active nuclei in soil science applications...

Andreas Pohlmeier

2014-08-01T23:59:59.000Z

12

Nuclear magnetic resonance quantum information processing  

Science Journals Connector (OSTI)

...Ivan S. Oliveira and Roberto M. Serra Nuclear magnetic resonance quantum information...and experiment . For the past decade, nuclear magnetic resonance (NMR) has been established...anticipate the contents of this issue. nuclear magnetic resonance|quantum information...

2012-01-01T23:59:59.000Z

13

The external magnetic field dependence of RF splitting of57Fe hyperfine lines. NMR + Mssbauer double resonance experiment  

Science Journals Connector (OSTI)

We present the results of an experimental investigation of a RF splitting of57Fe hyperfine lines in the regime of NMR and Mssbauer ... have been performed as a function of RF field intensity and static magnetic

F. G. Vagizov

1995-01-01T23:59:59.000Z

14

sup 13 C and sup 31 P NMR (Nuclear Magnetic Resonance) studies of prostate tumor metabolism  

SciTech Connect (OSTI)

The current research on prostate cancer by NMR spectroscopy and microscopy will most significantly contribute to tumor diagnosis and characterization only if sound biochemical models of tumor metabolism are established and tested. Prior searches focused on universal markers of malignancy, have to date, revealed no universal markers by any method. It is unlikely that NMRS will succeed where other methods have failed, however, NMR spectroscopy does provide a non-invasive means to analyze multiple compounds simultaneously in vivo. In order to fully evaluate the ability of NMRS to differentiate non-malignant from malignant tissues it is necessary to determine sufficient multiple parameters from specific, well-diagnosed, histological tumor types that, in comparison to normal tissue and non-neoplastic, non-normal pathologies from which the given neoplasm must be differentiated, one has enough degrees of freedom to make a mathematically and statistically significant determination. Confounding factors may consist of tumor heterogeneity arising from regional variations in differentiation, ischemia, necrosis, hemorrhage, inflammation and the presence of intermingled normal tissue. One related aspect of our work is the development of {l brace}{sup 13}C{r brace}-{sup 1}H metabolic imaging of {sup 13}C for metabolic characterization, with enhanced spatial localization (46). This should markedly extend the range of potential clinical NMR uses because the spatial variation in prostate metabolism may prove to be just as important in tumor diagnoses as bulk (volume-averaged) properties themselves. It is our hope that NMRS and spectroscopic imaging will reveal a sound correlation between prostate metabolism and tumor properties that will be clinically straightforward and useful for diagnosis.

Sillerud, L.O.; Halliday, K.R.; Freyer, J.P; Griffey, R.H.; Fenoglio-Preiser, C.

1989-01-01T23:59:59.000Z

15

High-Throughput 3D Structural Homology Detection via NMR Resonance Christopher James Langmead  

E-Print Network [OSTI]

's structure experimentally, via X-ray crystallography or Nuclear Magnetic Resonance (NMR), is very costly bipartite graph. Our experiments on real NMR data from 3 different proteins against a database of 4-646-3173. Fax: 603-646-1672. Email: brd@cs.dartmouth.edu Abbreviations used: NMR, nuclear magnetic resonance

Richardson, David

16

High-Throughput 3D Homology Detection via NMR Resonance Assignment  

E-Print Network [OSTI]

-ray crystallography or Nuclear Magnetic Resonance (NMR), is very costly and time-consuming. Consequently protein and c is the maximum edge weight in an integer- weighted bipartite graph. Our experiments on real experimental data. Abbreviations used: NMR, nuclear magnetic resonance; RDC, residual dipolar coupling; 3D

Langmead, Christopher James

17

Non-invasive NMR thermometry and temperature monitering using the proton resonance frequenccy method  

E-Print Network [OSTI]

The proton resonance frequency (PRF) method for nuclear magnetic resonance (NMR) thermometry has emerged as a notable method for non-invasive temperature measurement. The PRF method has been investigated by a number of researchers. The ability...

Naphuket, Sood Ratanadilok

2012-06-07T23:59:59.000Z

18

Optical nuclear magnetic resonance: theory, simulation, and animation  

Science Journals Connector (OSTI)

The theory of optical nuclear magnetic resonance (NMR) is introduced and developed with supercomputer simulation and animation. A powerful, circularly polarized pulse of laser...

Evans, Myron W; Pelkie, Chris R

1992-01-01T23:59:59.000Z

19

2-3 High Field Magnetic Resonance Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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)

20

Nuclear magnetic resonance characterization of peptide models of collagenfolding diseases  

Science Journals Connector (OSTI)

...Dobson, R. J. Ellis and A. R. Fersht Nuclear magnetic resonance characterization of...disease such as osteogenesis imperfecta. Nuclear magnetic resonance (NMR) studies of...can lead to pathological conditions. nuclear magnetic resonance|collagen|osteogenesis...

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.


21

Contact replacement for NMR resonance assignment  

Science Journals Connector (OSTI)

......experimental and synthetic datasets, it is robust to...edu 1 INTRODUCTION Nuclear magnetic resonance...experimental and synthetic datasets, it is robust to...edu 1 INTRODUCTION Nuclear magnetic resonance...an ensemble for a dataset, while bars indicate...replacement and nuclear vector replacement......

Fei Xiong; Gopal Pandurangan; Chris Bailey-Kellogg

2008-07-01T23:59:59.000Z

22

In Situ and Frontal Polymerization for the Consolidation of Porous Stones:? A Unilateral NMR and Magnetic Resonance Imaging Study  

Science Journals Connector (OSTI)

To achieve a deeper penetration of the polymeric consolidating agents, we have carefully studied two consolidation procedures using polymeric materials introduced into the stones by in situ and frontal polymerization, respectively. ... Unilateral NMR has been previously used as a diagnostic tool for studying early degradation in cellulose-based materials22,23 and detachment of the pictorial film from the plaster in frescos. ... The kinetics of the capillary rise phenomenon was studied for various building materials: 4 stones, 2 bricks, and 6 plasters. ...

Noemi Proietti; Donatella Capitani; Sara Cozzolino; Massimiliano Valentini; Enrico Pedemonte; Elisabetta Princi; Silvia Vicini; Anna Laura Segre

2006-11-09T23:59:59.000Z

23

Nuclear magnetic resonance imaging  

Science Journals Connector (OSTI)

Nuclear magnetic resonance imaging (NMRI) is a powerful imaging modality having a range of important applications to medicine and industry. The basic principles of NMRI are reviewed in...

Rothwell, William P

1985-01-01T23:59:59.000Z

24

Pulsed Nuclear Magnetic Resonance: Spin Echoes MIT Department of Physics  

E-Print Network [OSTI]

Pulsed Nuclear Magnetic Resonance: Spin Echoes MIT Department of Physics (Dated: February 5, 2014) In this experiment, the phenomenon of Nuclear Magnetic Resonance (NMR) is used to determine the magnetic moments-factor in atomic spectroscopy and is given by g = (µ/µN )/I, (2) and µN is the nuclear magneton, e /2mp

Seager, Sara

25

Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields  

DOE Patents [OSTI]

A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

2014-01-21T23:59:59.000Z

26

Investigation of Peptide Folding by Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

. Solution-state nuclear magnetic resonance (NMR) is a powerful technique to investigate protein structure, dynamics, and folding mechanisms, since it provides residue-specific information. One of the major contributions that govern protein structure appears...

Hwang, SoYoun

2012-07-16T23:59:59.000Z

27

Applications of Nuclear Magnetic Resonance to Oil Shale Evaluation and Processing  

Science Journals Connector (OSTI)

Nuclear Magnetic Resonance (NMR) is playing an increasing role in the characterization of the organic constituents of fossil fuels. The NMR techniques that currently are being applied to fossil fuel characteri...

Francis P. Miknis; Gary E. Maciel

1982-01-01T23:59:59.000Z

28

BATMANan R package for the automated quantification of metabolites from nuclear magnetic resonance spectra using a Bayesian model  

Science Journals Connector (OSTI)

......methods and its results on an example dataset fitting 26 metabolites are comparable...automated quantification of metabolites from nuclear magnetic resonance spectra using a Bayesian model. | Nuclear Magnetic Resonance (NMR) spectra are......

Jie Hao; William Astle; Maria De Iorio; Timothy M D Ebbels

2012-08-01T23:59:59.000Z

29

The Multidrug Resistance Phenotype: 31P Nuclear Magnetic Resonance Characterization and 2-Deoxyglucose Toxicity  

Science Journals Connector (OSTI)

...identify changes in 31P nuclear magnetic resonance...identify changes in 3IP nuclear magnetic resonance...observation of high-energy phosphate-containing...abbreviations used are: NMR. nuclear magnetic resonance...7, 8). p 170 is an energy-dependent transporter...

Ofer Kaplan; Jerzy W. Jaroszewski; Robert Clarke; Craig R. Fairchild; Patricia Schoenlein; Sarah Goldenberg; Michael M. Gottesman; and Jack S. Cohen

1991-03-15T23:59:59.000Z

30

Self-Diffusion of Water in Multicellular Spheroids Measured by Magnetic Resonance Microimaging  

Science Journals Connector (OSTI)

...the activation energy for diffusion was...demonstrate the ability of nuclear magnetic resonance...the activation energy for diffusion was...demonstrate the ability of nuclear magnetic resonance...States Department of Energy. J To whom requests...used are: NMR, nuclear magnetic resonance...

Michal Neeman; Kathryn A. Jarrett; Laurel O. Sillerud; and James P. Freyer

1991-08-01T23:59:59.000Z

31

A Novel Nuclear Magnetic Resonance (NMR) Imaging Method for Measuring the Water Front Penetration Rate in Hydrophilic Polymer Matrix Capsule Plugs and Its Role in Drug Release  

Science Journals Connector (OSTI)

An NMR imaging method was developed to estimate the rate of water movement in slow-release capsule ... transverse plane of each plug. The water penetration rate was determined by comparison of the cut ... the plu...

Muhammad Ashraf; Virginia L. luorno; David Coffin-Beach

1994-05-01T23:59:59.000Z

32

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

SciTech Connect (OSTI)

Conventional nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are fundamentally challenged by the insensitivity that stems from the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This dissertation is primarily concerned with the principles and practice of optically pumped nuclear magnetic resonance (OPNMR). The enormous sensitivity enhancement afforded by optical pumping noble gases can be exploited to permit a variety of novel NMR experiments across many disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, and zero-field NMR and MRI.

Goodson, Boyd M.

1999-12-01T23:59:59.000Z

33

Nuclear magnetic resonance offers new insights into Pu 239  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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."

34

Modulation of Murine Radiation-induced Fibrosarcoma-1 Tumor Metabolism and Blood Flow in Situ via Glucose and Mannitol Administration Monitored by 31P and 2H Nuclear Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...triphos phates; NMR, nuclear magnetic resonance; ~P, "high energy phosphates"; PCr...zpH meas ured by nuclear magnetic resonance...ischemia studied by nuclear magnetic resonance...B. K. Changes in energy state and acid-base...

Yuying C. Hwang; Seong-Gi Kim; Jeffrey L. Evelhoch; Mahmoud Seyedsadr; and Joseph J. H. Ackerman

1991-06-15T23:59:59.000Z

35

Multivoxel Magnetic Resonance Spectroscopy of Brain Tumors  

Science Journals Connector (OSTI)

...reprints should be addressed, Magnetic Resonance Science Center, Box 1290, 1 Irving...Francisco, CA 94143-1290 Magnetic Resonance Science Center, University of...failure of new treatments. | Magnetic Resonance Science Center, University of...

Sarah J. Nelson

2003-05-01T23:59:59.000Z

36

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

37

High Field Magnetic Resonance Facility  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

38

Magnetic resonance elastography  

Science Journals Connector (OSTI)

The goal of our research is to develop MRI?based methods for assessing the mechanical properties of tissues in vivo. We have focused on a novel MRI technique for visualizing propagating acoustic shear waves [Science 269 18541857 (1995)]. Suitable dynamic shear stress for Magnetic Resonance Elastography (MRE) can be generated by surface drivers inertial effects acoustic radiation pressure or endogenous physiologic mechanisms. The MRE acquisition sequence is capable of visualizing cyclic tissue motion of less than 1 micron in displacement amplitude with imaging times ranging from 100 ms to several minutes. Inversion algorithms based on continuum mechanics are used to process the acquired data to generate maps of mechanical properties such as depict stiffness viscosity attenuation and anisotropic behavior. We have applied MRE to assess specimens of a variety of tissues ranging in stiffness from lung to cartilage. Human studies have demonstrated that it is feasible to apply MRE to quantitatively image the mechanical properties of skeletal muscles gray and white matter in the brain thyroid kidney liver and skin. Our preliminary clinical studies have to date applied MRE to observe changes in tissue mechanical properties in patients with breast brain and thyroid tumors liver fibrosis and diffuse diseases of skeletal muscle.

2005-01-01T23:59:59.000Z

39

Nuclear magnetic resonance readable sensors  

E-Print Network [OSTI]

The monitoring of physiological biomarkers is fundamental to the diagnosis and treatment of disease. We describe here the development of molecular sensors which can be read by magnetic resonance (MR) relaxometry. MR is an ...

Ling, Yibo

2010-01-01T23:59:59.000Z

40

Practical nuclear magnetic resonance analysis of liquid oil in oilseeds: I factors affecting peak width  

Science Journals Connector (OSTI)

If proton nuclear magnetic resonance (NMR) spectra of single seeds can be improved, a rapid, low-cost method of screening seeds for oil composition could be developed for use as ... evaluate methods for improving...

Martin J. T. Reaney; Nancy J. Tyler

1999-01-01T23:59:59.000Z

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.


41

Structural Basis of the 1H-Nuclear Magnetic Resonance Spectra of EthanolWater Solutions Based on Multivariate Curve Resolution Analysis of Mid-Infrared Spectra  

Science Journals Connector (OSTI)

The 1H-nuclear magnetic resonance (NMR) chemical shifts of ethanol and water hydroxyl groups show a pattern change at a critical ethanol concentration. Below the critical...

Hu, Naiping; Wu, Dan; Cross, Kelly J; Schaefer, Dale W

2010-01-01T23:59:59.000Z

42

Noble gas magnetic resonator  

DOE Patents [OSTI]

Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.

Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert

2014-04-15T23:59:59.000Z

43

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

44

Nuclear magnetic resonance for foodomics beyond food analysis  

Science Journals Connector (OSTI)

Abstract Nuclear magnetic resonance (NMR) spectroscopy has a long tradition as a powerful platform in the hands of modern food scientists, with several applications related to food safety, traceability and authenticity. The continual advances in instrumental sensitivity and electronic stability, together with rapid growth in new, potent algorithms for multivariate data analysis, facilitate the use of NMR spectroscopy as a competitive, complementary analytical platform for observing the food metabolome. By adapting the holistic views of metabolomics research, foodomics emerges as a new discipline bringing food science and nutritional research closer together. This review mostly focuses on recent efforts dedicated to extraction and interpretation of NMR data, rather than providing technical details about their acquisition. With this aim, we present new trends in the exploitation of the information gained by NMR of food matter. We critically describe and illustrate, via representative examples, the limitations and the counterbalancing advantages of the technique.

Luca Laghi; Gianfranco Picone; Francesco Capozzi

2014-01-01T23:59:59.000Z

45

Through-bond Correlation Methods for Assigning Protein Resonances with Solid-State NMR Spectroscopy  

E-Print Network [OSTI]

Reson. , 40. Cavanagh, J. ; Fairbrother, W.J. ; Palmer, A.G.1987 . 31. Cavanagh, J. ; Fairbrother, W.J. Protein NMR

Chen, Lingling

2008-01-01T23:59:59.000Z

46

Magnetic resonance apparatus  

DOE Patents [OSTI]

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

47

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

48

Edward Purcell and Nuclear Magnetic Resonance (NMR)  

Office of Scientific and Technical Information (OSTI)

and in 1979, he received the National Medal of Science. Purcell served as a science advisor to Presidents Eisenhower, Kennedy, and Johnson."2 1Edited excerpts from Faculty of...

49

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

E-Print Network [OSTI]

before. We report here the first NMR observation of 23SU. The uranium hexafluoride has been chosenL-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

Paris-Sud XI, Université de

50

Temperature Dependence of Nuclear Magnetic Resonance of Fe57 in Magnetite  

Science Journals Connector (OSTI)

A report is made of an attempt to fit the temperature dependence of the observed nuclear magnetic resonance (NMR) frequencies for the two sublattices in magnetite to the measured temperature dependence of the magnetization. It is shown that when the microwave geff values as reported in the literature are used in this calculation, no fit between the NMR experiment and the moment measurement is obtained. If a geff=2 is assumed, however, the data may be brought into good agreement.

E. L. Boyd

1963-03-01T23:59:59.000Z

51

Magnetic resonance studies of cement based materials in inhomogeneous magnetic fields  

SciTech Connect (OSTI)

Single-sided magnets give hope that Nuclear Magnetic Resonance (NMR) might in future be used for in situ characterisation of hydration and water transport in the surface layers of concrete slabs. Towards that end, a portable NMR-MOUSE (MObile Universal Surface Explorer) has been used to follow the hydration of gypsum based plaster, a Portland cement paste and concrete mortar. The results compare favourably to those obtained using a standard laboratory bench-top spectrometer. Further, stray field imaging (STRAFI) based methods have been used with embedded NMR detector coils to study water transport across a mortar/topping interface. The measured signal amplitudes are found to correlate with varying sample conditions.

Boguszynska, Joanna [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznan (Poland); Brown, Marc C.A. [School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NR (United Kingdom); McDonald, Peter J. [School of Electronics and Physical Sciences, University of Surrey, Surrey, GU2 7XH (United Kingdom)]. E-mail: p.mcdonald@surrey.ac.uk; Mitchell, Jonathan [School of Electronics and Physical Sciences, University of Surrey, Surrey, GU2 7XH (United Kingdom); Mulheron, Mike [School of Engineering, University of Surrey, Surrey, GU2 7XH (United Kingdom); Tritt-Goc, Jadwiga [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznan (Poland); Verganelakis, Dimitris A. [Department of Chemical Engineering, University of Cambridge, Cambridge, CB2 3RA (United Kingdom)

2005-10-01T23:59:59.000Z

52

Development for Hardware for Programming of Spatial Magnetic Field Distributions in Nuclear Magnetic Resonance and Magnetic Resonance Imaging  

E-Print Network [OSTI]

The proposal of a project aimed on a design of hardware for programming 3D Magnetic Field shapes over sample volume in NMR and MRI is described.

Vladimir Korostelev

2012-01-13T23:59:59.000Z

53

A 31P-NMR study.  

Science Journals Connector (OSTI)

Jan 1, 2004 ... 31P nuclear magnetic resonance (NMR), a well established method in the fields of environmental science and engineer- ing, is used to identify...

2003-12-30T23:59:59.000Z

54

MagLab Audio Dictionary: Electron Magnetic Resonance (EMR)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron Magnetic Resonance (EMR)? Now Playing: What's Electron Magnetic Resonance (EMR)? Enable Javascript and Flash to stream the Magnet Minute Stephen Hill Associated Links The...

55

MagLab Audio Dictionary: Magnetic Resonance Imaging (MRI)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetic Resonance Imaging (MRI)? Now Playing: What's Magnetic Resonance Imaging (MRI)? Enable Javascript and Flash to stream the Magnet Minute Sam Grant Associated Links MRI: A...

56

1,3-Alternate calix[4]arene nitronyl nitroxide tetraradical and diradical: synthesis, X-ray crystallography, paramagnetic NMR spectroscopy, EPR spectroscopy, and magnetic studies  

SciTech Connect (OSTI)

Calix[4]arenes constrained to 1,3-alternate conformation and functionalized at the upper rim with four and two nitronyl nitroxides have been synthesized, and characterized by X-ray crystallography, magnetic resonance (EPR and {sup 1}H NMR) spectroscopy, and magnetic studies. Such calix[4]arene tetraradicals and diradicals provide scaffolds for through-bond and through-space intramolecular exchange couplings.

Rajca, Andrzej; Pink, Maren; Mukherjee, Sumit; Rajca, Suchada; Das, Kausik (UNL); (Indiana)

2008-04-02T23:59:59.000Z

57

Resonance assignment of the NMR spectra of disordered proteins using a multi-objective non-dominated sorting genetic algorithm  

E-Print Network [OSTI]

ARTICLE Resonance assignment of the NMR spectra of disordered proteins using a multi-objective non, for disordered membrane proteins (H A multi-objective genetic algorithm is intro- duced to predict the assignment of protein solid-state NMR

Hong, Mei

58

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

59

Rotational Doppler effect in magnetic resonance  

Science Journals Connector (OSTI)

We compute the shift in the frequency of the spin resonance in a solid that rotates in the field of a circularly polarized electromagnetic wave. Electron-spin resonance, nuclear magnetic resonance, and ferromagnetic resonance are considered. We show that contrary to the case of the rotating LC circuit, the shift in the frequency of the spin resonance has strong dependence on the symmetry of the receiver. The shift due to rotation occurs only when rotational symmetry is broken by the anisotropy of the gyromagnetic tensor, by the shape of the body or by magnetocrystalline anisotropy. General expressions for the resonance frequency and power absorption are derived and implications for experiment are discussed.

S. Lendnez; E. M. Chudnovsky; J. Tejada

2010-11-12T23:59:59.000Z

60

Novel nuclear magnetic resonance techniques for studying biological molecules  

SciTech Connect (OSTI)

Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone ({phi}/{psi}) dihedral angles by comparing experimentally determined {sup 13}C{sub a}, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of {alpha}-helical and {beta}-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly {beta}-sheet.

Laws, David D.

2000-06-01T23:59:59.000Z

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

Reconsidering complete search algorithms for protein backbone NMR assignment  

Science Journals Connector (OSTI)

......03755, USA Motivation: Nuclear magnetic resonance...cannot scale to realistic datasets. Results: This paper...software license. The datasets featured in the Results...backbone NMR assignment. | Nuclear magnetic resonance...cannot scale to realistic datasets. This paper presents......

Olga Vitek; Chris Bailey-Kellogg; Bruce Craig; Paul Kuliniewicz; Jan Vitek

2005-09-01T23:59:59.000Z

62

Spectrally Resolved Magnetic Resonance Imaging of the XenonBiosensor  

SciTech Connect (OSTI)

Due to its ability to non-invasively record images, as well as elucidate molecular structure, nuclear magnetic resonance is the method of choice for applications as widespread as chemical analysis and medical diagnostics. Its detection threshold is, however, limited by the small polarization of nuclear spins in even the highest available magnetic fields. This limitation can, under certain circumstances, be alleviated by using hyper-polarized substances. Xenon biosensors make use of the sensitivity gain of hyperpolarized xenon to provide magnetic resonance detection capability for a specific low-concentration target. They consist of a cryptophane cage, which binds one xenon atom, and which has been connected via a linker to a targeting moiety such as a ligand or antibody. Recent work has shown the possibility of using the xenon biosensor to detect small amounts of a substance in a heterogeneous environment by NMR. Here, we demonstrate that magnetic resonance (MR) provides the capability to obtain spectrally and spatially resolved images of the distribution of immobilized biosensor, opening the possibility for using the xenon biosensor for targeted imaging.

Hilty, Christian; Lowery, Thomas; Wemmer, David; Pines, Alexander

2005-07-15T23:59:59.000Z

63

Quantitative diffusion magnetic resonance imaging of the brain : validation, acquisition, and analysis  

E-Print Network [OSTI]

Engineering, Magnetic Resonance Imaging, Cognitive Science.on magnetic resonance imaging applications in brain science.

White, Nathan S.

2010-01-01T23:59:59.000Z

64

Magnetic resonance imaging (MRI) of solid materials entails numerous problems from short longitudinal relaxation (T2) times to  

E-Print Network [OSTI]

. Solid-State STRAFI NMR Probe for Material Imaging of Quadrupolar Nuclei, J. Magn. Reson. httpMagnetic resonance imaging (MRI) of solid materials entails numerous problems from short for broadband tuning, sample translation along z-axis, and electrodes for in situ battery studies. An Alderman

Weston, Ken

65

Plutonium less mysterious with nuclear magnetic resonance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

66

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.

67

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

68

Observation of higher order NMR larmor lines by SQUID in solids at low magnetic field  

Science Journals Connector (OSTI)

We describe an apparatus allowing the observation of the NMR static longitudinal component of nuclear magnetizationM z by a SQUID at low magnetic fields and atT

M. Kohl; M. Odehnal; V. Pet??ek; R. Tich

1988-08-01T23:59:59.000Z

69

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

70

Coherence of magnetic resonators in a metamaterial  

SciTech Connect (OSTI)

The coherence of periodic magnetic resonators (MRs) under oblique incidence is studied using simulations. The correlated phase of interaction including both the retardation effect and relative phase difference between two MRs is defined, and it plays a key role in the MR interaction. The correlated phase is anisotropic, as is the coherence condition. The coherence condition is the same as the Wood's anomaly and verified by the Fano resonance. This study shows that the applications of the Fano resonance of periodic MRs will become widespread owing to achieving the Fano resonance simply by tuning the incident angle.

Hou, Yumin, E-mail: ymhou@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

2013-12-15T23:59:59.000Z

71

Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects  

SciTech Connect (OSTI)

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

72

An efficient randomized algorithm for contact-based NMR backbone resonance assignment  

Science Journals Connector (OSTI)

......the through-space (nuclear Overhauser enhancement...experimental beta-sheet datasets. Our approach is able...edu 1 INTRODUCTION Nuclear Magnetic Resonance...experimental b-sheet datasets. Our approach is able...edu 1 INTRODUCTION Nuclear Magnetic Resonance......

Hetunandan Kamisetty; Chris Bailey-Kellogg; Gopal Pandurangan

2006-01-15T23:59:59.000Z

73

Nuclear magnetic resonance offers new insights into Pu 239  

E-Print Network [OSTI]

- 1 - Nuclear magnetic resonance offers new insights into Pu 239 May 29, 2012 Nuclear magnetic signal of plutonium 239's unique nuclear magnetic resonance signature has been detected by scientists on the subject, "Observation of 239 Pu Nuclear Magnetic Resonance," was published in the May 18 issue of Science

74

Nuclear magnetic resonance in a thallium single crystal.  

E-Print Network [OSTI]

??Nuclear magnetic resonance studies in single crystals of thallium have been performed for the first time. The resonance frequency, line width and second moment were (more)

Schratter, Jacob Jack

2012-01-01T23:59:59.000Z

75

Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold Flooding During Continuous Fuel Cell Operation. Magnetic Resonance Imaging (MRI) of PEM Dehydration and Gas Manifold...

76

Magnetic elliptical polarization of Schumann resonances  

SciTech Connect (OSTI)

Measurements of orthogonal, horizontal components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly polarized at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of polarization over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours. 16 references.

Sentman, D.D.

1987-08-01T23:59:59.000Z

77

Unraveling multi-spin effects in rotational resonance nuclear magnetic resonance using effective reduced density matrix theory  

SciTech Connect (OSTI)

A quantum-mechanical model integrating the concepts of reduced density matrix and effective Hamiltonians is proposed to explain the multi-spin effects observed in rotational resonance (R{sup 2}) nuclear magnetic resonance (NMR) experiments. Employing this approach, the spin system of interest is described in a reduced subspace inclusive of its coupling to the surroundings. Through suitable model systems, the utility of our theory is demonstrated and verified with simulations emerging from both analytic and numerical methods. The analytic results presented in this article provide an accurate description/interpretation of R{sup 2} experimental results and could serve as a test-bed for distinguishing coherent/incoherent effects in solid-state NMR.

SivaRanjan, Uppala; Ramachandran, Ramesh, E-mail: rramesh@iisermohali.ac.in [Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manauli, P.O. Box-140306, Mohali, Punjab (India)] [Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Manauli, P.O. Box-140306, Mohali, Punjab (India)

2014-02-07T23:59:59.000Z

78

Interaction of magnetic resonators studied by the magnetic field enhancement  

SciTech Connect (OSTI)

It is the first time that the magnetic field enhancement (MFE) is used to study the interaction of magnetic resonators (MRs), which is more sensitive than previous parametersshift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

Hou, Yumin, E-mail: ymhou@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

2013-12-15T23:59:59.000Z

79

NMR Characterization  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

80

A design flux injector for NMR superconducting magnets : results of operation with superconducting insert cells  

E-Print Network [OSTI]

It has been known for some time that high-temperature superconductors (HTS) are critical for the construction of NMR magnets generating 1 GHz and above. Such systems generally require an HTS insert to be placed in the inner ...

Mai, Rocky D. (Rocky Dikang)

2006-01-01T23:59:59.000Z

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.


81

Nuclear magnetic resonance analysis of proteinDNA interactions  

Science Journals Connector (OSTI)

...review-article Review articles 1004 30 15 Nuclear magnetic resonance analysis of protein-DNA...instrumental advances in solution-state nuclear magnetic resonance have opened up the...structural biology|protein-DNA complex|nuclear magnetic resonance| 1. Introduction...

2011-01-01T23:59:59.000Z

82

Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed  

Science Journals Connector (OSTI)

...Eakins, Fabrice Pierron and Clive Siviour Nuclear magnetic resonance measurements of velocity...Part 1) . We report the results of nuclear magnetic resonance imaging experiments...granular bed|ultrasonic fluidization|nuclear magnetic resonance|magnetic resonance...

2014-01-01T23:59:59.000Z

83

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

E-Print Network [OSTI]

&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Co-Chairs of Committee, A. Ted Watson John C. Slattery Committee Members, Randall L. Eubank David M. Ford Michael A. Bevan Head of Department, Kenneth R... Co?Chairs of Advisory Committee: Dr. A. Ted Watson Dr. John C. Slattery Advanced nuclear magnetic resonance (NMR) imaging methodologies have been developed to determine porous media properties associated with fluid flow pro- cesses. This dissertation...

Uh, Jinsoo

2007-04-25T23:59:59.000Z

84

National High Magnetic Field Laboratory - NMR/MRIs Advisory Committee  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Research Interests: Solution NMR Term ending: 6302016 Myriam Cotten Hamilton College Department of Chemistry 1075 Science Center Clinton, NY 13323 Phone:...

85

DEOTERIUM MAGNETIC RESONANCE OF SOME POLYMORPHIC LIQUID CRYSTALS: THE CONFORMATION OF THE ALIPHATIC END CHAINS  

E-Print Network [OSTI]

in "Magnetic Resonance in Colloid and Interface Science"in "Magnetic Resonance in Colloid and Interface Science"

Hsi, Shan

2011-01-01T23:59:59.000Z

86

Improving the chemical shift dispersion of multidimensional NMR spectra of intrinsically disordered proteins  

Science Journals Connector (OSTI)

Intrinsically disordered proteins (IDPs) have recently attracted the attention ... In the characterization of the dynamic features of proteins nuclear magnetic resonance spectroscopy (NMR) is...13C?, is proposed.

Wolfgang Bermel; Marta Bruix; Isabella C. Felli

2013-03-01T23:59:59.000Z

87

900-MHz NMR: Accelerating Scientific Discovery  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

88

An Estimate of the Signal-to-Noise Ratio in Nuclear Magnetic Resonance Measurements at Ultra-Low Temperatures  

Science Journals Connector (OSTI)

The signal-to-noise ratios for nuclear magnetic resonance (NMR) measurements by the Continuous Wave (CW) and the Pulsed NMR techniques are compared for applications at ultra-low temperatures. This comparison is made at 0.1, 1 and 10 mK as a function of the energy dissipation. The resonance signal is to be detected by a conventional method using a receiver r-f coil or by using a SQUID detector and the relative merits of the two detection methods are discussed for both the CW and the Pulse techniques. For the CW NMR, the SQUID detection method is found to have an advantage over the conventional method except at a relatively high applied DC field. For the pulsed NMR, the SQUID detection results in a better signal-to-noise ratio for a relatively high r-f field, (short pulses) while the conventional method becomes more advantageous with a decreasing r-f field.

Itsuhiro Fujii; Akira Ikushima; Yoshitaka Yoshida

1980-01-01T23:59:59.000Z

89

High field DNP and cryogenic MAS NMR : novel instrumentation and applications  

E-Print Network [OSTI]

Solid State Nuclear Magnetic Resonance (ssNMR) spectroscopy has blossomed over the last two decades. As ssNMR is progressively applied to more challenging systems, the sensitivity remains one of its major limiting factors. ...

Markhasin, Evgeny

2014-01-01T23:59:59.000Z

90

Journal of Magnetism and Magnetic Materials 286 (2005) 324328 Light-free magnetic resonance force microscopy for studies of  

E-Print Network [OSTI]

Journal of Magnetism and Magnetic Materials 286 (2005) 324­328 Light-free magnetic resonance force for Physical Sciences, College Park, MD, USA Available online 4 November 2004 Abstract Magnetic resonance force microscopy is a scanned probe technique capable of three-dimensional magnetic resonance imaging. Its

91

Nuclear Magnetic Resonance Studies of Macroscopic Morphology and Dynamics  

E-Print Network [OSTI]

Applications in Materials Magnetic Science, Agriculture andApplications in Materials Magnetic Science, Agriculture andMagnetic Resonance Studies of Macroscopic Morphology and Dynamics Geoffrey Alden Barrali Department of Chemistry University of California, Berkeley and Materials Sciences

Barrall, G.A.

2010-01-01T23:59:59.000Z

92

Resonant detection of axion mediated forces with Nuclear Magnetic Resonance  

E-Print Network [OSTI]

We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our approach can substantially improve upon current experimental limits set by astrophysics, and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to PQ axion decay constants between 10^9 and 10^12 GeV or axion masses between 10^-6 and 10^-3 eV, independent of the cosmic axion abundance.

Asimina Arvanitaki; Andrew A. Geraci

2014-03-05T23:59:59.000Z

93

Nuclear magnetic resonance experiments with dc SQUID amplifiers  

SciTech Connect (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

94

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

95

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

96

Electro-Mechanical Resonant Magnetic Field Sensor  

E-Print Network [OSTI]

We describe a new type of magnetic field sensor which is termed an Electro-Mechanical Resonant Sensor (EMRS). The key part of this sensor is a small conductive elastic element with low damping rate and therefore a high Q fundamental mode of frequency $f_1$. An AC current is driven through the elastic element which, in the presence of a magnetic field, causes an AC force on the element. When the frequency of the AC current matches the resonant frequency of the element, maximum vibration of the element occurs and this can be measured precisely by optical means. We have built and tested a model sensor of this type using for the elastic element a length of copper wire of diameter 0.030 mm formed into a loop shape. The wire motion was measured using a light emitting diode photo-transistor assembly. This sensor demonstrated a sensitivity better than 0.001G for an applied magnetic field of $ \\sim 1$G and a good selectivity for the magnetic field direction. The sensitivity can be easily improved by a factor of $\\sim ...

Temnykh, A B; Temnykh, Alexander B.; Lovelace, Richard V. E.

2002-01-01T23:59:59.000Z

97

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

98

Magnetic moment of Ag104m and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei  

Science Journals Connector (OSTI)

Nuclear magnetic resonance (NMR/ON) measurements with ?- and ?-ray detection have been performed on oriented Ag104g,m nuclei with the NICOLE He3-He4 dilution refrigerator setup at ISOLDE/CERN. For Ag104g (I?=5+) the ?-NMR/ON resonance signal was found at ?=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 |Bhf(AgFe)|=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, |Bhf(AgFe)|=44.692(30) T. For Ag104m (I?=2+), the anisotropy of the ? particles provided the NMR/ON resonance signal at ?=627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the magnetic moment ?(Ag104m)=+3.691(3) ?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 (?g9/2)7/2+-3(?d5/2?g7/2)5/2+ and the (?g9/2)9/2+-3(?d5/2?g7/2)5/2+ configurations. The magnetic moments of the ground and isomeric states of Ag104 can be explained by an almost complete mixing of these two configurations.

V. V. Golovko; I. S. Kraev; T. Phalet; B. Delaur; M. Beck; V. Yu. Kozlov; S. Coeck; F. Wauters; P. Herzog; Ch. Tramm; D. Zkouck; D. Vnos; D. Srnka; M. Honusek; U. Kster; N. Severijns

2010-05-28T23:59:59.000Z

99

Small-scale instrumentation for nuclear magnetic resonance of porous media  

Science Journals Connector (OSTI)

The investigation of fluids confined to porous media is the oldest topic of investigation with small-scale nuclear magnetic resonance (NMR) instruments, as such instruments are mobile and can be moved to the site of the object, such as the borehole of an oil well. While the analysis was originally restricted by the inferior homogeneity of the employed magnets to relaxation measurements, today, portable magnets are available for all types of NMR measurements concerning relaxometry, imaging and spectroscopy in two types of geometries. These geometries refer to closed magnets that surround the sample and open magnets, which are brought close to the object for measurement. The current state of the art of portable, small-scale NMR instruments is reviewed and recent applications of such instruments are featured. These include the porosity analysis and description of diesel particulate filters, the determination of the moisture content in walls from gray concrete, new approaches to analyze the pore space and moisture migration in soil, and the constitutional analysis of the mortar base of ancient wall paintings.

Bernhard Blmich; Federico Casanova; Martin Dabrowski; Ernesto Danieli; Loribeth Evertz; Agnes Haber; Maxime Van Landeghem; Sabina Haber-Pohlmeier; Alexandra Olaru; Juan Perlo; Oscar Sucre

2011-01-01T23:59:59.000Z

100

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 (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

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

Correlated ESR and NMR line-broadening effect associated with external-magnetic-field inhomogeneities  

Science Journals Connector (OSTI)

The unusual dynamic nuclear polarization (DNP) phenomena at the center of an inhomogeneously broadened ESR line arising from a correlated ESR and NMR line broadening have been investigated for the case of inhomogeneous external magnetic fields. It was found that DNP experimental data obtained for the central Cr3+ ESR and Al27 NMR lines in a single crystal of ruby were consistent with the phenomenological model developed for the correlated ESR and NMR line broadenings arising from the strain and c-axis-variation effects. This result can be taken as a direct verification of the phenomenological model.

