Sample records for magnetic resonance imaging

  1. Low field magnetic resonance imaging

    DOE Patents [OSTI]

    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

    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.

  2. Chapter 20. Magnetic Resonance Imaging Magnetic Resonance Imaging

    E-Print Network [OSTI]

    , and software training from Siemens Medical Solutions; research funding through the Siemens-MIT Alliance and Technology (HST). 2 Siemens Medical Solutions, Erlangen, Germany. #12;Chapter 20. Magnetic Resonance Imaging, Siemens Medical Solutions, Siemens-MIT Alliance, HST Martinos Catalyst Fund. Project Staff: Audrey P. Fan

  3. Instrumentation for parallel magnetic resonance imaging

    E-Print Network [OSTI]

    Brown, David Gerald

    2007-04-25T23:59:59.000Z

    Parallel magnetic resonance (MR) imaging may be used to increase either the throughput or the speed of the MR imaging experiment. As such, parallel imaging may be accomplished either through a "parallelization" of the MR experiment, or by the use...

  4. Single echo acquisition magnetic resonance imaging 

    E-Print Network [OSTI]

    McDougall, Mary Preston

    2006-04-12T23:59:59.000Z

    The dramatic improvement in magnetic resonance imaging (MRI) scan time over the past fifteen years through gradient-based methods that sample k-space more efficiently and quickly cannot be sustained, as thresholds regarding ...

  5. 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...

  6. Imaging agents for in vivo magnetic resonance and scintigraphic imaging

    DOE Patents [OSTI]

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

    1991-04-23T23:59:59.000Z

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

  7. Magnetic Resonance Imaging System Based on Earth's Magnetic Field

    E-Print Network [OSTI]

    Stepi?nik, Janez

    Magnetic Resonance Imaging System Based on Earth's Magnetic Field Ales Mohoric,1,* Gorazd Planinsic magnetic field can be partly compensated by the receiving coil design and shielding of electromagnetic pick and must be monitored accurately.[8­ 10] The importance of NMR in a non-uniform magnetic field

  8. Model-based reconstruction of magnetic resonance spectroscopic imaging

    E-Print Network [OSTI]

    Chatnuntawech, Itthi

    2013-01-01T23:59:59.000Z

    Magnetic resonance imaging (MRI) is a medical imaging technique that is used to obtain images of soft tissue throughout the body. Since its development in the 1970s, MRI has gained tremendous importance in clinical practice ...

  9. Magnetic resonance imaging of self-assembled biomaterial scaffolds

    SciTech Connect (OSTI)

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

    2014-09-16T23:59:59.000Z

    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.

  10. Designing and characterizing hyperpolarizable silicon nanoparticles for magnetic resonance imaging

    E-Print Network [OSTI]

    Anahtar, Melis Nuray

    2008-01-01T23:59:59.000Z

    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, ...

  11. Magnetic resonance spectroscopic imaging using parallel transmission at 7T

    E-Print Network [OSTI]

    Gagoski, Borjan Aleksandar

    2011-01-01T23:59:59.000Z

    Conventional magnetic resonance spectroscopic imaging (MRSI), also known as phase-encoded (PE) chemical shift imaging (CSI), suffers from both low signal-to-noise ratio (SNR) of the brain metabolites, as well as inflexible ...

  12. Improvements in magnetic resonance imaging excitation pulse design

    E-Print Network [OSTI]

    Zelinski, Adam Charles

    2008-01-01T23:59:59.000Z

    This thesis focuses on the design of magnetic resonance imaging (MRI) radio-frequency (RF) excitation pulses, and its primary contributions are made through connections with the novel multiple-system single-output (MSSO) ...

  13. Design algorithms for parallel transmission in magnetic resonance imaging

    E-Print Network [OSTI]

    Setsompop, Kawin

    2008-01-01T23:59:59.000Z

    The focus of this dissertation is on the algorithm design, implementation, and validation of parallel transmission technology in Magnetic Resonance Imaging (MRI). Novel algorithms are proposed which yield excellent excitation ...

  14. RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16T23:59:59.000Z

    Parallel excitation is an emerging technique to improve or accelerate multi-dimensional spatially selective excitations in magnetic resonance imaging (MRI) using multi-channel transmit arrays. The technique has potential in many applications...

  15. Surface-Based Analysis of Functional Magnetic Resonance Imaging Data

    E-Print Network [OSTI]

    Thompson, Paul

    Surface-Based Analysis of Functional Magnetic Resonance Imaging Data Theo G.M. van Erp1, Vikas Y School of Medicine, Los Angeles, CA 90095, USA Abstract. Surface-based visualization, atlases the integration of surface-based tech- niques with functional imaging data, combining surface-based nonlinear

  16. Original Research Magnetic Resonance Image-Guided Trans-Septal

    E-Print Network [OSTI]

    Atalar, Ergin

    vasculature. Key Words: interventional; magnetic resonance imaging; trans-septal catheterization; cardiac; MR with a pigtail catheter in the aorta and the use of His bundle/coronary sinus catheters (1), and, more recently from a percutaneous femoral vein ap- proach. MATERIALS AND METHODS Animal Model The Institutional

  17. Blood Flow Magnetic Resonance Imaging of Retinal Degeneration

    E-Print Network [OSTI]

    Duong, Timothy Q.

    Blood Flow Magnetic Resonance Imaging of Retinal Degeneration Yingxia Li,1 Haiying Cheng,1 Qiang. Duong1,2,3,4,5,6,7 PURPOSE. This study aims to investigate quantitative basal blood flow as well as hypercapnia- and hyperoxia-induced blood flow changes in the retinas of the Royal College of Surgeons (RCS

  18. Method for nuclear magnetic resonance imaging

    DOE Patents [OSTI]

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

    1988-05-26T23:59:59.000Z

    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.

  19. Parallel magnetic resonance imaging: characterization and comparison

    E-Print Network [OSTI]

    Rane, Swati Dnyandeo

    2005-11-01T23:59:59.000Z

    [Sodickson, 1997], GRAPPA [Griswold, 2002] and SPACE RIP [Kyriakos, 2000]; developed in the past decade have been studied, simulated and compared in this research. Because of the dependence of the parallel imaging methods on numerous factors such as receiver...

  20. Portable low-cost magnetic resonance imaging

    E-Print Network [OSTI]

    Cooley, Clarissa Zimmerman

    2014-01-01T23:59:59.000Z

    Purpose: As the premiere modality for brain imaging, MRI could find wider applicability if lightweight, portable systems were available for siting in unconventional locations such as intensive care units (ICUs), physician ...

  1. Magnetic Resonance Imaging 1 A new global optimization algorithm and its application to a

    E-Print Network [OSTI]

    Neumaier, Arnold

    Magnetic Resonance Imaging 1 A new global optimization algorithm and its application to a Magnetic-cost, low-field multipolar magnet for Magnetic Resonance Imaging with a high field uniformity, the proposed method em- ploys, as local search engine, a derivative free procedure. Under reasonable

  2. He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    3 He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System R. W. Butler,6 F. W. Hersman,4 and R. L. Walsworth1 The human lung and its functions are extremely sensitive lung restrict sub- jects to lying horizontally. Imaging of human lungs using inhaled laser-polarized 3

  3. Magnetic resonance imaging of living systems by remote detection

    DOE Patents [OSTI]

    Wemmer, David; Pines, Alexander; Bouchard, Louis; Xu, Shoujun; Harel, Elad; Budker, Dmitry; Lowery, Thomas; Ledbetter, Micah

    2013-10-29T23:59:59.000Z

    A novel approach to magnetic resonance imaging is disclosed. Blood flowing through a living system is prepolarized, and then encoded. The polarization can be achieved using permanent or superconducting magnets. The polarization may be carried out upstream of the region to be encoded or at the place of encoding. In the case of an MRI of a brain, polarization of flowing blood can be effected by placing a magnet over a section of the body such as the heart upstream of the head. Alternatively, polarization and encoding can be effected at the same location. Detection occurs at a remote location, using a separate detection device such as an optical atomic magnetometer, or an inductive Faraday coil. The detector may be placed on the surface of the skin next to a blood vessel such as a jugular vein carrying blood away from the encoded region.

  4. Respiratory Amplitude Guided 4-Dimensional Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Hu, Yanle, E-mail: yhu@radonc.wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States); Caruthers, Shelton D. [Department of Medicine, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Medicine, Washington University School of Medicine, St. Louis, Missouri (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)] [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Parikh, Parag J.; Mutic, Sasa [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)] [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-05-01T23:59:59.000Z

    Purpose: To evaluate the feasibility of prospectively guiding 4-dimensional (4D) magnetic resonance imaging (MRI) image acquisition using triggers at preselected respiratory amplitudes to achieve T{sub 2} weighting for abdominal motion tracking. Methods and Materials: A respiratory amplitude-based triggering system was developed and integrated into a commercial turbo spin echo MRI sequence. Initial feasibility tests were performed on healthy human study participants. Four respiratory states, the middle and the end of inhalation and exhalation, were used to trigger 4D MRI image acquisition of the liver. To achieve T{sub 2} weighting, the echo time and repetition time were set to 75 milliseconds and 4108 milliseconds, respectively. Single-shot acquisition, together with parallel imaging and partial k-space imaging techniques, was used to improve image acquisition efficiency. 4D MRI image sets composed of axial or sagittal slices were acquired. Results: Respiratory data measured and logged by the MRI scanner showed that the triggers occurred at the appropriate respiratory levels. Liver motion could be easily observed on both 4D MRI image datasets by sensing either the change of liver in size and shape (axial) or diaphragm motion (sagittal). Both 4D MRI image datasets were T{sub 2}-weighted as expected. Conclusions: This study demonstrated the feasibility of achieving T{sub 2}-weighted 4D MRI images using amplitude-based respiratory triggers. With the aid of the respiratory amplitude-based triggering system, the proposed method is compatible with most MRI sequences and therefore has the potential to improve tumor-tissue contrast in abdominal tumor motion imaging.

  5. SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

    SciTech Connect (OSTI)

    Moessle, Michael; Hatridge, Michael; Clarke, John

    2006-08-14T23:59:59.000Z

    Magnetic resonance imaging (MRI) has developed into a powerful clinical tool for imaging the human body (1). This technique is based on nuclear magnetic resonance (NMR) of protons (2, 3) in a static magnetic field B{sub 0}. An applied radiofrequency pulse causes the protons to precess about B{sub 0} at their Larmor frequency {nu}{sub 0} = ({gamma}/2{pi})B{sub 0}, where {gamma} is the gyromagnetic ratio; {gamma}/2{pi} = 42.58 MHz/tesla. The precessing protons generate an oscillating magnetic field and hence a voltage in a nearby coil that is amplified and recorded. The application of three-dimensional magnetic field gradients specifies a unique magnetic field and thus an NMR frequency in each voxel of the subject, so that with appropriate encoding of the signals one can acquire a complete image (4). Most clinical MRI systems involve magnetic fields generated by superconducting magnets, and the current trend is to higher magnetic fields than the widely used 1.5-T systems (5). Nonetheless, there is ongoing interest in the development of less expensive imagers operating at lower fields. Commercially available 0.2-T systems based on permanent magnets offer both lower cost and a more open access than their higher-field counterparts, at the expense of signal-to-noise-ratio (SNR) and spatial resolution. At the still lower field of 0.03 mT maintained by a conventional, room-temperature solenoid, Connolly and co-workers (6, 7) obtain good spatial resolution and signal-to-noise ratio (SNR) by prepolarizing the protons in a field B{sub p} of 0.3 T. Prepolarization (8) enhances the magnetic moment of an ensemble of protons over that produced by the lower precession field; after the polarizing field is removed, the higher magnetic moment produces a correspondingly larger signal during its precession in B{sub 0}. Using the same method, Stepisnik et al. (9) obtained MR images in the Earth's magnetic field ({approx} 50 {micro}T). Alternatively, one can enhance the signal amplitude in MRI using laser polarized noble gases such as {sup 3}He or {sup 129}Xe (10-12). Hyperpolarized gases were used successfully to image the human lung in fields on the order of several mT (13-15). To overcome the sensitivity loss of Faraday detection at low frequencies, ultrasensitive magnetometers based on the Superconducting QUantum Interference Device (SQUID) (16) are used to detect NMR and MRI signals (17-24). Recently, SQUID-based MRI systems capable of acquiring in vivo images have appeared. For example, in the 10-mT system of Seton et al. (18) signals are coupled to a SQUID via a superconducting tuned circuit, while Clarke and coworkers (22, 25, 26) developed a system at 132 {micro}T with an untuned input circuit coupled to a SQUID. In a quite different approach, atomic magnetometers have been used recently to detect the magnetization (27) and NMR signal (28) of hyperpolarized gases. This technique could potentially be used for low-field MRI in the future. The goal of this review is to summarize the current state-of-the-art of MRI in microtesla fields detected with SQUIDs. The principles of SQUIDs and NMR are briefly reviewed. We show that very narrow NMR linewidths can be achieved in low magnetic fields that are quite inhomogeneous, with illustrative examples from spectroscopy. After describing our ultralow-field MRI system, we present a variety of images. We demonstrate that in microtesla fields the longitudinal relaxation T{sub 1} is much more material dependent than is the case in high fields; this results in a substantial improvement in 'T{sub 1}-weighted contrast imaging'. After outlining the first attempts to combine microtesla NMR with magnetoencephalography (MEG) (29), we conclude with a discussion of future directions.

  6. Application of Parallel Imaging to Murine Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Chang, Chieh-Wei 1980-

    2012-09-21T23:59:59.000Z

    . This dissertation describes foundational level work to enable parallel imaging of mice on a 4.7 Tesla/40 cm bore research scanner. Reducing the size of the hardware setup associated with typical parallel imaging was an integral part of achieving the work, as animal...

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

    DOE Patents [OSTI]

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

    2014-01-21T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

    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

    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.

  9. Abstract--Magnetic Resonance Imaging (MRI) guided nanorobotic systems that could perform diagnostic, curative

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    groups have employed magnetized micro/ nanoparticles and have implemented magnetic propulsion techniquesAbstract-- Magnetic Resonance Imaging (MRI) guided nanorobotic systems that could perform on the use of a MRI scanner to induce the required external driving forces to guide magnetic nanocapsules

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

    E-Print Network [OSTI]

    Gollub, Randy L.

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

  11. A 16-Channel Receive Array Insert for Magnetic Resonance Imaging of the Breast at 7T

    E-Print Network [OSTI]

    By, Samantha

    2014-04-01T23:59:59.000Z

    Breast cancer is the second leading cause of cancer death among females in the United States. Magnetic resonance imaging (MRI) has emerged as a powerful tool for detecting and evaluating the disease, with notable advantages over other modalities...

  12. An iterative technique for refinement of selective excitations for magnetic resonance imaging

    E-Print Network [OSTI]

    Lebsack, Eliot Todd

    1999-01-01T23:59:59.000Z

    Selective RF pulses are needed or many application in magnetic resonance imaging (MRI). The desired excitation profile is omen used as the spectrum of the applied RF pulse; the modulation waveform of the RF pulse which approximately excites...

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

    E-Print Network [OSTI]

    Van Hyfte, John Bruce

    1997-01-01T23:59:59.000Z

    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...

  14. Eight-Channel Head Array and Control System for Parallel Transmit/Receive Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Moody, Katherine

    2014-08-11T23:59:59.000Z

    Interest in magnetic resonance imaging (MRI) at high fields strengths (3 Tesla and above) is driven by the associated improvements in signal-to-noise ratio and spectral resolution. In practice, however, technical challenges prevent these benefits...

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

    E-Print Network [OSTI]

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

    2005-01-01T23:59:59.000Z

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

  16. Classification of brain compartments and head injury lesions by neural networks applied to magnetic resonance images

    E-Print Network [OSTI]

    Kischell, Eric Robert

    1993-01-01T23:59:59.000Z

    ' (Member) A. D. Patton ( ead of epartment) August 1993 Major Subject: Electrical Engineering ABSTRACT Classification of Brain Compartments and Head Injury Lesions by Neural Networks Applied to Magnetic Resonance Images. (August 1993) Eric Robert... Kischell, B. S. , Northeastern University Chair of Advisory Committee: Dr. Nasser Kehtarnavaz An automatic neural network-based approach was ap- plied to segment brain compartments and closed-head-injury lesions in magnetic resonance (MR) images Two...

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

    E-Print Network [OSTI]

    Sherman, Byron Blake

    1991-01-01T23:59:59.000Z

    THE DEVELOPMENT OF MAGNETIC RESONANCE IMAGING FOR THE DETERMINATION OF POROSITY IN RESERVOIR CORE SAMPLES A Thesis by BYRON BLAKE SHERMAN 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 December 1991 Major Subject: Petroleum Engineering THE DEVELOPMENT OF MAGNETIC RESONANCE IMAGING FOR THE DETERMINATION OF POROSITY IN RESERVOIR CORE SAMPLES A Thesis by BYRON BLAKE SHERMAN Approved...

  18. Application of nuclear magnetic resonance imaging and spectroscopy to fluids in porous media

    E-Print Network [OSTI]

    Mandava, Shanthi Sree

    1991-01-01T23:59:59.000Z

    APPLICATION OF NUCLEAR MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY TO FLUIDS IN POROUS MEDIA A Thesis by SHANTHI SREE MANDAVA 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 May 1991 Major Subject: Chemical Engineering APPLICATION OF NUCLEAR MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY TO FLUIDS IN POROUS MEDIA A Thesis by SHANTHI SREE MANDAVA Approved as to style and content by: A. Ted...

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

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    nuclear magnetic resonance (NMR) active nuclei is planned using 0.15T Magnetic Resonance Imaging (MRI at each cycle within the object. The applied current pulse creates a measurable magnetic flux density. The component of magnetic flux density parallel to the main magnetic field accumulates an additional phase

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

    E-Print Network [OSTI]

    Schumann, Heidrun

    A REAL TIME 3D VISUALIZATION PROTOTYPE FOR INTERVENTIONAL MAGNETIC RESONANCE IMAGING JENS FISCHER­invasive examinations. This prototype allows simultaneous visualization of three different types of data: a 3D­Magnetic@informatik.uni­rostock.de Abstract: This paper describes a prototype of a visualization system which is designed to support

  1. Blood-flow magnetic resonance imaging of the retina Yingxia Li,a,1

    E-Print Network [OSTI]

    Duong, Timothy Q.

    Blood-flow magnetic resonance imaging of the retina Yingxia Li,a,1 Haiying Cheng,a,1 and Timothy Q 1 November 2007 This study describes a novel MRI application to image basal blood flow, physiologically induced blood-flow changes, and the effects of isoflurane concentration on blood flow

  2. Can Images Obtained With High Field Strength Magnetic Resonance Imaging Reduce Contouring Variability of the Prostate?

    SciTech Connect (OSTI)

    Usmani, Nawaid, E-mail: Nawaid.Usmani@albertahealthservices.ca [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Department of Oncology, University of Alberta, Edmonton, AB (Canada); Sloboda, Ron [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada); Kamal, Wafa [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Ghosh, Sunita [Department of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Experimental Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Pervez, Nadeem; Pedersen, John; Yee, Don; Danielson, Brita; Murtha, Albert; Amanie, John [Department of Radiation Oncology, Cross Cancer Institute, Edmonton, AB (Canada); Department of Oncology, University of Alberta, Edmonton, AB (Canada); Monajemi, Tara [Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada)

    2011-07-01T23:59:59.000Z

    Purpose: The objective of this study is to determine whether there is less contouring variability of the prostate using higher-strength magnetic resonance images (MRI) compared with standard MRI and computed tomography (CT). Methods and Materials: Forty patients treated with prostate brachytherapy were accrued to a prospective study that included the acquisition of 1.5-T MR and CT images at specified time points. A subset of 10 patients had additional 3.0-T MR images acquired at the same time as their 1.5-T MR scans. Images from each of these patients were contoured by 5 radiation oncologists, with a random subset of patients repeated to quantify intraobserver contouring variability. To minimize bias in contouring the prostate, the image sets were placed in folders in a random order with all identifiers removed from the images. Results: Although there was less interobserver contouring variability in the overall prostate volumes in 1.5-T MRI compared with 3.0-T MRI (p < 0.01), there was no significant differences in contouring variability in the different regions of the prostate between 1.5-T MRI and 3.0-T MRI. MRI demonstrated significantly less interobserver contouring variability in both 1.5-T and 3.0-T compared with CT in overall prostate volumes (p < 0.01, p = 0.01), with the greatest benefits being appreciated in the base of the prostate. Overall, there was less intraobserver contouring variability than interobserver contouring variability for all of the measurements analyzed. Conclusions: Use of 3.0-T MRI does not demonstrate a significant improvement in contouring variability compared with 1.5-T MRI, although both magnetic strengths demonstrated less contouring variability compared with CT.

  3. Nuclear magnetic resonance imaging of water content in the subsurface

    SciTech Connect (OSTI)

    J. Hendricks; T. Yao; A. Kearns

    1999-01-21T23:59:59.000Z

    Previous theoretical and experimental studies indicated that surface nuclear magnetic resonance (NMR) has the potential to provide cost-effective water content measurements in the subsurface and is a technology ripe for exploitation in practice. The objectives of this investigation are (a) to test the technique under a wide range of hydrogeological conditions and (b) to generalize existing NMR theories in order to correctly model NMR response from conductive ground and to assess properties of the inverse problem. Twenty-four sites with different hydrogeologic settings were selected in New Mexico and Colorado for testing. The greatest limitation of surface NMR technology appears to be the lack of understanding in which manner the NMR signal is influenced by soil-water factors such as pore size distribution, surface-to-volume ratio, paramagnetic ions dissolved in the ground water, and the presence of ferromagnetic minerals. Although the theoretical basis is found to be sound, several advances need to be made to make surface NMR a viable technology for hydrological investigations. There is a research need to investigate, under controlled laboratory conditions, how the complex factors of soil-water systems affect NMR relaxation times.

  4. Wavelet smoothing of functional magnetic resonance images: A ...

    E-Print Network [OSTI]

    1910-30-72T23:59:59.000Z

    The two types of images are then compared; the regions where there are significant ... techniques at various stages in the production of the magnitude images.

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

    DOE Patents [OSTI]

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

    2009-08-11T23:59:59.000Z

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

  6. Microfluidically Cryo-Cooled Planar Coils for Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Koo, Chiwan

    2013-08-09T23:59:59.000Z

    is approximately the same as the diameters of the microcoils. Here microfluidic technology is utilized to locally cryo-cool the microcoils and minimize the thermal isolation gap so that the imaging surface is within the imaging depth of the microcoils. The first...

  7. Simultaneous Electroencephalography and Functional Magnetic Resonance Imaging of General Anesthesia

    E-Print Network [OSTI]

    Purdon, Patrick Lee

    It has been long appreciated that anesthetic drugs induce stereotyped changes in electroencephalogram (EEG), but the relationships between the EEG and underlying brain function remain poorly understood. Functional imaging ...

  8. RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging 

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16T23:59:59.000Z

    , such as accelerating imaging speed, mitigating field inhomogeneity in high-field MRI, and alleviating the susceptibility artifact in functional MRI (fMRI). In these applications, controlling radiofrequency (RF) power deposition (quantified by Specific Absorption Rate...

  9. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

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

    1997-12-30T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Shapiro, Mikhail G.

    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 ...

  11. GPU-accelerated denoising of 3D magnetic resonance images

    SciTech Connect (OSTI)

    Howison, Mark; Wes Bethel, E.

    2014-05-29T23:59:59.000Z

    The raw computational power of GPU accelerators enables fast denoising of 3D MR images using bilateral filtering, anisotropic diffusion, and non-local means. In practice, applying these filtering operations requires setting multiple parameters. This study was designed to provide better guidance to practitioners for choosing the most appropriate parameters by answering two questions: what parameters yield the best denoising results in practice? And what tuning is necessary to achieve optimal performance on a modern GPU? To answer the first question, we use two different metrics, mean squared error (MSE) and mean structural similarity (MSSIM), to compare denoising quality against a reference image. Surprisingly, the best improvement in structural similarity with the bilateral filter is achieved with a small stencil size that lies within the range of real-time execution on an NVIDIA Tesla M2050 GPU. Moreover, inappropriate choices for parameters, especially scaling parameters, can yield very poor denoising performance. To answer the second question, we perform an autotuning study to empirically determine optimal memory tiling on the GPU. The variation in these results suggests that such tuning is an essential step in achieving real-time performance. These results have important implications for the real-time application of denoising to MR images in clinical settings that require fast turn-around times.

  12. Modeling Left Ventricle Wall Motion Using Tagged Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Alenezy, Mohammed D.