Sook Lee and D. C. Power

1980-02-01T23:59:59.000Z

102

Transverse Pulsed NMR of Superuid 3He in Aerogel| Unconventional Pairing in the Presence of Quenched Disorder.  

E-Print Network [OSTI]

?? This thesis reports the results of transverse pulsed nuclear magnetic resonance (NMR) experiments performed on superfluid He in a new class of highly uniform (more)

Pollanen, Johannes

2012-01-01T23:59:59.000Z

103

Science Drivers and Technical Challenges for Advanced Magnetic Resonance  

SciTech Connect (OSTI)

This report recaps the "Science Drivers and Technical Challenges for Advanced Magnetic Resonance" workshop, held in late 2011. This exploratory workshop's goal was to discuss and address challenges for the next generation of magnetic resonance experimentation. During the workshop, participants from throughout the world outlined the science drivers and instrumentation demands for high-field dynamic nuclear polarization (DNP) and associated magnetic resonance techniques, discussed barriers to their advancement, and deliberated the path forward for significant and impactful advances in the field.

Mueller, Karl T.; Pruski, Marek; Washton, Nancy M.; Lipton, Andrew S.

2013-03-07T23:59:59.000Z

104

Sorting out Mixtures with 2D NMR Gregory S. Boebinger, National High Magnetic Field Laboratory  

E-Print Network [OSTI]

of the resonances. The combination of 2D NMR spectra with full-resolution statistical analysis provides a platform for chemical and biological studies in cellular biochemistry, metabolomics, and chemical ecology. Alignment: Application to Nematode Chemical Ecology.", Analytical Chemistry 83 (5), 1649­1657 (2011). Support: NHMFL

Weston, Ken

105

Magnetic resonance imaging of self-assembled biomaterial scaffolds  

DOE Patents [OSTI]

Compositions and/or mixtures comprising peptide amphiphile compounds comprising one or more contrast agents, as can be used in a range of magnetic resonance imaging applications.

Bull, Steve R; Meade, Thomas J; Stupp, Samuel I

2014-09-16T23:59:59.000Z

106

arthritis magnetic resonance: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

during magnetic resonance imaging (MRI) is the distortion of the ECG due to electromagnetic interference cardiac activity that, unlike the ECG, is immune to electromagnetic...

107

Non-destructive quantification of water gradient in sludge composting with Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Sludge from a slaughter-house wastewater plant, and mixtures of bulking agent (crushed wood pallet) and sludge were studied by Nuclear Magnetic Resonance (NMR). The NMR spin-spin relaxation (T{sub 2}) and spin-lattice relaxation (T{sub 1}) signals for sludge, wet crushed wood pallet and mixtures of sludge and bulking agent were decomposed into three relaxation time components. Each relaxation time component was explained by a non-homogeneous water distribution on a microscopic length scale and by the porosity of the material. For all samples, the T{sub 2} relaxation time value of each component was directly related to the dry matter content. The addition of wet crushed wood to sludge induced a decrease in the relaxation time, explained by water transfer between the sludge and the wood. Magnetic Resonance Imaging (MRI) and respirometric measurements were performed on sludge and wood mixtures. MR images of the mixtures were successfully obtained at different biodegradation states. Based on specific NMR measurements in an identified area located in the MRI cells, the results showed that grey levels of MR images reflected dry matter content. This preliminary study showed that MRI would be a powerful tool to measure water distribution in sludge and bulking agent mixtures and highlights the potential of this technique to increase the understanding of sludge composting.

Duval, F.P.; Quellec, S. [Cemagref, UR TERE, 17 Avenue de Cucille, CS 64427, F-35044 Rennes (France); Universite europeenne de Bretagne (France); Tremier, A.; Druilhe, C. [Cemagref, UR GERE, F-35044 Rennes (France); Universite europeenne de Bretagne (France); Mariette, F., E-mail: francois.mariette@cemagref.f [Cemagref, UR TERE, 17 Avenue de Cucille, CS 64427, F-35044 Rennes (France); Universite europeenne de Bretagne (France)

2010-04-15T23:59:59.000Z

108

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

109

Nuclear magnetic resonance study of Gd-based nanoparticles to tag boron compounds in boron neutron capture therapy  

SciTech Connect (OSTI)

We report the investigation of new organic complexes containing a magnetic moment (Gd-based molecular nanomagnets), which can serve the double purpose of acting as boron neutron capture therapy (BNCT) agents, and at the same time act as contrast agents to detect the molecule in the tissue by a proton magnetic resonance imaging (MRI). We also explore the possibility of monitoring the concentration of the BNCT agent directly via proton and boron NMR relaxation. The absorption of {sup 10}B-enriched molecules inside tumoral liver tissues has been shown by NMR measurements and confirmed by {alpha} spectroscopy. A new molecular Gd-tagged nanomagnet and BNCT agent (GdBPA) has been synthesized and characterized measuring its relaxivity R{sub 1} between 10 kHz and 66 MHz, and its use as a contrast agent in MRI has been demonstrated. The NMR-based evidence of the absorption of GdBPA into living tumoral cells is also shown.

Corti, M.; Bonora, M.; Borsa, F. [Dipartimento di Fisica A.Volta, Unita CNISM e Unita INSTM, Via Bassi 6, Universita di Pavia, I-27100 Pavia (Italy); Bortolussi, S.; Protti, N.; Santoro, D.; Stella, S.; Altieri, S. [Dipartimento di Fisica Nucleare e Teorica e INFN Pavia, Via Bassi 6, Universita di Pavia, I-27100 Pavia (Italy); Zonta, C.; Clerici, A. M.; Cansolino, L.; Ferrari, C.; Dionigi, P. [Dipartimento di Scienze Chirurgiche, Laboratorio di Chirurgia Sperimentale Botta2, Via Ferrata 9, Universita di Pavia, I-27100 Pavia (Italy); Porta, A.; Zanoni, G.; Vidari, G. [Dipartimento di Chimica Organica, Via Taramelli 10, Universita di Pavia, I-27100 Pavia (Italy)

2011-04-01T23:59:59.000Z

110

Nuclear Magnetic Resonance Studies of Several Experimental and Human Malignant Tumors  

Science Journals Connector (OSTI)

...J. W. Nuclear Magnetic Resonance Studies of Living Muscle. Science, 147: 738-739...Detection by Nuclear Magnetic Resonance. Science,/71:1151-1153...in Vivo by Nuclear Magnetic Resonance. Science, 178: 1288-1290...

Donald P. Hollis; James S. Economou; Leon C. Parks; Joseph C. Eggleston; Leon A. Saryan; and Jeffrey L. Czeisler

1973-09-01T23:59:59.000Z

111

Tissue Water Content and Nuclear Magnetic Resonance in Normal and Tumor Tissues  

Science Journals Connector (OSTI)

...and Smith, E. G. A Nuclear Magnetic Resonance Investigation of Molecular...Tumor Detection by Nuclear Magnetic Resonance. Science. 171: 1151 1153, 1971. 5...Hydration and Proton Nuclear Magnetic Resonance Relaxa tion Times in...

Ion-Christian Kiricuta, Jr. and Virgil Simpl?ceanu

1975-05-01T23:59:59.000Z

112

Variability in functional magnetic resonance imaging : influence of the baseline vascular state and physiological fluctuations  

E-Print Network [OSTI]

cortex by magnetic resonance imaging. Science. 254, 716-719.cortex by magnetic resonance imaging. Science. 254, 716-719.cortex by magnetic resonance imaging. Science. 254, 716-719.

Behzadi, Yashar

2006-01-01T23:59:59.000Z

113

31P Nuclear Magnetic Resonance Study of a Human Colon Adenocarcinoma Cultured Cell Line  

Science Journals Connector (OSTI)

...research-article Basic Sciences 31P Nuclear Magnetic Resonance Study of...phosphorus-31 nuclear magnetic resonance reveals lowered...shock of Tetrahymena. Science (Wash. DC), 219...N. N. 31Pnuclear magnetic resonance studies of...

Franck Desmoulin; Jean-Philippe Galons; Paul Canioni; Jacques Marvaldi; and Patrick J. Cozzone

1986-08-01T23:59:59.000Z

114

Metalloporphyrin Enhancement of Magnetic Resonance Imaging of Human Tumor Xenografts in Nude Mice  

Science Journals Connector (OSTI)

...Weizmann Institute of Science, Rehovot 76100...should be addressed. Magnetic resonance imaging...Multicellular Spheroids: Magnetic Resonance Microimaging1...Weiunann institute of Science, Rehovot 76100, Israel ABSTRACT Magnetic resonance imaging...

Philip Furmanski and Clifford Longley

1988-08-15T23:59:59.000Z

115

Assessment of Tumor Energy and Oxygenation Status by Bioluminescence, Nuclear Magnetic Resonance Spectroscopy, and Cryospectrophotometry  

Science Journals Connector (OSTI)

...Assessment of Tumor Energy and Oxygenation Status...Bioluminescence, Nuclear Magnetic Resonance...Assessment of tumor energy and oxygenation status...bioluminescence, nuclear magnetic resonance...Assessment of Tumor Energy and Oxyg nationStatus by Bioluminescence, Nuclear Magnetic Resonance...

W. Mueller-Klieser; C. Schaefer; S. Walenta; E. K. Rofstad; B. M. Fenton; and R. M. Sutherland

1990-03-15T23:59:59.000Z

116

Use of PFG-NMR for Mixture Analysis: Measurement of Diffusion Coefficients of Cis and Trans Isomers of Proline-Containing Peptides  

Science Journals Connector (OSTI)

The analysis of complex mixtures is a prominent area of research that spans many disciplines of science. Recently, diffusion-based nuclear magnetic resonance (NMR) has found wide...

Derrick, Tiffany S; Larive, Cynthia K

1999-01-01T23:59:59.000Z

117

Controlling interactions between highly-magnetic atoms with Feshbach resonances  

E-Print Network [OSTI]

This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic $^7$S$_3$ chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on Dysprosium and Erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

Svetlana Kotochigova

2014-10-14T23:59:59.000Z

118

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

SciTech Connect (OSTI)

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

119

Coherent dynamical recoupling of diffusion-driven decoherence in magnetic resonance  

E-Print Network [OSTI]

During recent years, dynamical decoupling (DD) has gained relevance as a tool for manipulating quantum systems and extracting information from them. This is particularly relevant for spins involved in nuclear magnetic resonance (NMR), where DD sequences can be used to prolong quantum coherences, or for selectively couple/decouple the effects imposed by random environmental fluctuations. In this Letter, we show that one can exploit these concepts in order to selectively recouple diffusion processes in restricted spaces. The ensuing method provides a novel tool to measure restriction lengths in confined systems such as capillaries, pores or cells. The principles of this method for selectively recoupling diffusion-driven decoherence, its standing within the context of diffusion NMR, and corroborating experiments, are presented.

Gonzalo A. Alvarez; Noam Shemesh; Lucio Frydman

2014-09-07T23:59:59.000Z

120

Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance  

E-Print Network [OSTI]

Directly Mapping Magnetic Field Effects of Neuronal Activity by Magnetic Resonance Imaging Jinhu Xiong,* Peter T. Fox, and Jia-Hong Gao Research Imaging Center, University of Texas Health Science Center at San Antonio, San Antonio, Texas Abstract: Magnetic resonance imaging (MRI) of brain functional

Gabrieli, John

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

E-Print Network 3.0 - alternative magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

field provides a tool for tuning the dielectric resonance... resonator a magnetic field tunable dielectric resonances at frequencies much higher than usual ferromagnetic... , on...

122

MagLab - Solution Nuclear Magnetic Resonance  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

organisms. This probe, which now operates at UFs AMRIS NMR facility, is based on high temperature superconductor (HTS) technology. It is the first HTS probe to use a 1-mm...

123

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

124

Characteristics of the nuclear magnetic resonance logging response in fracture oil and gas reservoirs  

Science Journals Connector (OSTI)

Fracture oil and gas reservoirs exist in large numbers. The accurate logging evaluation of fracture reservoirs has puzzled petroleum geologists for a long time. Nuclear magnetic resonance (NMR) logging is an effective new technology for borehole measurement and formation evaluation. It has been widely applied in non-fracture reservoirs, and good results have been obtained. But its application in fracture reservoirs has rarely been reported in the literature. This paper studies systematically the impact of fracture parameters (width, number, angle, etc), the instrument parameter (antenna length) and the borehole condition (type of drilling fluid) on NMR logging by establishing the equation of the NMR logging response in fracture reservoirs. First, the relationship between the transverse relaxation time of fluid-saturated fracture and fracture aperture inthe condition of different transverse surface relaxation rates was analyzed; then, the impact of the fracture aperture, dip angle, length of two kinds of antennas and mud type was calculated through forward modeling and inversion. The results show that the existence of fractures affects the NMR logging; the characteristics of the NMR logging response become more obvious with increasing fracture aperture and number of fractures. It is also found that T2 distribution from the fracture reservoir will be affected by echo spacing, type of drilling fluids and length of antennas. A long echo spacing is more sensitive to the type of drilling fluid. A short antenna is more effective for identifying fractures. In addition, the impact of fracture dip angle on NMR logging is affected by the antenna length.

Lizhi Xiao; Kui Li

2011-01-01T23:59:59.000Z

125

Purcell factor of Mie resonators featuring electric and magnetic modes  

E-Print Network [OSTI]

We present a modal approach to compute the Purcell factor in Mie resonators exhibiting both electric and magnetic resonances. The analytic expressions of the normal modes are used to calculate the effective volumes. We show that important features of the effective volume can be predicted thanks to the translation-addition coefficients of a displaced dipole. Using our formalism, it is easy to see that, in general, the Purcell factor of Mie resonators is not dominated by a single mode, but rather by a large superposition. Finally we consider a silicon resonator homogeneously doped with electric dipolar emitters, and we show that the average electric Purcell factor dominates over the magnetic one.

Zambrana-Puyalto, Xavier

2015-01-01T23:59:59.000Z

126

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

127

National High Magnetic Field Laboratory - Science Starts Here...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

work "I do biomedical research, which utilizes my education and experience of Nuclear Magnetic Resonance (NMR). In particular, we design methods to increase the signal that we...

128

MagLab - Pioneers in Electricity and Magnetism: Paul Lauterbur  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Paul Lauterbur (1929-2007) Paul Lauterbur Chemist Paul Lauterbur pioneered the use of nuclear magnetic resonance (NMR) for medical imaging. Lauterbur developed a technique, now...

129

Detection of magnetic resonance signals using a magnetoresistive sensor  

DOE Patents [OSTI]

A method and apparatus are described wherein a micro sample of a fluidic material may be assayed without sample contamination using NMR techniques, in combination with magnetoresistive sensors. The fluidic material to be assayed is first subject to pre-polarization, in one embodiment, by passage through a magnetic field. The magnetization of the fluidic material is then subject to an encoding process, in one embodiment an rf-induced inversion by passage through an adiabatic fast-passage module. Thereafter, the changes in magnetization are detected by a pair of solid-state magnetoresistive sensors arranged in gradiometer mode. Miniaturization is afforded by the close spacing of the various modules.

Budker, Dmitry; Pines, Alexander; Xu, Shoujun; Hilty, Christian; Ledbetter, Micah P; Bouchard, Louis S

2013-10-01T23:59:59.000Z

130

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...

Koo, Chiwan

2013-08-09T23:59:59.000Z

131

Magnetism studies using resonant, coherent, x-ray scattering...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Magnetism studies using resonant, coherent, x-ray scattering Monday, September 10, 2012 - 10:00am SLAC, Bldg. 137, Room 226 Keoki Seu Seminar: With the advent of free electron...

132

Designing and characterizing hyperpolarizable silicon nanoparticles for magnetic resonance imaging  

E-Print Network [OSTI]

Magnetic Resonance Imaging (MRI) is one of the most powerful noninvasive tools for diagnosing human disease, but its utility is limited because current contrast agents are ineffective when imaging air-tissue interfaces, ...

Anahtar, Melis Nuray

2008-01-01T23:59:59.000Z

133

Nuclear magnetic resonance study of methane adsorbed on porous silicon  

E-Print Network [OSTI]

NUCLEAR MAGNETIC RESONANCE STUDY OF METHANE ADSORBED ON POROUS SILICON A Thesis by FENG I I Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 1992 Major Subject: Physics NUCLEAR MAGNETIC RESONANCE STUDY OF METHANE ADSORBED ON POROUS SILICON A Thesis by FENG LI Approved as to style and content by: . P. Kirk (Chair of Committee) i G. Agnolet (Member) J. H. Ross, r (Member) M...

Li, Feng

2012-06-07T23:59:59.000Z

134

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

E-Print Network [OSTI]

during magnetic resonance imaging (MRI) is the distortion of the ECG due to electromagnetic interference

135

Recent developments in nuclear magnetic resonance spectroscopy  

Science Journals Connector (OSTI)

...from these spec-tra are valuable in determining complex anisotropic or correlated molecular mo-tions. NMR imaging. We use...solid samples have been applied to studies of coal and oil shales. Rapid characterization can be achieved from 13C spectra...

GC Levy; DJ Craik

1981-10-16T23:59:59.000Z

136

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

137

Ferromagnetic resonance in $\\epsilon$-Co magnetic composites  

E-Print Network [OSTI]

We investigate the electromagnetic properties of assemblies of nanoscale $\\epsilon$-cobalt crystals with size range between 5 nm to 35 nm, embedded in a polystyrene (PS) matrix, at microwave (1-12 GHz) frequencies. We investigate the samples by transmission electron microscopy (TEM) imaging, demonstrating that the particles aggregate and form chains and clusters. By using a broadband coaxial-line method, we extract the magnetic permeability in the frequency range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance with respect to an externally applied magnetic field. We find that the zero-magnetic field ferromagnetic resonant peak shifts towards higher frequencies at finite magnetic fields, and the magnitude of complex permeability is reduced. At fields larger than 2.5 kOe the resonant frequency changes linearly with the applied magnetic field, demonstrating the transition to a state in which the nanoparticles become dynamically decoupled. In this regime, the particles inside clusters can ...

Chalapat, Khattiya; Huuppola, Maija; Koponen, Lari; Johans, Christoffer; Ras, Robin H A; Ikkala, Olli; Oksanen, Markku A; Seppl, Eira; Paraoanu, G S

2014-01-01T23:59:59.000Z

138

Nuclear Magnetic Resonance Investigations of Human Neoplastic and Abnormal Nonneoplastic Tissues  

Science Journals Connector (OSTI)

...Tumor Detection by Nuclear Magnetic Resonance. Science. ///: 1151 1153, 1971...Potassium (39K) Nuclear Magnetic Reso nance: Spin Signatures...Cancer in Vivo by Nuclear Magnetic- Resonance. Science. 178: 1288 1290. 1972...

Joseph C. Eggleston; Leon A. Saryan; and Donald P. Hollis

1975-05-01T23:59:59.000Z

139

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)

2007-12-11T23:59:59.000Z

140

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)

2010-06-29T23:59:59.000Z

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

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

142

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)

2009-10-27T23:59:59.000Z

143

Proton NMR characterization of gasolineethanol blends  

Science Journals Connector (OSTI)

Abstract Nuclear magnetic resonance (NMR) can be conveniently used for accurate measurement of water and ethanol concentrations in gasolineethanol fuel blends. The spectra also contain information on proton exchange rates. In addition, NMR pulsed-field-gradient diffusion measurement allows estimation of ethanolwater clusters and viscosity of the fuel blends.

A. Turanov; A.K. Khitrin

2014-01-01T23:59:59.000Z

144

NMRb: a web-site repository for raw NMR datasets  

Science Journals Connector (OSTI)

......confronted with the lack of raw datasets during the validation step...offers a database of NMR raw datasets, ordered by spectral characteristics...of structural genomics, the nuclear magnetic resonance (NMR...the lack of freely available datasets during the validation step......

J. L. Pons; T. E. Malliavin; D. Tramesel; M. A. Delsuc

2004-12-01T23:59:59.000Z

145

Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway  

SciTech Connect (OSTI)

The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. {sup 13}C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of ({sup 13}C-4) to ({sup 13}C-5)-glutamate, ({sup 13}C-3) to ({sup 13}C-2)-alanine or ({sup 13}C-3) to ({sup 13}C-2)-lactate produced when ({sup 13}C-2)-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the {sup 13}C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in {sup 13}C NMR human studies from the current literature.

Bolo, N.R.

1991-11-01T23:59:59.000Z

146

Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway  

SciTech Connect (OSTI)

The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. {sup 13}C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of [{sup 13}C-4] to [{sup 13}C-5]-glutamate, [{sup 13}C-3] to [{sup 13}C-2]-alanine or [{sup 13}C-3] to [{sup 13}C-2]-lactate produced when [{sup 13}C-2]-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the {sup 13}C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in {sup 13}C NMR human studies from the current literature.

Bolo, N.R.

1991-11-01T23:59:59.000Z

147

Optical pumping magnetic resonance in high magnetic fields: Characterization of nuclear relaxation during pumping  

E-Print Network [OSTI]

Optical pumping magnetic resonance in high magnetic fields: Characterization of nuclear relaxation during pumping Matthew P. Augustine and Kurt W. Zilm Department of Chemistry, Yale University, New Haven exchange with optically pumped Rb vapor is investigated in high magnetic field. Operation in a high field

Augustine, Mathew P.

148

On the dynamics of magnetic fluids in magnetic resonance imaging  

E-Print Network [OSTI]

The hydrodynamics of magnetic fluids, often termed ferrofluids, has been an active area of research since the mid 1960s. However, it is only in the past twenty years that these fluids have begun to be used in magnetic ...

Cantillon-Murphy, Pdraig J

2008-01-01T23:59:59.000Z

149

Nuclear Magnetic Resonance Studies of Some Materials Containing Divalent Europium  

Science Journals Connector (OSTI)

This paper reports the results of a low-temperature NMR experiment on Eu153 in EuO. The data, which are assumed to be linear with magnetization, are compared with calculated values using spin-wave theory. Values of J1kb=0.7500.0025K and J2kb=-0.09750.004K are found to give a good description of EuO. This paper also reports the results of NMR studies of the ligands F19 and Cs137 in EuF2 and CsEuF3. These experiments indicate that there is a reversal in sign of the unpaired spin density of the europium ion. The same results are obtained with europium-bearing glasses. This effect is discussed in terms of the Freeman-Watson model of Gd3+ and in terms of a virtual 5d state in Eu2+.

E. L. Boyd

1966-05-06T23:59:59.000Z

150

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

E-Print Network [OSTI]

McGeer. Science, Positron tomography and nuclear magneticmagnetic resonance technology for medical studies. Science,magnetic resonance images of the human arm. M easur'ement Science (

Wong-Foy, Annjoe G.

2010-01-01T23:59:59.000Z

151

E-Print Network 3.0 - abdominal magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

between men and women at rest and during lower Summary: resonance-compatible exercise bicycle, magnetic resonance imaging techniques, and custom data processing... at all. We have...

152

Optical pumping and xenon NMR  

SciTech Connect (OSTI)

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping [sup 129]Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the [sup 131]Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

Raftery, M.D.

1991-11-01T23:59:59.000Z

153

Optical pumping and xenon NMR  

SciTech Connect (OSTI)

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping {sup 129}Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the {sup 131}Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

Raftery, M.D.

1991-11-01T23:59:59.000Z

154

Nuclear magnetic resonances in weak fields  

E-Print Network [OSTI]

first choax@ation of nuclear resonances in weak f le). de was sade by k 0, S~ in fiel4u of 6 and lg gauss using a sanple siue of. 1 liter, The nagnetic fields were produced in a solenoi4 pou?x?d by a bazdz of lead storage batteriesx an4 the resonances..., Tbe poser was pxovided for the static nagnetic field by a bank of 20 lead storage cells connected in ssriesi The current was a+usted to the desired value with a variable xesistanoe which was connected in sex'ies with the solenoid. Qm source of field...

Mitchell, Richard Warren

2012-06-07T23:59:59.000Z

155

A nuclear magnetic resonance probe of group IV clathrates  

E-Print Network [OSTI]

A NUCLEAR MAGNETIC RESONANCE PROBE OF GROUP IV CLATHRATES A Dissertation by WEIPING GOU Submitted to the Oce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements for the degree of DOCTOR OF PHILOSOPHY August 2008... Major Subject: Physics A NUCLEAR MAGNETIC RESONANCE PROBE OF GROUP IV CLATHRATES A Dissertation by WEIPING GOU Submitted to the Oce of Graduate Studies of Texas A&M University in partial fulflllment of the requirements for the degree of DOCTOR...

Gou, Weiping

2008-10-10T23:59:59.000Z

156

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

157

On transition from Alfvn resonance to forced magnetic reconnection  

SciTech Connect (OSTI)

We revisit the transition from Alfvn resonance to forced magnetic reconnection with a focus on the property of their singularities. As the driven frequency tends to zero, the logarithmic singularity of Alfvn resonance shifts to the power-law singularity of forced reconnection, due to merging of the two resonance layers. The transition criterion depends on either kinetic effects or dissipations that resolve the singularity. As an example, a small but finite resistivity ? is introduced to investigate the transition process. The transition threshold is then obtained as the driven frequency reaches a level of ?O((?/k){sup 1/3})

Luan, Q. [MOE Key Lab of Materials Modification by Beams and School of Physics and Optoelectrical Technology, Dalian University of Technology, Dalian 116024 (China); Wang, X., E-mail: xgwang@hit.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China)

2014-07-15T23:59:59.000Z

158

Development of techniques in magnetic resonance and structural studies of the prion protein  

SciTech Connect (OSTI)

Magnetic resonance is the most powerful analytical tool used by chemists today. Its applications range from determining structures of large biomolecules to imaging of human brains. Nevertheless, magnetic resonance remains a relatively young field, in which many techniques are currently being developed that have broad applications. In this dissertation, two new techniques are presented, one that enables the determination of torsion angles in solid-state peptides and proteins, and another that involves imaging of heterogenous materials at ultra-low magnetic fields. In addition, structural studies of the prion protein via solid-state NMR are described. More specifically, work is presented in which the dependence of chemical shifts on local molecular structure is used to predict chemical shift tensors in solid-state peptides with theoretical ab initio surfaces. These predictions are then used to determine the backbone dihedral angles in peptides. This method utilizes the theoretical chemicalshift tensors and experimentally determined chemical-shift anisotropies (CSAs) to predict the backbone and side chain torsion angles in alanine, leucine, and valine residues. Additionally, structural studies of prion protein fragments are described in which conformationally-dependent chemical-shift measurements were made to gain insight into the structural differences between the various conformational states of the prion protein. These studies are of biological and pathological interest since conformational changes in the prion protein are believed to cause prion diseases. Finally, an ultra-low field magnetic resonance imaging technique is described that enables imaging and characterization of heterogeneous and porous media. The notion of imaging gases at ultra-low fields would appear to be very difficult due to the prohibitively low polarization and spin densities as well as the low sensitivities of conventional Faraday coil detectors. However, Chapter 5 describes how gas imaging at ultra-low fields is realized by incorporating the high sensitivities of a dc superconducting quantum interference device (SQUID) with the high polarizations attainable through optica11y pumping {sup 129}Xe gas.

Bitter, Hans-Marcus L.

2000-07-01T23:59:59.000Z

159

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

160

On the validation of magnetic resonance velocimetry in single-phase turbulent pipe flows  

SciTech Connect (OSTI)

A nuclear magnetic resonance imaging technique is used to measure velocity distributions in turbulent pipe flows up to Re = 24580. While turbulent intensity is usually determined from signal attenuation, we deduce turbulent intensity from velocity distribution with no need to suppose a Gaussian distribution for velocity fluctuations. Skewness and flatness measurements are also presented in this paper. Comparison with DNS show good agreement and we show that NMR data is sufficiently accurate to provide turbulent viscosity profile. The low field system used in this study allow the suppression of susceptibility artifacts and thus open its use for studying two-phase flows. We postulate that the method used here could be applied to two-phase flows and would thus provide valuable information on turbulent viscosity models. (authors)

Jullien, P.; Lemonnier, H. [CEA Grenoble, DTN LITA SE2T, F-38054 Grenoble 9, (France)

2012-03-15T23:59:59.000Z

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.


161

Distribution of Liposomes into Brain and Rat Brain Tumor Models by Convection-Enhanced Delivery Monitored with Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

...Convection-Enhanced Delivery Monitored with Magnetic Resonance Imaging Ryuta Saito...B, T 1-weighted coronal magnetic resonance image of a 9L-2 rat...assistance, Dr. David Newitt (Magnetic Resonance Science Center, University of California...

Ryuta Saito; John R. Bringas; Tracy R. McKnight; Michael F. Wendland; Christoph Mamot; Daryl C. Drummond; Dmitri B. Kirpotin; John W. Park; Mitchel S. Berger; and Krys S. Bankiewicz

2004-04-01T23:59:59.000Z

162

Selective Depletion of Tumor ATP by 2-Deoxyglucose and Insulin, Detected by 31P Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...and Insulin, Detected by 31P Magnetic Resonance Spectroscopy 1 1...Anne Speder Michael W. Weiner Magnetic Resonance Unit [G. S. K...cerebraldeoxyglucosemetabolismby 3'P nuclear magnetic resonance spectroscopy.Science (Washington DC), 228:1329...

Gregory S. Karczmar; Jeffrey M. Arbeit; B. James Toy; Anne Speder; and Michael W. Weiner

1992-01-01T23:59:59.000Z

163

Spin Magnetic Resonance in Perspectives of Spin Science and Spin Technology Development  

Science Journals Connector (OSTI)

The methods of magnetic resonance are widely used in many fields ... the pages of a specialized journal Applied Magnetic Resonance. This is even more important ... of MR methods in somewhat unusual fields of science

Kev M. Salikhov

2014-09-01T23:59:59.000Z

164

Instrumentation for parallel magnetic resonance imaging  

E-Print Network [OSTI]

of the art of parallel MR imaging. First, a low-cost desktop MR scanner was developed (< $13,000) for imaging small samples (2.54 cm fields-of view) at low magnetic field strengths (< 0.25 T). The performance of the prototype was verified through bench...

Brown, David Gerald

2007-04-25T23:59:59.000Z

165

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

166

Single-pulse excitation carbon-13 NMR measurements on the Argonne premium coal samples  

Science Journals Connector (OSTI)

Single-pulse excitation carbon-13 NMR measurements on the Argonne premium coal samples ... Interactions of Organic Liquids with Coals:? Analysis by Solid-State 13C Nuclear Magnetic Resonance ...

J. A. Franz; R. Garcia; J. C. Linehan; G. D. Love; C. E. Snape

1992-09-01T23:59:59.000Z

167

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...

Bowen, Sean Michael

2012-02-14T23:59:59.000Z

168

Towards the invisible cryogenic system for Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

With about 10 000 Magnetic Resonance Imaging (MRI) systems installed worldwide helium cooled magnets have become familiar equipment in hospitals and imaging centers. Patients and operators are only aware of the hissing sound of the Gifford-MacMahon refrigerator. Service technicians however still work with cryogenic fluids and cold gases e.g. for replenishing the helium reservoir inserting retractable current leads for magnet ramps or replacing burst disks after a magnet quench. We will describe the steps taken at Oxford Magnet Technology towards the ultimate goal of a superconducting magnet being as simple as a household fridge. Early steps included the development of resealing quench valves as well as permanently installed transfer siphons that only open when fully cooled to 4K. On recently launched 1.5 Tesla solenoid magnets 500 A current leads are permanently fixed into the service turret with hardly any boil-off penalty (4050 cc/hr total). Ramping of the magnet has been fully automated including electronic supervision of the gas-cooled current leads. One step ahead the 1 Tesla High Field Open magnet is refrigerated by a single 4K Gifford MacMahon coldhead relieving the user from the necessity to refill with helium. Our conduction cooled 0.2 Tesla HTS magnet testbed does not require liquid cryogens at any time in its life including initial cool-down.

F. Steinmeyer; P. W. Retz; K. White; A. Lang; W. Stautner; P. N. Smith; G. Gilgrass

2002-01-01T23:59:59.000Z

169

On the Dynamics of Magnetic Fluids in Magnetic Resonance Padraig J. Cantillon-Murphy  

E-Print Network [OSTI]

On the Dynamics of Magnetic Fluids in Magnetic Resonance Imaging by Padraig J. Cantillon-Murphy Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of Electric'algngineering and Computer Science May 22nd, 2008. Certified

170

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

SciTech Connect (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

171

Optically Detected Magnetic Resonance Studies on ?-conjugated semiconductor systems  

SciTech Connect (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

172

Resource Letter NMR-EPR-1 on Nuclear Magnetic Resonance and Electron Paramagnetic Resonance  

Science Journals Connector (OSTI)

Prepared at the request of the AAPT Committee on Resource Letters; supported by a grant from the National Science Foundation.

R. E. Norberg

1965-01-01T23:59:59.000Z

173

Diamond based single molecule magnetic resonance spectroscopy  

E-Print Network [OSTI]

The detection of a nuclear spin in an individual molecule represents a key challenge in physics and biology whose solution has been pursued for many years. The small magnetic moment of a single nucleus and the unavoidable environmental noise present the key obstacles for its realization. Here, we demonstrate theoretically that a single nitrogen-vacancy (NV) center in diamond can be used to construct a nano-scale single molecule spectrometer that is capable of detecting the position and spin state of a single nucleus and can determine the distance and alignment of a nuclear or electron spin pair. The proposed device will find applications in single molecule spectroscopy in chemistry and biology, such as in determining protein structure or monitoring macromolecular motions and can thus provide a tool to help unravelling the microscopic mechanisms underlying bio-molecular function.

Jianming Cai; Fedor Jelezko; Martin B. Plenio; Alex Retzker

2011-12-23T23:59:59.000Z

174

Precise wavefunction engineering with magnetic resonance  

E-Print Network [OSTI]

Controlling quantum fluids at their fundamental length scale will yield superlative quantum simulators, precision sensors, and spintronic devices. This scale is typically below the optical diffraction limit, precluding precise wavefunction engineering using optical potentials alone. We present a protocol to rapidly control the phase and density of a quantum fluid down to the healing length scale using strong time-dependent coupling between internal states of the fluid in a magnetic field gradient. We demonstrate this protocol by simulating the creation of a single stationary soliton and double soliton states in a Bose-Einstein condensate with control over the individual soliton positions and trajectories, using experimentally feasible parameters. Such states are yet to be realized experimentally, and are a path towards engineering soliton gases and exotic topological excitations.

L. M. Bennie; P. B. Wigley; S. S. Szigeti; M. Jasperse; J. J. Hope; L. D. Turner; R. P. Anderson

2014-12-22T23:59:59.000Z

175

X-ray resonant magnetic scattering from structurally and magnetically rough interfaces in multilayered systems. I. Specular reflectivity  

E-Print Network [OSTI]

X-ray resonant magnetic scattering from structurally and magnetically rough interfaces formulation of x-ray resonant magnetic scattering from rough surfaces and interfaces is given for specular/Fe multilayer. DOI: 10.1103/PhysRevB.68.224409 PACS number s : 75.70.Cn, 61.10.Kw I. INTRODUCTION X-ray

Haskel, Daniel

176

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

177

Effect of energy and momentum conservation on fluid resonances for resonant magnetic perturbations in a tokamak  

SciTech Connect (OSTI)

In this paper, the impact of momentum and energy conservation of the collision operator in the kinetic description for Resonant Magnetic Perturbations (RMPs) in a tokamak is studied. The particle conserving differential collision operator of Ornstein-Uhlenbeck type is supplemented with integral parts such that energy and momentum are conserved. The application to RMP penetration in a tokamak shows that energy conservation in the electron collision operator is important for the quantitative description of plasma shielding effects at the resonant surface. On the other hand, momentum conservation in the ion collision operator does not significantly change the results.

Leitner, Peter; Heyn, Martin F.; Kernbichler, Winfried [Fusion@AW, Institut fr Theoretische PhysikComputational Physics, TU Graz, Petersgasse 16, A-8010 Graz (Austria); Ivanov, Ivan B. [Fusion@AW, Institut fr Theoretische PhysikComputational Physics, TU Graz, Petersgasse 16, A-8010 Graz (Austria); St. Petersburg State University, Institute of Physics, Ulyanovskaya 1, Petrodvoretz 198504 (Russian Federation); Petersburg Nuclear Physics Institute, 188300 Gatchina, Leningrad Oblast (Russian Federation); Kasilov, Sergei V. [Fusion@AW, Institut fr Theoretische PhysikComputational Physics, TU Graz, Petersgasse 16, A-8010 Graz (Austria); Institute of Plasma Physics, National Science Center Kharkov Institute of Physics and Technology, Ul. Akademicheskaya 1, 61108 Kharkov (Ukraine)

2014-06-15T23:59:59.000Z

178

Nuclear Magnetic Resonance in Semiconductors. II. Quadrupole Broadening of Nuclear Magnetic Resonance Lines by Elastic Axial Deformation  

Science Journals Connector (OSTI)

Nuclear electric-quadrupole moments interact with electric-field gradients at the nucleus. In a perfect cubic crystal, the average gradients vanish and there are no quadrupolar interactions. Nuclear magnetic resonance studies of the semiconductors InSb and GaSb have revealed no quadrupolar interactions in our samples, indicating a high degree of crystalline perfection. By applying stresses to these crystals, we have been able to destroy the crystalline symmetry reversibly, thereby producing quadrupole broadening of the nuclear magnetic resonance lines. Strains of less than 10-4 have been detected and the resulting field gradients measured. The "gradient-elastic" proportionality constants connecting stress and field gradient are discussed in relation to crystal symmetry and have been deduced from the measurements.

R. G. Shulman; B. J. Wyluda; P. W. Anderson

1957-08-15T23:59:59.000Z

179

Model of a magnetic field in poloidal divertor tokamaks affected by resonant magnetic perturbations  

SciTech Connect (OSTI)

A generic analytical model for the description of magnetic field lines in poloidal divertor tokamaks in the presence of external resonant magnetic perturbations is proposed. It is based on the Hamiltonian description of magnetic field lines in tokamaks. The safety factor and the spectra of magnetic perturbations are chosen by the requirement to satisfy their generic behavior near the magnetic separatrix and at the magnetic axis. The field line equations of the model are integrated using symplectic efficient mappings of field lines. The analytical formulas for the quasilinear diffusion and convection coefficients of field lines are obtained. The latter describes the outwardly directed transport of field lines at the plasma edge. It was shown that they are in a good agreement with the corresponding numerically calculated coefficients.

Abdullaev, S. S. [Forschungszentrum Juelich GmbH, Institute of Energy Research IEF-4: Plasma Physics, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, 52425 Juelich (Germany)

2009-03-15T23:59:59.000Z

180

Hydration kinetics of cements by Time-Domain Nuclear Magnetic Resonance: Application to Portland-cement-derived endodontic pastes  

SciTech Connect (OSTI)

Time-Domain Nuclear Magnetic Resonance (TD-NMR) of {sup 1}H nuclei is used to monitor the maturation up to 30 days of three different endodontic cement pastes. The 'Solid-liquid' separation of the NMR signals and quasi-continuous distributions of relaxation times allow one to follow the formation of chemical compounds and the build-up of the nano- and subnano-structured C-S-H gel. {sup 1}H populations, distinguished by their different mobilities, can be identified and assigned to water confined within the pores of the C-S-H gel, to crystallization water and Portlandite, and to hydroxyl groups. Changes of the TD-NMR parameters during hydration are in agreement with the expected effects of the different additives, which, as it is known, can substantially modify the rate of reactions and the properties of cementitious pastes. Endodontic cements are suitable systems to check the ability of this non-destructive technique to give insight into the complex hydration process of real cement pastes.

Bortolotti, Villiam, E-mail: villiam.bortolotti@unibo.it [Department DICAM, University of Bologna, Via Terracini 28, 40131, Bologna (Italy); Fantazzini, Paola [Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127, Bologna (Italy); Mongiorgi, Romano [Centre of Biomineralogy, Crystallography and Biomaterials, Department of Earth and Geoenvironmental Sciences, University of Bologna, Piazza di Porta S. Donato, 40127, Bologna (Italy); Sauro, Salvatore [Department of Dental Biomaterials Science Kings College, London Dental Institute at Guy's, King's College and St Thomas' Hospitals, Floor 17 Guy's Tower, Guys Hospital, London Bridge, London SE1 9RT (United Kingdom); Dental Materials, School of Dentistry, University of Granada, Colegio Maximo, Campus de Cartuja, Granada (Spain); Zanna, Silvano [Centre of Biomineralogy, Crystallography and Biomaterials, Department of Earth and Geoenvironmental Sciences, University of Bologna, Piazza di Porta S. Donato, 40127, Bologna (Italy)

2012-03-15T23:59:59.000Z

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.


181

Magnetic Resonance Imaging in Follow-up Assessment of Sciatica  

Science Journals Connector (OSTI)

...treatment leads to physical and emotional suffering for the patient and substantial costs in terms of treatment, sick leave, and pensions for society. Magnetic resonance imaging (MRI), which is considered the imaging procedure of choice for patients in whom lumbar-disk herniation is suspected,, is frequently... In patients with symptomatic lumbar disk herniation treated with surgery or conservative care, there was no significant association between findings on MRI and clinical outcome at 1 year. Disk herniation persisted in 35% with a favorable outcome and 33% with an unfavorable outcome.

el Barzouhi A.; Vleggeert-Lankamp C.L.A.M.; Lycklama Nijeholt G.J.

2013-03-14T23:59:59.000Z

182

Resonance Effects in Magnetically Driven Mass?Spring Oscillations  

Science Journals Connector (OSTI)

Resonanceeffects are among the most intriguing phenomena in physics and engineering. The classical case of a mass?spring oscillator driven at its resonant frequency is one of the earliest examples that students encounter. Perhaps the most commonly depicted method of driving the vibrating system is mechanical. An alternative approach presented in this paper describes an electromagnetic driver that is convenient to use and that provides a frequency resolution of 0.001 Hz. A common mass?spring arrangement suspended vertically with a linear array of permanent magnets located at the bottom of the system is used for illustrating the technique.1

Ken Taylor

2011-01-01T23:59:59.000Z

183

E-Print Network 3.0 - ankle magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Search Powered by Explorit Topic List Advanced Search Sample search results for: ankle magnetic resonance Page: << < 1 2 3 4 5 > >> 1 Evaluation of Methods That Locate the...

184

Second Harmonic Generation by Metamagnetics: Interplay of Electric and Magnetic Resonances  

Science Journals Connector (OSTI)

We present the first experimental study of the interplay of electric and magnetic resonances in a metamaterial to measure their independent contributions to second-harmonic generation....

Chandrasekar, Rohith; Emani, Naresh; Lagutchev, Alexei; Shalaev, Vladimir M; Kildishev, Alexander; Ciraci, Cristian; Smith, David R

185

A study of phase transitions in sodium stearate by means of nuclear magnetic resonance.  

E-Print Network [OSTI]

??The mesomorphic phase transitions of sodium stearate occurring between 23C. and 200C. were investigated by means of the nuclear magnetic resonance of the hydrogen nuclei (more)

Grant, Rowland Frederick

2012-01-01T23:59:59.000Z

186

E-Print Network 3.0 - arch magnetic resonance Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The resonator having central frequency f0 5 GHz... are the development of magnetically tunable YIG band-pass ... Source: Srinivasan, Gopalan - Department of Physics, Oakland...

187

E-Print Network 3.0 - alzheimer-type magnetic resonance Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The resonator having central frequency f0 5 GHz... are the development of magnetically tunable YIG band-pass ... Source: Srinivasan, Gopalan - Department of Physics, Oakland...

188

E-Print Network 3.0 - acid-dcys-ser-lys-cys magnetic resonance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The resonator having central frequency f0 5 GHz... are the development of magnetically tunable YIG band-pass ... Source: Srinivasan, Gopalan - Department of Physics, Oakland...

189

E-Print Network 3.0 - authentic magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The resonator having central frequency f0 5 GHz... are the development of magnetically tunable YIG band-pass ... Source: Srinivasan, Gopalan - Department of Physics, Oakland...

190

E-Print Network 3.0 - activatable magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

The resonator having central frequency f0 5 GHz... are the development of magnetically tunable YIG band-pass ... Source: Srinivasan, Gopalan - Department of Physics, Oakland...

191

Ray trajectories near the electron cyclotron resonance surface in an axisymmetric magnetic trap  

SciTech Connect (OSTI)

Characteristic features of the propagation of electromagnetic electron cyclotron waves in the vicinity of the electron cyclotron resonance surface are investigated both analytically and numerically with allowance for variation in the magnetic field strength and a corresponding variation in the magnetic field direction. It is demonstrated that variation in the magnetic field direction can qualitatively change the wave propagation pattern and can markedly affect the efficiency of electron cyclotron resonance plasma heating in an axisymmetric magnetic trap.

Gospodchikov, E. D.; Smolyakova, O. B. [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

2011-09-15T23:59:59.000Z

192

EMSL Research and Capability Development Proposals Development of Live and LC-NMR Microbial Metabolomics Methods for Systems Biology Studies  

E-Print Network [OSTI]

-of-the-art in vitro metabolomics nuclear magnetic resonance (NMR) with advanced in vivo NMR bioreactor capabilities in an attempt to use the total reactor weight to control the fluid levels. Two cyclone vessels were constructed. "Technologies for Tomorrow: Expanded Capabilities at the EMSL User Facility Supporting

193

Algorithmic Cooling in Liquid State NMR  

E-Print Network [OSTI]

Algorithmic cooling is a method that employs thermalization to increase the qubits' purification level, namely it reduces the qubit-system's entropy. We utilized gradient ascent pulse engineering (GRAPE), an optimal control algorithm, to implement algorithmic cooling in liquid state nuclear magnetic resonance. Various cooling algorithms were applied onto the three qubits of 13C2-trichloroethylene, cooling the system beyond Shannon's entropy bound in several different ways. For example, in one experiment a carbon qubit was cooled by a factor of 4.61. This work is a step towards potentially integrating tools of NMR quantum computing into in vivo magnetic resonance spectroscopy.

Yosi Atia; Yuval Elias; Tal Mor; Yossi Weinstein

2014-11-17T23:59:59.000Z

194

Three-dimensional nuclear magnetic resonance imaging of green-state ceramics  

SciTech Connect (OSTI)

Objective is the development of nuclear magnetic resonance imaging techniques and technology applicable to the nondestructive characterization of green-state ceramics. To this end, a three-dimensional (3-D) NMR imaging technique has been developed, based on a back-projection acquisition protocol in combination with image reconstruction techniques that are based on 3-D Radon transform inversion. The method incorporates the experimental flexibility to overcome many of the difficulties associated with imaging of solid and semisolid broad-line materials, and also provides contiguously sampled data in three dimensions. This technique has been evaluated as a nondestructive characterizauon method for determining the spatial distribution of organic additves in green-state injection-molded cylindrical Si{sub 3}N{sup 4} tensile specimens. The technique has been evaluated on the basis of providing moderate image resolution over large sample volumes, high resolution over smaller specimen volumes, and sensitivity to variations in the concentration of organics. Resolution of 200{mu}m has been obtained with excellent sensitivity to concentration. A detailed account of the 3-D imaging results obtained from the study, a discussion of the difficulties and limitations of the imaging technique, and suggestions for technique and system improvements are included.

Dieckman, S.L.; Gopalsami, N.; Ford, J.M.; Raptis, A.C.; Ellingson, W.A. (Argonne National Lab., IL (United States)); Rizo, P. (CEA Centre d'Etudes Nucleaires de Grenoble, 38 (France). Lab. d'Electronique et de Technologie de l'Informatique); Tracey, D.M.; Pujari, V.K. (Norton Co., Northboro, MA (United States))

1991-09-01T23:59:59.000Z

195

Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.  

SciTech Connect (OSTI)

The production and aging of silicone materials remains an important issue in the weapons stockpile due to their utilization in a wide variety of components and systems within the stockpile. Changes in the physical characteristics of silicone materials due to long term desiccation has been identified as one of the major aging effects observed in silicone pad components. Here we report relaxation nuclear magnetic resonance imaging (R-NMRI) spectroscopy characterization of the silica-filled and unfilled polydimethylsiloxane (PDMS) and polydiphenylsiloxane (PDPS) copolymer (M9787) silicone pads within desiccating environments. These studies were directed at providing additional details about the heterogeneity of the desiccation process. Uniform NMR spin-spin relaxation time (T2) images were observed across the pad thickness indicating that the drying process is approximately uniform, and that the desiccation of the M9787 silicone pad is not a H2O diffusion limited process. In a P2O5 desiccation environment, significant reduction of T2 was observed for the silica-filled and unfilled M9787 silicone pad for desiccation up to 225 days. A very small reduction in T2 was observed for the unfilled copolymer between 225 and 487 days. The increase in relative stiffness with desiccation was found to be higher for the unfilled copolymer. These R-NMRI results are correlated to local changes in the modulus of the material

Alam, Todd M; Cherry, Brian Ray; Alam, Mary Kathleen

2004-06-01T23:59:59.000Z

196

Regional effects of age and sex in magnetic resonance spectroscopy  

Science Journals Connector (OSTI)

Objective To determine the regional effects of age and sex on the metabolic ratios obtained in the medial temporal lobe, the posteromedial region, and the frontal lobe at 1.5 T single-voxel magnetic resonance spectroscopy. Material and methods We used single-voxel magnetic resonance spectroscopy to study the areas of the brain most affected in neurodegenerative disease (the left frontal lobe, the left medial temporal lobe, and the posteromedial region) in 31 healthy subjects older than 55 years of age (group 1) and in 20 healthy subjects under 30 years of age (group 2). We calculated the following ratios for each voxel: N-acetyl-aspartate/creatine-phosphocreatine (NAA/Cr), N-acetylaspartate/ choline (NAA/Cho), N-acetyl-aspartate /myoinositol (NAA/mI), choline/ creatine-phosphocreatine (Cho/Cr), and myoinositol (mI/Cr). We compared the metabolic ratios in each region in each group and the correlation between age and the ratios within age ranges. Finally, we analyzed the differences in the metabolic ratios between groups and between sexes. Results In group 1, we found negative correlations between age and Cho/Cr in the frontal region and NAA/mI in the temporal region. In group 2, we found negative correlations between age and mI/Cr and NAA/Cho in the temporal region as well as a positive correlation between age and NAA/mI in the temporal region. In the frontal lobe and the posteromedial region, NAA/ Cr, NAA/Cho, and NAA/mI were lower in group 1 (P?0.003). No differences between groups were seen in Cho/Cr or mI/Cr. The values of the ratios differed regionally in all cases (P<0.001). In the temporal lobe, NAA/Cr and Cho/Cr were higher in women (P?0.034). Conclusions When using single-voxel magnetic resonance spectroscopy, especially in patients with neurodegenerative disease, variations due to region, age, and sex should always be taken into account.

J.M. Garca Santos; L.J. Fuentes; J.B. Vidal; M. Antequera; S. Torres Del Ro; C. Antnez; G. Ortega

2010-01-01T23:59:59.000Z

197

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

198

A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING  

E-Print Network [OSTI]

A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING JENS FISCHER.weiss@pfh.research.philips.com HEIDRUN SCHUMANN University of Rostock, Computer Science Department, D­18051 Rostock,Germany schumann radiologists during invasive and non­invasive magnetic resonance imaging. We use pre­acquired and real time

Schumann, Heidrun

199

A neural network approach for image reconstruction in electron magnetic resonance tomography  

Science Journals Connector (OSTI)

An object-oriented, artificial neural network (ANN) based, application system for reconstruction of two-dimensional spatial images in electron magnetic resonance (EMR) tomography is presented. The standard back propagation algorithm is utilized to train ... Keywords: Artificial neural networks, Back propagation, Electron magnetic resonance tomography, Filtered back projection, Image reconstruction, Multiplicative algebraic reconstruction technique

D. Christopher Durairaj; Murali C. Krishna; Ramachandran Murugesan

2007-10-01T23:59:59.000Z

200

Simultaneous phase and scatter correction for NMR datasets  

Science Journals Connector (OSTI)

Abstract Nuclear magnetic resonance (NMR) spectroscopy has proven invaluable in the diverse field of chemometrics due to its ability to deliver information-rich spectral datasets of complex mixtures for analysis by techniques such as principal component analysis (PCA). However, NMR datasets present a unique challenge during preprocessing due to differences in phase offsets between individual spectra, thus complicating the correction of random dilution factors that may also occur. We show that simultaneously correcting phase and dilution errors in NMR datasets representative of metabolomics data yields improved cluster quality in PCA scores space, even with significant initial phase errors in the data.

Bradley Worley; Robert Powers

2014-01-01T23:59:59.000Z

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.


201

Use of High-Resolution 31P-labeled Topical Magnetic Resonance Spectroscopy to Monitor in Vivo Tumor Metabolism in Rats  

Science Journals Connector (OSTI)

...research-article Basic Sciences Use of High-Resolution 31P-labeled Topical Magnetic Resonance Spectroscopy...J. R. 31PNuclear magnetic resonance studies of...detection by nuclear magnetic resonance. Science (Wash. DC), 171...

M. G. Irving; S. J. Simpson; J. Field; and D. M. Doddrell

1985-02-01T23:59:59.000Z

202

Effects of 2-Deoxyglucose on Drug-sensitive and Drug-resistant Human Breast Cancer Cells: Toxicity and Magnetic Resonance Spectroscopy Studies of Metabolism  

Science Journals Connector (OSTI)

...metabolism by "P nuclear magnetic resonance spectroscopy. Science (Wash. DC), 228...Phosphorous-31 nuclear magnetic resonance detection...of the Society for Magnetic Resonance Medicine...tumor response. Science (Wash. DC), 197...

Ofer Kaplan; Gil Navon; Robbe C. Lyon; Patrick J. Faustino; Eric J. Straka; and Jack S. Cohen

1990-02-01T23:59:59.000Z

203

Evaluation of LDH-A and Glutaminase Inhibition In Vivo by Hyperpolarized 13C-Pyruvate Magnetic Resonance Spectroscopy of Tumors  

Science Journals Connector (OSTI)

...Neurology and Brain Science Institute, Johns Hopkins...Hyperpolarized 13C magnetic resonance spectroscopy...31P and 13C nuclear magnetic resonance.Science 1979;205:160-6...hyperpolarized 13C magnetic resonance imaging for...

Prasanta Dutta; Anne Le; David L. Vander Jagt; Takashi Tsukamoto; Gary V. Martinez; Chi V. Dang; and Robert J. Gillies

2013-07-15T23:59:59.000Z

204

Nuclear Magnetic Resonance Analysis of Tumor Necrosis Factor-induced Alterations of Phospholipid Metabolites and pH in Friend Leukemia Cell Tumors and Fibrosarcomas in Mice  

Science Journals Connector (OSTI)

...research-article Basic Sciences Nuclear Magnetic Resonance Analysis...D. Proton nuclear magnetic resonance of intact...during differentiation. Science, (Wash. DC), 216...P. J. 31P Nuclear magnetic resonance study of...

Franca Podo; Giulia Carpinelli; Massimo Di Vito; Massimo Giannini; Enrico Proietti; Walter Fiers; Ion Gresser; and Filippo Belardelli

1987-12-15T23:59:59.000Z

205

Effect of demagnetization on magnetic resonance line shapes in bulk samples: Application to tungsten  

Science Journals Connector (OSTI)

A calculation of the contribution of a bulk specimen's nonuniform demagnetizing field to the inhomogeneous broadening of magnetic resonance lines is described. Demagnetization effects are of particular importance for substances with large bulk magnetic susceptibilities located in large static magnetic fields. Application is made to the nuclear acoustic resonance of W183 spins in a bulk cylindrical specimen of tungsten. In addition to explaining the observed inhomogeneous line broadening, the calculation predicts a "satellite" line which is also observed experimentally. Although attention is paid to specifically acoustic considerations, the calculation is applicable to magnetic resonance in general.

George Mozurkewich; H. I. Ringermacher; D. I. Bolef

1979-07-01T23:59:59.000Z

206

Use of 1H Nuclear Magnetic Resonance To Measure Intracellular Metabolite Levels during Growth and Asexual Sporulation in Neurospora crassa  

Science Journals Connector (OSTI)

...June 2011 research-article Articles Use of 1H Nuclear Magnetic Resonance...2 Graduate Program in Cell...Education Research and Training Program fellowships...in vivo 15N nuclear magnetic resonance...transcriptional program underlying...

James D. Kim; Kayla Kaiser; Cynthia K. Larive; Katherine A. Borkovich

2011-04-01T23:59:59.000Z

207

Does a Fast Nuclear Magnetic Resonance Spectroscopy- and X-Ray Crystallography Hybrid Approach Provide Reliable Structural Information of Ligand-Protein Complexes? A Case Study of Metalloproteinases  

Science Journals Connector (OSTI)

Does a Fast Nuclear Magnetic Resonance Spectroscopy- and X-Ray Crystallography Hybrid Approach Provide Reliable Structural Information of Ligand-Protein Complexes? ... In brief, a grid box of 70 70 70 was centered on the active site (the residue cluster displaying chemical shift perturbation upon inhibitor addition) with a grid spacing of 0.375 . Crossover-, mutation-, and elitism weights were set to 0.80, 0.02, and 1.0, respectively. ... Support from the EU-NMR Integrated Infrastructure Initiative, contract no. ...

Johan Isaksson; Susanne Nystrm; Dean Derbyshire; Hans Wallberg; Tatiana Agback; Helena Kovacs; Ivano Bertini; Andrea Giachetti; Claudio Luchinat

2009-02-24T23:59:59.000Z

208

Characterization of the sp2 bonds network in a-C:H layers with nuclear magnetic resonance, electron energy loss spectroscopy and electron spin resonance  

Science Journals Connector (OSTI)

a-C:H layers prepared at different ion energies have been investigated by several methods including 13C nuclear magnetic resonance (NMR), electron energy loss spectroscopy (EELS) and electron spin resonance (ESR). The sp2 fraction of the samples rose from 27% to about 60 at.% with increasing ion energies from 30 eV to 170 eV. In the EELS spectra of these layers the intensity of the ? ? ?? transition between 4 and 7 eV showed no significant variation. But a shift of the peak is observed from 7 eV to lower energy losses with increasing ion energies indicating an enhanced formation of larger sp2 cluster sizes. This shift is accompanied by a broadening of the energy loss peak, suggesting a broadening of the cluster size distribution. The ESR spectra showed an increase of the spin density by more than one order of magnitude with increasing ion energies. Simultaneously the linewidth of the ESR signal gets narrower. This can also be interpreted as an increasing cluster size from single benzene rings to three and four fused six-fold rings. Hence, the EELS and ESR spectra lead to the same conclusions with respect to the microstructure of the a-C:H network.

R. Kleber; K. Jung; H. Ehrhardt; I. Mhling; K. Breuer; H. Metz; F. Engelke

1991-01-01T23:59:59.000Z

209

Nuclear magnetic resonance studies of drug-nucleic acid interactions at the synthetic DNA level in solution  

Science Journals Connector (OSTI)

Nuclear magnetic resonance studies of drug-nucleic acid interactions at the synthetic DNA level in solution ...

Dinshaw J. Patel

1979-04-01T23:59:59.000Z

210

In Vivo Measurements of Intratumoral Metabolism, Modulation, and Pharmacokinetics of 5-Fluorouracil, Using 19F Nuclear Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...5-Fluorouracil, Using 19F Nuclear Magnetic Resonance Spectroscopy...part, by Department of Energy Grant FG03-84ER60219...CA 90033. In vivo 19F nuclear magnetic resonance spectroscopy...part, by Department of Energy Grant FG03- 84ER60219...abbreviations used are: NMRS. nuclear magnetic resonance spectros...

Ahmed El-Tahtawy and Walter Wolf

1991-11-01T23:59:59.000Z

211

Cellular Energetics Measured by Phosphorous Nuclear Magnetic Resonance Spectroscopy Are Not Correlated with Chronic Nutrient Deficiency in Multicellular Tumor Spheroids  

Science Journals Connector (OSTI)

...Assessment of tumor energy and oxyg nation status...bioluminescence, nuclear magnetic resonance...Sutherland, R. M. 31P nuclear magnetic resonance...studies of tumor energy metabolism and its...Evaluation of tumor energy metabolism and microvascular...administration using 3'P nuclear magnetic resonance...

James P. Freyer; Patricia L. Schor; Kathryn A. Jarrett; Michal Neeman; and Laurel O. Sillerud

1991-08-01T23:59:59.000Z

212

Loss of High-Energy Phosphate following Hyperthermia Demonstrated by in Vivo 31P-Nuclear Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...Sciences Loss of High-Energy Phosphate following...by in Vivo 31P-Nuclear Magnetic Resonance...Loss of high-energy phosphate following...by in vivo 31P-nuclear magnetic resonance...Loss of High-Energy Phosphate following...by in Vivo 31P-Nuclear Magnetic Resonance...

Michael B. Lilly; Thian C. Ng; William T. Evanochko; Charles R. Katholi; Narinder G. Kumar; Gabriel A. Elgavish; John R. Durant; Raymond Hiramoto; Vithal Ghanta; and Jerry D. Glickson

1984-02-01T23:59:59.000Z

213

Levels of High Energy Phosphates in Human Lung Cancer Cell Lines by 31P Nuclear Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...Sciences Levels of High Energy Phosphates in Human...Cell Lines by 31P Nuclear Magnetic Resonance...Levels of high energy phosphates in human...cell lines by 31P nuclear magnetic resonance...Levels of High Energy Phosphates in Human...Cell Lines by 31P Nuclear Magnetic Resonance...

Richard H. Knop; Desmond N. Carney; Chi Wan Chen; Jack S. Cohen; and John D. Minna

1987-07-01T23:59:59.000Z

214

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

E-Print Network [OSTI]

MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution potentials and the magnetic fields produced by the probing current are measured. Surface potentials are measured by using conventional electrical impedance tomography techniques and high resolution magnetic

Eyüboðlu, Murat

215

Potential hazards and artifacts of ferromagnetic and nonferromagnetic surgical and dental materials and devices in nuclear magnetic resonance imaging  

SciTech Connect (OSTI)

The risks to patients with metal surgical implants who are undergoing nuclear magnetic resonance (NMR) imaging and the artifacts caused by such implants were studied. Twenty-one aneurysm and other hemostatic clips and a variety of other materials (e.g., dental amalgam, 14 karat gold) were used. Longitudinal forces and torques were found to be exerted upon 16 of the 21 clips. With five aneurysm clips, forces and torques sufficient to produce risk of hemorrhage from dislocation of the clip from the vessel or aneurysm, or cerebral injury by clip displacement without dislodgement were identified. The induced ferromagnetism was shown to be related to the composition of the alloys from which the clips were manufactured. Clips with 10-14% nickel are evidently without sufficient induced ferromagnetism to cause hazard. The extent of NMR imaging artifacts was greater for materials with measurable ferromagnetic properties, but metals without measurable ferromagnetism in our tests also resulted in significant artifacts. Dental amalgam and 14 karat gold produced no imaging artifacts, but stainless steels in dentures and orthodontic braces produced extensive artifacts in the facial region.

New, P.F.J. (Massachusetts General Hospital, Boston, MA); Rosen, B.R.; Brady, T.J.; Buonanno, F.S.; Kistler, J.P.; Burt, C.T.; Hinshaw, W.S.; Newhouse, J.H.; Pohost, G.M.; Taveras, J.M.

1983-04-01T23:59:59.000Z

216

Phase imaging of magnetic nanostructures using resonant soft x-ray holography  

Science Journals Connector (OSTI)

We demonstrate phase imaging by means of resonant soft x-ray holography. Our holographic phase-contrast method utilizes the strong energy-dependence of the refractive index at a characteristic x-ray absorption resonance. The general concept is shown by using a Co?Pd multilayer sample which exhibits random nanosized magnetic domains. By tuning below the Co L-edge resonance, our quantitative and spectroscopic phase method allows high-contrast imaging of nanoscale electronic and magnetic order while increasing the probing depth and decreasing the radiation dose by an order of magnitude. The complex refractive index is quantitatively obtained through the interference between resonant and nonresonant scattering.

A. Scherz; W. F. Schlotter; K. Chen; R. Rick; J. Sthr; J. Lning; I. McNulty; Ch. Gnther; F. Radu; W. Eberhardt; O. Hellwig; S. Eisebitt

2007-12-17T23:59:59.000Z

217

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

218

A study of Overhauser pumping in weak magnetic fields  

E-Print Network [OSTI]

. s The physical phenomena which produce the magnetic resonance absorption and dispersion signals are well explained by the phenomenological Bloch equation. By simultaneous NMR and ESR excitation the nuclear signal can be enhanced through the coupling of a free.... s The physical phenomena which produce the magnetic resonance absorption and dispersion signals are well explained by the phenomenological Bloch equation. By simultaneous NMR and ESR excitation the nuclear signal can be enhanced through the coupling of a free...

Gondran, Gregory Rhea

2012-06-07T23:59:59.000Z

219

High Resolution NMR Spectroscopy of Nanocrystalline Proteins at Ultra-High Magnetic Field  

SciTech Connect (OSTI)

Solid-state NMR (SSNMR) spectroscopy is a powerful tool for studying protein structure and function, uniquely able to address macroscopically disordered proteins. Insights from SSNMR include atomic-resolution structure, site-specific dynamics, metal center chemistry, and orientation of membrane proteins in bilayers.

Sperling, Lindsay J.; Nieuwkoop, Andrew J.; Lipton, Andrew S.; Berthold, Deborah A.; Rienstra, Chad M.

2010-02-01T23:59:59.000Z

220

Integrated magnetic resonance imaging methods for speech science and technology  

Science Journals Connector (OSTI)

This presentation introduces our integration of magnetic resonance imaging(MRI) techniques at ATRBrain Activity Imaging Center (Kyoto Japan) toward research into speech science and technology. The first breakthrough in our application of MRI to speech research was the motion imaging of the speechorgans in articulation using a cardiac cine?MRI method. It enables us to acquire information in the time?space domain to reconstruct successive image frames using utterance repetitions synchronized with MRI scans. This cine?technique was further improved for high?quality imaging and expanded into three?dimensional (3D) visualization of articulatory movements. Using this technique we could successfully obtain temporal changes of vocal?tract area function during a Japanese five?vowel sequence. This effort also contributed to developing other techniques to overcome the limitations of MRI such as the post?hoc inclusion of teeth images in 3D volumes or the phonation?synchronized scan for crystal?sharp static imaging. Further a custom high?sensitivity coil was developed to visualize the fine structures of the lip muscles and laryngeal airway. The potentials of new MRI approaches such as ultra?high?resolution imaging with a higher?field scanner or real?time motion imaging during a single utterance will be discussed toward future contributions to speech science and technology.

Shinobu Masaki; Yukiko Nota; Sayoko Takano; Hironori Takemoto; Tatsuya Kitamura; Kiyoshi Honda

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.


221

Carbon-13 nuclear magnetic resonance studies of glycolysis in protozoa  

E-Print Network [OSTI]

, I. Scott. A ht gty ty 1 1 tt 1 t A E g1 ~gati h h studied by C NMR spectroscopy. The fate of C label was analyzed 13 13 in cell extracts and the glycolytic end products succinate, malate, acetate, and mannitol identified. Pathways of succinate... observed. ACKNOWLEDGMENTS I wish to express my gratitude to Dr. Neil Mackenzie for his gui- dance, patience, and support throughout this work. My sincere appre- ciation goes to Dr. Paul Fagerness for sharing his NMR expertise and to Dr. Ian l31agbrough...

Rhoades, Teresa Ann

2012-06-07T23:59:59.000Z

222

Artificial Neural Network (ANN) Morphological Classification of Magnetic Resonance Imaging in Multiple Sclerosis  

Science Journals Connector (OSTI)

Multiple Sclerosis (MS) is an autoimmune condition in which the immune system attacks the Central Nervous System. Magnetic Resonance Imaging (MRI) is today a crucial tool for diagnosis of MS by allowing in-vivo d...

Alessia Bramanti; Lilla Bonanno; Placido Bramanti

2013-01-01T23:59:59.000Z

223

Magnetic resonance spectroscopic imaging with 2D spectroscopy for the detection of brain metabolites  

E-Print Network [OSTI]

While magnetic resonance imaging (MRI) derives its signal from protons in water, additional biochemical compounds are detectable in vivo within the proton spectrum. The detection and mapping of these much weaker signals ...

Kok, Trina

2012-01-01T23:59:59.000Z

224

Accelerating magnetic resonance imaging by unifying sparse models and multiple receivers  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) is an increasingly versatile diagnostic tool for a variety of medical purposes. During a conventional MRI scan, samples are acquired along a trajectory in the spatial Fourier transform ...

Weller, Daniel (Daniel Stuart)

2012-01-01T23:59:59.000Z

225

T2*-weighted magnetic resonance imaging used to detect coagulative necrosis in tissue  

E-Print Network [OSTI]

to prevent unnecessary collateral damage to surrounding healthy tissue. This research focuses on using T2*-weighted FLASH magnetic resonance imaging to detect irreversible changes in i . n vitro bovine liver tissue and tissuesimulating polyacrylamide gel...

Van Hyfte, John Bruce

1997-01-01T23:59:59.000Z

226

Observation of disruptions in tokamak plasma under the influence of resonant helical magnetic fields  

Science Journals Connector (OSTI)

Disruptive instabilities were investigated in the small-tokamak TBR-1 during the application of resonant helical magnetic fields created by external helical windings. Indications were found that the main trigg...

M. S. T. Arajo; A. Vannucci; I. L. Caldas

1996-07-01T23:59:59.000Z

227

Developing improved nuclear magnetic resonance marginal oscillator spectrometers for advanced teaching laboratories  

E-Print Network [OSTI]

DEVELOPING IMPROVED NUCLEAR MAGNETIC RESONANCE MARGINAL OSCILLATOR SPECTROMETERS FOR ADVANCED TEACHING LABORATORIES A Thesis by FRANK PHILLIP WILLINGHAM Submitted to the Office of Graduate Studies of Texas ASM University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE D e cemb er 1988 Major Subject: Physics DEVELOPING IMPROVED NUCLEAR MAGNETIC RESONANCE MARGINAL OSCILLATOR SPECTROMETERS FOR ADVANCED TEACHING LABORATORIES A Thesis by FRANK PHILLIP...

Willingham, Frank Phillip

1988-01-01T23:59:59.000Z

228

Direct Simulation of Magnetic Resonance Relaxation Rates and Line Shapes from Molecular Trajectories  

Science Journals Connector (OSTI)

The Sydney Opera House (SOPHE) method(54) for simulating randomly oriented powder spectra is used to set the initial angles for the N trajectories included in the simulations. ... A new method for simulating randomly oriented powder spectra in magnetic resonance: the Sydney Opera House (SOPHE) method ... A new method named the Sydney Opera House (SOPHE) method for computer reconstruction of randomly oriented powder spectra in magnetic resonance is presented. ...

David P. Rangel; Philippe C. Baveye; Bruce H. Robinson

2012-04-27T23:59:59.000Z

229

Surfactant based imbibition and induced solution gas drive process: investigation by nuclear magnetic resonance  

E-Print Network [OSTI]

SURFACTANT BASED IMBIBITION AND INDUCED SOLUTION GAS DRIVE PROCESS: INVESTIGATION BY NUCLEAR MAGNETIC RESONANCE A Thesis by JAMES CALVIN COX Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment.... of the requirements for the degree of MASTER OF SCIENCE August 1993 Major Subject: Chemical Engineering SURFACTANT BASED IMBIBITION AND INDUCED SOLUTION GAS DRIVE PROCESS: INVESTIGATION BY NUCLEAR MAGNETIC RESONANCE A Thesis by JAMES CALVIN COX Approved...

Cox, James Calvin

2012-06-07T23:59:59.000Z

230

Neutron resonance spin echo, bootstrap method for increasing the effective magnetic field  

E-Print Network [OSTI]

1195 Neutron resonance spin echo, bootstrap method for increasing the effective magnetic field R donné en spectrométrie d'echos de spins de neutrons. Les limites théoriques et techniques à l field intensity in Neutron Resonance Spin Echo (NRSE) spectrometry. The limits, theoretical as well

Paris-Sud XI, Université de

231

Nuclear magnetic resonance studies of hydrogen in amorphous silicon  

SciTech Connect (OSTI)

Proton and deuteron NMR in hydrogenated amorphous silicon yield quantitative measures of species-specific structural configurations and their dynamics. Populations of silicon-bonded and molecular hydrogens correlate with photovoltaic quality, doping, illumination/dark anneal sequences, and with infrared and other characterizations. High quality films contain substantial populations of nanovoid-trapped molecular hydrogen.

Norberg, R.E.; Fedders, P.A.; Leopold, D.J. [Washington Univ., St. Louis, MO (United States). Dept. of Physics

1996-12-31T23:59:59.000Z

232

Syllabus Spring 2012 CHE 546 Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

: (1) Two semesters of calculus-based physics, (2) Organic chemistry with an introduction to NMR (CHE 325/335) or equivalent experience, (3) Physical chemistry that includes an introduction to quantum have a book that you think is sufficient. Otherwise, we recommend the following text, which has very

Raina, Ramesh

233

Study of the interplay between magnetic shear and resonances using Hamiltonian models for the magnetic field lines  

SciTech Connect (OSTI)

The issue of magnetic confinement in magnetic fusion devices is addressed within a purely magnetic approach. Using some Hamiltonian models for the magnetic field lines, the dual impact of low magnetic shear is shown in a unified way. Away from resonances, it induces a drastic enhancement of magnetic confinement that favors robust internal transport barriers (ITBs) and stochastic transport reduction. When low shear occurs for values of the winding of the magnetic field lines close to low-order rationals, the amplitude thresholds of the resonant modes that break internal transport barriers by allowing a radial stochastic transport of the magnetic field lines may be quite low. The approach can be applied to assess the robustness versus magnetic perturbations of general (almost) integrable magnetic steady states, including nonaxisymmetric ones such as the important single-helicity steady states. This analysis puts a constraint on the tolerable mode amplitudes compatible with ITBs and may be proposed as a possible explanation of diverse experimental and numerical signatures of their collapses.

Firpo, M.-C. [Laboratoire de Physique des Plasmas, CNRS--Ecole Polytechnique, 91128 Palaiseau Cedex (France); Constantinescu, D. [Department of Applied Mathematics, Association Euratom-MECI, University of Craiova, Craiova 200585 (Romania)

2011-03-15T23:59:59.000Z

234

The development of magnetic resonance imaging for the determination of porosity in reservoir core samples  

E-Print Network [OSTI]

to increase. This is the resonance condition and is the principle upon which magnetic resonance imaging is founded. The resonance frequency, tu, is directly proportional to the magnetic field and can be expressed as: where y is the gyromagnetic ratio and H... system is also precessing about y' with the same rotational frequency as M. This is the rotating frame of reference. By convention, z' is set equal to z and, therefore, H . As long as H remains at a constant strength and is the only field applied...