    2009-04-17T23:59:59.000Z

    can be calculated as M = ?nullN 2 tanh( ?nullB 0 2kT ) (2.3) In a biological sample that contains about 1mL of water, there are about 10 22 hydrogen nuclei, and at the room... population that is frequently in need of quality tomographic images for the assessment of congenital heart defects. MRI can characterize myocardial function through the use of cine MRI and tagged MRI. The latter provides a means to assess wall motion...

  13. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    SciTech Connect (OSTI)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob, E-mail: ihahn@caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-09-15T23:59:59.000Z

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  14. Potential Applications of Microtesla Magnetic Resonance ImagingDetected Using a Superconducting Quantum Interference Device

    SciTech Connect (OSTI)

    Myers, Whittier R.

    2006-05-18T23:59:59.000Z

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 {micro}T. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz{sup -1/2} referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm{sup 3} resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm{sup 3} images of bell peppers and 3 x 3 x 26 mm{sup 3} in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T{sub 1}) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The measured T{sub 1} of ex vivo normal and cancerous prostate tissue differ significantly at 132 {micro}T. A single-sided MRI system designed for prostate imaging could achieve 3 x 3 x 5 mm{sup 3} resolution in 8 minutes. Existing SQUID-based magnetoencephalography (MEG) systems could be used as microtesla MRI detectors. A commercial 275-channel MEG system could acquire 6-minute brain images with (4 mm){sup 3} resolution and SNR 16.

  15. A 64-channel personal computer based image reconstruction system and applications in single echo acquisition magnetic resonance elastography and ultra-fast magnetic resonance imaging.

    E-Print Network [OSTI]

    Yallapragada, Naresh

    2009-05-15T23:59:59.000Z

    , this value is 2? x 42.5759 MHz/Tesla. This translates to a Larmor frequency of 200.238 MHz for the 4.7T magnet situated in the Magnetic Resonance Systems Lab (MRSL). In the presence of the static ????the proton population aligns itself according...

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

    SciTech Connect (OSTI)

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

    1994-04-01T23:59:59.000Z

    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.

  17. 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

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

    SciTech Connect (OSTI)

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

    1994-12-01T23:59:59.000Z

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

  19. A Simple and Fast Iterative Soft-thresholding Algorithm for Tight Frames in Compressed Sensing Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Liu, Yunsong; Cai, Jian-Feng; Guo, Di; Chen, Zhong; Qu, Xiaobo

    2015-01-01T23:59:59.000Z

    Compressed sensing has shown great potentials in accelerating magnetic resonance imaging. Fast image reconstruction and high image quality are two main issues faced by this new technology. It has been shown that, redundant image representations, e.g. tight frames, can significantly improve the image quality. But how to efficiently solve the reconstruction problem with these redundant representation systems is still challenging. This paper attempts to address the problem of applying fast iterative soft-thresholding algorithm (FISTA) to tight frames based magnetic resonance image reconstruction. By introducing the canonical dual frame, we construct an orthogonal projection operator on the range of the analysis sparsity operator and propose a new algorithm, called the projected FISTA (pFISTA). We theoretically prove that pFISTA converges to the minimum of a function with a balanced tight frame sparsity. One major advantage of pFISTA is that only one extra parameter, the step size, is introduced and the numerical...

  20. Pulmonary Hemorrhage: Imaging with a New Magnetic Resonance Blood Pool Agent in Conjunction with Breathheld Three-Dimensional Magnetic Resonance Angiography

    SciTech Connect (OSTI)

    Weishaupt, Dominik; Hilfiker, Paul R.; Schmidt, Michaela; Debatin, Joerg F. [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland)

    1999-07-15T23:59:59.000Z

    Purpose: To describe the three-dimensional magnetic resonance angiography (3D MRA) imaging appearance of the pulmonary arteries following administration of a superparamagnetic iron oxide blood pool agent to human volunteers, and to demonstrate in an animal model (pigs) how this technique can be used to detect pulmonary parenchymal hemorrhage. Methods: Two volunteers were examined following the intravenous administration of a superparamagnetic iron oxide blood pool agent (NC100150 Injection, Nycomed Amersham Imaging, Wayne, PA, USA). T1-weighted 3D gradient recalled echo (GRE) image sets (TR/TE 5.1/1.4 msec, flip angle 30 deg.) were acquired breathheld over 24 sec. To assess the detectability of pulmonary bleeding with intravascular MR contrast, pulmonary parenchymal injuries were created in two animals under general anesthesia, and fast T1-weighted 3D GRE image sets collected before and after the injury. Results: Administration of the intravascular contrast in the two volunteers resulted in selective enhancement of the pulmonary vasculature permitting complete visualization and excellent delineation of central, segmental, and subsegmental arteries. Following iatrogenic injury in the two animals, pulmonary hemorrhage was readily detected on the 3D image sets. Conclusion: The data presented illustrate that ultrafast 3D GRE MR imaging in conjunction with an intravenously administered intravascular blood pool agent can be used to perform high-quality pulmonary MRA as well as to detect pulmonary hemorrhage.

  1. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources 

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the ...

  2. Neuroimaging at 1.5 T and 3.0 T: Comparison of Oxygenation-Sensitive Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Glover, Gary H.

    Neuroimaging at 1.5 T and 3.0 T: Comparison of Oxygenation-Sensitive Magnetic Resonance Imaging of the human brain at 1.5 and 3.0 T. At the higher field spiral gradient-echo (GRE) brain images revealed and becomes a larger fraction of the total noise at 3.0 T. Activation of the primary motor and visual cortex

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

    SciTech Connect (OSTI)

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

    2012-12-15T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    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

    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.

  5. Single-Shot Magnetic Resonance Spectroscopic Imaging with Partial Parallel Imaging

    E-Print Network [OSTI]

    spectroscopic imaging (MRSI) pulse se- quence based on proton­echo-planar-spectroscopic-imaging (PEPSI. Comparison with conventional PEPSI and PEPSI with fourfold SENSE accelera- tion demonstrated comparable-acetyl-aspartate (NAA) in vivo with concentration values in the ranges measured with conventional PEPSI and SENSE

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

    DOE Patents [OSTI]

    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

    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.

  7. Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Gazdzinski, Lisa M.; Cormier, Kyle [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada)] [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Lu, Fred G. [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada)] [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Lerch, Jason P. [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada) [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada) [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Nieman, Brian J., E-mail: bjnieman@phenogenomics.ca [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada)

    2012-12-01T23:59:59.000Z

    Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

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

    DOE Patents [OSTI]

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

    2006-01-24T23:59:59.000Z

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

  9. Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

    SciTech Connect (OSTI)

    Cao Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Wang Hesheng [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Johnson, Timothy D. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Hussain, Hero [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-01-01T23:59:59.000Z

    Purpose: To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials: Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results: There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions: This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which could aid in individualizing therapy, particularly for patients at risk for liver injury after RT.

  10. Cardiac Magnetic Resonance Imaging Findings in 20-year Survivors of Mediastinal Radiotherapy for Hodgkin's Disease

    SciTech Connect (OSTI)

    Machann, Wolfram; Beer, Meinrad [Department of Radiology, University of Wuerzburg (Germany); Breunig, Margret; Stoerk, Stefan; Angermann, Christiane [Department of Cardiology, University of Wuerzburg (Germany); Seufert, Ines; Schwab, Franz; Koelbl, Oliver; Flentje, Michael [Department of Radiation Oncology, University of Wuerzburg (Germany); Vordermark, Dirk, E-mail: dirk.vordermark@medizin.uni-halle.d [Department of Radiation Oncology, University of Wuerzburg (Germany); Department of Radiation Oncology, Martin Luther University Halle-Wittenberg (Germany)

    2011-03-15T23:59:59.000Z

    Purpose: The recognition of the true prevalence of cardiac toxicity after mediastinal radiotherapy requires very long follow-up and a precise diagnostic procedure. Cardiac magnetic resonance imaging (MRI) permits excellent quantification of cardiac function and identification of localized myocardial defects and has now been applied to a group of 20-year Hodgkin's disease survivors. Methods and materials: Of 143 patients treated with anterior mediastinal radiotherapy (cobalt-60, median prescribed dose 40 Gy) for Hodgkin's disease between 1978 and 1985, all 53 survivors were invited for cardiac MRI. Of those, 36 patients (68%) presented for MRI, and in 31 patients (58%) MRI could be performed 20-28 years (median, 24) after radiotherapy. The following sequences were acquired on a 1.5-T MRI: transversal T1-weighted TSE and T2-weighted half-fourier acquisition single-shot turbo-spin-echo sequences, a steady-state free precession (SSFP) cine sequence in the short heart axis and in the four-chamber view, SSFP perfusion sequences under rest and adenosine stress, and a SSFP inversion recovery sequence for late enhancement. The MRI findings were correlated with previously reconstructed doses to cardiac structures. Results: Clinical characteristics and reconstructed doses were not significantly different between survivors undergoing and not undergoing MRI. Pathologic findings were reduced left ventricular function (ejection fraction <55%) in 7 (23%) patients, hemodynamically relevant valvular dysfunction in 13 (42%), late myocardial enhancement in 9 (29%), and any perfusion deficit in 21 (68%). An association of regional pathologic changes and reconstructed dose to cardiac structures could not be established. Conclusions: In 20-year survivors of Hodgkin's disease, cardiac MRI detects pathologic findings in approximately 70% of patients. Cardiac MRI has a potential role in cardiac imaging of Hodgkin's disease patients after mediastinal radiotherapy.

  11. A Survey of Prostate Segmentation Methodologies in Ultrasound, Magnetic Resonance and Computed Tomography Images

    E-Print Network [OSTI]

    Boyer, Edmond

    A Survey of Prostate Segmentation Methodologies in Ultrasound, Magnetic Resonance and Computed@gmail.com (Soumya Ghose), aoliver@eia.udg.edu (Arnau Oliver), marly@eia.udg.edu (Robert Mart´i), llado@eia.udg.edu (Xavier Llad´o), jordif@eia.udg.edu (Jordi Freixenet), jhimlimitra@yahoo.com (Jhimli Mitra), desire

  12. Fast and contrast-enhanced phase-sensitive magnetic resonance imaging

    E-Print Network [OSTI]

    Son, Jong Bum

    2009-05-15T23:59:59.000Z

    two signals if the resonance frequencies are close. For example, in MR mammography, it is difficult to separate silicone breast implants signals (4.0 ppm) from fat signals (3.5 ppm); (2) the signal dynamic range of images acquired using Dixon...

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

    E-Print Network [OSTI]

    Jedynak, Bruno M.

    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

  14. Distortion-free magnetic resonance imaging in the zero-field limit

    SciTech Connect (OSTI)

    Kelso, Nathan; Lee, Seung-Kyun; Bouchard, Louis-S.; Demas, Vasiliki; Muck, Michael; Pines, Alexander; Clarke, John

    2009-07-09T23:59:59.000Z

    MRI is a powerful technique for clinical diagnosis and materials characterization. Images are acquired in a homogeneous static magnetic field much higher than the fields generated across the field of view by the spatially encoding field gradients. Without such a high field, the concomitant components of the field gradient dictated by Maxwell's equations lead to severe distortions that make imaging impossible with conventional MRI encoding. In this paper, we present a distortion-free image of a phantom acquired with a fundamentally different methodology in which the applied static field approaches zero. Our technique involves encoding with pulses of uniform and gradient field, and acquiring the magnetic field signals with a SQUID. The method can be extended to weak ambient fields, potentially enabling imaging in the Earth's field without cancellation coils or shielding. Other potential applications include quantum information processing and fundamental studies of long-range ferromagnetic interactions.

  15. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Pearson, William G., E-mail: bp1@bu.edu [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States); Hindson, David F. [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States)] [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States); Langmore, Susan E. [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States) [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States); Speech and Hearing Sciences, Boston University, Boston, Massachusetts (United States); Zumwalt, Ann C. [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)] [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)

    2013-03-01T23:59:59.000Z

    Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions: Muscles of both the suprahyoid and the longitudinal pharyngeal muscle groups are active in swallowing, and both swallowing exercises effectively target muscles elevating the hyolaryngeal complex. mfMRI is useful in testing swallowing muscle function.