Sherman, Byron Blake

2012-06-07T23:59:59.000Z

235

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2014-2015 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

236

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2012-2013 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

237

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, Name ID# Date  

E-Print Network [OSTI]

Bachelor of Science, Radiologic Sciences, Magnetic Resonance Imaging Emphasis, 2013-2014 Name ID Intro to Sociology 3 DLS Social Sciences course in a second field 3 CID HLTHST 382 Research Methods Pharmacology and Contrast Medias RADSCI 430 Comparative Sectional Imaging RADSCI 440 Principles of Magnetic

Barrash, Warren

238

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic resonance imaging findings and  

E-Print Network [OSTI]

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic to evaluate white matter architecture after preterm birth. The goals were (1) to compare white matter if sex, gestational age, birth- weight, white matter injury score from conventional magnetic resonance

Grill-Spector, Kalanit

239

Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth's  

E-Print Network [OSTI]

LETTERS Chemical analysis by ultrahigh-resolution nuclear magnetic resonance in the Earth spectroscopy2 in the Earth's magnetic field. We show that in the Earth's field the transverse relaxation time T electronics Data acquisition d.c. transmission coil Earth's field N S B0 B0 = 1 T Figure 1 Setup of mobile

Loss, Daniel

240

Sidebands in Optically Detected Magnetic Resonance Signals of Nitrogen Vacancy Centers in Diamond  

E-Print Network [OSTI]

We study features in the optically detected magnetic resonance (ODMR) signals associated with negatively charged nitrogen-vacancy (NV) centers coupled to other paramagnetic impurities in diamond. Our results are important for understanding ODMR line shapes and for optimization of devices based on NV centers. We determine the origins of several side features to the unperturbed NV magnetic resonance by studying their magnetic field and microwave power dependences. Side resonances separated by around 130 MHz are due to hyperfine coupling between NV centers and nearest-neighbor C-13 nuclear spins. Side resonances separated by approximately {40, 260, 300} MHz are found to originate from simultaneous spin flipping of NV centers and single substitutional nitrogen atoms. All results are in agreement with the presented theoretical calculations.

Maria Simanovskaia; Kasper Jensen; Andrey Jarmola; Kurt Aulenbacher; Neil Manson; Dmitry Budker

2012-12-23T23:59:59.000Z

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

Magnetically tunable resonance frequency beam utilizing a stress-sensitive film  

DOE Patents [OSTI]

Methods and apparatus for detecting particular frequencies of vibration utilize a magnetically-tunable beam element having a stress-sensitive coating and means for providing magnetic force to controllably deflect the beam element thereby changing its stiffness and its resonance frequency. It is then determined from the response of the magnetically-tunable beam element to the vibration to which the beam is exposed whether or not a particular frequency or frequencies of vibration are detected.

Davis, J. Kenneth (Kingston, TN); Thundat, Thomas G. (Knoxville, TN); Wachter, Eric A. (Oak Ridge, TN)

2001-01-01T23:59:59.000Z

242

A 4 K cryogenic probe for use in magnetic resonance force microscopy experiments  

SciTech Connect (OSTI)

The detailed design of a mechanically detected nuclear magnetic resonance probe using the SPAM (Springiness Preservation by Aligning Magnetization) geometry, operating at 4 K, in vacuum, and a several-Tesla magnetic field is described. The probe head is vibration-isolated well enough from the environment by a three-spring suspension system that the cantilever achieves thermal equilibrium with the environment without the aid of eddy current damping. The probe uses an ultra-soft Si cantilever with a Ni sphere attached to its tip, and magnetic resonance is registered as a change in the resonant frequency of the driven cantilever. The RF system uses frequency sweeps for adiabatic rapid passage using a 500 ?m diameter RF coil wound around a sapphire rod. The RF coil and optical fiber of the interferometer used to sense the cantilever's position are both located with respect to the cantilever using a Garbini micropositioner, and the sample stage is mounted on an Attocube nanopositioner.

Smith, Doran D.; Alexson, Dimitri A. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)] [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States); Garbini, Joseph L. [Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States)] [Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States)

2013-09-15T23:59:59.000Z

243

Quantitative Nuclear Magnetic Resonance Spectroscopy as a Tool To Evaluate Chemical Modification of Deep Hydrotreated Recycled Lube Oils  

Science Journals Connector (OSTI)

Quantitative Nuclear Magnetic Resonance Spectroscopy as a Tool To Evaluate Chemical Modification of Deep Hydrotreated Recycled Lube Oils ... Argonne National Laboratory, Argonne, Illinois 60439, United States ...

John V. Muntean; Joseph A. Libera; Seth W. Snyder; Tianpin Wu; Donald C. Cronauer

2012-12-13T23:59:59.000Z

244

MagLab - NMR/MRI Facilities: How to Request Magnet Time  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(for registered users) Magnet time at the MagLab is allocated on the basis of scientific peer review and is available at no cost to the awardee. However, users are expected to...

245

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

246

Nuclear Magnetic Resonance in FeAl and CoAl  

Science Journals Connector (OSTI)

We have investigated the Al27 nuclear magnetic resonance in Ni3Al, NiAl, FeAl, and both the Al27 and Co59 resonances in CoAl. The cobalt resonance in CoAl exhibits a weakly temperature-dependent, positive shift. This shift (?1.5%) is too large to be accounted for solely by the hyperfine field from conduction electrons polarized by the external magnetic field, and orbital paramagnetic effects appear to be the dominant factor, core polarization playing a relatively minor role. The aluminum Knight shift in CoAl is small (0.014%) and temperature-independent. This is to be contrasted with aluminum in FeAl which exhibits a large, negative, temperature-dependent shift (-0.38% at 293K). It is shown that both the large aluminum Knight shift in FeAl and the small aluminum Knight shift in CoAl are consistent with the predictions of the Ruderman-Kittel-Yosida (RKY) theory. However, it is now believed that the small shift observed in CoAl results from a lack of s character in the conduction-electron wave functions rather than from a node anticipated in the conduction-electron polarization. The temperature dependence of the resonance in FeAl can also be accounted for by the RKY mechanism if it is assumed that the temperature dependence of the magnetic susceptibility is associated with disorder in the material. This assumption is necessary because the Knight shift is not linearly related to the bulk susceptibility of the sample. The aluminum linewidth in FeAl increases as the temperature is lowered. At room temperature the linewidth is independent of magnetic field but greater than the calculated dipolar linewidth. At 77 and 4.2K the linewidth increases with increasing magnetic field. This effect is attributed mainly to inhomogeneous Knight-shift broadening, although inhomogeneous magnetization broadening also contributes. A similar situation is observed in CoAl. At room temperature the cobalt and aluminum resonances have essentially the same width. The linewidths are independent of magnetic field but greater than the dipolar values. As the temperature is lowered the linewidths increase and become magnetic-field-dependent. The cobalt resonance broadens more severely than the aluminum resonance. It is believed that inhomogeneous Knight-shift broadening and inhomogeneous magnetization broadening determine the cobalt linewidth at low temperatures. The aluminum nuclei in CoAl do not exhibit appreciable hyperfine coupling with the conduction electrons, so that only inhomogeneous magnetization broadening contributes to the linewidth.

J. A. Seitchik and R. H. Walmsley

1965-01-04T23:59:59.000Z

247

Nonperturbative broadening of paramagnetic resonance lines by transverse magnetic field gradients  

Science Journals Connector (OSTI)

We experimentally and theoretically study the broadening of paramagnetic resonance lines by transverse magnetic field gradients when a perturbative description is inadequate. The experiments are performed with an evanescent wave magnetometer using an octadecyltrichlorosilane-coated glass cell containing R87b and N2 buffer gas. We find that the transverse broadening of the resonance line is inversely proportional to the square root of the holding field. We also provide a quantitative theoretical explanation of the experimental results.

K. F. Zhao; M. Schaden; Z. Wu

2008-07-30T23:59:59.000Z

248

NMR apparatus for in situ analysis of fuel cells  

DOE Patents [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

249

National High Magnetic Field Laboratory - Ion Cyclotron Resonance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Radial Ion Motion in RF-Only Multipole Ion Guides Immersed in a Strong Magnetic Field Gradient, J. Am. Soc. Mass Spectr., 22, 591-601 (2011) 2 Blakney, G.T.; Hendrickson,...

250

Particle transport as a result of resonant magnetic perturbations  

E-Print Network [OSTI]

field of plasma physics with a particular focus on particlewe will focus on localized measurements at the plasma edgefocuses on the Magnetic confinement technique utilizing a Tokamak [91]. The goal of a burning plasma,

Mordijck, Saskia

2011-01-01T23:59:59.000Z

251

Superconducting properties of a textured NbN film from N93b NMR relaxation and magnetization measurements  

Science Journals Connector (OSTI)

Primarily motivated by the similarities between the underdoped superconducting cuprates and the granular systems in regards of electric conductivity, phase fluctuations of the order parameter, and nuclear spin-lattice relaxation, a study has been carried out in a NbN(111) textured film at controlled granularity by means of superconducting quantum interference device magnetization and N93b NMR measurements. The Meissner diamagnetism in zero-field-cooling and field-cooling conditions and for different orientation of the magnetic field and the isothermal magnetization curves around the superconducting transition temperature Tc, are studied. N93b spectra and relaxation measurements have been performed for two values of the external magnetic field in parallel and perpendicular geometry, in the temperature range 4300 K. In the superconducting phase the experimental findings for the textured film are similar to the one in bulk NbN. The nuclear spin-lattice relaxation process is the same as in bulk NbN in the temperature range 50300 K, confirming a dominant contribution to the density of states at the Fermi energy arising from the Nb 4d band. At variance, on cooling from about 40 K down to Tc (H), the N93b relaxation rate in the film dramatically departs from the expected behavior for the Fermi gas and mimics the opening of a spin gap. The interpretation of the spin-gap opening in terms of depletion in the density of states at the Fermi energy can justify the anomalous temperature behavior of the N93b relaxation rate on approaching Tc (H) from above. The experimental findings suggest the occurrence of superconducting fluctuations (density-of-states term) in one-dimensional regime, coupled to a reduction in the time of flight of the electrons, both effects being related to the granularity. The data also suggest that the spin-gap phase in underdoped cuprates could be connected more to granularity, rather than to exotic mechanisms of magnetic origin.

A. Lascialfari; A. Rigamonti; E. Bernardi; M. Corti; A. Gauzzi; J. C. Villegier

2009-09-09T23:59:59.000Z

252

An introduction to NMR-based approaches for measuring protein dynamics Ian R. Kleckner a  

E-Print Network [OSTI]

dispersion, (5) Rotating frame relaxation dispersion, (6) Nuclear spin relaxation, (7) Residual dipolar catalysis, binding, regulation and cellular structure. Nuclear magnetic resonance (NMR) spectroscopy ) . . . . . . . . . . . . . . . . . . . . . 0 3.4. Carr­Purcell Meiboom­Gill Relaxation Dispersion (CPMG RD) (ex0.3­10 ms; kex100­3000/s

Foster, Mark P.

253

Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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 measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature 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 for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, 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 with 100% lithium sulfonation due to the presence of ionic aggregation. Details of 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. [Pennsylvania State University, University Park, PA (United States); Dou, Shichen [Pennsylvania State University, University Park, PA (United States); Colby, Ralph H. [Pennsylvania State University, University Park, PA (United States); Mueller, Karl T. [Pacific Northwest Lab., Richland, WA (United States)

2012-01-06T23:59:59.000Z

254

CP-MAS13C Nuclear Magnetic Resonance Spectra for Identification of Functionality of Octadecylsilica Bonded Phases  

Science Journals Connector (OSTI)

......December 1989 research-article Articles CP-MAS13C Nuclear Magnetic Resonance Spectra...Technology, Toyohashi Cross-polarization (CP) and magic angle spinning (MAS) carbon-13...Chromatographic Science, Vol. 27, December 1989 CP-MAS13 C Nuclear Magnetic Resonance Spectra......

Kiyokatsu Jinno

1989-12-01T23:59:59.000Z

255

Investigating the Structural Dynamics of 1,4-Galactosyltransferase C from Neisseria meningitidis by Nuclear Magnetic Resonance  

E-Print Network [OSTI]

by Nuclear Magnetic Resonance Spectroscopy Patrick H. W. Chan,, Adrienne H. Cheung, Mark Okon,,§ Hong mobility. Accordingly, we have used nuclear magnetic resonance spectroscopy to probe the structural, and only the "b" state is competent for substrate binding. For both states, relaxation dispersion studies

McIntosh, Lawrence P.

256

Re-analysis of Magic Angle Spinning Nuclear Magnetic Resonance Determination of Interlamellar Waters in Lipid Bilayer Dispersions  

E-Print Network [OSTI]

Re-analysis of Magic Angle Spinning Nuclear Magnetic Resonance Determination of Interlamellar Waters in Lipid Bilayer Dispersions John F. Nagle,*# Yufeng Liu,* Stephanie Tristram-Nagle,# Richard M of multilamellar lipid vesicles using magic angle spinning nuclear magnetic resonance has been re

Nagle, John F.

257

Array combination for parallel imaging in Magnetic Resonance Imaging  

E-Print Network [OSTI]

Exdx? ? =? ??? null null nullnull [2.7] where ? is the sample conductivity. Substituting Eq. [2.5] into this, it is rewriting in terms of the magnetic vector potential, () () 2 sample V PAxAxd?? ? =? ??? null null null nullnull [2.8] Recalling that power... is also defined as 2 1 2 PIR= , [2.9] then () () 2 2 sample V R Ax Ax dx?? ? =? ??? null null null nullnull [2.10] assuming the magnetic vector potential, A null , is calculated using a unit current. The resistance of a conductive wire...

Spence, Dan Kenrick

2007-09-17T23:59:59.000Z

258

A Multimodal Nanoparticle for Preoperative Magnetic Resonance Imaging and Intraoperative Optical Brain Tumor Delineation  

Science Journals Connector (OSTI)

...humidified 5% CO2 atmosphere in DMEM supplemented...resonating at 200 MHz. Multiple slice...CO). The area of each region...not seen with larger magnetic particles...Methods). The areas obtained from...estimation of tumor area by Cy5.5 fluorescence...they are too large to undergo renal...do not bind plasma proteins and...

Moritz F. Kircher; Umar Mahmood; Raymond S. King; Ralph Weissleder; and Lee Josephson

2003-12-01T23:59:59.000Z

259

Roadmap: Radiologic Imaging Sciences Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences ­ Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) - Bachelor of Radiologic Imaging Sciences Technology [RE-BRIT-RIS-MRHA] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 1-May-13/LNHD This roadmap is a recommended

Sheridan, Scott

260

Roadmap: Radiologic Imaging Sciences -Magnetic Resonance Imaging (with AAS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Magnetic Resonance Imaging (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-MRRT] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 1-May-13/LNHD This roadmap is a recommended semester

Sheridan, Scott

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

Roadmap: Radiologic Imaging Sciences Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences ­ Magnetic Resonance Imaging (with certification and ATS Radiologic Technology) - Bachelor of Radiologic Imaging Sciences Technology [RE-BRIT-RIS-MRHA] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 11-Apr-12/LNHD This roadmap is a recommended

Sheridan, Scott

262

Roadmap: Radiologic Imaging Sciences -Magnetic Resonance Imaging (with AAS Radiologic Technology) -  

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Magnetic Resonance Imaging (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-MRRT] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 21-May-12/LNHD This roadmap is a recommended semester

Sheridan, Scott

263

Qualification of a Noninvasive Magnetic Resonance Imaging Biomarker to Assess Tumor Oxygenation  

Science Journals Connector (OSTI)

...23. Ogawa S , Lee TM, Kay AR Tank DW.Brain magnetic resonance imaging with contrast...intensity-modulated radiation therapy for head and neck cancer.Expert Rev Anticancer...Radiation-Induced Toxicity for Patients with Head and Neck Carcinoma in the IMRT Era: A...

Florence Colliez; Marie-Aline Neveu; Julie Magat; Thanh Trang Cao Pham; Bernard Gallez; Bndicte F. Jordan

2014-11-01T23:59:59.000Z

264

Performance of reimbursement schemes in valuation of technologies: The example of Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

Different reimbursement schemes for health care providers have been developed worldwide. They have evolved over time and have been influenced by politics, costs, patient needs and technological progress. Different methods in the valuation of technologies ... Keywords: Magnetic Resonance Imaging, Valuation, payment, reimbursement schemes, technologies

R. Blankart; J. Schreygg; R. Busse

2008-08-01T23:59:59.000Z

265

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

SciTech Connect (OSTI)

Topics covered are: anomalous transport and E x 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.

Pankin, Alexei Y.; Kritz, Arnold H.

2011-07-19T23:59:59.000Z

266

The Effect of Magnesium Coordination on the and "N Magnetic Resonance Spectra of Chlorophyll a.  

E-Print Network [OSTI]

7058 The Effect of Magnesium Coordination on the and "N Magnetic Resonance Spectra of Chlorophyll a magnesium-free derivative pheophytin a have been assigned. Emphasis is placed on the quaternary carbon atoms was developed to permit these assign- ments. On complexation with magnesium, large downfield chemical

Boxer, Steven G.

267

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

268

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

2007-10-02T23:59:59.000Z

269

Nuclear Magnetic Resonance and Nuclear-Spin Dynamics in InP  

Science Journals Connector (OSTI)

Pulsed- and steady-state nuclear-magnetic-resonance measurements are reported for P31 in InP. Measurements on "solid echoes" permit identification of various contributions to the second moment of the resonance. The dominant P31-In115,113 contribution is found to be about a factor of 2 smaller than expected from dipole-dipole interactions alone. A proposed explanation is based on interference between pseudodipolar and dipolar interactions of similar magnitude but opposite sign. The time evolution of the P31 magnetization along the effective field in the rotating frame indicates the presence of a significant cross-relaxation effect involving the resonant spin-Zeeman reservoir and the nonresonant spin-spin reservoir.

M. Engelsberg and R. E. Norberg

1972-05-01T23:59:59.000Z

270

Electrical, optical and magnetic resonance studies of novel. pi. -conjugated polymers  

SciTech Connect (OSTI)

Conductivity, optical properties including visible and infrared absorption and photoluminescence, and magnetic resonance properties including electron spin resonance and optically detected magnetic resonance have been studied in polydiethynylsilanes (PDES) and poly(2,5-dibutoxyparaphenyleneacetylene) (PDBOPA), which have been recently synthesized. PDES and PDBOPA blend and PDBOPA-based electroluminescent preliminary diodes which were fabricated by the author were also explored. The undoped one-dimensional gap of PDES polymers, which have average molecular weight from {approximately}2{times}10{sup 5} to 1{times}10{sup 6}, is 2.0 eV in both films and solutions; photoluminescence is barely observed. I{sub 2} doping induces a single absorption band at {approximately}1.05 eV in solutions and lightly doped films, but another at {approximately}0.55 eV in heavily doped films. Both are correlated with strong IR-active vibrations associated with known lines in Raman scattering.

Ni, Qing-Xiao.

1992-04-20T23:59:59.000Z

271

Electrical, optical and magnetic resonance studies of novel {pi}-conjugated polymers  

SciTech Connect (OSTI)

Conductivity, optical properties including visible and infrared absorption and photoluminescence, and magnetic resonance properties including electron spin resonance and optically detected magnetic resonance have been studied in polydiethynylsilanes (PDES) and poly(2,5-dibutoxyparaphenyleneacetylene) (PDBOPA), which have been recently synthesized. PDES and PDBOPA blend and PDBOPA-based electroluminescent preliminary diodes which were fabricated by the author were also explored. The undoped one-dimensional gap of PDES polymers, which have average molecular weight from {approximately}2{times}10{sup 5} to 1{times}10{sup 6}, is 2.0 eV in both films and solutions; photoluminescence is barely observed. I{sub 2} doping induces a single absorption band at {approximately}1.05 eV in solutions and lightly doped films, but another at {approximately}0.55 eV in heavily doped films. Both are correlated with strong IR-active vibrations associated with known lines in Raman scattering.

Ni, Qing-Xiao

1992-04-20T23:59:59.000Z

272

All-optical high-resolution magnetic resonance using a nitrogen-vacancy spin in diamond  

E-Print Network [OSTI]

We propose an all-optical scheme to prolong the quantum coherence of a negatively charged nitrogen-vacancy (NV) center in diamond. Optical control of the NV spin suppresses energy fluctuations of the $^{3}\\text{A}_{2}$ ground states and forms an energy gap protected subspace. By optical control, the spectral linewidth of magnetic resonance is much narrower and the measurement of the frequencies of magnetic field sources has higher resolution. The optical control also improves the sensitivity of the magnetic field detection and can provide measurement of the directions of signal sources.

Zhen-Yu Wang; Jian-Ming Cai; Alex Retzker; Martin B. Plenio

2014-04-04T23:59:59.000Z

273

Light narrowing of magnetic resonance lines in dense, optically pumped alkali-metal vapor  

Science Journals Connector (OSTI)

A new and unusual phenomenon which we call light narrowing is reported and discussed in this paper. We discovered this effect in dense, spin-polarized cesium vapor optically pumped with a cw blue dye laser beam tuned to the second resonance D1 line (4593 ). We observe a significant narrowing of the radio-frequency power-broadened magnetic resonance lines (linewidths narrow by as much as a factor of 2.5) when the intensity of the circularly polarized incident dye laser beam is increased by either focusing the beam or by the removal of attenuating filters from the focused beam. The magnetic resonance linewidths in spin-polarized cesium vapor were measured over a wide range of cesium number densities (51012 cm-3 ?[Cs]?11016 cm-3). This corresponds to cesium spinexchange rates of 4.5103 to 9106 sec-1. For low cesium number densities (51012 11015 cm-3) this light-narrowing effect almost completely disappears. In the limit of low-radio-frequency power the magnetic resonance linewidths for focused and unfocused dye laser beam are nearly the same. Experimental observations on this new effect are presented in detail. In the latter part of this paper a self-contained theoretical treatment of the light-narrowing effect is developed. Using Bloch equations in the presence of optical pumping, spin relaxation (diffusion, electron randomization), rapid spin exchange, and radio-frequency magnetic field, expressions for magnetic resonance line shapes are derived. In general, we find good agreement between our experimental results and the theory.

N. D. Bhaskar; J. Camparo; W. Happer; A. Sharma

1981-06-01T23:59:59.000Z

274

Plasma resonance at low magnetic fields as a probe of vortex line meandering in layered superconductors  

Science Journals Connector (OSTI)

We consider the magnetic-field dependence of the plasma resonance frequency in pristine and in irradiated Bi2Sr2CaCu2O8 crystals near Tc. At low magnetic fields we relate linear in field corrections to the plasma frequency to the average distance between the pancake vortices in the neighboring layers (wandering length). We calculate the wandering length in the case of thermal wiggling of vortex lines, taking into account both Josephson and magnetic interlayer coupling of pancakes. Analyzing experimental data, we found that (i) the wandering length becomes comparable with the London penetration depth near Tc and (ii) at small melting fields (line liquid phase in this field range. We also found that pinning by columnar defects affects weakly the field dependence of the plasma resonance frequency near Tc.

L. N. Bulaevskii; A. E. Koshelev; V. M. Vinokur; M. P. Maley

2000-02-01T23:59:59.000Z

275

Plasma resonance at low magnetic fields as a probe of vortex line meandering in layered superconductors  

E-Print Network [OSTI]

We consider the magnetic field dependence of the plasma resonance frequency in pristine and in irradiated Bi$_2$Sr$_2$CaCu$_2$O$_8$ crystals near $T_c$. At low magnetic fields we relate linear in field corrections to the plasma frequency to the average distance between the pancake vortices in the neighboring layers (wandering length). We calculate the wandering length in the case of thermal wiggling of vortex lines, taking into account both Josephson and magnetic interlayer coupling of pancakes. Analyzing experimental data, we found that (i) the wandering length becomes comparable with the London penetration depth near T$_{c}$ and (ii) at small melting fields ($line liquid phase in this field range. We also found that pinning by columnar defects affects weakly the field dependence of the plasma resonance frequency near $T_c$.

L. N. Bulaevskii; A. E. Koshelev; V. M. Vinokur; M. P. Maley

1999-07-29T23:59:59.000Z

276

In Situ NMR Spectroscopy of Combustion  

Science Journals Connector (OSTI)

In situ nuclear magnetic resonance spectroscopy (NMR) of high-temperature reactions is of potential value for the investigation of catalytic combustion and other high-temperature applications of catalysts such as partial oxidation of hydrocarbons and steam reforming. ... Two-dimensional (2D) studies of gas exchange within different heat zones of the combustion process provide valuable insights into the gas-phase dynamics. ... This may be the case at the high combustion temperatures, but neither experimental nor theoretical xenon chemical shift data is available in current literature for temperatures above 1000 K. ...

Satyanarayana Anala; Galina E. Pavlovskaya; Prakash Pichumani; Todd J. Dieken; Michael D. Olsen; Thomas Meersmann

2003-10-07T23:59:59.000Z

277

Resonance scattering formalism for the hydrogen lines in the presence of magnetic and electric fields  

Science Journals Connector (OSTI)

We derive a formalism for the computation of resonance-scattering polarization of hydrogen lines in the presence of simultaneous magnetic and electric fields, within a framework of the quantum theory of polarized line formation in the limit of complete frequency redistribution and of collisionless regime. Quantum interferences between fine-structure levels are included in this formalism. In the presence of a magnetic field, these interferences affect, together with the magnetic Hanle effect, the polarization of the atomic levels. In the presence of an electric field, interferences between distinct orbital configurations are also induced, further affecting the polarization of the hydrogen levels. In turn, the electric field is expected to affect the polarization of the atomic levels (electric Hanle effect), in a way analogous to the magnetic Hanle effect. We find that the simultaneous action of electric and magnetic fields give rise to complicated patterns of polarization and depolarization regimes, for varying geometries and field strengths.

Roberto Casini

2005-06-22T23:59:59.000Z

278

Effect of magnetic field profile on the uniformity of a distributed electron cyclotron resonance plasma  

SciTech Connect (OSTI)

This study extensively measured the uniformity of an electron cyclotron resonance (ECR) plasma versus the magnetic field distribution. The influence of magnetic field distribution on the generation of uniform ECR plasma was examined. It is suggested that in addition to the uniformity of the magnetic field distribution at ECR zone and at the downstream zone near the substrate, the transition of the magnetic field between these two zones is also crucial. A uniform ECR plasma with the electron density uniformity of 7.7% over 500 500 mm{sup 2} was measured at the downstream. The idea of generating uniform ECR plasma can be scaled up to a much larger area by using an n n microwave input array and a well-designed magnetic system.

Huang, C. C.; Chou, S. F. [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan (China)] [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, T. H.; Chao, H. W. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)] [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China); Chen, C. C. [Chung-Shan Institute of Science and Technology, Lung-Tan, Taoyuan, Taiwan (China)] [Chung-Shan Institute of Science and Technology, Lung-Tan, Taoyuan, Taiwan (China)

2013-07-15T23:59:59.000Z

279

In Vivo 14N Nuclear Magnetic Resonance Spectroscopy of Tumors: Detection of Ammonium and Trimethylamine Metabolites in the Murine Radiation Induced Fibrosarcoma 1  

Science Journals Connector (OSTI)

...ammonium in the tumor to nuclear magnetic resonance...possible pathway for energy production in the...ammonium in the tumor to nuclear magnetic resonance...possible pathway for energy production in the...ammonium in the tumor to nuclear magnetic resonance...possible pathway for energy production in the...

Michael P. Gamcsik; Ioannis Constantinidis; and Jerry D. Glickson

1991-07-01T23:59:59.000Z

280

31P Nuclear Magnetic Resonance Spectroscopy Studies of Tumor Energy Metabolism and Its Relationship to Intracapillary Oxyhemoglobin Saturation Status and Tumor Hypoxia  

Science Journals Connector (OSTI)

...Special Lecture 31P Nuclear Magnetic Resonance...Studies of Tumor Energy Metabolism and Its...MLS, OWI). Tumor energy metabolism was studied in vivo by 31P nuclear magnetic resonance...by hypoxia. 31P nuclear magnetic resonance...studies of tumor energy metabolism and its...

Einar K. Rofstad; Paul DeMuth; Bruce M. Fenton; and Robert M. Sutherland

1988-10-01T23:59:59.000Z

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.


281

E-Print Network 3.0 - anisotropic nmr samples Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

resonance (NMR) in solution. This review surveys... the method of NMR structure determination. First, a brief introduction to ... Source: Wider, Gerhard - Institut fr...

282

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

283

Identification of breast calcification using magnetic resonance imaging  

SciTech Connect (OSTI)

MRI phase and magnitude images provide information about local magnetic field variation ({Delta}B{sub 0}), which can consequently be used to understand tissue properties. Often, phase information is discarded. However, corrected phase images are able to produce contrast as a result of magnetic susceptibility differences and local field inhomogeneities due to the presence of diamagnetic and paramagnetic substances. Three-dimensional (3D) susceptibility weighted imaging (SWI) can be used to probe changes in MRI phase evolution and, subsequently, result in an alternate form of contrast between tissues. For example, SWI has been useful in the assessment of negative phase induced {Delta}B{sub 0} modulation due to the presence of paramagnetic substances such as iron. Very little, however, has been done to assess positive phase induced contrast changes resulting from the presence of diamagnetic substances such as precipitated calcium. As ductal carcinoma in situ, which is the precursor of invasive ductal cancer, is often associated with breast microcalcification, the authors proposed using SWI as a possible visualization technique. In this study, breast phantoms containing calcifications (0.4-1.5 mm) were imaged using mammography, computed tomography (CT), and SWI. Corrected phase and magnitude images acquired using SWI allowed identification and correlation of all calcifications seen on CT. As the approach is a 3D technique, it could potentially allow for more accurate localization and biopsy and maybe even reduce the use of gadolinium contrast. Furthermore, the approach may be beneficial to women with dense breast tissue where the ability to detect microcalcification with mammography is reduced.

Fatemi-Ardekani, Ali; Boylan, Colm; Noseworthy, Michael D. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada) and Imaging Research Centre, Brain-Body Institute, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Diagnostic Imaging, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada) and Department of Radiology, McMaster University, Hamilton, Ontario L8N 3Z5 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario L8S 4K1 (Canada); Imaging Research Centre, Brain-Body Institute, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Diagnostic Imaging, St. Joseph's Healthcare, Hamilton, Ontario L8N 4A6 (Canada); Department of Radiology, McMaster University, Hamilton, Ontario L8N 3Z5 (Canada) and Electrical and Computer Engineering, and School of Biomedical Engineering, McMaster University, Hamilton, Ontario L8S 4K1 (Canada)

2009-12-15T23:59:59.000Z

284

Laboratory studies of the dynamic of resonance cones formation in magnetized plasmas  

SciTech Connect (OSTI)

The paper is devoted to experimental studies of formation of resonance cones in magnetized plasmas by pulsed RF source in the lower-hybrid (whistler) and the upper-hybrid frequency ranges. It is shown that in both frequency ranges, resonance cones exhibit similar dynamics after switching-on the RF source: at first, wide maxima of radiation are formed in non-resonance directions, which then become narrower, with their direction approaching the resonance one. While the resonance cones are being formed, one observes a fine structure in the form of secondary radiation maxima. It is shown that the characteristic formation time of stationary resonance cones is determined by the minimal value of the group velocity of the quasi-electrostatic waves excited by the antenna. In the low-temperature plasma, this value is limited in the lower-hybrid frequency range by the spatial spectrum of the emitting antenna and in the upper-hybrid range, by the effects of spatial plasma dispersion.

Nazarov, V. V.; Starodubtsev, M. V.; Kostrov, A. V. [Russian Academy of Sciences, Institute of Applied Physics, Nizhny Novgorod (Russian Federation)

2013-03-15T23:59:59.000Z

285

Magnet tests and status of the superconducting electron cyclotron resonance source SERSE  

SciTech Connect (OSTI)

At Laboratorio Nazionale del Sud a superconducting 14.5 GHz electron cyclotron resonance (ECR) source will be used as injector for the K-800 superconducting cyclotron. The original project of its magnetic system has been upgraded by taking into account the results of the high B mode operation of the 6.4 GHz SC-ECRIS at MSU-NSCL and now the mirror field may achieve 2.7 T, which is much higher than the confining field of any other ECR source. The magnet design will allow us to operate in a wide range of magnetic configurations making it easy to tune the source. The status of the project will be outlined and the preliminary results of the tests of the superconducting magnets will be described. A brief description of the tests to be carried out on the source during the first period of operation on the test bench in Grenoble follows. {copyright} {ital 1996 American Institute of Physics.}

Ciavola, G.; Gammino, S.; Cafici, M.; Castro, M.; Chines, F.; Marletta, S. [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy)] [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy); Alessandria, F. [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy)] [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy); Bourg, F.; Briand, P.; Melin, G.; Lagnier, R.; Seyfert, P. [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France)] [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France); Gaggero, G.; Losasso, M.; Penco, R. [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)] [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)

1996-03-01T23:59:59.000Z

286

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

287

Theory of high-power cyclotron-resonance heating in an inhomogeneous magnetic field  

Science Journals Connector (OSTI)

Wave-energy absorption of a plasma due to cyclotron harmonic resonance is evaluated analytically and by a simulation. The static magnetic field is characterized with B??B=0, and a longitudinal wave is supposed to propagate across the magnetic field. In the calculation an orbit modification of the cyclotron motion of particles is taken into account. It is found that the absorption for the fundamental harmonic resonance (m=1) is depressed from that of the conventional linear theory while the absorptions for m?2 are enhanced, where m is the harmonic number. The enhancement is significant when k?t?1 (k the perpendicular wave number and ?t the gyroradius of the thermal particle) and when the interaction time between the plasma particles and the wave exceeds a critical value that is obtainable analytically. For all m and k?t, there appear peaks or saturations in the time evolution of the absorbed energy.

Ryo Sugihara and Yuichi Ogawa

1992-03-15T23:59:59.000Z

288

Florence, 28/02/2011: Two applied inverse problems: Introduction 1 -Problem #1: Studying the protein fold via NMR constraints.  

E-Print Network [OSTI]

the protein fold via NMR constraints. In collaboration with the CERM (Centre for Magnetic Resonance problems. #12;Florence, 28/02/2011: Two applied inverse problems: The problem of protein folding 2 H CCN) Backbone #12;Florence, 28/02/2011: Two applied inverse problems: The problem of protein folding 3 Genoma

Pedicini, Marco

289

Evaluation of Hydatid Disease of the Heart with Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Two patients with cardiac involvement of hydatid disease are presented: one with hydatid cyst of the interventricular septum and pulmonary arteries and the other with multiple pulmonary cysts associated with intracardiac and pericardial cysts. The ability of magnetic resonance imaging (MRI) to provide a global view of cardiac anatomy in any plane with high contrast between flowing blood and soft tissue ensures it an important role in the diagnosis and preoperative assessment of hydatid disease of the heart.

Kotoulas, Grigoris K.; Magoufis, George L.; Gouliamos, Athanasios D.; Athanassopoulou, Alexandra K.; Roussakis, Arcadios C.; Koulocheri, Dimitra P.; Kalovidouris, Angelos; Vlahos, Labros [Department of Radiology, CT-MRI Unit, Areteion Hospital, University of Athens, 76 Vas. Sophias Ave., GR-115 28 Athens (Greece)

1996-05-15T23:59:59.000Z

290

Shapiro-like resonance in ultracold molecule production via an oscillating magnetic field  

SciTech Connect (OSTI)

We study the process of the production of ultracold molecules from ultracold atoms using a sinusoidally oscillating magnetic-field modulation. Our study is based on a two-mode mean-field treatment of the problem. When the magnetic field is resonant roughly with the molecular binding energy, Shapiro-like resonances are observed. Their resonance profiles are well fitted by the Lorentzian functions. The linewidths depend on both the amplitude and the duration of the applied modulations and are found to be dramatically broadened by the thermal dephasing effect. The resonance centers shift due to both the many-body effect and the finite temperature effect. Our theory is consistent with a recent experiment [S. T. Thompson, E. Hodby, and C. E. Wieman, Phys. Rev. Lett. 95, 190404 (2005)]. Our model predicts a 1/3 ceiling for the molecular production yield in uncondensed ultracold atomic clouds for a long coupling time, while for condensed atoms the optimal conversion yield could be beyond the limit.

Liu Bin [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Graduate School, China Academy of Engineering Physics, Beijing 100088 (China); Fu Libin; Liu Jie [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Center for Applied Physics and Technology, Peking University, Beijing 100084 (China)

2010-01-15T23:59:59.000Z

291

Construction of a two-parameter empirical model of left ventricle wall motion using cardiac tagged magnetic resonance imaging data  

E-Print Network [OSTI]

visualized using cardiac tagged magnetic resonance imaging (tMRI) covering the contraction and relaxation phases. Based on the characteristics of the overall dynamics of the LV wall, its motion was represented by a combination of two components - radial...

Shi, Jack J; Alenezy, Mohammed D.; Smirnova, Irina V.; Bilgen, Mehmet

2012-10-24T23:59:59.000Z

292

JOURNAL OF MAGNETIC RESONANCE 87,620-627 ( 1990) Practical Aspectsof Proton-Carbon-Carbon-Proton Three-  

E-Print Network [OSTI]

JOURNAL OF MAGNETIC RESONANCE 87,620-627 ( 1990) Practical Aspectsof Proton-Carbon-Carbon and demonstrate improvements that greatly reduce their intensity. 0022-2364190 $3.00 Copyright 0 1990 by Academic

Clore, G. Marius

293

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

294

Imaging in population science: cardiovascular magnetic resonance in 100,000 participants of UK Biobank - rationale, challenges and approaches  

Science Journals Connector (OSTI)

Steffen E Petersen et al discuss the rationale, challenges and approaches of the large Cardiovascular Magnetic Resonance imaging study that will be part of the UK Biobank project investigating major life-threatening illnesses such as heart disease and stroke.