  16. Magnetic Resonance Pulse Sequences for Fluorine-19

    E-Print Network [OSTI]

    Terry, Robin

    2014-07-11T23:59:59.000Z

    . Magnetic resonance imaging (MRI) has the ability to noninvasively track the transplanted cells to ensure they are in the desired destination. Unlike other MRI contrast agents, fluorine-19 has the ability to provide unambiguous cell tracking for two reasons...

  17. Optically Enhanced Magnetic Resonance

    E-Print Network [OSTI]

    Suter, Dieter

    , like spatial structures or molecular dynamics. While the direct excitation of nuclear spin transitions.1 Motivation The physical mechanism of nuclear magnetic resonance spectroscopy, the excitation of transitions light for polarizing the spin system or for observing its dynamics. This possibility arises from

  18. Magnetic resonance visualization of conductive structures by sequence-triggered direct currents and spin-echo phase imaging

    SciTech Connect (OSTI)

    Eibofner, Frank; Wojtczyk, Hanne; Graf, Hansjörg, E-mail: hansjoerg.graf@med.uni-tuebingen.de, E-mail: drGraf@t-online.de [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany); Clasen, Stephan [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)] [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)

    2014-06-15T23:59:59.000Z

    Purpose: Instrument visualization in interventional magnetic resonance imaging (MRI) is commonly performed via susceptibility artifacts. Unfortunately, this approach suffers from limited conspicuity in inhomogeneous tissue and disturbed spatial encoding. Also, susceptibility artifacts are controllable only by sequence parameters. This work presents the basics of a new visualization method overcoming such problems by applying sequence-triggered direct current (DC) pulses in spin-echo (SE) imaging. SE phase images allow for background free current path localization. Methods: Application of a sequence-triggered DC pulse in SE imaging, e.g., during a time period between radiofrequency excitation and refocusing, results in transient field inhomogeneities. Dependent on the additional z-magnetic field from the DC, a phase offset results despite the refocusing pulse. False spatial encoding is avoided by DC application during periods when read-out or slice-encoding gradients are inactive. A water phantom containing a brass conductor (water equivalent susceptibility) and a titanium needle (serving as susceptibility source) was used to demonstrate the feasibility. Artifact dependence on current strength and orientation was examined. Results: Without DC, the brass conductor was only visible due to its water displacement. The titanium needle showed typical susceptibility artifacts. Applying triggered DC pulses, the phase offset of spins near the conductor appeared. Because SE phase images are homogenous also in regions of persistent field inhomogeneities, the position of the conductor could be determined with high reliability. Artifact characteristic could be easily controlled by amperage leaving sequence parameters unchanged. For an angle of 30° between current and static field visualization was still possible. Conclusions: SE phase images display the position of a conductor carrying pulsed DC free from artifacts caused by persistent field inhomogeneities. Magnitude and phase images are acquired simultaneously under the same conditions without the use of extra measurement time. The presented technique offers many advantages for precise instrument localization in interventional MRI.

  19. 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

  20. Assessment of Wall Shear Stress Changes in Arteries and Veins of Arteriovenous Polytetrafluoroethylene Grafts Using Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Misra, Sanjay, E-mail: Misra.sanjay@mayo.edu; Woodrum, David A. [Mayo Clinic, Department of Radiology (United States); Homburger, Jay [Medical College of Georgia, Department of Vascular Surgery (United States); Elkouri, Stephane [Centre Hospitalier de I'Universite de Montreal, Department of Vascular Surgery (Canada); Mandrekar, Jayawant N. [Mayo Clinic, Division of Biostatistics (United States); Barocas, Victor [University of Minnesota, Department of Biomedical Engineering (United States); Glockner, James F. [Mayo Clinic, Department of Radiology (United States); Rajan, Dheeraj K. [Toronto General Hospital, University Health Network, Department of Medical Imaging, Division of Vascular and Interventional Radiology (Canada); Mukhopadhyay, Debabrata [Mayo Clinic, Department of Biochemistry and Molecular Biology (United States)

    2006-08-15T23:59:59.000Z

    The purpose of the study was to determine simultaneously the temporal changes in luminal vessel area, blood flow, and wall shear stress (WSS) in both the anastomosed artery (AA) and vein (AV) of arteriovenous polytetrafluoroethylene (PTFE) grafts. PTFE grafts were placed from the iliac artery to the ipsilateral iliac vein in 12 castrated juvenile male pigs. Contrast-enhanced magnetic resonance angiograpgy with cine phase-contrast magnetic resonance imaging was performed. Luminal vessel area, blood flow, and WSS in the aorta, AA, AV, and inferior vena cava were determined at 3 days (D3), 7 days (D7), and 14 days (D14) after graft placement. Elastin von Gieson staining of the AV was performed. The average WSS of the AA was highest at D3 and then decreased by D7 and D14. In contrast, the average WSS and intima-to-media ratio of the AV increased from D3 to D7 and peaked by D14. Similarly, the average area of the AA was highest by D7 and began to approximate the control artery by D14. The average area of the AV had decreased to its lowest by D7. High blood flows through the AA causes a decrease in average WSS and increase in the average luminal vessel area, whereas at the AV, the average WSS and intima-to-media ratio both increase while the average luminal vessel area decreases.

  1. Magnetic Resonance Facility (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-03-01T23:59:59.000Z

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

  2. Classification System for Identifying Women at Risk for Altered Partial Breast Irradiation Recommendations After Breast Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Kowalchik, Kristin V. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); Vallow, Laura A., E-mail: vallow.laura@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); McDonough, Michelle [Department of Radiology, Mayo Clinic, Jacksonville, Florida (United States); Thomas, Colleen S.; Heckman, Michael G. [Section of Biostatistics, Mayo Clinic, Jacksonville, Florida (United States); Peterson, Jennifer L. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); Adkisson, Cameron D. [Department of General Surgery, Mayo Clinic, Jacksonville, Florida (United States); Serago, Christopher [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); McLaughlin, Sarah A. [Department of General Surgery, Mayo Clinic, Jacksonville, Florida (United States)

    2013-09-01T23:59:59.000Z

    Purpose: To study the utility of preoperative breast MRI for partial breast irradiation (PBI) patient selection, using multivariable analysis of significant risk factors to create a classification rule. Methods and Materials: Between 2002 and 2009, 712 women with newly diagnosed breast cancer underwent preoperative bilateral breast MRI at Mayo Clinic Florida. Of this cohort, 566 were retrospectively deemed eligible for PBI according to the National Surgical Adjuvant Breast and Bowel Project Protocol B-39 inclusion criteria using physical examination, mammogram, and/or ultrasound. Magnetic resonance images were then reviewed to determine their impact on patient eligibility. The patient and tumor characteristics were evaluated to determine risk factors for altered PBI eligibility after MRI and to create a classification rule. Results: Of the 566 patients initially eligible for PBI, 141 (25%) were found ineligible because of pathologically proven MRI findings. Magnetic resonance imaging detected additional ipsilateral breast cancer in 118 (21%). Of these, 62 (11%) had more extensive disease than originally noted before MRI, and 64 (11%) had multicentric disease. Contralateral breast cancer was detected in 28 (5%). Four characteristics were found to be significantly associated with PBI ineligibility after MRI on multivariable analysis: premenopausal status (P=.021), detection by palpation (P<.001), first-degree relative with a history of breast cancer (P=.033), and lobular histology (P=.002). Risk factors were assigned a score of 0-2. The risk of altered PBI eligibility from MRI based on number of risk factors was 0:18%; 1:22%; 2:42%; 3:65%. Conclusions: Preoperative bilateral breast MRI altered the PBI recommendations for 25% of women. Women who may undergo PBI should be considered for breast MRI, especially those with lobular histology or with 2 or more of the following risk factors: premenopausal, detection by palpation, and first-degree relative with a history of breast cancer.

  3. Prediction of the reversibility of the ultrasound-induced blood-brain barrier opening using passive cavitation detection with magnetic resonance imaging

    E-Print Network [OSTI]

    Konofagou, Elisa E.

    cavitation detection with magnetic resonance imaging validation Tao Sun1 , Gesthimani Samiotaki1 and Elisa E (diameters: 1-2, 4-5, or 6-8 m). A 10-MHz passive cavitation detector was used to acquire cavitation signals that the stable cavitation dose increased with the number of days required for closing while it reached a plateau

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

    SciTech Connect (OSTI)

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

    2012-02-15T23:59:59.000Z

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

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

    Office of Science (SC) Website

    supported by: NIH, NASA Impactbenefit to spin-off field: Static & dynamic imaging of lungs, heart, and possibly the brain, possible imaging of astronauts 'Hyperpolarized gas...

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

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

    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.

  7. HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2002

    E-Print Network [OSTI]

    Gollub, Randy L.

    Provides information relevant to the conduct and interpretation of human brain mapping studies. Provides in-depth coverage of the physics of image formation, mechanisms of image contrast, and the physiological basis for ...

  8. HST.583 Functional Magnetic Resonance Imaging: Data Acquisition and Analysis, Fall 2004

    E-Print Network [OSTI]

    Gollub, Randy L.

    Provides information relevant to the conduct and interpretation of human brain mapping studies. Provides in-depth coverage of the physics of image formation, mechanisms of image contrast, and the physiological basis for ...

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

    E-Print Network [OSTI]

    in Magnetic Resonance Imaging by Padraig J. Cantillon-Murphy B.E., Electrical and Electronic EngineeringOn 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

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

    SciTech Connect (OSTI)

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

    2012-02-15T23:59:59.000Z

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

  11. Developing novel polymer architectures for applications In magnetic resonance imaging and self-assembly

    E-Print Network [OSTI]

    McCombs, Jessica R. (Jessica Rose)

    2013-01-01T23:59:59.000Z

    Macromolecular scaffolds for drug delivery, self-assembly, and imaging applications have attracted significant attention over the last several decades. As polymerization techniques become more sophisticated, it becomes ...

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

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

    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.

  13. Magnetic Imaging Wolfgang Kuch

    E-Print Network [OSTI]

    Kuch, Wolfgang

    Magnetic Imaging Wolfgang Kuch Freie Universit¨at Berlin, Institut f¨ur Experimentalphysik, Arnimallee 14, 14195 Berlin, Germany kuch@physik.fu-berlin.de Abstract. Imaging of magnetic domains has- ern techniques is used nowadays routinely for magnetic imaging of magnetic ma- terials

  14. Coil performance evaluation based on electrodynamics : tools for hardware design and validation in magnetic resonance imaging

    E-Print Network [OSTI]

    Lattanzi, Riccardo

    2008-01-01T23:59:59.000Z

    Parallel MRI techniques allow acceleration of MR imaging beyond traditional speed limits. In parallel MRI, radiofrequency (RF) detector coil arrays are used to perform some degree of spatial encoding which complements ...

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

    SciTech Connect (OSTI)

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

    2012-06-15T23:59:59.000Z

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

  16. An analysis of the PERL Magnetic Resonance Imaging theory and implementation

    E-Print Network [OSTI]

    Kremkus, Mark Christian

    2013-02-22T23:59:59.000Z

    The goal of PERL MRI in its most basic form is single shot imaging without the need to rapidly switch gradients to encode spatial information into the signal. PERL MRI incorporates the application of the PERL field into the standard spin echo...

  17. Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20T23:59:59.000Z

    70% increase in SNR [62]. The same group used an array of four arc shaped coils around a cylinder for microscopy for SENSE and GRAPPA accelerated imaging [63]. The greater field of view provided by an array of small coils was noted by Laistler et...

  18. Intensity inhomogeneity correction for magnetic resonance imaging of human brain at 7T

    SciTech Connect (OSTI)

    Uwano, Ikuko; Yamashita, Fumio; Higuchi, Satomi; Ito, Kenji; Sasaki, Makoto [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan)] [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694 (Japan); Kudo, Kohsuke, E-mail: kkudo@huhp.hokudai.ac.jp; Goodwin, Jonathan; Harada, Taisuke [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan and Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido 060-8648 (Japan)] [Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan and Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Hokkaido 060-8648 (Japan); Ogawa, Akira [Department of Neurosurgery, Iwate Medical University, Morioka, Iwate 020-8505 (Japan)] [Department of Neurosurgery, Iwate Medical University, Morioka, Iwate 020-8505 (Japan)

    2014-02-15T23:59:59.000Z

    Purpose: To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. Materials: Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the “New Segment” module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images. Results: In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images. Conclusions: Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences.

  19. Noble gas magnetic resonator

    DOE Patents [OSTI]

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

    2014-04-15T23:59:59.000Z

    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.

  20. artery magnetic resonance: Topics by E-print Network

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

    10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Whole Brain Isotropic Arterial Spin Labeling Magnetic Resonance Imaging in a transgenic mouse...

  1. Modeling sickle cell vasoocculsion in the rat leg: Quantification of trapped sickle cells and correlation with sup 31 P metabolic and sup 1 H magnetic resonance imaging changes

    SciTech Connect (OSTI)

    Fabry, M.E.; Rajanayagam, V.; Fine, E.; Holland, S.; Gore, J.C.; Nagel, R.L.; Kaul, D.K. (Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY (USA))

    1989-05-01T23:59:59.000Z

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m ({sup 99m}Tc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative {sup 99m}Tc imaging, {sup 31}P magnetic resonance spectroscopy by surface coil at 2 teslas, and {sup 1}H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 {mu}l of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T{sub 1} reached a broad maximum at 18-28 hr. When T{sub 1} obtained at this time was plotted against the volume of cells trapped, an increase of T{sub 1} over the control value of 411 {plus minus} 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by {sup 1}H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate.

  2. Magnetic resonance apparatus

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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.

  3. Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

    SciTech Connect (OSTI)

    Bloch, B. Nicolas [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria)], E-mail: nbloch@bidmc.harvard.edu; Lenkinski, Robert E. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Helbich, Thomas H. [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Ngo, Long [Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Oismueller, Renee [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Jaromi, Silvia; Kubin, Klaus [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Hawliczek, Robert [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Kaplan, Irving D. [Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Rofsky, Neil M. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States)

    2007-09-01T23:59:59.000Z

    Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of data read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.

  4. Abstract--This study presents a system designed to assist the surgeon during interventional procedures performed by Magnetic Resonance Imaging (MRI). In order to reach the target during guidance in a double obliquity trajectory, this

    E-Print Network [OSTI]

    Boyer, Edmond

    on the instrument are detected [4]. Two commercial solutions have recently appeared on the market: a robotic system of ionizing radiations, Magnetic Resonance Imaging is a well adapted modality for interventional practice. MRI stiff and short, enabling the use of passive detection and/or optical localisation. Passive tracking

  5. Real-Time Color-Flow Magnetic ResonanceImaging of Congenital Heart Disease E. De La Pena-Almaguer, K. S. Nayak, M. Terashima, P.C. Yang,

    E-Print Network [OSTI]

    Southern California, University of

    Real-Time Color-Flow Magnetic ResonanceImaging of Congenital Heart Disease E. De La Pena used for the diagnosis of congenital heart disease (CHD), although it has limitations. Conventional MRI flow pulse sequence.A low flip- angle water selective spectral-spatial excitation is followed

  6. Unentangling nuclear magnetic resonance Matthias Bechmann 1

    E-Print Network [OSTI]

    Stepney, Susan

    Unentangling nuclear magnetic resonance computing Matthias Bechmann 1 , John A. Clark 2 , Angelika of York, UK, YO10 5DD Abstract. Nuclear magnetic resonance (NMR) is typically thought of as a possible could be used to perform non-quantum computation: from addressable 3D memory, to a programmable 3D

  7. Magnetic Resonance Imaging of Acute Reperfused Myocardial Infarction: Intraindividual Comparison of ECIII-60 and Gd-DTPA in a Swine Model

    SciTech Connect (OSTI)

    Jin Jiyang; Teng Gaojun [Zhongda Hospital of Southeast University, Department of Radiology (China); Feng Yi; Wu Yanping [Zhongda Hospital of Southeast University, Department of Cardiology (China); Jin Qindi [Zhongda Hospital of Southeast University, Department of Radiology (China); Wang Yu [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Zhen [Zhongda Hospital of Southeast University, Department of Anaesthesiology (China); Lu Qin [Zhongda Hospital of Southeast University, Department of Radiology (China); Jiang Yibo [Zhongda Hospital of Southeast University, Department of Cardiology (China); Wang Shengqi; Chen Feng [Zhongda Hospital of Southeast University, Department of Radiology (China); Marchal, Guy; Ni Yicheng [University Hospitals, University of Leuven, Department of Radiology (Belgium)], E-mail: yicheng.ni@med.kuleuven.ac.be

    2007-04-15T23:59:59.000Z

    Purpose. To compare a necrosis-avid contrast agent (NACA) bis-Gd-DTPA-pamoic acid derivative (ECIII-60) after intracoronary delivery with an extracellular agent Gd-DTPA after intravenous injection on magnetic resonance imaging (MRI) in a swine model of acute reperfused myocardial infarction (MI). Methods. Eight pigs underwent 90 min of transcatheter coronary balloon occlusion and 60 min of reperfusion. After intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg, all pigs were scanned with T1-weighted MRI until the delayed enhancement of MI disappeared. Then they were intracoronarily infused with ECIII-60 at 0.0025 mmol/kg and imaged for 5 hr. Signal intensity, infarct-over-normal contrast ratio and relative infarct size were quantified, compared, and correlated with the results of postmortem MRI and triphenyltetrazolium chloride (TTC) histochemical staining. Results. A contrast ratio over 3.0 was induced by both Gd-DTPA and ECIII-60. However, while the delayed enhancement with Gd-DTPA virtually vanished in 1 hr, ECIII-60 at an 80x smaller dose depicted the MI accurately over 5 hr as proven by ex vivo MRI and TTC staining. Conclusion. Both Gd-DTPA and ECIII-60 strongly enhanced acute MI. Comparing with fading contrast in a narrow time window with intravenous Gd-DTPA, intracoronary ECIII-60 persistently demarcated the acute MI, indicating a potential method for postprocedural assessment of myocardial viability after coronary interventions.

  8. Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte...

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

    Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for Vanadium Redox Flow Battery . Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for...

  9. A 200-MHz fully-differential CMOS front-end with an on-chip inductor for magnetic resonance imaging

    E-Print Network [OSTI]

    Ayala, Julio Enqrique, II

    2007-04-25T23:59:59.000Z

    with an observed liquid sample. In [5], an implantable solenoidal microcoil is designed to be 5 used in NMR microspectroscopy experiments in a 2-Tesla magnet (85.13-MHz). The outer diameter of the coil was approximately 200 ?m and the length was 580 ?m. The coil... microspec- troscopy. Liquid samples were loaded into a fused silica capillary positioned 50 ?m above a 3.5-turn microcoil so that approximately 1 nL of the sample was present above the sensitive region of the microcoil. At 5.9-Tesla magnet (250-MHz), NMR...

  10. Cerebral edema induced in mice by a convulsive dose of soman. Evaluation through diffusion-weighted magnetic resonance imaging and histology

    SciTech Connect (OSTI)

    Testylier, Guy [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France)]. E-mail: guytestylier@crssa.net; Lahrech, Hana [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Montigon, Olivier [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Foquin, Annie [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Delacour, Claire [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Bernabe, Denis [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Segebarth, Christoph [Inserm, UMR-S 836-Grenoble Institut des Neurosciences, Grenoble, F-38043 (France); Universite Joseph Fourier, Grenoble, F-38043 (France); Dorandeu, Frederic [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France); Carpentier, Pierre [Centre de Recherches du Service Sante des Armees, Departement de Toxicologie, BP87, F-38702 La Tronche cedex (France)

    2007-04-15T23:59:59.000Z

    Purpose: In the present study, diffusion-weighted magnetic resonance imaging (DW-MRI) and histology were used to assess cerebral edema and lesions in mice intoxicated by a convulsive dose of soman, an organophosphate compound acting as an irreversible cholinesterase inhibitor. Methods: Three hours and 24 h after the intoxication with soman (172 {mu}g/kg), the mice were anesthetized with an isoflurane/N{sub 2}O mixture and their brain examined with DW-MRI. After the imaging sessions, the mice were sacrificed for histological analysis of their brain. Results: A decrease in the apparent diffusion coefficient (ADC) was detected as soon as 3 h after the intoxication and was found strongly enhanced at 24 h. A correlation was obtained between the ADC change and the severity of the overall brain damage (edema and cellular degeneration): the more severe the damage, the stronger the ADC drop. Anesthesia was shown to interrupt soman-induced seizures and to attenuate edema and cell change in certain sensitive brain areas. Finally, brain water content was assessed using the traditional dry/wet weight method. A significant increase of brain water was observed following the intoxication. Conclusions: The ADC decrease observed in the present study suggests that brain edema in soman poisoning is mainly intracellular and cytotoxic. Since entry of water into Brain was also evidenced, this type of edema is certainly mixed with others (vasogenic, hydrostatic, osmotic). The present study confirms the potential of DW-MRI as a non-invasive tool for monitoring the acute neuropathological consequences (edema and neurodegeneration) of soman-induced seizures.

  11. Use of T2-weighted magnetic resonance imaging of the optic nerve sheath to detect raised intracranial pressure

    E-Print Network [OSTI]

    Geeraerts, Thomas; Newcombe, Virginia F J; Coles, Jonathan P; Abate, Maria Giulia; Perkes, Iain E; Hutchinson, Peter J A; Outtrim, Jo G; Chatfield, Dot A; Menon, David K

    2008-09-11T23:59:59.000Z

    is accurate at measuring ONSD [27,28] and has been proposed to detect raised ICP in idiopathic hydrocephalus and to diagnose shunt malfunction [12,14,29,30]. On T2-weighted sequences, water (and CSF) exhibits a high signal (white). Fat and grey matter appear... as light grey, and white matter as dark grey. The perioptic CSF is surrounded by orbital fat. Contrast between CSF and orbital fat can be improved with fat suppression, increasing the image resolution for the ONSD measurement [12,13]. We have con- firmed...

  12. Use of Non-Invasive Phase Contrast Magnetic Resonance Imaging for Estimation of Atrial Septal Defect Size and Morphology: A Comparison with Transesophageal Echo

    SciTech Connect (OSTI)

    Piaw, Chin Sze; Kiam, Ong Tiong [Sarawak General Hospital, Department of Cardiology (Malaysia); Rapaee, Annuar [University of Malaysia Sarawak (Malaysia)], E-mail: rannuar@fmhs.unimas.myp; Khoon, Liew Chee; Bang, Liew Houng; Ling, Chan Wei [Sarawak General Hospital, Department of Cardiology (Malaysia); Samion, Hasri [National Heart Institute, Pediatric of Cardiology (Malaysia); Hian, Sim Kui [Sarawak General Hospital, Department of Cardiology (Malaysia)

    2006-04-15T23:59:59.000Z

    Background: Transesophageal echocardiography (TEE) is a trusted method of sizing atrial septal defect (ASD) prior to percutaneous closure but is invasive, uncomfortable, and may carry a small risk of morbidity and mortality. Magnetic resonance imaging (MRI) may be useful non-invasive alternative in such patients who refuse or are unable to tolerate TEE and may provide additional information on the shape of the A0SD. Purpose: To validate the accuracy of ASD sizing by MRI compared with TEE.Method: Twelve patients (mean age 30 years; range 11-60 years) scheduled for ASD closure underwent TEE, cine balanced fast field echo MRI (bFFE-MRI) in four-chamber and sagittal views and phase-contrast MRI (PC-MRI) with reconstruction using the two orthogonal planes of T2-weighted images as planning. The average of the three longest measurements for all imaging modalities was calculated for each patient. Results: Mean maximum ASD length on TEE was 18.8 {+-} 4.6 mm, mean length by bFFE-MRI was 20.0 {+-} 5.0 mm, and mean length by PC-MRI was 18.3 {+-} 3.6 mm. The TEE measurement was significantly correlated with the bFFE-MRI and PC-MRI measurements (Pearson r = 0.69, p = 0.02 and r = 0.59, p = 0.04, respectively). The mean difference between TEE and bFFE-MRI measurements was -1.2mm (95% CI: -3.7, 1.3) and between TEE and PC-MRI was 0.5 mm (95% CI: -1.9, 2.9). Bland-Altman analysis also determined general agreement between both MRI methods and TEE. The ASDs were egg-shaped in two cases, circular in 1 patient and oval in the remaining patients. Conclusion: ASD sizing by MRI using bFFE and phase-contrast protocols correlated well with TEE estimations. PC-MRI provided additional information on ASD shapes and proximity to adjacent structures.