Steffen E Petersen; Paul M Matthews; Fabian Bamberg; David A Bluemke; Jane M Francis; Matthias G Friedrich; Paul Leeson; Eike Nagel; Sven Plein; Frank E Rademakers; Alistair A Young; Steve Garratt; Tim Peakman; Jonathan Sellors; Rory Collins; Stefan Neubauer

2013-05-28T23:59:59.000Z

295

NMR studies of oriented molecules  

SciTech Connect (OSTI)

Deuterium and proton magnetic resonance are used in experiments on a number of compounds which either form liquid crystal mesophases themselves or are dissolved in a liquid crystal solvent. Proton multiple quantum NMR is used to simplify complicated spectra. The theory of nonselective multiple quantum NMR is briefly reviewed. Benzene dissolved in a liquid crystal are used to demonstrate several outcomes of the theory. Experimental studies include proton and deuterium single quantum (..delta..M = +-1) and proton multiple quantum spectra of several molecules which contain the biphenyl moiety. 4-Cyano-4'-n-pentyl-d/sub 11/-biphenyl (5CB-d/sub 11/) is studied as a pure compound in the nematic phase. The obtained chain order parameters and dipolar couplings agree closely with previous results. Models for the effective symmetry of the biphenyl group in 5CB-d/sub 11/ are tested against the experimental spectra. The dihedral angle, defined by the planes containing the rings of the biphenyl group, is found to be 30 +- 2/sup 0/ for 5DB-d/sub 11/. Experiments are also described for 4,4'-d/sub 2/-biphenyl, 4,4' - dibromo-biphenyl, and unsubstituted biphenyl.

Sinton, S.W.

1981-11-01T23:59:59.000Z

296

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

297

Flow units from integrated WFT and NMR data  

SciTech Connect (OSTI)

Reliable and continuous permeability profiles are vital as both hard and soft data required for delineating reservoir architecture. They can improve the vertical resolution of seismic data, well-to-well stratigraphic correlations, and kriging between the well locations. In conditional simulations, permeability profiles are imposed as the conditioning data. Variograms, covariance functions and other geostatistical indicators are more reliable when based on good quality permeability data. Nuclear Magnetic Resonance (NMR) logging and Wireline Formation Tests (WFT) separately generate a wealth of information, and their synthesis extends the value of this information further by providing continuous and accurate permeability profiles without increasing the cost. NMR and WFT data present a unique combination because WFTs provide discrete, in situ permeability based on fluid-flow, whilst NMR responds to the fluids in the pore space and yields effective porosity, pore-size distribution, bound and moveable fluid saturations, and permeability. The NMR permeability is derived from the T{sub 2}-distribution data. Several equations have been proposed to transform T{sub 2} data to permeability. Regardless of the transform model used, the NMR-derived permeabilities depend on interpretation parameters that may be rock specific. The objective of this study is to integrate WFT permeabilities with NMR-derived, T{sub 2} distribution-based permeabilities and thereby arrive at core quality, continuously measured permeability profiles. We outlined the procedures to integrate NMR and WFT data and applied the procedure to a field case. Finally, this study advocates the use of hydraulic unit concepts to extend the WFT-NMR derived, core quality permeabilities to uncored intervals or uncored wells.

Kasap, E.; Altunbay, M.; Georgi, D.

1997-08-01T23:59:59.000Z

298

Magnetic Field Decay Due to the Wave-Particle Resonances in the Outer Crust of the Neutron Star  

E-Print Network [OSTI]

Bearing in mind the application to the outer crust of the neutron stars (NSs), we investigate the magnetic field decay by means of the fully relativistic Particle-In-Cell simulations. Numerical computations are carried out in 2-dimensions, in which the initial magnetic fields are set to be composed both of the uniform magnetic fields that model the global fields penetrating the NS and of the turbulent magnetic fields that would be originated from the Hall cascade of the large-scale turbulence. Our results show that the whistler cascade of the turbulence transports the magnetic energy preferentially in the direction perpendicular to the uniform magnetic fields. It is also found that the distribution function of electrons becomes anisotropic because electrons with lower energies are predominantly heated in the direction parallel to the uniform magnetic fields due to the Landau resonance, while electrons with higher energies are heated mainly by the cyclotron resonance that makes the distribution function isotro...

Takahashi, Hiroyuki R; Yasutake, Nobutoshi

2010-01-01T23:59:59.000Z

299

Observations of thermally excited ferromagnetic resonance on spin torque oscillators having a perpendicularly magnetized free layer  

SciTech Connect (OSTI)

Measurements of thermally excited ferromagnetic resonance were performed on spin torque oscillators having a perpendicularly magnetized free layer and in-plane magnetized reference layer (abbreviated as PMF-STO in the following) for the purpose of obtaining magnetic properties in the PMF-STO structure. The measured spectra clearly showed a large main peak and multiple smaller peaks on the high frequency side. A Lorentzian fit on the main peak yielded Gilbert damping factor of 0.0041. The observed peaks moved in proportion to the out-of-plane bias field. From the slope of the main peak frequency as a function of the bias field, Lande g factor was estimated to be about 2.13. The mode intervals showed a clear dependence on the diameter of the PMF-STOs, i.e., intervals are larger for a smaller diameter. These results suggest that the observed peaks should correspond to eigenmodes of lateral spin wave resonance in the perpendicularly magnetized free layer.

Tamaru, S., E-mail: shingo.tamaru@aist.go.jp; Kubota, H.; Yakushiji, K.; Konoto, M.; Nozaki, T.; Fukushima, A.; Imamura, H.; Taniguchi, T.; Arai, H.; Tsunegi, S.; Yuasa, S. [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Suzuki, Y. [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

2014-05-07T23:59:59.000Z

300

Modeling two-dimensional magnetic resonance measurements in coupled pore systems  

Science Journals Connector (OSTI)

We present numerical simulations of a two-dimensional (2D) nuclear magnetic resonance process, T2-storage-T2, on a simple mixed porosity system, the micrograin consolidation (?GC) model. The results of these calculations are compared with predictions based on the analytic two-site exchange model, for which we have independently established numerical values for all the input parameters. Although there is qualitative and semiquantitative agreement between the two models, we identify specific instances where the two-site model fails to properly describe the combined effects of relaxation and diffusion. Generally, these instances occur when a gradient in magnetization within the large pores of the ?GC model is established during the initial phase of the 2D process. The two-site model assumes that the magnetization is spatially uniform within each of its subpore systems and thus cannot describe such effects.

L. M. Schwartz; D. L. Johnson; J. Mitchell; T. C. Chandrasekera; E. J. Fordham

2013-09-30T23:59:59.000Z

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.


301

Complementary polarized neutron and resonant x-ray magnetic reflectometry measurements in Fe/Gd heterostructures : case of inhomogeneous intralayer magnetic structure.  

SciTech Connect (OSTI)

A unified approach combining polarized neutron and resonant x-ray magnetic reflectometry has been applied to determine the magnetic structure in an [Fe(35 {angstrom})/Gd(50 {angstrom})]{sub 5} multilayer as a function of temperature and magnetic field. Simultaneous self-consistent refinement of neutron and x-ray data made it possible to resolve the element-specific magnetization profile in the multilayer with unprecedented accuracy. It is shown that the small number of bilayer periods together with the asymmetric termination (Fe-top, Gd-bottom) lead to unique low-temperature magnetic phases characterized by significant twisting of Fe and Gd magnetic moments and nonuniform distribution of vectorial magnetization within Gd layers. A twisted magnetic state was found to be stable at small magnetic fields and at a low temperature of 20 K, which is well below the compensation temperature of this artificial ferrimagnetic system.

Kravtsov, E.; Haskel, D.; teVelthuis, S. G. E.; Jiang, J. S.; Kirby, B. J.; NIST Center for Neutron Research

2009-01-01T23:59:59.000Z

302

An ex Vivo Model for the Study of Tumor Metabolism by Nuclear Magnetic Resonance: Characterization of the Phosphorus-31 Spectrum of the Isolated Perfused Morris Hepatoma 7777  

Science Journals Connector (OSTI)

...el al. In vivo "P nuclear magnetic resonance spectroscopy...M. J. Phosphorus nuclear magnetic resonance of...Nunnally, R. L. High-energy phosphates and function...monilored by in vivo 31P nuclear magnelic resonance speclroscopy...adminislralion on Ihe energy slale of in vivo liver...

Robert A. Graham; Truman R. Brown; and Ronald A. Meyer

1991-02-01T23:59:59.000Z

303

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

304

An UHV apparatus for X-ray resonant magnetic reflectivity in the hard X-ray range  

SciTech Connect (OSTI)

We present the development of a novel UHV compact reflectometer designed and developed for the investigation of magnetic properties of thin films at the ID12-E.S.R.F. beamline. This new instrument is dedicated to x-ray resonant magnetic reflectivity experiment from thin film or multilayered sample. We present the principles of this versatile and simple instrument. We report also the results of resonant magnetic reflectivity experiments carried out for the Fe/Ir multilayers. This will demonstrate the capability to record either angle or energy dependent measurements at the L edges of Ir simultaneously to the XMCD spectra.

Jaouen, N.; Wilhelm, F.; Rogalev, A.; Goulon, J. [European Synchrotron Radiation Facility, BP220, F-38043 Grenoble (France); Tonnerre, J.M. [Laboratoire de Cristallographie, CNRS, BP166, F-38042 Grenoble (France)

2004-05-12T23:59:59.000Z

305

Polypeptide backbone resonance assignments and secondary structure of Bacillus subtilis enzyme III sup glc determined by two-dimensional and three-dimensional heteronuclear NMR spectroscopy  

SciTech Connect (OSTI)

The enzyme III{sup glc}-like domain of Bacillus subtilis II{sup glc} (III{sup glc}; 162 residues, 17.4 kDa) has been cloned and overexpressed in Escherichia coli. Sequence-specific assignment of the backbone {sup 1}H and {sup 15}N resonances has been carried out with a combination of mohonuclear and heteronuclear two-dimensional and heteronuclear three-dimensional (3D) NMR spectroscopy. Amide proton solvent exchange rate constants have been determined from a series of {sup 1}H-{sup 15}N heteronuclear single-quantum coherence (HSQC) spectra acquired following dissolution of the protein in D{sub 2}O. Major structural features of III{sup glc} have been inferred from the pattern of short-, medium- and long-range NOEs in 3D heteronuclear {sup 1}H nuclear Overhauser effect {sup 1}H-{sup 15}N multiple-quantum coherence (3D NOESY-HMQC) spectra, together with the exchange rate constants. III{sup glc} contains three antiparallel {beta}-sheets comprised of eight, three, and two {beta}-strands. In addition, five {beta}-bulges were identified. no evidence of regular helical structure was found. The N-terminal 15 residues of the protein appear disordered, which is consistent with their being part of the Q-linker that connects the C-terminal enzyme III{sup glc}-like domain to the membrane-bound II{sup glc} domain. Significantly, two histidine residues, His 68 and His 83, which are important for phosphotransferase function, are found from NOE measurements to be in close proximity at the ends of adjacent strands in the major {beta}-sheet.

Fairbrother, W.J.; Cavanagh, J.; Dyson, H.J.; Palmer, A.G. III; Wright, P.E. (Research Inst. of Scripps Clinic, La Jolla, CA (United States)); Sutrina, S.L.; Reizer, J.; Saier, M.H. Jr. (Univ. of California, San Diego (United States))

1991-07-16T23:59:59.000Z

306

The reaction $?p \\to ?^\\circ ?^\\prime p$ and the magnetic dipole moment of the $?^+(1232)$ resonance  

E-Print Network [OSTI]

The reaction $\\gamma p \\to \\pi^\\circ \\gamma^\\prime p$ has been measured with the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for energies between $\\sqrt{s}$ = 1221--1331 MeV. Cross sections differential in angle and energy have been determined for all particles in the final state in three bins of the excitation energy. This reaction channel provides access to the magnetic dipole moment of the $\\Delta^{+}(1232)$ resonance and, for the first time, a value of $\\mu_{\\Delta^+} = (2.7_{-1.3}^{+1.0}(stat.) \\pm 1.5 (syst.) \\pm 3(theo.)) \\mu_N$ has been extracted.

M. Kotulla; J. Ahrens; J. R. M. Annand; R. Beck; G. Caselotti; L. S. Fog; D. Hornidge; S. Janssen; B. Krusche; J. C. McGeorge; I. J. D. McGregor; K. Mengel; J. G. Messchendorp; V. Metag; R. Novotny; M. Pfeiffer; M. Rost; S. Sack; R. Sanderson; S. Schadmand; D. P. Watts

2002-10-31T23:59:59.000Z

307

A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization  

SciTech Connect (OSTI)

The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate magnetic resonance (MR) techniques and acoustic measurements to improve predictability of the pay zone in two hydrocarbon reservoirs. This was accomplished by extracting the fluid property parameters using MR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurements were compared with petrographic analysis results to determine the relative roles of petrographic elements such as porosity type, mineralogy, texture, and distribution of clay and cement in creating permeability heterogeneity.

Parra, J.O.

2001-01-26T23:59:59.000Z

308

Abnormal Subendocardial Perfusion in Cardiac Syndrome X Detected by Cardiovascular Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

Between 10 and 20 percent of patients with typical anginal chest pain are found to have normal coronary angiograms. A subgroup of these patients, who also have classic downsloping ST-segment depression on exercise testing, are classified as having cardiac syndrome X. The exact pathophysiological... Patients with cardiac syndrome X have angina and abnormal exercise-test results but normal findings on coronary angiography. Although myocardial ischemia has been suspected to be the cause, this has been difficult to document. In this study, myocardial-perfusion magnetic resonance imaging demonstrated abnormal subendocardial perfusion during adenosine infusion in 20 patients with the syndrome.

Panting J.R.; Gatehouse P.D.; Yang G.-Z.

2002-06-20T23:59:59.000Z

309

An implementation of the Deutsch-Jozsa algorithm on a three-qubit NMR quantum computer  

E-Print Network [OSTI]

A new approach to the implementation of a quantum computer by high-resolution nuclear magnetic resonance (NMR) is described. The key feature is that two or more line-selective radio-frequency pulses are applied simultaneously. A three-qubit quantum computer has been investigated using the 400 MHz NMR spectrum of the three coupled protons in 2,3-dibromopropanoic acid. It has been employed to implement the Deutsch-Jozsa algorithm for distinguishing between constant and balanced functions. The extension to systems containing more coupled spins is straightforward and does not require a more protracted experiment.

N Linden H Barjat R Freeman

1998-08-21T23:59:59.000Z

310

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

311

Edge Stability and Transport Control with Resonant Magnetic Perturbations in Collisionless Tokamak Plasmas  

SciTech Connect (OSTI)

A critical issue for fusion plasma research is the erosion of the first wall of the experimental device due to impulsive heating from repetitive edge magneto-hydrodynamic (MHD) instabilities known as 'edge-localized modes' (ELMs). Here, we show that the addition of small resonant magnetic field perturbations completely eliminates ELMs while maintaining a steady-state high-confinement (H-mode) plasma. These perturbations induce a chaotic behavior in the magnetic field lines, which reduces the edge pressure gradient below the ELM instability threshold. The pressure gradient reduction results from a reduction in particle content of the plasma, rather than an increase in the electron thermal transport. This is inconsistent with the predictions of stochastic electron heat transport theory. These results provide a first experimental test of stochastic transport theory in a highly rotating, hot, collisionless plasma and demonstrate a promising solution to the critical issue of controlling edge instabilities in fusion plasma devices.

Evans, T E; Moyer, R A; Burrell, K H; Fenstermacher, M E; Joseph, I; Leonard, A W; Osborne, T H; Porter, G D; Schaffer, M J; Snyder, P B; Thomas, P R; Watkins, J G; West, W P

2006-06-13T23:59:59.000Z

312

Application of polarized neutron reflectometry and x-ray resonant magnetic reflectometry for determining the inhomogeneous magnetic structure in Fe/Gd multilayers.  

SciTech Connect (OSTI)

The evolution of the magnetic structure of multilayer [Fe (35 {angstrom})/Gd (50 {angstrom}){sub 5}] with variation in temperature and an applied magnetic field was determined using a complementary approach combining polarized neutron and X-ray resonant magnetic reflectometry. Self-consistent simultaneous analysis of X-ray and neutron spectra allowed us to determine the elemental and depth profiles in the multilayer structure with unprecedented accuracy, including the identification of an inhomogeneous intralayer magnetic structure with near-atomic resolution.

Kravtsov, E. A.; Haskel, D.; te Velthuis, S. G. E.; Jiang, J. S.; Kirby, B. J. (Materials Science Division); ( XSD); (Russian Academy of Sciences and Ural Federal Univ.); (Ural State Technical Univ.); (NIST Center for Neutron Research)

2010-01-01T23:59:59.000Z

313

Iron-57 nuclear magnetic resonance chemical shifts of hindered iron porphyrins. Ruffling as a possible mechanism for d-orbital energy level inversion  

Science Journals Connector (OSTI)

Iron-57 nuclear magnetic resonance chemical shifts of hindered iron porphyrins. ... Ruffling as a possible mechanism for d-orbital energy level inversion ...

Lars Baltzer; Marie Landergren

1990-03-01T23:59:59.000Z

314

NMR and EPR  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

294 Science Drivers and Technical Challenges for Advanced Magnetic Resonance KT Mueller NM Washton M Pruski AS Lipton Report: March 2013 Prepared for the U.S. Department of...

315

Received: 21 August 2008, Revised: 17 February 2009, Accepted: 13 March 2009, Published online in Wiley InterScience: 2009 H NMR metabolomics study of age profiling  

E-Print Network [OSTI]

of aging, as a vast number of effects such as stress, dietary choices, environmental factors, daily by 1 H NMR spectroscopy of urine. The effect of age on the urinary metabolite profile was observed profiling; metabolomics; metabonomics; nuclear magnetic resonance; orthogonal signal correction; principal

Xi, Bowei

316

Roles of chemically inequivalent N(CH3)4 ions in phase transition temperatures in [N(CH3)4]2CoCl4 by single-crystal NMR and MAS NMR  

Science Journals Connector (OSTI)

Abstract The temperature dependences of the 1H and 13C spinlattice relaxation time in the laboratory frame, T1, and in the rotating frame, T1?, in [N(CH3)4]2CoCl4 were measured by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. In the ferroelastic phase, 1H T1? underwent molecular motion according to the BloembergenPurcellPound theory. Two inequivalent ions, a-N(CH3)4 and b-N(CH3)4, were identified by 13C cross polarization (CP)/MAS NMR. On the basis of the 13C NMR results, the existence of two chemically inequivalent a-N(CH3)4 and b-N(CH3)4 ions in the ferroelectric phase and the existence of the ferroelastic twin structure of the N(CH3)4 ions in the ferroelastic phase were discussed.

Ae Ran Lim

2014-01-01T23:59:59.000Z

317

NMR characterization of thin films  

DOE Patents [OSTI]

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

318

Magnet options for sensors for the pulp and paper industry  

SciTech Connect (OSTI)

The Lawrence Berkeley National Laboratory (LBNL) has been developing sensors for the pulp and paper industry that uses a magnetic field. The applications for magnetic sensors that have studied include (1) sensors for the measurement of the water and ice content of wood chips entering the pulping mill, (2) sensors for measuring the water content and other constituents of the black liquor leaving the paper digester, and (3) sensors for measuring paper thickness and water content as the paper is being processed. These tasks can be done using nuclear magnetic resonance (NMR). The magnetic field used for doing the NMR can come from either permanent magnets or superconducting magnets. The choice of the magnet is dependent on a number of factors, which include the size of the sample and field strength needed to do the sensing task at hand. This paper describes some superconducting magnet options that can be used in the pulp and paper industry.

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

2001-05-05T23:59:59.000Z

319

Two approaches to 3D reconstruction in NMR zeugmatography  

SciTech Connect (OSTI)

In nuclear magnetic resonance (NMR) zeugmatography, the primary data pertain to integrals of the unknown nuclear spin density f(x,y,z) over planes instead of lines in R/sup 3/. Two natural approaches to reconstructing f from such data are: (1) By numerical implementation of the inverse Radon transform in three dimensions (the direct approach), and (2) by application, in two successive stages, of existing well-known algorithms for inverting the two-dimensional Radon transform (the two-stage approach). These two approaches are discussed and compared, both from a theoretical standpoint and through computer results obtained with real NMR data. For the cases studied to date the two methods appear to produce qualitatively similar results.

Marr, R B; Chen, C N; Lauterbur, P C

1980-01-01T23:59:59.000Z

320

The NMR solution conformation of unligated human cyclophilin A  

Science Journals Connector (OSTI)

The nuclear magnetic resonance (NMR) solution structure of free, unligated cyclophilin A (CypA), which is an 18 kDa protein from human T-lymphocytes that was expressed in Escherichia coli for the present study, was determined using multidimensional heteronuclear NMR techniques. Sequence-specific resonance assignments for 99.5% of all backbone amide protons and non-labile hydrogen atoms provided the basis for collection of an input of 4101 nuclear Overhauser enhancement (NOE) upper distance constraints and 371 dihedral angle constraints for distance geometry calculations and energy minimization with the programs DIANA and OPAL. The average RMSD values of the 20 best energy-refined NMR conformers relative to the mean coordinates are 0.49 for the backbone atoms and 0.88 for all heavy atoms of residues 2 to 165. The molecular architecture includes an eight-stranded antiparallel ?-barrel that is closed by two amphipathic ?-helices. Detailed comparisons with the crystal structure of free CypA revealed subtle but significant conformational differences that can in most cases be related to lattice contacts in the crystal structure. 15N spin relaxation times and NMR lineshape analyses for CypA in the free form and complexed with cyclosporin A (CsA) revealed transitions of polypeptide loops surrounding the ligand-binding site from locally flexible conformations in the free protein, some of which include well-defined conformational equilibria, to well-defined spatial arrangements in the CypA-CsA complex. Compared to the crystal structure of free CypA, where the ligand-binding area is extensively involved in lattice contacts, the NMR structure presents a highly relevant reference for studies of changes in structure and internal mobility of the binding pocket upon ligand binding, and possible consequences of this conformational variability for calcineurin recognition by the CypA-CsA complex.

Marcel Ottiger; Oliver Zerbe; Peter Gntert; Kurt Wthrich

1997-01-01T23:59:59.000Z

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.


321

NMR CHARACTERIZATIONS OF PROPERTIES OF HETEROGENEOUS MEDIA  

SciTech Connect (OSTI)

A critical and long-standing need within the petroleum industry is the specification of suitable petrophysical properties for mathematical simulation of fluid flow in petroleum reservoirs (i.e., reservoir characterization). The development of accurate reservoir characterizations is extremely challenging. Property variations may be described on many scales, and the information available from measurements reflect different scales. In fact, experiments on laboratory core samples, well-log data, well-test data, and reservoir-production data all represent information potentially valuable to reservoir characterization, yet they all reflect information about spatial variations of properties at different scales. Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) provide enormous potential for developing new descriptions and understandings of heterogeneous media. NMR has the rare capability to probe permeable media non-invasively, with spatial resolution, and it provides unique information about molecular motions and interactions that are sensitive to morphology. NMR well-logging provides the best opportunity ever to resolve permeability distributions within petroleum reservoirs. We develop MRI methods to determine, for the first time, spatially resolved distributions of porosity and permeability within permeable media samples that approach the intrinsic scale: the finest resolution of these macroscopic properties possible. To our knowledge, this is the first time that the permeability is actually resolved at a scale smaller than the sample. In order to do this, we have developed a robust method to determine of relaxation distributions from NMR experiments and a novel implementation and analysis of MRI experiments to determine the amount of fluid corresponding to imaging regions, which are in turn used to determine porosity and saturation distributions. We have developed a novel MRI experiment to determine velocity distributions within flowing experiments, and developed methodology using that data to determine spatially resolved permeability distributions. We investigate the use of intrinsic properties for developing improved correlations for predicting permeability from NMR well-logging data and for obtaining more accurate estimates of multiphase flow properties--the relative permeability and capillary pressure--from displacement experiments. We demonstrate the use of MRI measurements of saturation and relaxation for prediction wetting-phase relative permeability for unstable experiments. Finally, we developed an improved method for determining surface relaxivity with NMR experiments, which can provide better descriptions of permeable media microstructures and improved correlations for permeability predictions.

C.T. Philip Chang; Changho Choi; Jeromy T. Hollenshead; Rudi Michalak; Jack Phan; Ramon Saavedra; John C. Slattery; Jinsoo Uh; Randi Valestrand; A. Ted Watson; Song Xue

2005-01-01T23:59:59.000Z

322

Nuclear Magnetic Resonance Inverse Spectra of InGaAs Quantum Dots: Atomistic Level Structural Information  

E-Print Network [OSTI]

A wealth of atomistic information is buried within a self-assembled quantum dot (QD), carrying the legacy of its chemical composition and the growth history. In the presence of quadrupolar nuclei, as in InGaAs QDs, much of this is inherited to nuclear spins. With this computational study, we identify what sorts of atomistic information can be tapped from a single InGaAs QD, as probed optically by the recently introduced highly sensitive inverse spectra nuclear magnetic resonance technique. To capture the fingerprints of alloying in the spectra, we compare In0.2Ga0.8As QD with the compound InAs QD of the same shape, as well as performing a search over the parameter space of the inverse spectra technique. We display how both the elemental nuclear properties and local bonding take roles. The arsenic nuclei with their small gyromagnetic ratio are the most vulnerable to strain at a given magnetic field. Furthermore, because of their large S44 gradient elastic tensor components, the deviation of the major electric field gradient axis from the static magnetic field is also the largest. Moreover, this axial tilting has a big variance caused by the availability of various arsenic-centric nearest-neighbor configurations under cation alloying. We identify that a signature of alloying as opposed to segregated binaries within the QD is a peak that appears like an additional satellite transition of 75As. The local chemical and strain environment distinctly affect the isotopic line profiles, in particular the central transitions, for which we provide an in-depth analysis. We demonstrate the possibility of restoring to a large extend a monoenergetic distribution of isotopic nuclear spins by simply tilting the sample within a range of angles with respect to static magnetic field.

Ceyhun Bulutay; E. A. Chekhovich; A. I. Tartakovskii

2014-08-02T23:59:59.000Z

323

Sub-nanometer resolution in three-dimensional magnetic-resonance imaging of individual dark spins  

E-Print Network [OSTI]

Magnetic resonance imaging (MRI) has revolutionized biomedical science by providing non-invasive, three-dimensional biological imaging. However, spatial resolution in conventional MRI systems is limited to tens of microns, which is insufficient for imaging on molecular and atomic scales. Here we demonstrate an MRI technique that provides sub-nanometer spatial resolution in three dimensions, with single electron-spin sensitivity. Our imaging method works under ambient conditions and can measure ubiquitous 'dark' spins, which constitute nearly all spin targets of interest and cannot otherwise be individually detected. In this technique, the magnetic quantum-projection noise of dark spins is measured using a single nitrogen-vacancy (NV) magnetometer located near the surface of a diamond chip. The spatial distribution of spins surrounding the NV magnetometer is imaged with a scanning magnetic-field gradient. To evaluate the performance of the NV-MRI technique, we image the three-dimensional landscape of dark electronic spins at and just below the diamond surface and achieve an unprecedented combination of resolution (0.8 nm laterally and 1.5 nm vertically) and single-spin sensitivity. Our measurements uncover previously unidentified electronic spins on the diamond surface, which can potentially be used as resources for improved magnetic imaging of samples proximal to the NV-diamond sensor. This three-dimensional NV-MRI technique is immediately applicable to diverse systems including imaging spin chains, readout of individual spin-based quantum bits, and determining the precise location of spin labels in biological systems.

M. S. Grinolds; M. Warner; K. De Greve; Y. Dovzhenko; L. Thiel; R. L. Walsworth; S. Hong; P. Maletinsky; A. Yacoby

2014-01-12T23:59:59.000Z

324

Site-Selective Determination of Magnetic Helices in BaTiCoFe{sub 10}O{sub 19} by Resonant Magnetic Scattering  

SciTech Connect (OSTI)

Synchrotron radiation intensity measurements were made for single crystals of ferrimagnetic BaTiCoFe{sub 10}O{sub 19} at the BL-6C(3A) beamline of the Photon Factory. The resonant x-ray magnetic scattering (RXMS) method at the Fe K edge makes it possible to determine the magnetic crystal structure, having the magnetic helices for Fe ions in tetrahedral 4f{sub 1}, bipyramidal 2b, and octahedral 2a, 4f{sub 2} and 12k sites. Based on the information on x-ray magnetic circular dichroism (XMCD) and a resonant magnetic scattering factor f''{sub m} ( = 0.23) estimated from BaFe{sub 12}O{sub 19} at E = 7128.2 eV, the magnetic structures have been determined from an asymmetrical ratio {Delta}R (Y{sup +}-Y{sup -})/(Y{sup +}+Y{sup -}), where Y{sup +} and Y{sup -} are scattering intensities for left- and right-circular polarizations, respectively. Spin orientations were estimated in the least-squares procedure to minimize a residual factor of {Sigma}({Delta}R{sub obs}-{Delta}R{sub calc}){sup 2}. The canting angles estimated in this study are 180 deg., 19 deg., 118 deg., 180 deg. and 65 deg. for the magnetic moments of Fe ions in 4f{sub 1}, 2b, 2a, 4f{sub 2} and 12k sites, respectively.

Okube, Maki; Kaneko, Yuhei; Ohsawa, Seiji; Sasaki, Satoshi [Materials and Structures Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226-8503 (Japan); Toyoda, Takeshi [Industrial Research Institute of Ishikawa, Kuratsuki 2-1, Kanazawa 920-8203 (Japan); Mori, Takeharu [Photon Factory, Institute of Materials Structure Science, KEK, Oho 1-1, Tsukuba 305-0801 (Japan)

2010-06-23T23:59:59.000Z

325

Structural analysis of lithium-excess lithium manganate cathode materials by 7Li magic-angle spinning nuclear magnetic resonance spectroscopy  

Science Journals Connector (OSTI)

The local structures of lithium-excess lithium manganese spinel oxides were studied by high-resolution solid-state 7Li magic-angle spinning (MAS) NMR spectroscopy. Two resonance lines at ?500 and ?555 ppm were observed for the spinels in 7Li MAS NMR spectra. Spinel stability tests in which spinel powder was stored in electrolyte solution were performed to analyze the changes in the lithium local structure after manganese dissolution. After the spinel stability test, the intensity of the resonance at ?500 ppm decreased, whereas new resonance line at 0 ppm was observed. The lithium content of the 0 ppm peak increases with the storage time in electrolyte. SEM and chemical analysis suggested a surface coating of non-spinel lithium compounds, the presence of defects on particles surface and fluorine incorporation into the aged spinel. In addition, about 6070% of lithium remains in the spinel framework after the storage.

Hideyuki Oka; Senshi Kasahara; Tadashi Okada; Eiichi Iwata; Masaki Okada; Takayuki Shoji; Hiroshi Ohki; Tsutomu Okuda

2001-01-01T23:59:59.000Z

326

Magnetic resonance detection of individual proton spins using a quantum reporter network  

E-Print Network [OSTI]

We demonstrate a method of magnetic resonance imaging with single nuclear-spin sensitivity under ambient conditions. It employs a network of isolated electronic-spin quantum bits (qubits) that act as quantum reporters on the surface of high purity diamond. The reporter spins are localized with nanometer-scale uncertainty, and their quantum state is coherently manipulated and measured optically via a proximal nitrogen-vacancy (NV) color center located a few nanometers below the diamond surface. The quantum reporter network is then used for sensing, coherent coupling and imaging individual proton spins on the diamond surface with angstrom resolution. This approach may enable direct structural imaging of complex molecules that cannot be accessed from bulk studies. It realizes a new platform for probing novel materials, monitoring chemical reactions, and manipulation of complex systems on surfaces at a quantum level.

Alexander O. Sushkov; Igor Lovchinsky; Nicholas Chisholm; Ronald L. Walsworth; Hongkun Park; Mikhail D. Lukin

2014-10-14T23:59:59.000Z

327

Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance  

SciTech Connect (OSTI)

The water-endofullerene H{sub 2}O@C{sub 60} provides a unique chemical system in which freely rotating water molecules are confined inside homogeneous and symmetrical carbon cages. The spin conversion between the ortho and para species of the endohedral H{sub 2}O was studied in the solid phase by low-temperature nuclear magnetic resonance. The experimental data are consistent with a second-order kinetics, indicating a bimolecular spin conversion process. Numerical simulations suggest the simultaneous presence of a spin diffusion process allowing neighbouring ortho and para molecules to exchange their angular momenta. Cross-polarization experiments found no evidence that the spin conversion of the endohedral H{sub 2}O molecules is catalysed by {sup 13}C nuclei present in the cages.

Mamone, Salvatore, E-mail: s.mamone@soton.ac.uk; Concistr, Maria; Carignani, Elisa; Meier, Benno; Krachmalnicoff, Andrea; Johannessen, Ole G.; Denning, Mark; Carravetta, Marina; Whitby, Richard J.; Levitt, Malcolm H., E-mail: mhl@soton.ac.uk [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom); Lei, Xuegong; Li, Yongjun [Department of Chemistry, Columbia University, New York, New York 10027 (United States)] [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Goh, Kelvin; Horsewill, Anthony J. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2014-05-21T23:59:59.000Z

328

Nuclear-Magnetic-Resonance Line Narrowing by a Rotating rf Field  

Science Journals Connector (OSTI)

A nuclear-magnetic-resonance method is explored, which effectively attenuates the dipolar interaction in solids. The experimental technique corresponds to the observation of a free-induction decay in a frame of reference rotating with the frequency of an applied rf field. When the amplitude H1 of this field is much greater than the local field in the solid, and when its frequency is appropriately chosen, the secular part of the dipolar interaction is removed. As a result the rotary saturation line is extremely narrowed. At smaller values of H1, nonsecular terms in the dipolar interaction come into play and contribute to line broadening. These nonsecular effects are investigated both theoretically and experimentally. All the measurements were made in single crystals of calcium fluoride. The calculation of the nonsecular contribution to the line width utilizes the unitary transformation method of Jordhal and Pryce. Theory and experiment are in good agreement.

Moses Lee and Walter I. Goldburg

1965-11-15T23:59:59.000Z

329

Intra-pixel multispectral processing of magnetic resonance brain images for tissue characterisation  

Science Journals Connector (OSTI)

Magnetic resonance (MR) image analysis is generally performed by spatial domainbased image processing, referred to as inter-pixel image processing, which takes advantage of spatial correlation among sample pixels. Unfortunately, in many areas, several tissue substances are usually present and mixed in a single image pixel in which such an inter-pixel processing either fails or is ineffective. To resolve this dilemma, this paper develops an unconventional approach, called intra-pixel processing, which considers MR images as multispectral images where a multispectral MR image pixel is actually a pixel vector, of which each component is captured by a particular image pulse sequence used for MR image acquisition. Since the commonly used receiver operating characteristic (ROC) curves cannot directly deal with the issues arising in intra-pixel processing, a 3D ROC analysis is developed by including a parameter t as the third dimension that represents abundance fractions thresholded by ?.

Clayton Chi-Chang Chen; Englin Wong; Hsian-Min Chen; Shih-Yu Chen; Jyh-Wen Chai; Ching-Wen Yang; San-Kan Lee; Yong-Kie Wong; Chein-I Chang

2013-01-01T23:59:59.000Z

330

Use of Superparamagnetic Nanoparticle/Block Copolymer Electrostatic Complexes as Contrast Agents in Magnetic Resonance Imaging  

E-Print Network [OSTI]

During the past years we have investigated the complexation between nanocolloids and oppositely charged polymers. The nanocolloids examined were ionic surfactant micelles and inorganic oxide nanoparticles. For the polymers, we used homopolyelectrolytes and block copolymers with linear and comb architectures. In general, the attractive interactions between oppositely charged species are strong and as such, the simple mixing of solutions containing dispersed constituents yield to a precipitation, or to a phase separation. We have developed means to control the electrostatically-driven attractions and to preserve the stability of the mixed solution. With these approaches, we designed novel core-shell nanostructures, e.g. as those obtained with polymers and iron oxide superparamagnetic nanoparticles. In this presentation, we show that electrostatic complexation can be used to tailor new functionalized nanoparticles and we provide examples related to biomedical applications in the domain of contrast agents for Magnetic Resonance Imaging.

Jean-Francois Berret; Regis Cartier

2007-01-26T23:59:59.000Z

331

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

332

Nuclear magnetic resonance (N.M.R.) studies of alkyl formates and of alcohol-water azeotropes  

E-Print Network [OSTI]

from Eq. 2 for 12 Alkyl Formates in Carbon tetrachloride at 37'. Typical N. M. R. Spectrum of a Non-Azeotropic Ethanol- Water Mixture . 16 N. M. R. Spectrum Occasionally Found for Azeotropic Ethanol-Water Mixtures 17 PART I. ALKYL FORMATES... CHAPTER I. INTRODUCTION 1 It has been shown that eq. 1 applies almost exactly to the data for the alkaline hydrolysis of 9 acetate eaters (CH COOR ) in 40% 0 aqueous p - dioxane at 35 . In eq. 1, k is the second-order rate log k = l. 35 + 0. 688 o + 0...

O'Brien, Patrick William

2012-06-07T23:59:59.000Z

333

Quantitative Analysis of Constituents in Heavy Fuel Oil by 1H Nuclear Magnetic Resonance (NMR) Spectroscopy and Multivariate Data Analysis  

Science Journals Connector (OSTI)

This applies in particular to the shipping industry. ... The fuel oil samples were collected during the bunkering of the oil in various ports around the world and sent to Lloyds Registers Fuel Oil Bunker Analysis and Advisory Service (FOBAS) for detailed physicochemical characterization. ... The mixture of two incompatible fuels leads to extensive formation of solid material, with devastating effects in the case where the precipitation takes place in the engine or tank of a HFO-powered ship or power plant. ...

Katrine Ellemann Nielsen; Jens Dittmer; Anders Malmendal; Niels Chr. Nielsen

2008-11-05T23:59:59.000Z

334

Introduction to resonant magnetic perturbation coils of the J-TEXT Tokamak  

Science Journals Connector (OSTI)

Abstract To investigate the interactions between both the static and rotating resonant magnetic perturbations (RMP) and the tokamak plasma, two sets of coils, namely static RMP (SRMP) and dynamic RMP (DRMP), are constructed on the J-TEXT tokamak. SRMP is reconstructed from TEXT-U and mainly produces static m/n=1/1, 2/1 and 3/1 resonant perturbation field, where m and n are the poloidal and toroidal mode numbers, respectively. DRMP, newly designed and installed inside the vacuum vessel, can generate pure 2/1 RMP. DRMP is also designed to operate in the AC mode and can produce rotating 2/1 RMP which will be used to study the tearing mode control. Due to the effect of the eddy current in the vacuum vessel wall, the amplitudes of the 2/1 component will be attenuated to about 1/3.6 of the DC value when the operation frequency is larger than 500Hz. However, DRMP can still provide sufficient large rotating 2/1 perturbation for tearing mode related studies.

B. Rao; G. Wang; Y.H. Ding; K.X. Yu; Q.L. Li; N.C. Wang; B. Yi; J.Y. Nan; Y.S. Cen; Q.M. Hu; W. Jin; J.C. Li; H. Jin; M. Zhang; G. Zhuang

2014-01-01T23:59:59.000Z

335

Effect of Ambipolar Plasma Flow on the Penetration of Resonant Magnetic Perturbations in a Quasi-Axisymmetric Stellarator  

E-Print Network [OSTI]

1 Effect of Ambipolar Plasma Flow on the Penetration of Resonant Magnetic Perturbations in a Quasi been varied and their penetration threshold determined.[3,4,5] This paper considers the flow code[7], as well as the DEGAS code for #12;2 estimating the momentum transfer rate to neutrals

Hudson, Stuart

336

K-space reconstruction of magnetic resonance inverse imaging (K-InI) of human visuomotor systems  

E-Print Network [OSTI]

MRI InI Visual MRI Neuroimaging K-InI Inverse solution MEG EEG Electroencephalography channels of a radio-frequency coil array, magnetic resonance inverse imaging (InI) can achieve ultra. Mathematically, the InI reconstruction is a generalization of parallel MRI (pMRI), which includes image space

337

E-Print Network 3.0 - artery magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resonance Imaging Laboratory Winter 2010 Syllabus Week... resonance Build your own coil and use it to scan Compare predicted and measured field profiles 8 Diffusion......

338

NMR experimental realization of seventh-order coupling transformations and the seven-qubit modified Deutsch-Jozsa algorithm  

E-Print Network [OSTI]

We propose a scalable method on the basis of nth-order coupling operators to construct f-dependent phase transformations in the n-qubit modified Deutsch-Jozsa (D-J) quantum algorithm. The novel n-qubit entangling transformations are easily implemented via J-couplings between neighboring spins. The seven-qubit modified D-J quantum algorithm and seventh-order coupling transformations are then experimentally demonstrated with liquid state nuclear magnetic resonance (NMR) techniques. The method may offer the possibility of creating generally entangled states of n qubits and simulating n-body interactions on n-qubit NMR quantum computers.

Daxiu Wei; Jun Luo; Xiaodong Yang; Xianping Sun; Xizhi Zeng; Maili Liu; Shangwu Ding; Mingsheng Zhan

2003-01-10T23:59:59.000Z

339

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...

Zeng, Haifeng

2012-07-16T23:59:59.000Z

340

Evaluation of Low-Field Nuclear Magnetic Resonance Spectrometry for At-Line Process Analysis  

Science Journals Connector (OSTI)

A low-field medium-resolution NMR spectrometer, with an operating frequency of 29 MHz for 1H, has been developed for use in process analysis. The information that is...

Nordon, Alison; McGill, Colin A; Littlejohn, David

2002-01-01T23:59:59.000Z

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.


341

Suppression of electron correlations in the collapsed tetragonal phase of CaFe2As2 under ambient pressure demonstrated by As75 NMR/NQR measurements  

SciTech Connect (OSTI)

The static and the dynamic spin correlations in the low-temperature collapsed tetragonal and the high-temperature tetragonal phase in CaFe2As2 have been investigated by As75 nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. Through the temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T1) and the Knight shifts, although stripe-type antiferromagnetic (AFM) spin correlations are realized in the high-temperature tetragonal phase, no trace of the AFM spin correlations can be found in the nonsuperconducting, low-temperature, collapsed tetragonal (cT) phase. Given that there is no magnetic broadening in As75 NMR spectra, together with the T-independent behavior of magnetic susceptibility ? and the T dependence of 1/T1T?, we conclude that Fe spin correlations are completely quenched statically and dynamically in the nonsuperconducting cT phase in CaFe2As2.

Furukawa, Yuji [Ames Laboratory; Roy, Beas [Ames Laboratory; Ran, Sheng [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

2014-03-20T23:59:59.000Z

342

Nuclear magnetic resonance solution structure of hirudin(151) and comparison with corresponding three-dimensional structures determined using the complete 65-residue hirudin polypeptide chain  

Science Journals Connector (OSTI)

The three-dimensional structure of the N-terminal 51-residue domain of recombinant hirudin in aqueous solution was determined by 1H nuclear magnetic resonance (NMR) spectroscopy, and the resulting high-quality solution structure was compared with corresponding structures obtained from studies with the intact, 65-residue polypeptide chain of hirudin. On the basis of 580 distance constraints derived from nuclear Overhauser effects and 109 dihedral angle constraints, a group of 20 conformers representing the solution structure of hirudin(151) was computed with the program DIANA and energyminimized with a modified version of the program AMBER. Residues 3 to 30 and 37 to 48 form a well-defined molecular core with two antiparallel ?-sheets composed of residues 14 to 16 and 20 to 22, and 27 to 31 and 36 to 40, and three reverse turns at residues 8 to 11 (type II), 17 to 20 (type II?) and 23 to 26 (type II). The average root-mean-square deviation of the individual NMR conformers relative to their mean co-ordinates is 0.38 for the backbone atoms and 0.77 for all heavy atoms of these residues. Increased structural disorder was found for the N-terminal dipeptide segment, the loop at residues 31 to 36, and the C-terminal tripeptide segment. The solution structure of hirudin(151) has the same molecular architecture as the corresponding polypeptide segment in natural hirudin and recombinant desulfatohirudin. It is also closely similar to the crystal structure of the N-terminal 51-residue segment of hirudin in a hirudin-thrombin complex, with root-mean-square deviations of the crystal structure relative to the mean solution structure of 0.61 for the backbone atoms and 0.91 for all heavy atoms of residues 3 to 30 and 37 to 48. Further coincidence is found for the loop formed by residues 31 to 36, which shows increased structural disorder in all available solution structures of hirudin, and of which residues 32 to 35 are not observable in the electron density map of the thrombin complex. Significant local structural differences between hirudin(151) in solution and hirudin in the crystalline thrombin complex were identified mainly for the N-terminal tripeptide segment and residues 17 to 21. These are further analyzed in an accompanying paper.

T. Szyperski; P. Gntert; S.R. Stone; K. Wthrich

1992-01-01T23:59:59.000Z

343

Potential Structure Modified by Electron Cyclotron Resonance in a Plasma Flow along Magnetic Field Lines with Mirror Configuration  

Science Journals Connector (OSTI)

A plasma potential structure is modified by the electron cyclotron resonance (ECR) in a collisionless plasma flow along magnetic field lines with simple mirror configuration. In the presence of a single ECR point at the bottom of the magnetic well, there appears a potential dip (thermal barrier) around this point, being followed by a potential hump (plug potential) in the downstream side. The result in this simplified configuration gives a clear-cut physics to the formation of field-aligned plug potential with thermal barrier.

T. Kaneko; R. Hatakeyama; N. Sato

1998-03-23T23:59:59.000Z

344

Velocity and Concentration Studies of Flowing Suspensions by Nuclear Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging (NMRI) techniques were developed to study concentrated suspension flows. Some of the proposed tasks were completed and others partly completed before the funding was terminated. The tasks completed were (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The task tackled with good progress is to develop rapid imaging techniques by analog compensation of eddy currents generated by the gradient pulses and real-time image reconstruction from the rapidly obtained data. The most suitable combination of materials arrived at is pharmaceutical beads in silicon oil. Their relaxation times T, are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80-90W transmission oil flowing in a 5 cm diameter pipe. A series of distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the velocity and concentration profiles agree with the earlier lower resolution experiments.

Fukushima, E.

1997-04-01T23:59:59.000Z

345

Velocity and Concentration Studies of Flowing Suspensions by Nuclear Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging (NMRI) techniques were developed to study concentrated suspension flows. Some of the proposed tasks were completed and others partly completed before the funding was terminated. The tasks completed were (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The task tackled with good progress is to develop rapid imaging techniques by analog compensation of eddy currents generated by the gradient pulses and real-time image reconstruction from the rapidly obtained data. The most suitable combination of materials arrived at is pharmaceutical beads in silicon oil. Their relaxation times T, are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80-90W transmission oil flowing in a 5 cm diameter pipe. A series of distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the velocity and concentration profiles agree with the earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels including the uniform field compensation term. In addition, we have implemented a rapid reconstruction hardware that processes and displays images in a fraction of a second.

Fukushima, E.

1997-01-01T23:59:59.000Z

346

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

347

E-Print Network 3.0 - advanced magnetic resonance Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(Namikawa, 1985; Gibbs, 1988) channels. These include studies... weak, synchrotron radiation brightness, together with resonant ... Source: Haskel, Daniel - Advanced Photon...

348

Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets  

SciTech Connect (OSTI)

In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2012-02-15T23:59:59.000Z

349

Resonant amplification of vortex-core oscillations by coherent magnetic-field pulses  

E-Print Network [OSTI]

structure of magnetic vortex cores. Science 298, 577580 (D. A. et al. Magnetic domain-wall logic. Science 309, 1688 (L. Magnetic domain-wall racetrack memory. Science 320, 190

Yu, Young-Sang

2014-01-01T23:59:59.000Z

350

Magnetic resonance imaging of the left atrial appendage post pulmonary vein isolation: Implications for percutaneous left atrial appendage occlusion  

Science Journals Connector (OSTI)

AbstractBackground There is increasing interest in performing left atrial appendage (LAA) occlusion at the time of atrial fibrillation (AF) ablation procedures. However, to date there has been no description of the acute changes to the LAA immediately following pulmonary vein (PV) isolation and additional left atrium (LA) substrate modification. This study assessed changes in the size and tissue characteristics of the LAA ostium in patients undergoing PV isolation. Methods This series included 8 patients who underwent cardiovascular magnetic resonance evaluation of the LA with delayed enhancement magnetic resonance imaging and contrast enhanced 3-D magnetic resonance angiography pre-, within 48h of, and 3 months post ablation. Two independent cardiac radiologists evaluated the ostial LAA diameters and area at each time point in addition to the presence of gadolinium enhancement. Results Compared to pre-ablation values, the respective median differences in oblique diameters and LAA area were +1.8mm, +1.7mm, and +0.6cm2 immediately post ablation (all NS) and ?2.7mm, ?2.3mm, and ?0.5cm2 at 3 months (all NS). No delayed enhancement was detected in the LAA post ablation. Conclusion No significant change to LAA diameter, area, or tissue characteristics was noted after PV isolation. While these findings suggest the safety and feasibility of concomitant PV isolation and LAA device occlusion, the variability in the degree and direction of change of the LAA measurements highlights the need for further study.

Sheldon M. Singh; Laura Jimenez-Juan; Asaf Danon; Gorka Bastarrika; Andriy V. Shmatukha; Graham A. Wright; Eugene Crystal

2014-01-01T23:59:59.000Z

351

Carbon-13 nuclear magnetic resonance studies of metabolism in Crithidia fasciculata  

E-Print Network [OSTI]

in Fig. 13. 59 16 Time course "C NMR spectra of anaerobic metabolism of [U-"C] glucose by Cri thidia fasci culata. 68 17 "C NMR spectrum of a typical cell extract of C. fasciculata incubated with [U-"C] glucose under anaerobic conditions. 69 18 (A... of Biochemistry. / '( -S-C3. , ~ iy A?~ NIFURTIMOX (A) &J~ Q~ CHsOH MELARSOPROL (C) BENZNIDAZOLE (B) Nao~s Nsa S 0 o 0 CH) HSC SQNa SO3Na SURAMIN (E) (F) NaosS Fig. 1. Drugs used for the treatment of Trypanosoma cruzi (A&B) and Trypanosoma...

McCloskey, Diane Elizabeth

2012-06-07T23:59:59.000Z

352

A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization  

SciTech Connect (OSTI)

The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate NMR techniques and acoustic measurements to improve predictability of the pay zone in hydrocarbon reservoirs. This is accomplished by extracting the fluid property parameters using NMR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurement techniques and core imaging are being linked with a balanced petrographical analysis of the core and theoretical model.

Parra, Jorge O.; Hackert, Chris L.; Collier, Hughbert A.; Bennett, Michael

2002-01-29T23:59:59.000Z

353

MagLab - MagLab Dictionary: Electron Magnetic Resonance (Transcript...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

an electron has a negative charge. When charged objects spin, they produce magnetism In other words, a spinning electron behaves like a tiny magnet. Indeed, THIS IS the...

354

The proton magnetic resonance spectra of seventeen isomeric C b6 sH b12 solefins and several related l-alkenes  

E-Print Network [OSTI]

REPORT OF INVESTIGATION of the AMERICAN PETROLEUM INSTITUTE RESEARCH PROJECT 44 THE PROTON MAGNETIC RESONANCE SPECTRA OF SEVENTEEN ISOMERIC C6H12 OLEFINS AND SEVERAL RELATED 1-ALKENES By Jerry C. Poradek and Alfred Danti CHEMICAL... THERMODYNAMIC PROPERTIES CENTER Department of Chemistry Agricultural and Meohonical College of Texas College Station, Texas June 30, 1963 AMERICAN PETROLEUM INSTITUTE RESEARCH PROJECT 44 MASTER'S THESIS THE PROTON MAGNETIC RESONANCE SPECTRA OF SEVENTEEN...

Poradek, Jerry Charles

2012-06-07T23:59:59.000Z

355

Investigation of wettability by NMR microscopy and spin-lattice relaxation  

SciTech Connect (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

356

The Multidrug Resistance Phenotype: 31P Nuclear Magnetic Resonance Characterization and 2-Deoxyglucose Toxicity  

Science Journals Connector (OSTI)

...bromide. M, 170,000 plasma membrane glycoprotein...at 37 Cin a humidified atmosphere containing 5% carbon...Palo Alto, CA) at 162 MHz using radiofrequency pulses...Karlsruhe, Ger many) at 122 MHz at the same conditions...31P NMR spectra (162 MHz) of wild type and resistant...

Ofer Kaplan; Jerzy W. Jaroszewski; Robert Clarke; Craig R. Fairchild; Patricia Schoenlein; Sarah Goldenberg; Michael M. Gottesman; and Jack S. Cohen

1991-03-15T23:59:59.000Z

357

Impact of screening of resonant magnetic perturbations in three dimensional edge plasma transport simulations for DIII-D  

SciTech Connect (OSTI)

The impact of resonant magnetic perturbations (RMPs) on the plasma edge can be analyzed in detail by three dimensional computer simulations, which take the underlying magnetic field structure as input. Previously, the 'vacuum approximation' has been used to calculate the magnetic field structure although plasma response effects may result in a screening (or even an amplification) of the external perturbations. Simulation results for an ITER similar shape plasma at the DIII-D tokamak are presented for the full vacuum perturbation field and an ad hoc screening case in comparison to the unperturbed configuration. It is shown that the RMP induced helical patterns in the plasma edge and on the divertor target shrink once screening is taken into account. However, a flat temperature profile is still found in the 'open field line domain' inside the separatrix, while the 'density pump out effect' found in the vacuum RMP case is considerably weakened.

Frerichs, H.; Reiter, D.; Schmitz, O. [Institute of Energy and Climate Research-Plasma Physics, Forschungszentrum Juelich GmbH, Association EURATOM-FZJ, Partner in the Trilateral Euregio Cluster, Juelich (Germany); Cahyna, P. [Institute of Plasma Physics AS CR, v.v.i., Association EURATOM/IPP.CR, Prague (Czech Republic); Evans, T. E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Feng, Y. [Max-Planck Institute for Plasma Physics, Greifswald (Germany); Nardon, E. [Association EURATOM-CEA, IRFM, CEA Cadarache, St-Paul-lez-Durance (France)

2012-05-15T23:59:59.000Z

358

NMR and Structural Genomics  

Science Journals Connector (OSTI)

NMR and Structural Genomics ... The role of NMR in structural genomics is outlined, with particular emphasis on using protein domains as targets. ... Targets in Structural Genomics ...

David Staunton; Jo Owen; Iain D. Campbell

2002-12-07T23:59:59.000Z

359

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

SciTech Connect (OSTI)

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

360

E-Print Network 3.0 - angio-magnetic resonance finding Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

resonator is placed in contact with soil medium and the real and imaginary parts of soil Source: Sarabandi, Kamal - Radiation Laboratory & Department of Electrical Engineering and...

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

Solid State Nuclear Magnetic Resonance Investigation of Polymer Backbone Dynamics in Poly(Ethylene Oxide) Based Lithium and Sodium Polyether-ester-sulfonate Ionomers  

SciTech Connect (OSTI)

Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (Tg) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and 1H spin-lattice relaxation rate measurements. Previous 1H and 7Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of 13C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time 1H-13C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from 1H to 13C nuclei, becomes similar for T ? 1.1 Tg in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of previous findings, for the dependence of backbone dynamics on cation density (and here, cation identity as well) in these amorphous PEO-based ionomer systems.

Roach, David J. [Penn State Univ., State College, PA (United States). Dept. of Chemistry; Dou, Shichen [Penn State Univ., State College, PA (United States). Dept. of Materials Science and Engineering; Colby, Ralph H. [Penn State Univ., State College, PA (United States). Dept. of Materials Science and Engineering; Mueller, Karl T. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Penn State Univ., State College, PA (United States). Dept. of Chemistry

2013-05-21T23:59:59.000Z

362

Magnetic fields at resonant conditions for the hydrogen ion affect neurite outgrowth in PC-12 cells: A test of the ion parametric resonance model  

SciTech Connect (OSTI)

PC-12 cells primed with nerve growth factor (NGF) were exposed to sinusoidal extremely-low-frequency (ELF) magnetic fields (MFs) selected to test the predictions of the ion parametric resonance (IPR) model under resonance conditions for a single ion (hydrogen). The authors examined the field effects on the neurite outgrowth (NO) induced by NGF using three different combinations of flux densities of the parallel components of the AC MF (B{sub ac}) and the static MF (B{sub dc}). The first test examined the NO response in cells exposed to 45 Hz at a B{sub dc} of 2.96 {micro}T with resonant conditions for H{sup +} according to the model. The B{sub ac} values ranged from 0.29 to 4.11 {micro}T root-mean-square (rms). In the second test, the MF effects at off-resonance conditions (i.e., no biologically significant ion at resonance) were examined using the frequency of 45 Hz with a B{sub dc} of 1.97 {micro}T and covering a B{sub ac} range between 0.79 and 2.05 {micro}T rms. In the third test, the Ac frequency was changed to 30 Hz with the subsequent change in B{sub dc} to 1.97 {micro}T to tune for H{sup +} as in the first test. The B{sub ac} values ranged from 0.79 to 2.05 {micro}T rms. After a 23 h incubation and exposure to the MF in the presence of NGF (5 ng/ml), the NO was analyzed using a stereoscopic microscope. The results showed that the NGF stimulation of neurite outgrowth (NSNO) was affected by MF combinations over most of the B{sub ac} exposure range generally consistent with the predictions of the IPR model. However, for a distinct range of B{sub ac} where the IPR model predicted maximal ionic influence, the observed pattern of NSNO contrasted sharply with those predictions. The symmetry of this response suggests that values of B{sub ac} within this distinct range may trigger alternate or additional cellular mechanisms that lead to an apparent lack of response to the MF stimulus.

Trillo, M.A.; Ubeda, A. [Hospital Ramon y Cajal, Madrid (Spain). Dept. Investigacion] [Hospital Ramon y Cajal, Madrid (Spain). Dept. Investigacion; Blanchard, J.P. [Bechtel Corp., San Francisco, CA (United States). Research and Development Dept.] [Bechtel Corp., San Francisco, CA (United States). Research and Development Dept.; House, D.E.; Blackman, C.F. [Environmental Protection Agency, Research Triangle Park, NC (United States)] [Environmental Protection Agency, Research Triangle Park, NC (United States)

1996-04-01T23:59:59.000Z

363

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock magnetic, and electron microscopy  

E-Print Network [OSTI]

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock,2 Timothy D. Raub,3,4 Dirk Schumann,5 Hojatollah Vali,5 Alexei V. Smirnov,3,6 and Joseph L. Kirschvink1 controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR

364

Interface defects in SiC power MOSFETs - An electrically detected magnetic resonance study based on spin dependent recombination  

SciTech Connect (OSTI)

This study presents electrically detected magnetic resonance (EDMR) measurements on a silicon carbide (SiC) MOSFET having the structure of a double-diffused silicon MOSFET (DMOS). The resonance pattern of a SiC DMOS was measured by monitoring the change of the recombination current between the source/body and the drain. The amplitude of the response has a maximum when the device is biased in depletion due to the equal concentrations of electrons and holes at the interface resulting in the most efficient recombination. The measured anisotropic g-tensor has axial symmetry with g{sub ?} = 2.0051(4) (B ? c-axis), and g{sub ?} = 2.0029(4) (B? c-axis) and the pattern shows several hyperfine (HF) peaks. We tentatively identify the observed defect as a silicon vacancy located directly at the interface.

Gruber, Gernot [KAI GmbH, Europastrasse 8, 9500 Villach, Austria and Graz University of Technology - Institute of Solid State Physics, Petersgasse 16, 8020 Graz (Austria); Hadley, Peter [Graz University of Technology - Institute of Solid State Physics, Petersgasse 16, 8020 Graz (Austria); Koch, Markus [Graz University of Technology - Institute of Experimental Physics, Petersgasse 16, 8020 Graz (Austria); Peters, Dethard [Infineon Technologies, Schottkystrasse 10, 91058 Erlangen (Germany); Aichinger, Thomas [Infineon Technologies, Siemensstrasse 2, 9500 Villach (Australia)

2014-02-21T23:59:59.000Z

365

Helical Tomotherapy Planning for Lung Cancer Based on Ventilation Magnetic Resonance Imaging  

SciTech Connect (OSTI)

To investigate the feasibility of lung ventilation-based treatment planning, computed tomography and hyperpolarized (HP) helium-3 (He-3) magnetic resonance imaging (MRI) ventilation images of 6 subjects were coregistered for intensity-modulated radiation therapy planning in Tomotherapy. Highly-functional lungs (HFL) and less-functional lungs (LFL) were contoured based on their ventilation image intensities, and a cylindrical planning-target-volume was simulated at locations adjacent to both HFL and LFL. Annals of an anatomy-based plan (Plan 1) and a ventilation-based plan (Plan 2) were generated. The following dosimetric parameters were determined and compared between the 2 plans: percentage of total/HFL volume receiving {>=}20 Gy, 15 Gy, 10 Gy, and 5 Gy (TLV{sub 20}, HFLV{sub 20}, TLV{sub 15}, HFLV{sub 15}, TLV{sub 10}, HFLV{sub 10}, TLV{sub 5}, HFLV{sub 5}), mean total/HFL dose (MTLD/HFLD), maximum doses to all organs at risk (OARs), and target dose conformality. Compared with Plan 1, Plan 2 reduced mean HFLD (mean reduction, 0.8 Gy), MTLD (mean reduction, 0.6 Gy), HFLV{sub 20} (mean reduction, 1.9%), TLV{sub 20} (mean reduction, 1.5%), TLV{sub 15} (mean reduction, 1.7%), and TLV{sub 10} (mean reduction, 2.1%). P-values of the above comparisons are less than 0.05 using the Wilcoxon signed rank test. For HFLV{sub 15}, HFLV{sub 10}, TLV{sub 5}, and HTLV{sub 5}, Plan 2 resulted in lower values than plan 1 but the differences are not significant (P-value range, 0.063-0.219). Plan 2 did not significantly change maximum doses to OARs (P-value range, 0.063-0.563) and target conformality (P = 1.000). HP He-3 MRI of patients with lung disease shows a highly heterogeneous ventilation capacity that can be utilized for functional treatment planning. Moderate but statistically significant improvements in sparing functional lungs were achieved using helical tomotherapy plans.

Cai Jing; McLawhorn, Robert [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Altes, Tallisa A.; Lange, Eduard de [Department of Radiology, University of Virginia, Charlottesville, VA (United States); Read, Paul W.; Larner, James M.; Benedict, Stanley H. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Sheng Ke, E-mail: ks2mc@virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

2011-01-01T23:59:59.000Z

366

31P NMR study of the interaction of a commercial succinimide-type lubricating oil dispersant with zinc(II) bis(O,O'-di-iso-butyldithiophosphate)  

Science Journals Connector (OSTI)

31P nuclear magnetic resonance (NMR) spectroscopy has been employed to study the interactions between zinc(II) bis(O,O?-di-iso-butyldithiophosphate) and a commercial poly(isobutenyl)succinimide polyamine dispersant at both ambient and subambient (213293 K) temperatures. The major species in solutions containing high N:Zn ratios is a complex between the two components in which only two nitrogen atoms of the polyamine dispersant are bonded to the zinc.

Philip G. Harrison; Paul Brown; James McManus

1992-01-01T23:59:59.000Z

367

Double layer created by electron cyclotron resonance heating in an inhomogeneously magnetized plasma with high-speed ion flow  

SciTech Connect (OSTI)

A potential jump, i.e., an electric double layer (DL) is formed near an electron cyclotron resonance (ECR) point when an electron cyclotron wave is injected into an inhomogeneously magnetized plasma with high-speed ion flow. A charge separation is caused by an electron reflection due to -{mu}{nabla}B{sub z} force enhanced by ECR heating and ion inertia. It is clearly demonstrated in the experiment that the potential height of the DL is almost proportional to the field-aligned ion flow energy; the DL is found to be self-consistently formed for maintaining charge neutrality by reflecting a part of the flowing ions.

Takahashi, K.; Kaneko, T.; Hatakeyama, R. [Department of Electronic Engineering, Tohoku University, Sendai, 980-8579 (Japan)

2008-07-15T23:59:59.000Z

368

Near-resonant spatial images of confined Bose-Einstein condensates in a 4-Dee magnetic bottle  

Science Journals Connector (OSTI)

We present quantitative measurements of the spatial density profile of Bose-Einstein condensates of sodium atoms confined in a 4-Dee magnetic bottle. The condensates are imaged in transmission with near-resonant laser light. We demonstrate that the Thomas-Fermi surface of a condensate can be determined to better than 1%. More generally, we obtain excellent agreement with mean-field theory. We conclude that precision measurements of atomic scattering lengths and interactions between phase-separated cold atoms in a harmonic trap can be performed with high precision using this method.

Lene Vestergaard Hau; B. D. Busch; Chien Liu; Zachary Dutton; Michael M. Burns; J. A. Golovchenko

1998-07-01T23:59:59.000Z

369

An AldermanGrant resonator for S-Band Dynamic Nuclear Polarization  

Science Journals Connector (OSTI)

Abstract An AldermanGrant resonator with resonance at 2GHz (S-Band) was simulated, developed and constructed for Dynamic Nuclear Polarization (DNP) experiments at 73mT. The resonator fits into magnet bores with a minimum diameter of 20mm and is compatible with standard 3mm NMR tubes. The compact resonator design achieves good separation of electric and magnetic fields and therefore can be used with comparatively large sample volumes with only small sample heating effects comparable to those obtained with optimized X- and W-Band DNP setups. The saturation efficiency and sample heating effects were investigated for Overhauser DNP experiments of aqueous solutions of TEMPOL radical, showing relative saturation better than 0.9 and sample heating not exceeding a few Kelvin even at high microwave power and long irradiation time. An application is demonstrated, combining the DNP setup with a commercial fast field cycling NMR relaxometer. Using this resonator design at low microwave frequencies can provide DNP polarization for a class of low-field and time-domain NMR experiments and therefore may enable new applications that benefit from increased sensitivity.

Oliver Neudert; Hans-Peter Raich; Carlos Mattea; Siegfried Stapf; Kerstin Mnnemann

2014-01-01T23:59:59.000Z

370

MagLab - Meet the Magnets: 45 Tesla Hybrid  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Features > Meet the Magnets Meet the Magnets Choose a Magnet 45 Tesla Hybrid 900 MHz NMR Magnet 25 Tesla Split Magnet 14.5 Tesla ICR Magnet 100 Tesla Multi-shot Magnet 600 MHz...

371

Advanced Magnetic Resonance Imaging of the Physical Processes in Human Glioblastoma  

Science Journals Connector (OSTI)

...tumor angiogenesis.Magn Reson Med 1998;40:793-9. 69. Einstein A . [uber die von der molekularkinetischen Theorie der Warme geforderte Bewegung von in ruhenden Flussigkeiten suspendierten Teilchen].Annalen der Physik 1905;322:549-60. 70...

Jayashree Kalpathy-Cramer; Elizabeth R. Gerstner; Kyrre E. Emblem; Ovidiu C. Andronesi; Bruce Rosen

2014-09-01T23:59:59.000Z

372

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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)

373

Sixth Moment of Dipolar-Broadened Magnetic-Resonance-Absorption Line Shapes in Crystals  

Science Journals Connector (OSTI)

Several recently developed theories of broad-line NMR presume the knowledge of the first several moments of the line shape. An exact expression for the sixth moment for the purely dipolar-broadened case is presented here. The result indicates that the sixth moment consists of one type of two-particle term, five types of three-particle terms, and nine types of four-particle terms, one of which has a vanishing coefficient. Most of the contribution comes from the four-particle terms.

E. T. Cheng and J. D. Memory

1972-09-01T23:59:59.000Z

374

A solid-state nuclear magnetic resonance study of the reactions of propene on HY zeolite  

E-Print Network [OSTI]

, and condensation. The main objective of this study was to determine the reaction mechanism (including the observation of intermediates) for propane adsorbed on HY zeolite. C enriched propene was adsorbed on HY zeolite at room temperature, and it was observed..., as denoted by arrows C CP/MAS spectrum of propene-2- C 13 adsorbed on HY zeolite at room temperature 10 The polymerization reaction proposed in reference 13 for the adsorption of propene on HY zeolite The Bloch decay pulse sequence in NMR experiments...

Oshiro, Irene Sueko

2012-06-07T23:59:59.000Z

375

E-Print Network 3.0 - acoustic nuclear magnetic resonance Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Biochemistry, Florida State University Collection: Chemistry 57 Calculation Method of Permanent Magnet Pickups for Electric Guitars Summary: from two points of view that have to be...

376

Two dimensional NMR and NMR relaxation studies of coal structure  

SciTech Connect (OSTI)

This report covers the progress made on the title project and summarizes the accomplishments for the project period. Four major areas of inquiry have been pursued. Advanced solid state NMR methods are being developed to assay the distribution of the various important functional groups in coals that determine the reactivity of coals. Other methods are being developed which will also determine how these functional groups are linked together. A third area of investigation concerns how molecular mobility in coals impacts NMR relaxation times, which is important for interpretation of such data in terms of the mobile phase in coals model. Along the same lines the authors are also using these studies to establish protocols for obtaining the best quantitative response from coals in solid state C-13 NMR spectra. The effects of very high MAS rates (>10 kHz) on cross polarization dynamics are also being investigated for similar reasons. The authors have concentrated on a theoretical treatment of pairs of tightly coupled spin {1/2} nuclei under magic angle spinning conditions. The average Hamiltonian theory developed here is required for a quantitative understanding of two dimensional NMR experiments of such spin pairs in solids. These experiments in turn provide a means of determining connectivities between resonances in solid state NMR spectra. Development of these techniques will allow us to establish connectivities between functional components in coals. The complete description of these spin dynamics has turned out to be complex, and is necessary to provide a foundation upon which such experiments may be quantitatively interpreted in complex mixtures such as coals. 25 refs., 4 figs., 3 tabs.

Zilm, K.W.

1990-01-01T23:59:59.000Z

377

Two-channel R-matrix analysis of magnetic-field-induced Feshbach resonances  

SciTech Connect (OSTI)

A Feshbach resonance arises in cold atom scattering due to the complex interplay between several coupled channels. However, the essential physics of the resonance may be encapsulated in a simplified model consisting of just two coupled channels. In this paper we describe in detail how such an effective Feshbach model can be constructed from knowledge of a few key parameters, characterizing the atomic Born-Oppenheimer potentials and the low energy scattering near the resonance. These parameters may be obtained either from experiment or full coupled-channel calculations. Using R-matrix theory we analyze the bound state spectrum and the scattering properties of the two-channel model, and find it to be in good agreement with exact calculations.

Nygaard, Nicolai; Schneider, Barry I.; Julienne, Paul S. [Danish National Research Foundation Center for Quantum Optics, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Physics Division, National Science Foundation, Arlington, Virginia 22230 (United States) and Electron and Optical Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Atomic Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

2006-04-15T23:59:59.000Z

378

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  

SciTech Connect (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

379

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

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

380

A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization  

SciTech Connect (OSTI)

This report contains eight sections. Some individual subsections contain lists of references as well as figures and conclusions when appropriate. The first section includes the introduction and summary of the first-year project efforts. The next section describes the results of the project tasks: (1) implementation of theoretical relations between effect dispersion and the stochastic medium, (2) imaging analyses using core and well log data, (3) construction of dispersion and attenuation models at the core and borehole scales in poroelastic media, (4) petrophysics and a catalog of core and well log data from Siberia Ridge field, (5) acoustic/geotechnical measurements and CT imaging of core samples from Florida carbonates, and (6) development of an algorithm to predict pore size distribution from NMR core data. The last section includes a summary of accomplishments, technology transfer activities and follow-on work for Phase II.

Parra, Jorge O.; Hackert, Chris L.; Ni, Qingwen; Collier, Hughbert A.

2000-09-22T23:59:59.000Z

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.


381

High-Resolution Solid-State Nuclear Magnetic Resonance Experiments on Highly Radioactive Ceramics  

SciTech Connect (OSTI)

A triple containment magic-angle spinning rotor insert system has been developed and a sample handling procedure formulated for safety analyzing highly radioactive solids by high resolution solid state NMR. The protocol and containment system have been demonstrated for magic angle spinning (MAS) experiments on ceramic samples containing 5-10 wt% 239Pu and 238Pu at rotation speeds of 3500 Hz. The technique has been used to demonstrate that MASNMR experiments can be used to measure amorphous atomic number fractions produced during accelerated internal radioactive decay. This will allow incorporated ?-emitters with short half-lives to be used to model the long-term radiation tolerance of potential ceramic radioactive waste forms. It is believed to be the first example of MASNMR spectroscopy on samples containing fissionable isotopes.

Farnan, Ian E.; Cho, Herman M.; Weber, William J.; Scheele, Randall D.; Johnson, Nigel R.; Kozelisky, Anne E.

2004-12-01T23:59:59.000Z

382

Study of aldose reductase inhibition in intact lenses by 13C nuclear magnetic resonance spectroscopy  

Science Journals Connector (OSTI)

...the conditions of high plasma-sugar concentra-II...respectively. As expected, a large sorbitol resonance was...incubated at 37C under an atmosphere of5% CO2 and 95% air...13C specta at 50.32 MHz, with a pulse width...integrated sorbitol peak areas in the absence and presence...

WF Williams; JD Odom

1986-07-11T23:59:59.000Z

383

Magnetic resonance investigation of the dynamics of F centers in LiF  

E-Print Network [OSTI]

the paramagnetic F centers created by radiation doses that vary by several orders of magnitude. We measured; E. Nuclear resonances 1. Introduction Ionizing radiation in ionic crystals creates a large variety by the electronic spin±lattice relaxation. In the studied temperature range from 4 to 300 K, the electron spin

Suter, Dieter

384

Directed evolution of a magnetic resonance imaging contrast agent for noninvasive imaging of dopamine  

E-Print Network [OSTI]

The development of molecular probes that allow in vivo imaging of neural signaling processes with high temporal and spatial resolution remains challenging. Here we applied directed evolution techniques to create magnetic ...

Shapiro, Mikhail G.

385

2H NMR | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NMR Leads No leads are available at this time. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR...

386

EMSL - 2H NMR  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

tags2h-nmr en Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR http:www.emsl.pnl.govemslweb...