  13. SU-E-T-136: Dosimetric Robustness of a Magnetic Resonance Imaging Guided Radiation Therapy (MR-IGRT) System

    SciTech Connect (OSTI)

    Rodriguez, V; Green, O; Wooten, H; Kashani, R; Mutic, S; Li, H [Washington University School of Medicine, St. Louis, MO (United States); Dempsey, J [View Ray Incorporated, Oakwood Village, OH (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To test the radiation delivery robustness of the first MR-IGRT system using a commercial cylindrical diode array detector (ArcCHECK) and an ionization thimble chamber (Exradin A18). Methods: The MR-IGRT system is composed of three evenly spaced Co-60 sources on a rotating gantry located between two magnet halves. The collimator for each source consists of 30 doubly-focused leaf pairs that allow the system to deliver both conformal and intensity modulated (IMRT) treatment plans. The system's delivery robustness was tested over a span of 6 months from September 2013 through February 2014. This was achieved by repeatedly delivering 10 patient plans. These plans consisted of 2 conformal prostates, 2 IMRT prostates, 2 IMRT head and neck, 2 IMRT breast, 1 IMRT pancreas, and 1 IMRT bladder. The plans were generated with the system's treatment planning software. Once the plans were generated, quality assurance plans were created on a digital ArcCHECK dataset. The ArcCHECK used for testing was specially designed to be MR-compatible by moving the power supply outside of the magnetic field. The A18 ionization chamber was placed in a custom plastic plug insert in the center of the ArcCHECK. Gamma analysis was used with the ArcCHECK for relative dose evaluating both 3%/3mm and 2%/2mm. Absolute point dose was compared between ion chamber measurement and treatment plan. Results: The ArcCHECK passing rate remained constant over the 6 month period. The average passing rate for 3%/3mm and 2%/2mm analysis was 98.6% ± 0.7 and 88.8% ± 2.9, respectively. The ion chamber measurements showed little variation with an average percent difference between planned dose verses measured dose of 0.9% ± 0.7. Conclusion: Minimal differences were noted in the delivery of the 10 patient plans. Over a period that included acceptance testing, commissioning, and clinical deliveries, the MR-IGRT system remained consistent in radiation delivery.

  14. Refreshing One of Several Active Representations: Behavioral and Functional Magnetic Resonance

    E-Print Network [OSTI]

    Johnson, Marcia K.

    Refreshing One of Several Active Representations: Behavioral and Functional Magnetic Resonance with this interpretation, in a functional magnetic resonance imaging study, young adults showed two areas of left they just opened the refrigerator door, telling a story multiple times to the same person, or forgetting

  15. Lensless Imaging of Magnetic Nanostructures

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

    this technique has been especially popular in imaging such complex structures as aerogels and yeast cells. When applying the CDI technique to a magnetic system, the same...

  16. An Atlas-Based Electron Density Mapping Method for Magnetic Resonance Imaging (MRI)-Alone Treatment Planning and Adaptive MRI-Based Prostate Radiation Therapy

    SciTech Connect (OSTI)

    Dowling, Jason A., E-mail: jason.dowling@csiro.au [Australian e-Health Research Center, CSIRO ICT Commonwealth Scientific and Industrial Research Organisation Information and Communication Technologies Centre, Queensland (Australia); Lambert, Jonathan [Calvary Mater Newcastle Hospital, New South Wales (Australia); University of Newcastle, New South Wales (Australia); Parker, Joel [Calvary Mater Newcastle Hospital, New South Wales (Australia); Salvado, Olivier; Fripp, Jurgen [Australian e-Health Research Center, CSIRO ICT Commonwealth Scientific and Industrial Research Organisation Information and Communication Technologies Centre, Queensland (Australia); Capp, Anne; Wratten, Chris; Denham, James W.; Greer, Peter B. [Calvary Mater Newcastle Hospital, New South Wales (Australia); University of Newcastle, New South Wales (Australia)

    2012-05-01T23:59:59.000Z

    Purpose: Prostate radiation therapy dose planning directly on magnetic resonance imaging (MRI) scans would reduce costs and uncertainties due to multimodality image registration. Adaptive planning using a combined MRI-linear accelerator approach will also require dose calculations to be performed using MRI data. The aim of this work was to develop an atlas-based method to map realistic electron densities to MRI scans for dose calculations and digitally reconstructed radiograph (DRR) generation. Methods and Materials: Whole-pelvis MRI and CT scan data were collected from 39 prostate patients. Scans from 2 patients showed significantly different anatomy from that of the remaining patient population, and these patients were excluded. A whole-pelvis MRI atlas was generated based on the manually delineated MRI scans. In addition, a conjugate electron-density atlas was generated from the coregistered computed tomography (CT)-MRI scans. Pseudo-CT scans for each patient were automatically generated by global and nonrigid registration of the MRI atlas to the patient MRI scan, followed by application of the same transformations to the electron-density atlas. Comparisons were made between organ segmentations by using the Dice similarity coefficient (DSC) and point dose calculations for 26 patients on planning CT and pseudo-CT scans. Results: The agreement between pseudo-CT and planning CT was quantified by differences in the point dose at isocenter and distance to agreement in corresponding voxels. Dose differences were found to be less than 2%. Chi-squared values indicated that the planning CT and pseudo-CT dose distributions were equivalent. No significant differences (p > 0.9) were found between CT and pseudo-CT Hounsfield units for organs of interest. Mean {+-} standard deviation DSC scores for the atlas-based segmentation of the pelvic bones were 0.79 {+-} 0.12, 0.70 {+-} 0.14 for the prostate, 0.64 {+-} 0.16 for the bladder, and 0.63 {+-} 0.16 for the rectum. Conclusions: The electron-density atlas method provides the ability to automatically define organs and map realistic electron densities to MRI scans for radiotherapy dose planning and DRR generation. This method provides the necessary tools for MRI-alone treatment planning and adaptive MRI-based prostate radiation therapy.

  17. 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

  18. Enlarge Image Peer pressure. Magnetic

    E-Print Network [OSTI]

    Thywissen, Joseph

    to stick it to your refrigerator, but an ultra-cold gas magnetizes itself just as do metals such as ironEnlarge Image Peer pressure. Magnetic domains in steel (vertical bans) arise when neighboring electrons point their magnetic poles in the same direction. CREDIT: ZUREKS, CHRIS VARDON

  19. Enhanced oil recovery through water imbibition in fractured reservoirs using Nuclear Magnetic Resonance 

    E-Print Network [OSTI]

    Hervas Ordonez, Rafael Alejandro

    1994-01-01T23:59:59.000Z

    -iicro-fracture system. Nuclear Magnetic Resonance (NNM) sets of longitudinal and transverse profiles and images were recorded to visualize and quantify changes in fluid saturation inside the rock samples during the imbibition displacement tests. NMR oil saturation...

  20. Enhanced oil recovery through water imbibition in fractured reservoirs using Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Hervas Ordonez, Rafael Alejandro

    1994-01-01T23:59:59.000Z

    -iicro-fracture system. Nuclear Magnetic Resonance (NNM) sets of longitudinal and transverse profiles and images were recorded to visualize and quantify changes in fluid saturation inside the rock samples during the imbibition displacement tests. NMR oil saturation...

  1. Magnetic Resonance Imaging of concrete

    E-Print Network [OSTI]

    Burgoyne, Chris

    velocity · Relates Elastic modulus to speed of sound Assumes Concrete heterogeneous Can be affected by steel Modulus related to speed of sound Strength of concrete related to modulus Location of flaws structure · In both cases procedure is destructive Systems to monitor concrete modulus · Ultra-sonic pulse

  2. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    SciTech Connect (OSTI)

    Dimopoulos, Johannes C.A. [Department of Radiation Oncology, Metropolitan Hospital, Athens (Greece); Schmid, Maximilian P., E-mail: maximilian.schmid@akhwien.at [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria); Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria)

    2012-04-01T23:59:59.000Z

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable range. First clinical results indicate excellent LC. Further prospective multicenter studies are needed to establish this method and to confirm these results.

  3. Surface Plasmon Resonance Imaging Measurements of Electrostatic Biopolymer

    E-Print Network [OSTI]

    Surface Plasmon Resonance Imaging Measurements of Electrostatic Biopolymer Adsorption onto surface plasmon resonance (SPR) imaging experiments is used to charac- terize the differential/RAS) and surface plasmon resonance (SPR) thickness mea- surements. A schematic diagram of the scanning SPR

  4. Methods for magnetic resonance analysis using magic angle technique

    DOE Patents [OSTI]

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

    2011-11-22T23:59:59.000Z

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

  5. Enlarge Image Peer pressure. Magnetic

    E-Print Network [OSTI]

    Enlarge Image Peer pressure. Magnetic domains in steel (vertical bans) arise when neighboring electrons point their magnetic poles in the same direction. CREDIT: ZUREKS, CHRIS VARDON/WIKIMEDIA By Adrian Cho ScienceNOW Daily News 18 September 2009 It would be tough to stick it to your refrigerator

  6. The magnetic resonance force microscope: A new microscopic probe of magnetic materials

    SciTech Connect (OSTI)

    Hammel, P.C.; Zhang, Z. [Los Alamos National Lab., NM (United States); Midzor, M.; Roukes, M.L. [California Inst. of Tech., Pasadena, CA (United States); Wigen, P.E. [Ohio State Univ., Columbus, OH (United States); Childress, J.R. [Univ. of Florida, Gainesville, FL (United States)

    1997-08-06T23:59:59.000Z

    The magnetic resonance force microscope (MRFM) marries the techniques of magnetic resonance imaging (MRI) and atomic force microscopy (AFM), to produce a three-dimensional imaging instrument with high, potentially atomic-scale, resolution. The principle of the MRFM has been successfully demonstrated in numerous experiments. By virtue of its unique capabilities the MRFM shows promise to make important contributions in fields ranging from three-dimensional materials characterization to bio-molecular structure determination. Here the authors focus on its application to the characterization and study of layered magnetic materials; the ability to illuminate the properties of buried interfaces in such materials is a particularly important goal. While sensitivity and spatial resolution are currently still far from their theoretical limits, they are nonetheless comparable to or superior to that achievable in conventional MRI. Further improvement of the MRFM will involve operation at lower temperature, application of larger field gradients, introduction of advanced mechanical resonators and improved reduction of the spurious coupling when the magnet is on the resonator.

  7. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect (OSTI)

    Mukai, Y. [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Hirori, H., E-mail: hirori@icems.kyoto-u.ac.jp [Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Yamamoto, T. [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Kageyama, H. [Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Tanaka, K., E-mail: kochan@scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); CREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan)

    2014-07-14T23:59:59.000Z

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  8. Electro-Mechanical Resonant Magnetic Field Sensor

    E-Print Network [OSTI]

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

    2002-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Baudoin, Geneviève

    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

  10. Pretreatment Endorectal Coil Magnetic Resonance Imaging Findings Predict Biochemical Tumor Control in Prostate Cancer Patients Treated With Combination Brachytherapy and External-Beam Radiotherapy

    SciTech Connect (OSTI)

    Riaz, Nadeem [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Afaq, Asim; Akin, Oguz [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Pei Xin; Kollmeier, Marisa A.; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Hricak, Hedvig [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-11-01T23:59:59.000Z

    Purpose: To investigate the utility of endorectal coil magenetic resonance imaging (eMRI) in predicting biochemical relapse in prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Methods and Materials: Between 2000 and 2008, 279 men with intermediate- or high-risk prostate cancer underwent eMRI of their prostate before receiving brachytherapy and supplemental intensity-modulated radiotherapy. Endorectal coil MRI was performed before treatment and retrospectively reviewed by two radiologists experienced in genitourinary MRI. Image-based variables, including tumor diameter, location, number of sextants involved, and the presence of extracapsular extension (ECE), were incorporated with other established clinical variables to predict biochemical control outcomes. The median follow-up was 49 months (range, 1-13 years). Results: The 5-year biochemical relapse-free survival for the cohort was 92%. Clinical findings predicting recurrence on univariate analysis included Gleason score (hazard ratio [HR] 3.6, p = 0.001), PSA (HR 1.04, p = 0.005), and National Comprehensive Cancer Network risk group (HR 4.1, p = 0.002). Clinical T stage and the use of androgen deprivation therapy were not correlated with biochemical failure. Imaging findings on univariate analysis associated with relapse included ECE on MRI (HR 3.79, p = 0.003), tumor size (HR 2.58, p = 0.04), and T stage (HR 1.71, p = 0.004). On multivariate analysis incorporating both clinical and imaging findings, only ECE on MRI and Gleason score were independent predictors of recurrence. Conclusions: Pretreatment eMRI findings predict for biochemical recurrence in intermediate- and high-risk prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Gleason score and the presence of ECE on MRI were the only significant predictors of biochemical relapse in this group of patients.