387

Hart AG, Bowtell RW, Kckenberger W, Wenseleers T, Ratnieks FLW. 2003. Magnetic resonance imaging in entomology: a critical review. 9pp. Journal of Insect Science, 3:5, Available online: insectscience.org/3.5  

E-Print Network [OSTI]

.5 Journal of Insect Science insectscience.org Magnetic resonance imaging in entomology: a critical reviewHart AG, Bowtell RW, Köckenberger W, Wenseleers T, Ratnieks FLW. 2003. Magnetic resonance imaging in entomology: a critical review. 9pp. Journal of Insect Science, 3:5, Available online: insectscience.org/3

Wenseleers, Tom

388

Grid computing for improving conformational sampling in NMR structurecalculation  

Science Journals Connector (OSTI)

......address highly ambiguous datasets, because of the much...tere@pasteur.fr Nuclear Magnetic Resonance...Methods for automatic nuclear magnetic resonance...address highly ambiguous datasets, because of the much...Non-U.S. Gov't | Nuclear Magnetic Resonance......

Fabien Mareuil; Christophe Blanchet; Thrse E. Malliavin; Michael Nilges

2011-06-15T23:59:59.000Z

389

Magnetic resonance investigation of Zn{sub 1?x}Fe{sub x}O properties influenced by annealing atmosphere  

SciTech Connect (OSTI)

ZnO is an attractive system for a wide variety of practical applications, being a chemically stable oxide semiconductor. It has been shown that Fe doping produces ferromagnetic semiconductor at room temperature. This material, therefore, has the potential for use in spintronic devices such as spin transistors, spin light emitting diodes, very high density nonvolatile semiconductor memory and optical emitters. It is believed that oxygen vacancies and substitutional incorporation are important to produce ferromagnetism in semiconductor oxide doped with transition metal ions. The present paper reports detailed electron paramagnetic resonance investigations (EPR) of the samples in order to investigate how annealing atmosphere (Air and Argon) influenced the magnetic behavior of the samples. X-band electron paramagnetic resonance (EPR) studies of Fe{sup 3+} ions in Zn{sub 1?x}Fe{sub x}O powders with x = 1%, 3% is reported. These samples are interesting to investigate as Fe doping produce ferromagnetism in ZnO, making a promising ferromagnetic semiconductor at room temperature.

Raita, O.; Popa, A.; Toloman, D.; Stan, M.; Giurgiu, L. M. [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies Donath 65-103, 400293, Cluj-Napoca (Romania)

2013-11-13T23:59:59.000Z

390

Low-field vortex matter in YBa2Cu3O7 : An atomic beam magnetic-resonance study Harald Hauglin  

E-Print Network [OSTI]

the rate that rf magnetic-resonance hyperfine tran- sitions are excited in atoms as they pass over Department of Physics, University of Oslo, N-0316 Oslo, Norway Nathan G. Woodard, Samuel Dapore-Schwartz, and Gregory P. Lafyatis Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106 Received

Johansen, Tom Henning

391

Water-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers Investigated by Solid-State Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

from water to proteins.1 For microcrystalline proteins in the solid-state, magic-angle- spinning (MASWater-Protein Interactions of an Arginine-Rich Membrane Peptide in Lipid Bilayers Investigated by Solid-State Nuclear Magnetic Resonance Spectroscopy Shenhui Li, Yongchao Su, Wenbin Luo, and Mei Hong

Hong, Mei

392

Effects of diffusion and surface interactions on the line shape of electron paramagnetic resonances in the presence of a magnetic field gradient  

Science Journals Connector (OSTI)

In an evanescent wave magnetometer the Zeeman polarization is probed at micrometer to submicrometer distances from the cell surface. The electron paramagnetic resonance lines of an evanescent wave magnetometer in the presence of a magnetic field gradient exhibit edge enhancement seen previously in nuclear magnetic resonance lines. We present a theoretical model that describes quantitatively the shape of the magnetic resonance lines of an evanescent wave magnetometer under a wide range of experimental conditions. It accounts for diffusion broadening in the presence of a magnetic field gradient as well as interactions of spin polarized Rb atoms with the coated Pyrex glass surfaces. Depending on the field gradient, cell thickness, and buffer gas pressure, the resonance line may have the form of a single asymmetric peak or two peaks localized near the front and back surfaces in frequency space. The double-peaked response depends on average characteristics of the surface interactions. Its shape is sensitive to the dwell time, relaxation probability, and average phase shift of adsorbed spin polarized Rb atoms.

M. Schaden; K. F. Zhao; Z. Wu

2007-12-07T23:59:59.000Z

393

Automatic Landmarking of Magnetic Resonance brain Images Camille Izard*a,b, Bruno M. Jedynaka,b and Craig E.L. Starkc  

E-Print Network [OSTI]

Automatic Landmarking of Magnetic Resonance brain Images Camille Izard*a,b, Bruno M. JedynakaDepartment of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD ABSTRACT Landmarking MR images is crucial in registering brain structures from different images. It consists in locating the voxel

Jedynak, Bruno M.

394

ROM-based quantum computation: Experimental explorations using Nuclear Magnetic Resonance, and future prospects  

E-Print Network [OSTI]

ROM-based quantum computation (QC) is an alternative to oracle-based QC. It has the advantages of being less ``magical'', and being more suited to implementing space-efficient computation (i.e. computation using the minimum number of writable qubits). Here we consider a number of small (one and two-qubit) quantum algorithms illustrating different aspects of ROM-based QC. They are: (a) a one-qubit algorithm to solve the Deutsch problem; (b) a one-qubit binary multiplication algorithm; (c) a two-qubit controlled binary multiplication algorithm; and (d) a two-qubit ROM-based version of the Deutsch-Jozsa algorithm. For each algorithm we present experimental verification using NMR ensemble QC. The average fidelities for the implementation were in the ranges 0.9 - 0.97 for the one-qubit algorithms, and 0.84 - 0.94 for the two-qubit algorithms. We conclude with a discussion of future prospects for ROM-based quantum computation. We propose a four-qubit algorithm, using Grover's iterate, for solving a miniature ``real-world'' problem relating to the lengths of paths in a network.

D. R. Sypher; I. M. Brereton; H. M. Wiseman; B. L. Hollis; B. C. Travaglione

2001-12-20T23:59:59.000Z

395

In vivo magnetic resonance vascular imaging using laser-polarized 3He microbubbles  

Science Journals Connector (OSTI)

...because of its larger magnetic moment...filled to ?2 atmosphere. Two cubic centimeters of gas (at 1 atmosphere = 101.3 kPa...Squibb) and two plasma volume expanders...both small and large diameter counting...operating at 65.1 MHz and 85.5 MHz...3 He to target areas for MRI. 1 Happer...

Mark S. Chawla; X. Josette Chen; Harald E. Mller; Gary P. Cofer; C. Ted Wheeler; Laurence W. Hedlund; G. Allan Johnson

1998-01-01T23:59:59.000Z

396

Effective Cerebral Connectivity during Silent Speech Reading Revealed by Functional Magnetic Resonance  

E-Print Network [OSTI]

Effective Cerebral Connectivity during Silent Speech Reading Revealed by Functional Magnetic Y-H, Lin F-H, Chou Y-J, Tsai KW-K, Kuo W-J, et al. (2013) Effective Cerebral Connectivity during that no competing interests exist. * E-mail: fhlin@ntu.edu.tw . These authors contributed equally to this work

397

Peak divergence in the curve of magnetoelectric coefficient versus dc bias magnetic field at resonance region for bi-layer magnetostrictive/piezoelectric composites  

SciTech Connect (OSTI)

Magnetoelectric (ME) coefficient dependence on the bias magnetic field at resonance frequencies for the bi-layered bonded Terfenol-D/Pb(Zr,Ti)O{sub 3} composite was investigated. The resonance frequency decreases first and then increases with the bias magnetic field (H{sub DC}), showing a V shape in the range of 0 ? 5 kOe. Below the resonance frequency, the pattern of ME coefficient dependence on the H{sub DC} shows a single peak, but splits into a double-peak pattern when the testing frequency increases into a certain region. With increasing the frequency, a divergent evolution of the H{sub DC} patterns was observed. Domain motion and ?E effect combined with magnetostriction-piezoelectric coupling effect were employed to explain this experimental result.

Zuo, Z. J.; Pan, D. A., E-mail: pandean@mater.ustb.edu.cn; Zhang, S. G.; Qiao, L. J. [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)] [Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Jia, Y. M. [Department of Physics, Zhejiang Normal University, Jinhua 321004, Zhejiang Province (China)] [Department of Physics, Zhejiang Normal University, Jinhua 321004, Zhejiang Province (China)

2013-12-15T23:59:59.000Z

398

First Principles Calculations and NMR Spectroscopy of Electrode...  

Broader source: Energy.gov (indexed) [DOE]

and C. P. Grey, Inorg. Chem., 52, 8540-8550 (2013). * "Paramagnetic electrodes and bulk magnetic susceptibility effects in the in situ NMR studies of batteries: Application to Li...

399

NMR and EPR | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sarah D Burton, David Hoyt View all NMR and EPR Instruments Publications Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of...

400

Structural studies of bacterial transcriptional regulatory proteins by multidimensional heteronuclear NMR  

SciTech Connect (OSTI)

Nuclear magnetic resonance spectroscopy was used to elucidate detailed structural information for peptide and protein molecules. A small peptide was designed and synthesized, and its three-dimensional structure was calculated using distance information derived from two-dimensional NMR measurements. The peptide was used to induce antibodies in mice, and the cross-reactivity of the antibodies with a related protein was analyzed with enzyme-linked immunosorbent assays. Two proteins which are involved in regulation of transcription in bacteria were also studied. The ferric uptake regulation (Fur) protein is a metal-dependent repressor which controls iron uptake in bacteria. Two- and three-dimensional NMR techniques, coupled with uniform and selective isotope labeling allowed the nearly complete assignment of the resonances of the metal-binding domain of the Fur protein. NTRC is a transcriptional enhancer binding protein whose N-terminal domain is a {open_quote}receiver domain{close_quote} in the family of {open_quote}two-component{close_quote} regulatory systems. Phosphorylation of the N-terminal domain of NTRC activates the initiation of transcription of aeries encoding proteins involved in nitrogen regulation. Three- and four-dimensional NMR spectroscopy methods have been used to complete the resonance assignments and determine the solution structure of the N-terminal receiver domain of the NTRC protein. Comparison of the solution structure of the NTRC receiver domain with the crystal structures of the homologous protein CheY reveals a very similar fold, with the only significant difference being the position of helix 4 relative to the rest of the protein. The determination of the structure of the NTRC receiver domain is the first step toward understanding a mechanism of signal transduction which is common to many bacterial regulatory systems.

Volkman, B.F.

1995-02-01T23:59:59.000Z

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.


401

Magnetic moments of the low-lying $J^P=\\,1/2^-$, $3/2^-$ $?$ resonances within the framework of the chiral quark model  

E-Print Network [OSTI]

The magnetic moments of the low-lying spin-parity $J^P=$ $1/2^-$, $3/2^-$ $\\Lambda$ resonances, like, for example, $\\Lambda(1405)$ $1/2^-$, $\\Lambda(1520)$ $3/2^-$, as well as their transition magnetic moments, are calculated using the chiral quark model. The results found are compared with those obtained from the nonrelativistic quark model and those of unitary chiral theories, where some of these states are generated through the dynamics of two hadron coupled channels and their unitarization.

A. Martnez Torres; K. P. Khemchandani; Neetika Sharma; Harleen Dahiya

2012-08-02T23:59:59.000Z

402

The Structure of Hydrated Electron. Part 1. Magnetic Resonance of Internally Trapping Water Anions: A Density Functional Theory Study  

E-Print Network [OSTI]

Density functional theory (DFT) is used to rationalize magnetic parameters of hydrated electron trapped in alkaline glasses as observed using Electron Paramagnetic Resonance (EPR) and Electron Spin Echo Envelope Modulation (ESEEM) spectroscopies. To this end, model water cluster anions (n=4-8 and n=20,24) that localize the electron internally are examined. It is shown that EPR parameters of such water anions (such as hyperfine coupling tensors of H/D nuclei in the water molecules) are defined mainly by the cavity size and the coordination number of the electron; the water molecules in the second solvation shell play a relatively minor role. An idealized model of hydrated electron (that is usually attributed to L. Kevan) in which six hydroxyl groups arranged in an octahedral pattern point towards the common center is shown to provide the closest match to the experimental parameters, such as isotropic and anisotropic hyperfine coupling constants for the protons (estimated from ESEEM), the second moment of the EPR spectra, and the radius of gyration. The salient feature of these DFT models is the significant transfer (10-20%) of spin density into the frontal O 2p orbitals of water molecules. Spin bond polarization involving these oxygen orbitals accounts for small, negative hyperfine coupling constants for protons in hydroxyl groups that form the electron-trapping cavity. In Part 2, these results are generalized for more realistic geometries of core anions obtained using a dynamic one-electron mixed qunatum/classical molecular dynamics model.

I. A. Shkrob

2006-07-25T23:59:59.000Z

403

Interstudy reproducibility of dimensional and functional measurements between cine magnetic resonance studies in the morphologically abnormal left ventricle  

Science Journals Connector (OSTI)

The validity of geometric formulas to derive mass and volumes in the morphologically abnormal left ventricule is problematic. Imaging techniques that are tomographic and therefore inherently three-dimensional should be more reliable and reproducible between studies in such ventricles. Determination of reproducibility between studies is essential to define the limits of an imaging technique for evaluating the response to therapy. Sequential cine magnetic resonance (MR) studies were performed on patients with dilated cardiomyopathy (n=11) and left ventricular hypertrophy (n=8) within a short interval in order to assess interstudy reproducbility. Left ventricular mass, volumes, ejection fraction, and end-systolic wall stress were determined by two independent observers. Between studies, left ventricular mass was highly reproducible for hypertrophied and dilated ventricles, with percent variability less than 6%. Ejection fraction and end-diastolic volume showed close reproducibility between studies, with percent variability less than 5%. End-systolic volume varied by 4.3% and 4.5% in dilated cardiomyopathy and 8.4% and 7.2% in left ventricular hypertrophy for the two observers. End-systolic wall stress, which is derived from multiple measurements, varied the greatest, with percent variability of 17.2% and 15.7% in dilated cardiomyopathy and 14.8% and 13% in left ventricular hypertrophy, respectively. The results of this study demonstrate that mass, volume, and functional measurements are reproducible in morphologically abnormal ventricles.

Richard C. Semelka; Ernesto Tomei; Stefan Wagner; John Mayo; Gary Caputo; Margaret O'Sullivan; William W. Parmley; Kanu Chatterjee; Christopher Wolfe; Charles B. Higgins

1990-01-01T23:59:59.000Z

404

Development of a System for Rapid Detection of Contaminants in Water Supplies Using Magnetic Resonance and Nanoparticles  

SciTech Connect (OSTI)

To keep the water supply safe and to ensure a swift and accurate response to a water supply contamination event, rapid and robust methods for microbial testing are necessary. Current technologies are complex, lengthy and costly and there is a need for rapid, reliable, and precise approaches that can readily address this fundamental security and safety issue. T2 Biosystems is focused on providing solutions to this problem by making breakthroughs in nanotechnology and biosensor techniques that address the current technical restrictions facing rapid, molecular analysis in complex samples. In order to apply the T2 Biosystems nucleic acid detection procedure to the analysis of nucleic acid targets in unprocessed water samples, Bacillus thuringeinsis was selected as a model organism and local river water was selected as the sample matrix. The initial assay reagent formulation was conceived with a manual magnetic resonance reader, was optimized using a high throughput system, and transferred back to the MR reader for potential field use. The final assay employing the designed and manufactured instruments was capable of detecting 10 CFU/mL of B. thuringiensis directly within the environmental water sample within 90 minutes. Further, discrimination of two closely related species of Bacilli was accomplished using the methods of this project; greater than 3-fold discrimination between B. cereus and B. thuringiensis at a concentrations spanning 10 CFU/mL to 10{sup 5} CFU/mL was observed.

Lowery, Thomas J; Neely, Lori; Chepin, James; Wellman, Parris; Toso, Ken; Murray, Paul; Audeh, Mark; Demas, Vasiliki; Palazzolo, Robert; Min, Michael; Phung, Nu; Blanco, Matt; Raphel, Jordan; O'Neil, Troy

2010-09-14T23:59:59.000Z

405

Velocity and concentration studies of flowing suspensions by nuclear magnetic resonance imaging. Final report, October 7, 1994--October 6, 1996  

SciTech Connect (OSTI)

Nuclear magnetic resonance imaging techniques were developed to study concentrated suspension flows. The tasks completed were: (1) materials selection for imaging of both particle and fluid components, (2) pipe flow measurements, and (3) flows in complex geometries. The partially completed task is the development of rapid imaging techniques by analog compensation of eddy currents, generated by the gradient pulses, and real-time image reconstruction from the data. The best combination of materials found is pharmaceutical beads in silicon oil. Their relaxation times T{sub 1} are sufficiently different to permit imaging the two components separately. The pipe flow experiment used 3 mm, neutrally buoyant, plastic particles, up to 40% by volume, in 80--90W transmission oil flowing in a 5 cm diameter pipe. Distances ranging from 60 cm to 6 m downstream from a commercial mixer was studied. The flow is fully developed at 6 m and the concentration and velocity profiles agree with earlier lower resolution experiments. The eddy current compensation scheme works well for two channels and is being extended to eight channels. The authors have also built a rapid reconstruction hardware that processes and displays images in a fraction of a second. They studied the flow of neutrally buoyant concentrated suspension past a step expansion and contraction in a cylindrical pipe. Interesting transition is observed at the expansion whereby the high fluids-fraction outer layer spreads to become the outer layer in the larger pipe.

NONE

1996-12-31T23:59:59.000Z

406

NMR logging apparatus  

DOE Patents [OSTI]

Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

Walsh, David O; Turner, Peter

2014-05-27T23:59:59.000Z

407

{sup 1}H and {sup 31}P nuclear magnetic resonance study of proton-irradiated KH{sub 2}PO{sub 4}  

SciTech Connect (OSTI)

We have studied the microscopic structure and dynamics in a proton-irradiated KH{sub 2}PO{sub 4} single crystal. Our {sup 1}H and {sup 31}P nuclear magnetic resonance measurements indicate that proton irradiation gives rise to a decrease in the local dipolar order of the rigid lattice protons and an increase in interstitial protons as well as structural distortion of the PO{sub 4} tetrahedra.

Kim, Se-Hun [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Faculty of Science Education and Educational Research Institute, Cheju National University, Cheju 690-756 (Korea, Republic of); Lee, Kyu Won; Oh, B. H.; Lee, Cheol Eui [Department of Physics and Institute for Nano Science, Korea University, Seoul 136-713 (Korea, Republic of); Hong, K. S. [Korea Basic Science Institute, Daejeon 305-333 (Korea, Republic of)

2007-11-01T23:59:59.000Z

408

Folic Acid-Conjugated MnO Nanoparticles as a T1 Contrast Agent for Magnetic Resonance Imaging of Tiny Brain Gliomas  

Science Journals Connector (OSTI)

Folic Acid-Conjugated MnO Nanoparticles as a T1 Contrast Agent for Magnetic Resonance Imaging of Tiny Brain Gliomas ... Detection of brain gliomas at the earliest stage is of great importance to improve the outcomes but remains the most challenging task. ... Accordingly, the in vivo MR images demonstrated that MnO-TETT-FA NPs could efficiently enhance the MRI contrast for tiny brain gliomas. ...

Ning Chen; Chen Shao; Yanming Qu; Shuai Li; Wei Gu; Tingting Zheng; Ling Ye; Chunjiang Yu

2014-10-21T23:59:59.000Z

409

Magnetism  

Science Journals Connector (OSTI)

Historically, magnetism is related to rock magnetism, due to a few minerals exhibiting spontaneous magnetization. Attractive properties of magnetite were already known in Antiquity and were used for navigation...

Guillaume Morin

1998-01-01T23:59:59.000Z

410

Solid-state NMR examination of alteration layers on nuclear waste glasses  

Science Journals Connector (OSTI)

Abstract Solid-state nuclear magnetic resonance (NMR) is a powerful tool for probing the role and significance of alteration layers in determining the kinetics for the corrosion of nuclear waste glass. NMR methods are used to probe the chemical structure of the alteration layers to elucidate information about their chemical complexity, leading to increased insight into the mechanism of altered layer formation. Two glass compositions were examined in this study: a glass preliminarily designed for nuclear waste immobilization (called AFCI) and a simplified version of this AFCI glass (which we call SA1R). Powdered glasses with controlled and known particle sizes were corroded in ASTM type I water at 90C for periods of one and five months with a glass surface-area to solution-volume ratio of 100,000m?1. 1H29Si cross-polarization Carr-Purcell-Meiboom-Gill (CP-CPMG) magic angle spinning (MAS) NMR, 1H27Al CP-MAS NMR, 1H11B CP-MAS NMR, and 1H23Na CP-MAS NMR experiments provided isolated structural information about the alteration layers, which differ in structure from that of the pristine glass. Both glasses studied here develop alteration layers composed primarily of [IV]Si species. Aluminum is also retained in the alteration layers, perhaps facilitated by the observed increase in coordination from [IV]Al to [VI]Al, which correlates with a loss of charge balancing cations. The mechanism of increasing coordination appears to occur through an unstable [V]Al intermediate. 1H11B CP-MAS NMR observations indicated a retention of boron in the hydrated glass layers, which has not been characterized by previous work. For the AFCI glass, secondary phase formation begins during the corrosion times considered here, and these new phases are detected within the alteration layers. We identify new phases (termed as precursor phases) as crystalline sodium metasilicates. An important finding is that simple glass compositions, while providing general trends about the formation of alteration layers, do not account for all of the various reaction products that occur in the corrosion of more complex nuclear waste glass compositions.

Kelly A. Murphy; Nancy M. Washton; Joseph V. Ryan; Carlo G. Pantano; Karl T. Mueller

2013-01-01T23:59:59.000Z

411

Geometric accuracy of 3D coordinates of the Leksell stereotactic skull frame in 1.5 Tesla- and 3.0 Tesla-magnetic resonance imaging: a comparison of three different fixation screw materials  

Science Journals Connector (OSTI)

......In addition, spatial accuracy over the entire brain is necessary when multiple metastatic brain tumors are being treated. Regarding image distortion...magnetic resonance imaging for postimplantation deep brain stimulator lead localization. Neurosurgery......

Hisato Nakazawa; Yoshimasa Mori; Osamu Yamamuro; Masataka Komori; Yuta Shibamoto; Yukio Uchiyama; Takahiko Tsugawa; Masahiro Hagiwara

2014-11-01T23:59:59.000Z

412

Nuclear Magnetic Resonance (NMR) Spectroscopic Investigation of Interaction Energies of Ephedrine Stereoisomers in Noncrystalline Solids and Its Correlation with Thermodynamic Data  

Science Journals Connector (OSTI)

Equations relating the interaction energies of each of the binary mixtures of ephedrine from linear combinations of the energies of the individual isomers are presented. The interaction energies in the noncrystal...

Walter F. Schmidt; Irwin L. Honigberg

1991-09-01T23:59:59.000Z

413

An NMR (nuclear magnetic resonance) investigation of the chemical association and molecular dynamics in asphalt ridge tar sand ore and bitumen  

SciTech Connect (OSTI)

Preliminary studies on tar sand bitumen given in this report have shown that the reassociation of tar sand bitumen to its original molecular configuration after thermal stressing is a first-order process requiring nearly a week to establish equilibrium. Studies were also conducted on the dissolution of tar sand bitumen in solvents of varying polarity. At a high-weight fraction of solute to solvent the apparent molecular weight of the bitumen molecules was greater than that of the original bitumen when dissolved in chloroform-d/sub 1/ and benzene-d/sub 6/. This increase in the apparent molecular weight may be due to micellar formation or a weak solute-solvent molecular complex. Upon further dilution with any of the solvents studied, the apparent molecular weight of the tar sand bitumen decreased because of reduced van der Waals forces of interaction and/or hydrogen bonding. To define the exact nature of the interactions, it will be necessary to have viscosity measurements of the solutions. 30 refs., 3 figs., 3 tabs.

Netzel, D.A.; Coover, P.T.

1987-09-01T23:59:59.000Z

414

Abstract 4100: Nutrition and breast cancer prevention: adipose tissue proton magnetic resonance spectroscopy (1H-NMR) as biomarker of past dietary intake of lipids  

Science Journals Connector (OSTI)

...rapeseed oils enriched with 8% of an oil without (palm oil) or with DHA (DHASCO, containing...the mixture of peanut and rapeseed oils. All five groups (n=6 per group...groups. For example, expressed as peak area %, mean values for DHA ranged...

Lobna Ouldamer; Lydie Nadal-Desbarats; Stephan Chevalier; Caroline Goupille; and Philippe Bougnoux

2014-10-01T23:59:59.000Z

415

magnetism  

Science Journals Connector (OSTI)

magnetism [A class of physical phenomena associated with moving electricity, including the mutual mechanical forces among magnets and electric currents] ? Magnetismus m

2014-08-01T23:59:59.000Z

416

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

SciTech Connect (OSTI)

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

417

31P-Nuclear Magnetic Resonance Spectroscopy Studies of the Response of Rat Mammary Tumors to Endocrine Therapy  

Science Journals Connector (OSTI)

...study by 3IP-NMR because their energy metab olism is poised between...modalities are likely to perturb the energy Received 7/21/86; revised...2. Assays of tumor nucleo- tides by high performance liquid chromatography...temperature until it has lost its high energy phosphate signals. Tumor thus...

Loreta M. Rodrigues; Caroline J. Midwood; R. Charles Coombes; Anthony N. Stevens; Marion Stubbs; and John R. Griffiths

1988-01-01T23:59:59.000Z

418

Influence of open and sealed fractures on fluid flow and water saturation in sandstone cores using Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

......problems in hydrocarbon production or the safe deep storage of high-level waste. 2 Principles of nmr and mri techniques Nuclear...obtained by coring at surface exposure subject to long-term interaction with the atmosphere, and are hence......

S. Baraka-Lokmane; G. Teutsch; I. G. Main

2001-11-01T23:59:59.000Z

419

Application of polarized neutron reflectometry and X-ray resonant magnetic reflectometry for determining the inhomogeneous magnetic structure in Fe/Gd multilayers  

Science Journals Connector (OSTI)

The evolution of the magnetic structure of multilayer [Fe (35 )/Gd (50 )5...] with variation in temperature and an applied magnetic field was determined using a complementary approach combining polarized neutron

E. A. Kravtsov; D. Haskel

2010-10-01T23:59:59.000Z

420

Femtosecond Opto-Magnetism  

Science Journals Connector (OSTI)

We demonstrate that circularly polarized laser pulses may selectively excite different modes of magnetic resonance, realize quantum control of magnons, trigger magnetic phase...

Kimel, Alexey; Kirilyuk, A; Rasing, Th

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

X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er)  

SciTech Connect (OSTI)

Electricity and magnetism were unified into a common subject by James Clerk Maxwell in the nineteenth century yielding the electromagnetic theory. Four equations govern the dynamics of electric charges and magnetic fields, commonly known as Maxwell's equations. Maxwell's equations demonstrate that an accelerated charged particle can produce magnetic fields and a time varying magnetic field can induce a voltage - thereby linking the two phenomena. However, in solids, electric and magnetic ordering are most often considered separately and usually with good reason: the electric charges of electrons and ions are responsible for the charge effects, whereas the electron spin governs magnetic properties.

Nandi, Shibabrata

2009-12-19T23:59:59.000Z

422

NMR-assignments of a cytosolic domain of the C-terminus of polycystin-2  

E-Print Network [OSTI]

ARTICLE NMR-assignments of a cytosolic domain of the C-terminus of polycystin-2 Frank H. Schumann ?. The backbone and side chain resonances were assigned by multidimensional NMR methods, the obtained chemical contained 1 g NH4Cl, 6 g glucose, F. H. Schumann Á M. Schmidt Á R. Bader Á H. R. Kalbitzer (&) Institute

Witzgall, Ralph - Naturwissenschaftliche Fakultät III

423

1H NMR investigation of the spin dynamics of the spin-frustrated trinuclear Fe cluster (NH4)[Fe3(?3-OH)(H2L)3(HL)3]?(H3L=orotic acid)  

Science Journals Connector (OSTI)

Proton nuclear-magnetic-resonance (NMR) measurements have been performed in the cluster (NH4)[Fe3(?3-OH)(H2L)3(HL)3]?(H3L=orotic acid) in order to investigate the electron spin dynamics of the Fe trinuclear unit. The proton NMR spectra and spin-lattice relaxation times T1 have been measured at temperatures between 3 K and room temperature. The 1/T1 rate exhibits a broad maximum around 50 K, which is attributed to slow local-field fluctuations of the electronic spin system of the order of the Larmor period, associated with magnetic excitations between the discrete low-lying energy levels of the cluster. The observation and relaxation analysis of the 1/T1 maximum provide an independent measurement of the energy difference between the ground and the first-excited state of the trinuclear unit and corroborates the results of previous static susceptibility measurements.

M. Fardis; G. Diamantopoulos; M. Karayianni; G. Papavassiliou; V. Tangoulis; A. Konsta

2001-11-30T23:59:59.000Z

424

Magnetic Resonance Imaging  

Science Journals Connector (OSTI)

The diagnosis of diastolic heart failure requires a combination of clinical, laboratory, and technical findings, providing evidence of the existence of heart failure, the absence of (significant) systolic abno...

Frank E. Rademakers MD; PhD; Jan Bogaert MD; PhD

2008-01-01T23:59:59.000Z

425

Magnetism  

Science Journals Connector (OSTI)

... dipoles in applied fields". It deals with the classical (Langevin) theory of para-magnetism, anisotropy fields and magnetic measurements. In the next chapter "Atomic structure" the author ... special relevance to ferrites and the inclusion of a quite lengthy discussion of Pauli para-magnetism and of Stoner's treatment of itinerant electron ferromagnetism, though it does much to ...

E. W. LEE

1972-03-31T23:59:59.000Z

426

A Prospective Study of the Utility of Magnetic Resonance Imaging in Determining Candidacy for Partial Breast Irradiation  

SciTech Connect (OSTI)

Purpose: Retrospective data have demonstrated that breast magnetic resonance imaging (MRI) may change a patient's eligibility for partial breast irradiation (PBI) by identifying multicentric, multifocal, or contralateral disease. The objective of the current study was to prospectively determine the frequency with which MRI identifies occult disease and to establish clinical factors associated with a higher likelihood of MRI prompting changes in PBI eligibility. Methods and Materials: At The University of Chicago, women with breast cancer uniformly undergo MRI in addition to mammography and ultrasonography. From June 2009 through May 2011, all patients were screened prospectively in a multidisciplinary conference for PBI eligibility based on standard imaging, and the impact of MRI on PBI eligibility according to National Surgical Adjuvant Breast and Bowel Project protocol B-39/Radiation Therapy Oncology Group protocol 0413 entry criteria was recorded. Univariable analysis was performed using clinical characteristics in both the prospective cohort and in a separate cohort of retrospectively identified patients. Pooled analysis was used to derive a scoring index predictive of the risk that MRI would identify additional disease. Results: A total of 521 patients were screened for PBI eligibility, and 124 (23.8%) patients were deemed eligible for PBI based on standard imaging. MRI findings changed PBI eligibility in 12.9% of patients. In the pooled univariable analysis, tumor size ?2 cm on mammography or ultrasonography (P=.02), age <50 years (P=.01), invasive lobular histology (P=.01), and HER-2/neu amplification (P=.01) were associated with a higher likelihood of MRI changing PBI eligibility. A predictive score was generated by summing the number of significant risk factors. Patients with a score of 0, 1, 2, and 3 had changes to eligibility based on MRI findings in 2.8%, 13.2%, 38.1%, and 100%, respectively (P<.0001). Conclusions: MRI identified additional disease in a significant number of patients eligible for PBI, based on standard imaging. Clinical characteristics may be useful in directing implementation of MRI in the staging of PBI candidates.

Dorn, Paige L.; Al-Hallaq, Hania A.; Haq, Farah; Goldberg, Mira [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States); Abe, Hiroyuki [Department of Radiology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiology, University of Chicago Medical Center, Chicago, Illinois (United States); Hasan, Yasmin [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)] [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States); Chmura, Steven J., E-mail: schmura@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois (United States)

2013-03-01T23:59:59.000Z

427

Magnetic Resonance Imaging-Based Radiation-Absorbed Dose Estimation of 166Ho Microspheres in Liver Radioembolization  

Science Journals Connector (OSTI)

Purpose To investigate the potential of magnetic resonance imaging (MRI) for accurate assessment of the three-dimensional 166Ho activity distribution to estimate radiation-absorbed dose distributions in 166Ho-loaded poly (L-lactic acid) microsphere (166Ho-PLLA-MS) liver radioembolization. Methods and Materials MRI, computed tomography (CT), and single photon emission CT (SPECT) experiments were conducted on an anthropomorphic gel phantom with tumor-simulating gel samples and on an excised human tumor-bearing liver, both containing known amounts of 166Ho-PLLA-MS. Three-dimensional radiation-absorbed dose distributions were estimated at the voxel level by convolving the 166Ho activity distribution, derived from quantitative MRI data, with a 166Ho dose point-kernel generated by MCNP (Monte Carlo N-Particle transport code) and from Medical Internal Radiation Dose Pamphlet 17. MRI-based radiation-absorbed dose distributions were qualitatively compared with CT and autoradiography images and quantitatively compared with SPECT-based dose distributions. Both MRI- and SPECT-based activity estimations were validated against dose calibrator measurements. Results Evaluation on an anthropomorphic phantom showed that MRI enables accurate assessment of local 166Ho-PLLA-MS mass and activity distributions, as supported by a regression coefficient of 1.05 and a correlation coefficient of 0.99, relating local MRI-based mass and activity calculations to reference values obtained with a dose calibrator. Estimated MRI-based radiation-absorbed dose distributions of 166Ho-PLLA-MS in an exvivo human liver visually showed high correspondence to SPECT-based radiation-absorbed dose distributions. Quantitative analysis revealed that the differences in local and total amounts of 166Ho-PLLA-MS estimated by MRI, SPECT, and the dose calibrator were within 10%. Excellent agreement was observed between MRI- and SPECT-based dosevolume histograms. Conclusions Quantitative MRI was demonstrated to provide accurate three-dimensional 166Ho-PLLA-MS activity distributions, enabling localized intrahepatic radiation-absorbed dose estimation by convolution with a 166Ho dose point-kernel for liver radioembolization treatment optimization and evaluation.

Peter R. Seevinck; Gerrit H. van de Maat; Tim C. de Wit; Maarten A.D. Vente; Johannes F.W. Nijsen; Chris J.G. Bakker

2012-01-01T23:59:59.000Z

428

Design of a compact, permanent magnet electron cyclotron resonance ion source for proton and H{sub 2}{sup +} beam production  

SciTech Connect (OSTI)

A 2.45 GHz microwave ion source was developed at China Institute of Atomic Energy (CIAE) for proton beam production of over 60 mA [B.-Q. Cui, Y.-W. Bao, L.-Q. Li, W.-S. Jiang, and R.-W. Wang, Proceedings of the High Current Electron Cyclotron Resonance (ECR) Ion Source for Proton Accelerator, APAC-2001, 2001 (unpublished)]. For various proton beam applications, another 2.45 GHz microwave ion source with a compact structure is designed and will be built at CIAE as well for high current proton beam production. It is also considered to be used for the test of H{sub 2}{sup +} beam, which could be injected into the central region model cyclotron at CIAE, and accelerated to 5 MeV before extraction by stripping. The required ECR magnetic field is supplied by all the permanent magnets rather than electrical solenoids and six poles. The magnetic field distribution provided by this permanent magnets configuration is a large and uniformly volume of ECR zone, with central magnetic field of a magnitude of {approx}875 Gs[T. Taylor and J. S. C. Wills, Nucl. Instrum. Methods Phys. Res. A 309, 37 (1991)]. The field adjustment at the extraction end can be implemented by moving the position of the magnet blocks. The results of plasma, coupling with 2.45 GHz microwave in the ECR zone inside the ion source are simulated by particle-in-cell code to optimize the density by adjusting the magnetic field distribution. The design configuration of the ion source will be summarized in the paper.

Jia Xianlu; Zhang Tianjue; Wang Chuan; Zheng Xia; Yin Zhiguo; Zhong Junqing; Wu Longcheng; Qin Jiuchang [China Institute of Atomic Energy, P.O. Box 275(3), Beijing 102413 (China); Luo Shan [The 6th Department, Communication Command Academy, Wuhan 430010 (China)

2010-02-15T23:59:59.000Z

429

Biomass Fractionation for the Biorefinery: Heteronuclear Multiple Quantum CoherenceNuclear Magnetic Resonance Investigation of Lignin Isolated from Solvent Fractionation of Switchgrass  

Science Journals Connector (OSTI)

Biomass Fractionation for the Biorefinery: Heteronuclear Multiple Quantum CoherenceNuclear Magnetic Resonance Investigation of Lignin Isolated from Solvent Fractionation of Switchgrass ... Center for Renewable Carbon, Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio), University of Tennessee, 2506 Jacob Drive, Knoxville, Tennessee 37996, United States ... The results show that solvent fractionation conditions between about 120 C and 0.1 M H2SO4 and 160 C and 0.025 M H2SO4 are optimal for separating biomass in the biorefinery to give process streams most suitable for biobased fuel and chemical production. ...