  11. Pulsed Nuclear Magnetic Resonance: Spin Echoes MIT Department of Physics

    E-Print Network [OSTI]

    Seager, Sara

    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

  12. Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE

    E-Print Network [OSTI]

    Addis, Donna Rose

    Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE IMAGING DATA USING SPM-ordinates (with signs reversed) into table as translations right, fwd and up · Check origin is at the AC · Select images (a_seg1.img, a_seg2 and brain_a.img) · Name output file (grey_clean) · Enter formula

  13. Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy

    E-Print Network [OSTI]

    Morphology of the Small-Animal Lung Using Magnetic Resonance Microscopy Laurence W. Hedlund and G motion control and animal support, the lungs of the live, small animal can be imaged. Although in vivo He, it is possible to image the tissue and gas compartments of the lung. This capability

  14. Surface Plasmon Resonance Imaging Measurements of Antibody Arrays for the

    E-Print Network [OSTI]

    Surface Plasmon Resonance Imaging Measurements of Antibody Arrays for the Multiplexed Detection molecular weight protein biomarkers with surface plasmon resonance imaging (SPRI). A one methodology would be to use an optical method that can directly detect antigen binding. Surface plasmon

  15. Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances

    E-Print Network [OSTI]

    Urzhumov, Yaroslav; Bingham, Chris; Padilla, Willie; Smith, David R

    2011-01-01T23:59:59.000Z

    We propose that macroscopic objects built from negative-permeability metamaterials may experience resonantly enhanced magnetic force in low-frequency magnetic fields. Resonant enhancement of the time-averaged force originates from magnetostatic surface resonances (MSR) which are analogous to the electrostatic resonances of negative-permittivity particles, well known as surface plasmon resonances in optics. We generalize the classical problem of MSR of a homogeneous object to include anisotropic metamaterials, and consider the most extreme case of anisotropy where the permeability is negative in one direction but positive in the others. It is shown that deeply subwavelength objects made of such indefinite (hyperbolic) media exhibit a pronounced magnetic dipole resonance that couples strongly to uniform or weakly inhomogeneous magnetic field and provides strong enhancement of the magnetic force, enabling applications such as enhanced magnetic levitation.

  16. Science Drivers and Technical Challenges for Advanced Magnetic Resonance

    SciTech Connect (OSTI)

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

    2013-03-07T23:59:59.000Z

    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.

  17. Novel nuclear magnetic resonance techniques for studying biological molecules

    E-Print Network [OSTI]

    Laws, David D.

    2010-01-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Goodson, Boyd M.

    1999-12-01T23:59:59.000Z

    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.

  19. Tumor Metabolism and Perfusion in Head and Neck Squamous Cell Carcinoma: Pretreatment Multimodality Imaging With {sup 1}H Magnetic Resonance Spectroscopy, Dynamic Contrast-Enhanced MRI, and [{sup 18}F]FDG-PET

    SciTech Connect (OSTI)

    Jansen, Jacobus F.A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Maastricht University Medical Center, Maastricht (Netherlands); Schoeder, Heiko [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Stambuk, Hilda E. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wang Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Fury, Matthew G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Patel, Senehal G. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Pfister, David G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shah, Jatin P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Koutcher, Jason A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shukla-Dave, Amita, E-mail: davea@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-01-01T23:59:59.000Z

    Purpose: To correlate proton magnetic resonance spectroscopy ({sup 1}H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and {sup 18}F-labeled fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally, pretreatment multimodality imaging was evaluated for its efficacy in predicting short-term response to treatment. Methods and Materials: Metastatic neck nodes were imaged with {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET in 16 patients with newly diagnosed HNSCC, before treatment. Short-term patient radiological response was evaluated at 3 to 4 months. Correlations among {sup 1}H-MRS (choline concentration relative to water [Cho/W]), DCE-MRI (volume transfer constant [K{sup trans}]; volume fraction of the extravascular extracellular space [v{sub e}]; and redistribution rate constant [k{sub ep}]), and [{sup 18}F]FDG PET (standard uptake value [SUV] and total lesion glycolysis [TLG]) were calculated using nonparametric Spearman rank correlation. To predict short-term responses, logistic regression analysis was performed. Results: A significant positive correlation was found between Cho/W and TLG ({rho} = 0.599; p = 0.031). Cho/W correlated negatively with heterogeneity measures of standard deviation std(v{sub e}) ({rho} = -0.691; p = 0.004) and std(k{sub ep}) ({rho} = -0.704; p = 0.003). Maximum SUV (SUVmax) values correlated strongly with MRI tumor volume ({rho} = 0.643; p = 0.007). Logistic regression indicated that std(K{sup trans}) and SUVmean were significant predictors of short-term response (p < 0.07). Conclusion: Pretreatment multimodality imaging using {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET is feasible in HNSCC patients with nodal metastases. Additionally, combined DCE-MRI and [{sup 18}F]FDG PET parameters were predictive of short-term response to treatment.

  20. Refining 31 P nuclear magnetic resonance spectroscopy for marine

    E-Print Network [OSTI]

    Paytan, Adina

    Refining 31 P nuclear magnetic resonance spectroscopy for marine particulate samples: Storage 31 P nuclear magnetic resonance (NMR) spectroscopy has recently been used to characterize phosphorus.e., no storage, refrigeration, freezing, and oven-drying and grinding) prior to extraction for solution 31 P

  1. Controlling interactions between highly-magnetic atoms with Feshbach resonances

    E-Print Network [OSTI]

    Svetlana Kotochigova

    2014-10-14T23:59:59.000Z

    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.

  2. Lensless Imaging of Magnetic Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -ofLearningLensless Imaging of Magnetic

  3. Lensless Imaging of Magnetic Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -ofLearningLensless Imaging of MagneticLensless

  4. Ventilation-Synchronous Magnetic Resonance Microscopy of Pulmonary Structure and Ventilation in

    E-Print Network [OSTI]

    Ventilation-Synchronous Magnetic Resonance Microscopy of Pulmonary Structure and Ventilation helium (3 He) gas to acquire images that dem- onstrate pulmonary vasculature and ventilated airways of these structures relative to the less vascular surrounding tissues. A constant- flow ventilator was developed

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2003-12-30T23:59:59.000Z

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

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2004-12-28T23:59:59.000Z

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

  7. Magnetic resonance studies of cement based materials in inhomogeneous magnetic fields

    SciTech Connect (OSTI)

    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

    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.

  8. acoustic nuclear magnetic resonance: Topics by E-print Network

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

    acoustic nuclear magnetic resonance First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1...

  9. Target-specific contrast agents for magnetic resonance microscopy

    E-Print Network [OSTI]

    Hepler Blackwell, Megan Leticia

    2007-01-01T23:59:59.000Z

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

  10. 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...

  11. Nuclear magnetic resonance study of methane adsorbed on porous silicon

    E-Print Network [OSTI]

    Li, Feng

    1992-01-01T23:59:59.000Z

    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...

  12. Long-Range Surface Plasmon Resonance Imaging for Bioaffinity Sensors

    E-Print Network [OSTI]

    Long-Range Surface Plasmon Resonance Imaging for Bioaffinity Sensors Alastair W. Wark, Hye Jin Lee A novel bioaffinity sensor based on surface plasmon resonance (SPR) imaging measurements of a multiple- layered structure that supports the generation of long- range surface plasmons (LRSPs) at the water

  13. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2010-07-13T23:59:59.000Z

    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.

  14. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2009-10-27T23:59:59.000Z

    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.

  15. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2009-11-10T23:59:59.000Z

    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.

  16. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2010-06-29T23:59:59.000Z

    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.

  17. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2007-12-11T23:59:59.000Z

    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.

  18. High-Grade Glioma Radiation Therapy Target Volumes and Patterns of Failure Obtained From Magnetic Resonance Imaging and {sup 18}F-FDOPA Positron Emission Tomography Delineations From Multiple Observers

    SciTech Connect (OSTI)

    Kosztyla, Robert, E-mail: rkosztyla@bccancer.bc.ca [Department of Medical Physics, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Chan, Elisa K.; Hsu, Fred [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Wilson, Don [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Ma, Roy; Cheung, Arthur [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Zhang, Susan [Department of Medical Physics, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Moiseenko, Vitali [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California (United States); Benard, Francois [Department of Functional Imaging, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Nichol, Alan [Department of Radiation Oncology, British Columbia Cancer Agency, Vancouver, British Columbia (Canada)

    2013-12-01T23:59:59.000Z

    Purpose: The objective of this study was to compare recurrent tumor locations after radiation therapy with pretreatment delineations of high-grade gliomas from magnetic resonance imaging (MRI) and 3,4-dihydroxy-6-[{sup 18}F]fluoro-L-phenylalanine ({sup 18}F-FDOPA) positron emission tomography (PET) using contours delineated by multiple observers. Methods and Materials: Nineteen patients with newly diagnosed high-grade gliomas underwent computed tomography (CT), gadolinium contrast-enhanced MRI, and {sup 18}F-FDOPA PET/CT. The image sets (CT, MRI, and PET/CT) were registered, and 5 observers contoured gross tumor volumes (GTVs) using MRI and PET. Consensus contours were obtained by simultaneous truth and performance level estimation (STAPLE). Interobserver variability was quantified by the percentage of volume overlap. Recurrent tumor locations after radiation therapy were contoured by each observer using CT or MRI. Consensus recurrence contours were obtained with STAPLE. Results: The mean interobserver volume overlap for PET GTVs (42% ± 22%) and MRI GTVs (41% ± 22%) was not significantly different (P=.67). The mean consensus volume was significantly larger for PET GTVs (58.6 ± 52.4 cm{sup 3}) than for MRI GTVs (30.8 ± 26.0 cm{sup 3}, P=.003). More than 95% of the consensus recurrence volume was within the 95% isodose surface for 11 of 12 (92%) cases with recurrent tumor imaging. Ten (91%) of these cases extended beyond the PET GTV, and 9 (82%) were contained within a 2-cm margin on the MRI GTV. One recurrence (8%) was located outside the 95% isodose surface. Conclusions: High-grade glioma contours obtained with {sup 18}F-FDOPA PET had similar interobserver agreement to volumes obtained with MRI. Although PET-based consensus target volumes were larger than MRI-based volumes, treatment planning using PET-based volumes may not have yielded better treatment outcomes, given that all but 1 recurrence extended beyond the PET GTV and most were contained by a 2-cm margin on the MRI GTV.

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

    E-Print Network [OSTI]

    Maroncelli, Mark

    Superconducting Magnet Safety Nuclear Magnetic Resonance (NMR) facilities present unique hazards not found in most laboratory environments. The NMR facilities maintain superconducting magnets which have the units. Facility design and installation: Design and installation of a new NMR facility requires a number

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

    E-Print Network [OSTI]

    Augustine, Mathew P.

    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

  1. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    SciTech Connect (OSTI)

    Kirchheim,, A. P.; Dal Molin, D.C.; Emwas, Abdul-Hamid; Provis, J.L.; Fischer, P.; Monteiro, P.J.M.

    2010-12-01T23:59:59.000Z

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C{sub 3}A or 3CaO {center_dot} Al{sub 2}O{sub 3}) and Na-doped tricalcium aluminate (orthorhombic C{sub 3}A or Na{sub 2}Ca{sub 8}Al{sub 6}O{sub 18}), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by {sup 27}Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C{sub 3}A hydration during the early stages. There are differences in the hydration mechanism between the two types of C{sub 3}A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C{sub 3}A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C{sub 3}A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping.

  2. Magnetic Resonance Imaging-Based Target Volume Delineation in Radiation Therapy Treatment Planning for Brain Tumors Using Localized Region-Based Active Contour

    SciTech Connect (OSTI)

    Aslian, Hossein [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Sadeghi, Mahdi [Agricultural, Medical and Industrial Research School, Karaj (Iran, Islamic Republic of); Mahdavi, Seied Rabie [Department of Medical Physics, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Babapour Mofrad, Farshid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Astarakee, Mahdi, E-mail: M-Astarakee@Engineer.com [Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Khaledi, Navid [Department of Medical Radiation, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Fadavi, Pedram [Department of Radiation Oncology, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2013-09-01T23:59:59.000Z

    Purpose: To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials: A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists’ contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results: Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions: Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer.