Joseph J. Bozell; C. J. O'Lenick; Stacy Warwick

2011-07-27T23:59:59.000Z

430

High Core Electron Confinement Regimes in FTU Plasmas with Low- or Reversed-Magnetic Shear and High Power Density Electron-Cyclotron-Resonance Heating  

Science Journals Connector (OSTI)

Electron temperatures in excess of 8 keV have been obtained by electron-cyclotron-resonance heating on FTU plasmas at peak densities up to 81019 m -3. The magnetic shear in the plasma core is low or negative, and the electron heat diffusivity remains at, or below, the Ohmic level (0.2 m 2/s), in spite of the very large heating power density (1020 MW/m 3) which produces extremely high temperature gradients (up to 120 keV/m). The ion heat transport remains at the neoclassical level.

P. Buratti et al.

1999-01-18T23:59:59.000Z

431

A method for the rapid, accurate prediction of the physical properties of middle distillate fuels from LC- sup 1 H NMR derived data  

SciTech Connect (OSTI)

A method has been developed whereby various physical properties of middle distillate fuels may be rapidly and accurately calculated by a group property approach from data obtained from a directly coupled Liquid Chromatograph - {sup 1}H Nuclear Magnetic Resonance Spectrometer (LC-{sup 1}H NMR). The physical properties include cetane number, cetane index, density, specific gravity, pour point, flash point, viscosity, filterability, heat of combustion, cloud point, volume percent aromatics, residual carbon content, and initial, 10%, 50%, 90%, and end boiling points. These property predictions have accuracies approaching the error for measurement of the experimental physical property and require less than two hours analysis time per fuel. An interface was developed between the NMR spectrometer and a personal computer to aid in automation of the LC-{sup 1}H NMR data collection and to perform off-line analysis of the LC-{sup 1}H NMR data. This interface and all associated software is described. Also presented is a series of model compounds studies in which the physical properties of pure hydrocarbons (i.e., alkanes, monocyclic and dicyclic aromatics) were predicted by a similar group property approach.

Caswell, K.A.

1988-01-01T23:59:59.000Z

432

Impact of oxygen annealing on the heat capacity and magnetic resonance of superconducting Pr0.88LaCe0.12CuO4?  

SciTech Connect (OSTI)

We use thermodynamic and neutron-scattering measurements to study the effect of oxygen annealing on the superconductivity and magnetism in Pr0.88LaCe0.12CuO4?. Although the transition temperature Tc measured by susceptibility and superconducting coherence length increases smoothly with gradual oxygen removal from the annealing process, bulk superconductivity, marked by a specific-heat anomaly at Tc and the presence of a neutron magnetic resonance, only appears abruptly when Tc is close to the largest value. These results suggest that the effect of oxygen annealing must first be determined in order to establish a Ce doping dependence of antiferromagnetism and superconductivity phase diagram for electron-doped copper oxides.

Li, Shiliang [University of Tennessee, Knoxville (UTK); Chi, Songxue [University of Tennessee, Knoxville (UTK); Zhao, Jun [ORNL; Wen, H. H. [Chinese Academy of Sciences; Stone, Matthew B [ORNL; Lynn, J. W. [National Institute of Standards and Technology (NIST); Dai, Pengcheng [ORNL

2008-01-01T23:59:59.000Z

433

x-ray resonant magnetic reflectivity of stratified magnetic structures: eigen-wave formalism and application to a Fe thin film  

E-Print Network [OSTI]

or polarized neutron scattering: a sensitivity to the orientation and the amplitude of the local magnetic a classical de- scription with Maxwell equations and a permittivity built from the quantum scattering amplitude. Approximations on the relative power of the Thomson scattering and the magnetic terms are track

434

The Heating of Electrons in Magnetic Traps of Low-Pressure Electron-Cyclotron-Resonance Microwave-Frequency Reactors  

Science Journals Connector (OSTI)

Methods are analyzed of maintaining plasma in low-pressure electron-cyclotron-resonance reactors in which the ionization is ... The key part played by zones of electron-cyclotron heating of electrons by the elect...

A. B. Petrin

435

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

SciTech Connect (OSTI)

This thesis describes several studies in which nuclear magnetic resonance (nmr) spectroscopy has been used to probe the structure, orientation and dynamics of liquid crystal mesogens and molecules dissolved in liquid crystalline phases. In addition, a modern high field nmr spectrometer is described which has been used to perform such nmr studies. Chapter 1 introduces the quantum mechanical formalisms used throughout this thesis and briefly reviews the fundamentals of nuclear spin physics and pulsed nmr spectroscopy. First the density operator is described and a specific form for the canonical ensemble is derived. Then Clebsch-Gordon coefficients, Wigner rotation matrices, and irreducible tensor operators are reviewed. An expression for the equilibrium (Curie) magnetization is obtained and the linear response of a spin system to a strong pulsed r.f. irradiation is described. Finally, the spin interaction Hamiltonians relevant to this work are reviewed together with their truncated forms. Chapter 2 is a deuterium magnetic resonance study of two 'nom' liquid crystals which possess several low temperature mesomorphic phases. Specifically, deuterium quadrupolar echo spectroscopy is used to determine the orientation of the liquid crystal molecules in smectic phases, the changes in molecular orientation and motion that occur at smectic-smectic phase transitions, and the order of the phase transitions. For both compounds, the phase sequence is determined to be isotropic, nematic, smectic A, smectic C, smectic B{sub A}, smectic B{sub C}, and crystalline. The structure of the smectic A phase is found to be consistent with the well-known model of a two dimensional liquid in which molecules are rapidly rotating about their long axes and oriented at right angles to the plane of the layers. Molecules in the smectic C phase are found to have their long axes tilted with respect to the layer normal, and the tilt angle is temperature dependent, increasing from zero at the smectic A - smectic C transition and reaching a maximum at 9{sup o} at the smectic C - smectic B{sub A} transition. This finding contradicts the results of X-ray diffraction studies which indicate that the tilt angle is 18{sup o} and temperature independent. The smectic B{sub A} - smectic B{sub C} phase transition is observed for the first time, and is found to be first order, a result that contradicts the prediction of a mean theory by McMillian. Chapter 3 is a multiple quantum nmr study of n-hexane oriented in a nematic liquid crystal solvent. The basic three pulse multiple quantum experiment is discussed which enables the observation of transitions for which |{Delta}m|>1, and then the technique of the separation of multiple quantum orders by phase incrementation in the multiple quantum evolution period is reviewed (TPPI). An explicit example of multiple quantum nmr is given by the calculation of the multiple quantum spectrum of an oriented methyl group.

Drobny, G.P.

1982-11-01T23:59:59.000Z

436

Vanishing amplitude of backbone dynamics causes a true protein dynamical transition: H2 NMR studies on perdeuterated C-phycocyanin  

Science Journals Connector (OSTI)

Using a combination of H2 nuclear magnetic resonance (NMR) methods, we study internal rotational dynamics of the perdeuterated protein C-phycocyanin (CPC) in dry and hydrated states over broad temperature and dynamic ranges with high angular resolution. Separating H2 NMR signals from methyl deuterons, we show that basically all backbone deuterons exhibit highly restricted motion occurring on time scales faster than microseconds. The amplitude of this motion increases when a hydration shell exists, while it decreases upon cooling and vanishes near 175 K. We conclude that the vanishing of the highly restricted motion marks a dynamical transition, which is independent of the time window and of a fundamental importance. This conclusion is supported by results from experimental and computational studies of the proteins myoglobin and elastin. In particular, we argue based on findings in molecular dynamics simulations that the behavior of the highly restricted motion of proteins at the dynamical transition resembles that of a characteristic secondary relaxation of liquids at the glass transition, namely the nearly constant loss. Furthermore, H2 NMR studies on perdeuterated CPC reveal that, in addition to highly restricted motion, small fractions of backbone segments exhibit weakly restricted dynamics when temperature and hydration are sufficiently high.

Kerstin Kmpf; Beke Kremmling; Michael Vogel

2014-03-17T23:59:59.000Z

437

Ion Heating in the Field-Reversed Configuration by Rotating Magnetic Fields near the Ion-Cyclotron Resonance  

Science Journals Connector (OSTI)

The trajectories of ions confined in a field-reversed configuration (FRC) equilibrium magnetic geometry and heated with a small-amplitude, odd-parity rotating magnetic field (RMF) have been studied with a Hamiltonian computer code. When the RMF frequency is in the ion-cyclotron range, explosive heating occurs. Higher-energy ions are found to have betatron-type orbits, preferentially localized near the FRC's midplane. These results are relevant to a compact magnetic-fusion-reactor design.

Samuel A. Cohen and Alan H. Glasser

2000-12-11T23:59:59.000Z

438

Toroid cavities as NMR detectors in high pressure probes  

SciTech Connect (OSTI)

A cylindrical toroid cavity has been developed for application as an NMR detector for high sensitivity and high resolution spectroscopy in metal vessel probes. Those probes are used for in situ investigations at high temperature and pressure. Since the transmitted r.f. field is completely confined within the torus, the cavity can be placed inside the pressurized system without magnetic coupling to the metal vessel. Resonance frequencies up to 400 MHz make the toroid cavity detector especially suited for use in {sup 1}H and {sup 19}F spectroscopy. Typically achieved static {sup 1}H linewidths, measured on CHCl{sub 3} using cavities in Be-Cu pressure vessels, are 2.0 Hz. On the basis of theoretical considerations that include the radial dependence of the r.f. field within cylindrical or circular toroid detectors, equations were evolved to predict the signal intensity as a function of the pulse width. The equations precisely describe the deviations from the sinusoidal approximation, which is generally used for signal intensities derived from Helmholtz or solenoid coils.

Woelk, K.; Rathke, J.W.; Klingler, R.J.

1993-03-01T23:59:59.000Z

439

Magnetism  

Science Journals Connector (OSTI)

... THIS is a good book, and we are glad to see the subject of magnetism fully treated in a popularly written text-book. It is a second edition of ... of importance, accuracy, and exhaustiveness, places the present treatise, as far as terrestrial magnetism is concerned, much before any similar book with which we are acquainted. The correction ...

JAMES STUART

1872-03-07T23:59:59.000Z

440

NMR imaging of materials  

SciTech Connect (OSTI)

Interest in the area of NMR imaging has been driven by the widespread success of medical imaging. John M. Listerud of the Pendergrass Diagnostic Research Laboratories, Steven W. Sinton of Lockheed, and Gary P. Drobny of the University of Washington describe the principal image reconstruction methods, factors limiting spatial resolution, and applications of imaging to the study of materials.

Listerud, J.M.; Sinton, S.W.; Drobny, G.P.

1989-01-01T23:59:59.000Z

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441

Benford distributions in NMR  

E-Print Network [OSTI]

Benford's Law is an empirical law which predicts the frequency of significant digits in databases corresponding to various phenomena, natural or artificial. Although counter intuitive at the first sight, it predicts a higher occurrence of digit 1, and decreasing occurrences to other larger digits. Here we report the Benford analysis of various NMR databases and draw several interesting inferences. We observe that, in general, NMR signals follow Benford distribution in time-domain as well as in frequency domain. Our survey included NMR signals of various nuclear species in a wide variety of molecules in different phases, namely liquid, liquid-crystalline, and solid. We also studied the dependence of Benford distribution on NMR parameters such as signal to noise ratio, number of scans, pulse angles, and apodization. In this process we also find that, under certain circumstances, the Benford analysis can distinguish a genuine spectrum from a visually identical simulated spectrum. Further we find that chemical-shift databases and amplitudes of certain radio frequency pulses generated using optimal control techniques also satisfy Benford's law to a good extent.

Gaurav Bhole; Abhishek Shukla; T. S. Mahesh

2014-06-27T23:59:59.000Z

442

Identification and quantification of metabolites in 1H NMR spectra by Bayesian model selection  

Science Journals Connector (OSTI)

......Martin Bishop Motivation: Nuclear magnetic resonance...show using a simulated dataset, a spike-in experiment...2006), such as nuclear magnetic resonance...Bayesian model selection. | Nuclear magnetic resonance...show using a simulated dataset, a spike-in experiment......

Cheng Zheng; Shucha Zhang; Susanne Ragg; Daniel Raftery; Olga Vitek

2011-06-15T23:59:59.000Z

443

WaVPeak: picking NMR peaks through wavelet-based smoothing and volume-based filtering  

Science Journals Connector (OSTI)

......Tramontano Motivation: Nuclear magnetic resonance...the literature. The dataset comprises 32 2D and 3D...the last two decades, nuclear magnetic resonance...volume-based filtering. | Nuclear magnetic resonance...the literature. The dataset comprises 32 2D and 3D......

Zhi Liu; Ahmed Abbas; Bing-Yi Jing; Xin Gao

2012-04-01T23:59:59.000Z

444

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

SciTech Connect (OSTI)

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

445

Applications of toroids in high-pressure NMR spectroscopy  

SciTech Connect (OSTI)

Toroid detectors have distinct NMR sensitivity and imaging advantages. The magnetic field lines are nearly completely contained within the active volume element of a toroid. This results in high NMR signal sensitivity. In addition, the toroid detector may be placed next to the metallic walls of a containment vessel with minimal signal loss due to magnetic coupling with the metal container. Thus, the toroid detector is ideal for static high pressure or continuous flow monitoring systems. Toroid NMR detectors have been used to follow the hydroformylation of olefins in supercritical fluids under industrial process conditions. Supercritical fluids are potentially ideal media for conducting catalytic reactions that involve gaseous reactants, including H{sub 2}, CO, and CO{sub 2}. The presence of a single homogeneous reaction phase eliminates the gas-liquid mixing problem of alternative two-phase systems, which can limit process rates and adversely affect hydroformylation product selectivities. A second advantage of toroid NMR detectors is that they exhibit a well-defined gradient in the rf field. This magnetic field gradient can be used for NMR imaging applications. Distance resolutions of 20 {mu} have been obtained.

Klingler, R.J.; Rathke, J.W.; Woelk, K. [and others

1995-12-01T23:59:59.000Z

446

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

SciTech Connect (OSTI)

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

447

900-MHz NMR: Accelerating Scientific Discovery Scientific Innovation Through Integration  

E-Print Network [OSTI]

When the U.S. Department of Energy's (DOE's) Office of Biological and Environmental Research approved, the highest magnetic field available was 750 MHz. DOE's decision and the ultimate success of its 900-MHz NMR. Influencing collaborators In addition to advancing many fields of fundamental research, the high-quality data

448

Amide proton exchange in the. cap alpha. -amylase polypeptide inhibitor tendamistat studied by two-dimensional /sup 1/H nuclear magnetic resonance  

SciTech Connect (OSTI)

The individual amide proton exchange rates in Tendamistat at pH 3.0 and 50/sup 0/C were measured by using two-dimensional ..cap alpha..H nuclear magnetic resonance. Overall, it was found that the distribution of exchange rates along the sequence is dominated by the interstrand hydrogen bonds of the ..beta..-sheet structures. The slowly exchanging protons in the core of the two ..beta..-sheets were shown to exchange via an EX2 mechanism. Further analysis of the data indicates that different large-scale structure fluctuations are responsible for the exchange from the two ..beta..-sheets, even though the three-dimensional structure of Tendamistat appears to consist of a single structural domain.

Wang, O.; Kline, A.D.; Wuethrich, K.

1987-10-06T23:59:59.000Z

449

High-dimensionality 13C direct-detected NMR experiments for the automatic assignment of intrinsically disordered proteins  

Science Journals Connector (OSTI)

We present three novel exclusively heteronuclear 5D 13C direct-detected NMR experiments, namely (HN-flipN)CONCACON, (HCA)CONCACON and (H)CACON(CA)CON, designed for easy sequence-specific resonance assignment of i...

Wolfgang Bermel; Isabella C. Felli; Leonardo Gonnelli

2013-12-01T23:59:59.000Z

450

Partnering with Engineers to Identify and Empirically Evaluate Delays in Magnetic Resonance Imaging: Laying the Foundations for Quality Improvement and System-based Practice in Radiology  

Science Journals Connector (OSTI)

Rationale and Objectives The aim of this study was to evaluate the feasibility of partnering with engineering students and critically examining the merit of the problem identification and analyses students generated in identifying sources impeding effective turnaround in a large university department of diagnostic radiology. Turnaround involves the time and activities beginning when a patient enters the magnetic resonance scanner room until the patient leaves, minus the time the scanner is conducting the protocol. Materials and Methods A prospective observational study was conducted, in which four senior undergraduate industrial and operations engineering students interviewed magnetic resonance staff members and observed all shifts. On the basis of 150 hours of observation, the engineering students identified 11 process steps (eg, changing coils). They charted machine use for all shifts, providing a breakdown of turnaround time between appropriate process and non-value-added time. To evaluate the processes occurring in the scanning room, the students used a work-sampling schedule in which a beeper sounded 2.5 times per hour, signaling the technologist to identify which of 11 process steps was occurring. This generated 2147 random observations over a 3-week period. Results The breakdown of machine use over 105 individual studies showed that non-value-added time accounted for 62% of turnaround time. Analysis of 2147 random samples of work showed that scanners were empty and waiting for patients 15% of the total time. Analyses showed that poor communication delayed the arrival of patients and that no one had responsibility for communicating when scanning was done. Conclusions Engineering students used rigorous study design and sampling methods to conduct interviews and observations. This led to data-driven definition of problems and potential solutions to guide systems-based improvement.

Catherine J. Brandon; Michael Holody; Geoffrey Inch; Michael Kabcenell; Diane Schowalter; Patricia B. Mullan

2012-01-01T23:59:59.000Z

451

Neutron Spin Resonance in Iron-based Superconductors | The Ames...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Neutron Spin Resonance in Iron-based Superconductors The propagation of a novel magnetic excitation in the superconducting state, called a spin resonance, has been observed in iron...

452

MagLab Audio Dictionary: Fourier Transform Ion Cyclotron Resonance...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fourier Transform Ion Cyclotron Resonance (FT-ICR)? Now Playing: What's Fourier Transform Ion Cyclotron Resonance (FT-ICR)? Enable Javascript and Flash to stream the Magnet Minute...

453

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

454

magnets  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

455

Role of dopant incorporation on the magnetic properties of Ce1-xNixO2 nanoparticles: An electron paramagnetic resonance study  

SciTech Connect (OSTI)

Nickel doping has been found to produce weak room-temperature ferromagnetism in CeO2 [1]. The saturation magnetization of the chemically synthesized Ce1-xNixO2 samples showed a maximum for x = 0.04, above which the magnetization decreased gradually. For Ce1-xNixO2 samples with x ? 0.04, an activation process involving slow annealing of the sample to 500 oC increased the saturation magnetization by more than two orders of magnitude [1]. However, no such activation effect was observed in samples with x < 0.04. Electron paramagnetic resonance (EPR), a sensitive technique to investigate the ionic states and local environments and interactions, has been used here in this work to investigate (i) why the ferromagnetic behavior gradually weakened and disappeared for x > 0.04 and (ii)_what causes the saturation magnetization to dramatically increase in the activated Ce1-xNixO2 samples with x ? 0.04 and why this process is absent in samples with x < 0.04. Our X-band (~9.4 GHz) EPR experiments and detailed simulation analysis on several as-prepared Ce1-xNixO2 samples with 0.01 ? x ? 0.10 at 5 K and 300 K indicate the presence of two magnetically inequivalent Ni2+ ions with the ionic spin of 1, one Ce3+ ion with spin , and three O2-. Spectra of samples with x < 0.04 are dominated by a single Ni2+ EPR line ascribed to dopant ions in substitutional sites whereas in samples with x ? 0.04, an additional signal attributed to Ni2+ ions in interstitial sites is also present. In the activated sample, the EPR line due to the interstitial Ni2+ is completely absent and only the lines due to substituional Ni2+ ions are present suggesting that the enhanced ferromagnetism results from conversion of interstitial Ni2+ ions to substitutional sites.

Misra, S. K.; Andronenko, S. I.; Engelhard, Mark H.; Thurber, Aaron P.; Reddy, K. M.; Punnoose, Alex

2008-04-01T23:59:59.000Z

456

A BLOCH DECAY AND ULTRA HIGH SPEED CP/MAS 13C NMR STUDY OF THE ARGONNE PREMIUM COALS AND SELECTED OXIDISED LOW-RANK COALS  

Science Journals Connector (OSTI)

Publisher Summary This chapter presents the results of a Bloch decay and ultrahigh speed cross-polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) study of the Argonne premium coals and selected oxidized low-rank coals. A Varian Associates VXR-300 NMR spectrometer operating at 75.4 \\{MHz\\} (13C) equipped with a Doty, Scientific, Inc. high-speed cross-polarization/magic angle probe was employed. Solid-state Bloch decay 13C NMR spectra were determined using 90 carbon pulse, 74 kHz dipolar proton decoupling during acquisition, and a 200-s recycle delay with 13 kHz magic angle spinning. The probe and sample rotor exhibited a background signal amounting to ca. 20% of the total intensity of the coal spectrum, and required careful FID scaling and subtraction of the signal obtained from the empty rotor and caps. CP/MAS spectra were determined at variable contact times from 25 ?S to 25 ms, with 5 s recycle times. The chapter presents a comparison of CP/MAS and Bloch decay results for the Argonne premium coals, a standard humic acid, and for a selection of oxidized coals.

J.C. Linehan; J.A. Franz

1991-01-01T23:59:59.000Z

457

100 MHz NMR Thorium (Solids) | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

100 MHz NMR Thorium (Solids) 100 MHz NMR Thorium (Solids) Research applications Samples containing paramagnetics Soils (SOM and NOM) Metal oxide materials for catalysis...

458

Varian investment pays off in major NMR advances  

Science Journals Connector (OSTI)

Varian investment pays off in major NMR advances ... Varian's investment in NMR had slowed accordingly. ...

RUBY M. BAUM

1985-11-04T23:59:59.000Z

459

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

SciTech Connect (OSTI)

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

460

Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization  

DOE Patents [OSTI]

In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.

Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

2000-12-19T23:59:59.000Z

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461

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

SciTech Connect (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

462

Solution structure of a fragment of the dimerization domain of DP-1 determined by 1H-nuclear magnetic resonance and distance geometry  

Science Journals Connector (OSTI)

The structure of a synthesized peptide with the sequence of NHILPNESAYDQKNIRRRVYDALNVLMAMNIISK that corresponds to residues 151184 of transcription factor DP-1 (Girling et al., Nature 362 (1993) 8387) was determined by 1H-nuclear magnetic resonance in water and 40% d3-trifluoroethanol/water, respectively. Nuclear Overhauser effect cross peaks, ?H chemical shifts and J-coupling constants of ?HNH show that the peptide consists a helix from Ser-8 to Ser-33 in solution. Fifty structures were constructed with 288 upper distance limits and 21 angle constraints by DIANA (Guntert et al., J. Mol. Biol. 217 (1991) 517530). Although the N-terminal of the peptide exhibits a random conformation, the 20 best structures show a root mean square deviation of 0.890.36 for backbone atoms and 1.800.34 for heavy atoms from residue Ser-8 to Ser-33. This result supports the proposal that DP-1 and E2F-1 may dimerize with a coiled-coil type interaction.

Shouhong Guang; Jihui Wu; Tianning Yu; Youlin Xia; Yunyu Shi

1998-01-01T23:59:59.000Z

463

Solution structure of a fragment of the dimerization domain of E2F-1 determined by circular dichroism, 1H nuclear magnetic resonance and distance geometry  

Science Journals Connector (OSTI)

The structure of a synthesized peptide with the sequence GVVDLNWAAEVLKVQKRRIYDITNVLEGIQ which corresponds to residues 149178 of transcription factor E2F-1 was determined by 1H nuclear magnetic resonance in 40% d3-TFE/water. NOE cross peaks and ?H chemical shifts indicate that the peptide consists of a helix from Ala-8 to Leu-26 in this solution. Circular dichroism measurements confirm the presence of nearly 45% helix in TFE/water solution but show no evidence of helicity in water solution of this peptide. Fifty structures were constructed with 329 upper distance limits by DIANA. The 20 best conformers show a RMSD of 0.78 for backbone atoms and 1.78 for heavy atoms from residue Ala-8 to Leu-26. This result, together with our previous work on the solution structure of a fragment of DP-1, supports the proposal that E2F-1 and DP-1 may dimerize with a coiled-coil type interaction.

Shouhong Guang; Jihui Wu; Limei Tao; Youlin Xia; Yunyu Shi

1998-01-01T23:59:59.000Z

464

Two?dimensional nuclear magnetic resonance studies on a single crystal of l?alanine. Separation of the local dipolar fields; and 2D exchange spectroscopy of the 1 4N relaxation processes  

Science Journals Connector (OSTI)

Two types of 2DNMR techniques namely separated local field 2DNMR (SLF 2DNMR) and 2D exchange NMR spectroscopy were applied to a single crystal of l?alanine at room temperature. In the SLF 2DNMR experiments we found that the 1 3C1H dipolar field at the C?carbon nucleus could be separated not only from the chemical shift interaction but also from the 1 3C?1 4N dipolar field. The angular variation of the 1 3C?1H dipolar splitting was measured when the static magnetic field was rotated about three orthogonal axes (a b and c axes). The 1 3C??1H dipolar coupling tensor was determined and the C?H bond length was evaluated to be 1.073 . In the 2D exchange NMR experiment for C?carbon nucleus the off?diagonal cross peaks due to the single quantum and the double quantum transitions for the spin?lattice relaxation processes of the adjacent 1 4N nucleus were observed. The single quantum transition rate constant was evaluated to be 0.8 s? 1 and the double quantum transition rate constant was estimated to be much smaller. Inspection of the experimental results of the 2D exchange NMR together with the theory indicates that (1) the double quantum cross peaks which appeared when a long mixing time (? m =1.0 s) was used is brought about by two consecutive single quantum processes and (2) the main spin?lattice relaxation process of the NH+ 3 nitrogen nucleus is the fluctuation of 1 4N1H dipolar interaction rather than the fluctuation of 1 4N quadrupole interaction.

A. Naito; P. B. Barker; C. A. McDowell

1984-01-01T23:59:59.000Z

465

Cyclotron Resonance in Gallium  

Science Journals Connector (OSTI)

Azbel'-Kaner cyclotron resonance has been studied at 36 and 9 Gc/sec at 1.2K in the three principal symmetry planes of gallium with the microwave currents both parallel and perpendicular to the applied magnetic field. The resonance signals were characterized by extreme complexity and high resolution (long relaxation times). Mass values are determined as a function of orientation of the magnetic field in the sample surfaces. No interpretation of the mass branches on a model Fermi surface is attempted, but some correlations with previous de Haas-van Alphen data are presented.

T. W. Moore

1968-01-15T23:59:59.000Z

466

Localized In Vivo 1H NMR Detection of Neurotransmitter Labeling in Rat Brain During Infusion of [1-13C] D-Glucose  

E-Print Network [OSTI]

Localized In Vivo 1H NMR Detection of Neurotransmitter Labeling in Rat Brain During Infusion of [1 infusions of 13C-labeled glucose. Magn Reson Med 41:1077­1083, 1999. 1999 Wiley-Liss, Inc. Key words] glucose infusion In vivo 13C NMR spectroscopy with localization is emerg- ing as an important tool

Jegelka, Stefanie

467

NMR analysis on microfluidic devices by remote detection  

E-Print Network [OSTI]

large coil. Keywords: microfluidics, microcoil, NMR, remoteapplications for NMR with microfluidics have been proposed.xenon for NMR with microfluidics, the absolute limit of the

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

2005-01-01T23:59:59.000Z

468

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]

. 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...

Adams, Aaron J.

2007-04-25T23:59:59.000Z

469

Assignment of 1H Nuclear Magnetic Resonance Visible Polyunsaturated Fatty Acids in BT4C Gliomas Undergoing Ganciclovir-Thymidine Kinase Gene Therapy-induced Programmed Cell Death  

Science Journals Connector (OSTI)

...Orlando, FL Abstract 380: Magnetic nanoplatforms for tumor...MA. We have developed magnetic nano-liposomes (MNL...and breast cancer cell lines. They preferentially...that is essential for magnetic targeting, MR contrast...Application of a magnetic field enables redistribution...

Julian L. Griffin; Kimmo K. Lehtimki; Piia K. Valonen; Olli H. J. Grhn; Mikko I. Kettunen; Seppo Yl-Herttuala; Asla Pitknen; Jeremy K. Nicholson; and Risto A. Kauppinen

2003-06-15T23:59:59.000Z

470

Metabolic Characterization of Human Non-Hodgkin's Lymphomas in Vivo with the Use of Proton-decoupled Phosphorus Magnetic Resonance Spectroscopy  

Science Journals Connector (OSTI)

...Orlando, FL Abstract 380: Magnetic nanoplatforms for tumor...MA. We have developed magnetic nano-liposomes (MNL...and breast cancer cell lines. They preferentially...that is essential for magnetic targeting, MR contrast...Application of a magnetic field enables redistribution...

William G. Negendank; Kristin A. Padavic-Shaller; Chun-Wei Li; Joseph Murphy-Boesch; Radka Stoyanova; Robert L. Krigel; Russell J. Schilder; Mitchell R. Smith; and Truman R. Brown

1995-08-01T23:59:59.000Z

471

Gregory S. Boebinger, National High Magnetic Field Laboratory  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ring Coil for Neuroimaging at 21.1 T Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 NMR Facility - 900MHz UWB Magnet While today s clinical...

472

Noninvasive Monitoring of Microvascular Changes With Partial Irradiation Using Dynamic Contrast-Enhanced and Blood Oxygen Level-Dependent Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: The microvasculature of a tumor plays an important role in its response to radiation therapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and blood oxygen level-dependent (BOLD) MRI are both sensitive to vascular characteristics. The present study proposed a partial irradiation approach to a xenograft tumor to investigate the intratumoral response to radiation therapy using DCE and BOLD MRI. Methods and Materials: TRAMP-C1 tumors were grown in C57BL/6J mice. Partial irradiation was performed on the distal half of the tumor with a single dose of 15 Gy. DCE MRI was performed to derive the endothelium transfer constant, K{sup trans}, using pharmacokinetic analysis. BOLD MRI was performed using quantitative R2* measurements with carbogen breathing. The histology of the tumor was analyzed using hematoxylin and eosin staining and CD31 staining to detect endothelial cells. The differences between the irradiated and nonirradiated regions of the tumor were assessed using K{sup trans} values, ?R2* values in response to carbogen and microvascular density (MVD) measurements. Results: A significantly increased K{sup trans} and reduced BOLD response to carbogen were found in the irradiated region of the tumor compared with the nonirradiated region (P<.05). Histologic analysis showed a significant aggregation of giant cells and a reduced MVD in the irradiated region of the tumor. The radiation-induced difference in the BOLD response was associated with differences in MVD and K{sup trans}. Conclusions: We demonstrated that DCE MRI and carbogen-challenge BOLD MRI can detect differential responses within a tumor that may potentially serve as noninvasive imaging biomarkers to detect microvascular changes in response to radiation therapy.

Lin, Yu-Chun [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Electrical Engineering, Chang Gung University, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Jiun-Jie [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Hong, Ji-Hong [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lin, Yi-Ping [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)] [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Wai, Yau-Yau; Ng, Shu-Hang; Wu, Yi-Ming [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Chun-Chieh, E-mail: jjwang@adm.cgmh.org.tw [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)

2013-04-01T23:59:59.000Z

473

Noninvasive Assessment of Tumor Microenvironment Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging and {sup 18}F-Fluoromisonidazole Positron Emission Tomography Imaging in Neck Nodal Metastases  

SciTech Connect (OSTI)

Purpose: To assess noninvasively the tumor microenvironment of neck nodal metastases in patients with head-and-neck cancer by investigating the relationship between tumor perfusion measured using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and hypoxia measured by {sup 18}F-fluoromisonidazole ({sup 18}F-FMISO) positron emission tomography (PET). Methods and Materials: Thirteen newly diagnosed head-and-neck cancer patients with metastatic neck nodes underwent DCE-MRI and {sup 18}F-FMISO PET imaging before chemotherapy and radiotherapy. The matched regions of interests from both modalities were analyzed. To examine the correlations between DCE-MRI parameters and standard uptake value (SUV) measurements from {sup 18}F-FMISO PET, the nonparametric Spearman correlation coefficient was calculated. Furthermore, DCE-MRI parameters were compared between nodes with {sup 18}F-FMISO uptake and nodes with no {sup 18}F-FMISO uptake using Mann-Whitney U tests. Results: For the 13 patients, a total of 18 nodes were analyzed. The nodal size strongly correlated with the {sup 18}F-FMISO SUV ({rho} = 0.74, p < 0.001). There was a strong negative correlation between the median k{sub ep} (redistribution rate constant) value ({rho} = -0.58, p = 0.042) and the {sup 18}F-FMISO SUV. Hypoxic nodes (moderate to severe {sup 18}F-FMISO uptake) had significantly lower median K{sup trans} (volume transfer constant) (p = 0.049) and median k{sub ep} (p = 0.027) values than did nonhypoxic nodes (no {sup 18}F-FMISO uptake). Conclusion: This initial evaluation of the preliminary results support the hypothesis that in metastatic neck lymph nodes, hypoxic nodes are poorly perfused (i.e., have significantly lower K{sup trans} and k{sub ep} values) compared with nonhypoxic nodes.

Jansen, Jacobus [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Schoeder, Heiko [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wang Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2010-08-01T23:59:59.000Z

474

Two dimensional NMR and NMR relaxation studies of coal structure  

SciTech Connect (OSTI)

This report covers the progress made on the title project during the current reporting 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 in coals that determine the reactivity of coals. Other methods are being developed which will also determine how these functional groups are linked together. A third area of investigation concerns how molecular mobility in coals impacts NMR relaxation times, which is important for interpretation of such data in terms of the mobile phase in coals model. Along the same lines we are also using these studies to establish protocols for obtaining the best quantitative response from coals in sold state C-13 NMR spectra. This quarter we have focussed on spin lattice relaxation measurements for several of the Argonne coals.

Zilm, K.W.

1991-01-01T23:59:59.000Z

475

Split-ball resonator  

E-Print Network [OSTI]

We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...

Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris

2014-01-01T23:59:59.000Z

476

1H NMR-Based Metabolomic Analysis of Liver, Serum, and Brain Following Ethanol Administration in Rats  

Science Journals Connector (OSTI)

Where possible, peak assignments were made using the literature and internet databases, and well-resolved resonant peaks were integrated, allowing absolute quantification of metabolites in serum (in units of mM) and tissue (in units of mmol/kg wet weight). ... Govindaraju, V., Young, K., and Maudsley, A. A. ( 2000) Proton NMR chemical shifts and coupling constants for brain metabolites NMR Biomed. ... abuse or dependence against those who had never been abusers or dependent. ...

Peter C. Nicholas; Daniel Kim; Fulton T. Crews; Jeffrey M. Macdonald

2007-12-21T23:59:59.000Z

477

Small-Angle X-Ray Scattering- and Nuclear Magnetic Resonance-Derived Conformational Ensemble of the Highly Flexible Antitoxin PaaA2  

Science Journals Connector (OSTI)

Summary Antitoxins from prokaryotic type II toxin-antitoxin modules are characterized by a high degree of intrinsic disorder. The description of such highly flexible proteins is challenging because they cannot be represented by a single structure. Here, we present a combination of SAXS and NMR data to describe the conformational ensemble of the PaaA2 antitoxin from the human pathogen E.coli O157. The method encompasses the use of SAXS data to filter ensembles out of a pool of conformers generated by a custom NMR structure calculation protocol and the subsequent refinement by a block jackknife procedure. The final ensemble obtained through the method is validated by an established residual dipolar coupling analysis. We show that the conformational ensemble of PaaA2 is highly compact and that the protein exists in solution as two preformed helices, connected by a flexible linker, that probably act as molecular recognition elements for toxin inhibition.

YannG.J. Sterckx; AlexanderN. Volkov; WimF. Vranken; Jaka Kragelj; MaleneRingkjbing Jensen; Lieven Buts; Abel Garcia-Pino; Thomas Jov; Laurence VanMelderen; Martin Blackledge; NicoA.J. vanNuland; Remy Loris

2014-01-01T23:59:59.000Z

478

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

479

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

SciTech Connect (OSTI)

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

480

Strong reduction of V{sup 4+} amount in vanadium oxide/hexadecylamine nanotubes by doping with Co{sup 2+} and Ni{sup 2+} ions: Electron paramagnetic resonance and magnetic studies  

SciTech Connect (OSTI)

In this work we present a complete characterization and magnetic study of vanadium oxide/hexadecylamine nanotubes (VO{sub x}/Hexa NT's) doped with Co{sup 2+} and Ni{sup 2+} ions. The morphology of the NT's has been characterized by transmission electron microscopy, while the metallic elements have been quantified by the instrumental neutron activation analysis technique. The static and dynamic magnetic properties were studied by collecting data of magnetization as a function of magnetic field and temperature and by electron paramagnetic resonance. At difference of the majority reports in the literature, we do not observe magnetic dimers in vanadium oxide nanotubes. Also, we observed that the incorporation of metallic ions (Co{sup 2+}, S = 3/2 and Ni{sup 2+}, S = 1) decreases notably the amount of V{sup 4+} ions in the system, from 14-16% (nondoped case) to 2%-4%, with respect to the total vanadium atoms (fact corroborated by XPS experiments) anyway preserving the tubular nanostructure. The method to decrease the amount of V{sup 4+} in the nanotubes improves considerably their potential technological applications as Li-ion batteries cathodes.

Saleta, M. E.; Troiani, H. E.; Ribeiro Guevara, S.; Ruano, G.; Sanchez, R. D. [Centro Atomico Bariloche, CNEA, (8400) S. C. de Bariloche (Argentina); Malta, M. [Depto. de Cs. Exatas e da Terra, Univ. do Estado da Bahia, Cabula Salvador CP 2555 (Brazil); Torresi, R. M. [Instituto de Quimica, Universidad de Sao Paulo, Sao Paulo CP 26077, 05513-970 (Brazil)

2011-05-01T23:59:59.000Z