  3. NMR (nuclear magnetic resonance) imaging for detecting binder/plasticizers in green-state structural ceramics. [SiC, Al/sub 2/O/sub 3/, and Si/sub 3/N/sub 4/

    SciTech Connect (OSTI)

    Ellingson, W.A.; Ackerman, J.L.; Gronemeyer, S.; Garrido, L.

    1987-06-01T23:59:59.000Z

    We have explored both a small-bore (<10 cm) experimental imaging system as well as a state-of-the-art medical imaging system relative to detection of the soft-solid (wax-like) binders used in ceramics. The ability to detect binders was evaluated on a 1.5-T medical MRI imager (Siemens Magnetom) using T/sub 1/-weighted imaging techniques and a 10-cm eye coil standard with the system. The ability to detect binders was also studied with a modified small-bore coil Technicare Facility using special rf and gradient coils. The initial results show that a medical system may not be able to detect binders unless elevated temperatures are used, whereas the experimental small-bore system shows the distribution quite well. In addition, higher magnetic field strength should be better for ceramics, since proton signal strength increases rapidly with the magnetic field strength. 11 refs., 9 figs., 3 tabs.

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

    SciTech Connect (OSTI)

    Bitter, Hans-Marcus L.

    2000-07-01T23:59:59.000Z

    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.

  5. assessing dynamic magnetic: Topics by E-print Network

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

    0 Assessment of Carotid Flow Using Magnetic Resonance Imaging and Computational Fluid Dynamics) direct, model-independent velocity mapping using flow-encoded magnetic resonance...

  6. On transition from Alfvén resonance to forced magnetic reconnection

    SciTech Connect (OSTI)

    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

    We revisit the transition from Alfvén 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 Alfvén 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})

  7. FY08 Annual Report for Nuclear Resonance Fluorescence Imaging

    SciTech Connect (OSTI)

    Warren, Glen A.; Caggiano, Joseph A.

    2009-01-06T23:59:59.000Z

    FY08 annual report for project the "Nuclear Resonance Fluorescence Imaging" project. Reviews accomplishments of last 3 years, including U-235 signature search, comparison of different photon sources, and examination of NRF measurements using monochromatic photon source.

  8. Co-Funding for the Conference on Magnetic Resonance in Biological Systems

    SciTech Connect (OSTI)

    Alan McLaughlin, Ph.D., Director, Division of Applied Science & Technology, NIBIB, NIH

    2008-10-01T23:59:59.000Z

    The XXIst International Conference on Magnetic Resonance in Biological Systems (ICMRBS 2005), '60th anniversary of the discovery of Nuclear Magnetic Resonance,' was held between 16 and 21 January 2005 in Hyderabad, India. The meeting focused on a broad range of magnetic resonance methods as applied to studies of biological processes related to human health. The biennial ICMRBS has become the major venue for discussion of advances in nuclear and electron magnetic resonance (NMR & EMR/EPR) studies of the structure, dynamics, and chemical properties of important classes of biomolecules. Magnetic resonance has become an established tool in structural biology, and its special importance derives from its ability to provide atomic level information. It is becoming increasingly evident that the dynamic features of biomolecules, their intermolecular interactions, and accessible conformations in solution are data of key importance in understanding molecular recognition and function. NMR, which is already contributing to approximately 25% of the new structures being deposited with the Protein Data Bank, is destined to be a major player in the post genomic structure age with its emphasis on structure and function. In-vivo magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) results shed light on human metabolic processes and on the cellular ramifications of cancer, stroke, cardiovascular disease, and other pathologies. New methodologies in metabonomics may lead to development of new drugs and medical diagnosis. The ICMRBS is the one conference that brings together experts from high-resolution NMR, solid state NMR, EPR, in-vivo MRS and MRI, and developers of instrumentation, techniques, software, and databases. Symposia at this ICMRBS are designed to continue the fruitful cross-fertilization of ideas that has been so successful in driving the spectacular advances in this field. ICMRBS 2005 maintained the traditional format of poster sessions, and plenary lectures that highlight major advances in each of the major areas, and three parallel symposia that focused on particular biological systems, interfacial applications of magnetic resonance, and rapidly advancing technology. Funds provided partial travel support for 33 younger scientists from the U.S. (graduate students, postdoctoral research associates, and beginning faculty), selected from those who submitted accepted posters; 12 of these were invited to contribute oral presentations. Those receiving travel support were selected by a committee composed of the U.S. members of the International Advisory Committee for the meeting. Particular emphasis was placed on facilitating participation of minority and women scientists.

  9. Magnetic field imaging with atomic Rb vapor

    E-Print Network [OSTI]

    Eugeniy E. Mikhailov; I. Novikova; M. D. Havey; F. A. Narducci

    2009-07-27T23:59:59.000Z

    We demonstrate the possibility of dynamic imaging of magnetic fields using electromagnetically induced transparency in an atomic gas. As an experimental demonstration we employ an atomic Rb gas confined in a glass cell to image the transverse magnetic field created by a long straight wire. In this arrangement, which clearly reveals the essential effect, the field of view is about 2 x 2 mm^2 and the field detection uncertainty is 0.14 mG per 10 um x 10 um image pixel.

  10. Single Spin Optically Detected Magnetic Resonance with E-Band Microwave Resonators

    E-Print Network [OSTI]

    Nabeel Aslam; Matthias Pfender; Rainer Stöhr; Philipp Neumann; Marc Scheffler; Hitoshi Sumiya; Hiroshi Abe; Shinobu Onoda; Takeshi Ohshima; Junichi Isoya; Jörg Wrachtrup

    2015-03-13T23:59:59.000Z

    Magnetic resonance with ensembles of electron spins is nowadays performed in frequency ranges up to 240 GHz and in corresponding magnetic fields of up to 10 T. However, experiments with single electron and nuclear spins so far only reach into frequency ranges of several 10 GHz, where existing coplanar waveguide structures for microwave (MW) delivery are compatible with single spin readout techniques (e.g. electrical or optical readout). Here, we explore the frequency range up to 90 GHz, respectively magnetic fields of up to $\\approx 3\\,$T for single spin magnetic resonance in conjunction with optical spin readout. To this end, we develop MW resonators with optical single spin access. In our case, rectangular E-band waveguides guarantee low-loss supply of microwaves to the resonators. Three dimensional cavities, as well as coplanar waveguide resonators enhance MW fields by spatial and spectral confinement with a MW efficiency of $1.36\\,\\mathrm{mT/\\sqrt{W}}$. We utilize single NV centers as hosts for optically accessible spins, and show, that their properties regarding optical spin readout known from smaller fields (sensor. Regarding spin based quantum registers, high fields lead to a purer product basis of electron and nuclear spins, which promises improved spin lifetimes. For example, during continuous single-shot readout the $^{14}$N nuclear spin shows second-long longitudinal relaxation times.

  11. Single echo acquisition magnetic resonance imaging

    E-Print Network [OSTI]

    McDougall, Mary Preston

    2006-04-12T23:59:59.000Z

    ) for comparison to quasi- static field pattern modeling .................................................................................................37 3.25 Coil pattern with the appropriate signal and noise calculation areas marked for SNR evaluation...

  12. Nanoscale magnetic resonance imaging C. L. Degena

    E-Print Network [OSTI]

    Leonardo, Degiorgi

    tobacco mosaic virus particles sitting on a nanometer-thick layer of ad- sorbed hydrocarbons. This result, which represents a 100 million- fold improvement in volume resolution over conventional MRI considerable effort, attempts to push the spatial resolution of conventional MRI into the realm of high

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

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    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

  14. Biomarker Profiling by Nuclear Magnetic Resonance Spectroscopy for the Prediction of All-Cause Mortality

    E-Print Network [OSTI]

    Reid, Nancy

    Biomarker Profiling by Nuclear Magnetic Resonance Spectroscopy for the Prediction of All University Hospital, Oulu, Finland, 5 NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern by nuclear magnetic resonance spectroscopy of non- fasting plasma samples from a random subset

  15. Magnetic Resonance Pulse Sequences for Fluorine-19 

    E-Print Network [OSTI]

    Terry, Robin

    2014-07-11T23:59:59.000Z

    : Fluorinated agents are more readily inert and will not be metabolized quickly so their movement progression can be monitored Additionally, ^(19)F has a limited background MR signal so resulting images will yield positively labeled cells, thus providing...

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

    SciTech Connect (OSTI)

    Parra, J.O.

    2001-01-26T23:59:59.000Z

    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.

  17. Magnetic particle imaging of blood coagulation

    SciTech Connect (OSTI)

    Murase, Kenya, E-mail: murase@sahs.med.osaka-u.ac.jp; Song, Ruixiao; Hiratsuka, Samu [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)

    2014-06-23T23:59:59.000Z

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  18. Optically Detected Magnetic Resonance Studies on ?-conjugated semiconductor systems

    SciTech Connect (OSTI)

    Chen, Ying

    2011-12-06T23:59:59.000Z

    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.

  19. Sub-surface characterization and three dimensional profiling of semiconductors by magnetic resonance force microscopy

    SciTech Connect (OSTI)

    Hammel, P.C.; Moore, G.; Roukes, M.; Zhenyong Zhang

    1996-10-01T23:59:59.000Z

    This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project successfully developed a magnetic resonance force microscope (MRFM) instrument to mechanically detect magnetic resonance signals. This technique provides an intrinsically subsurface, chemical-species-specific probe of structure, constituent density and other properties of materials. As in conventional magnetic resonance imaging (MRI), an applied magnetic field gradient selects a well defined volume of the sample for study. However mechanical detection allows much greater sensitivity, and this in turn allows the reduction of the size of the minimum resolvable volume. This requires building an instrument designed to achieve nanometer-scale resolution at buried semiconductor interfaces. High-resolution, three-dimensional depth profiling of semiconductors is critical in the development and fabrication of semiconductor devices. Currently, there is no capability for direct, high-resolution observation and characterization of dopant density, and other critical features of semiconductors. The successful development of MRFM in conjunction with modifications to improve resolution will enable for the first time detailed structural and electronic studies in doped semiconductors and multilayered nanoelectronic devices, greatly accelerating the current pace of research and development.

  20. Precise wavefunction engineering with magnetic resonance

    E-Print Network [OSTI]

    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

    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.

  1. Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data

    SciTech Connect (OSTI)

    ALAM,TODD M.; ALAM,M. KATHLEEN

    2000-07-20T23:59:59.000Z

    Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.

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

    SciTech Connect (OSTI)

    Leitner, Peter; Heyn, Martin F.; Kernbichler, Winfried [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, TU Graz, Petersgasse 16, A-8010 Graz (Austria); Ivanov, Ivan B. [Fusion@ÖAW, Institut für Theoretische Physik—Computational 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@ÖAW, Institut für Theoretische Physik—Computational 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

    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.

  3. Lensless Imaging of Magnetic Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your HomeLatest News ReleasesDepartmentLending a HandImaging of

  4. Lensless Imaging of Magnetic Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |Is Your HomeLatest News ReleasesDepartmentLending a HandImaging

  5. Lensless Imaging of Magnetic Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -ofLearningLensless Imaging of

  6. Continuum resonance induced electromagnetic torque by a rotating plasma response to static resonant magnetic perturbation field

    SciTech Connect (OSTI)

    Liu Yueqiang; Connor, J. W.; Cowley, S. C.; Ham, C. J.; Hastie, R. J.; Hender, T. C. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2012-10-15T23:59:59.000Z

    A numerical study is carried out, based on a simple toroidal tokamak equilibrium, to demonstrate the radial re-distribution of the electromagnetic torque density, as a result of a rotating resistive plasma (linear) response to a static resonant magnetic perturbation field. The computed electromagnetic torque peaks at several radial locations even in the presence of a single rational surface, due to resonances between the rotating response, in the plasma frame, and both Alfven and sound continuum waves. These peaks tend to merge together to form a rather global torque distribution, when the plasma resistivity is large. The continuum resonance induced net electromagnetic torque remains finite even in the limit of an ideal plasma.

  7. Near-electrode imager

    DOE Patents [OSTI]

    Rathke, Jerome W. (Lockport, IL); Klingler, Robert J. (Westmont, IL); Woelk, Klaus (Wachtberg, DE); Gerald, II, Rex E. (Brookfield, IL)

    2000-01-01T23:59:59.000Z

    An apparatus, near-electrode imager, for employing nuclear magnetic resonance imaging to provide in situ measurements of electrochemical properties of a sample as a function of distance from a working electrode. The near-electrode imager uses the radio frequency field gradient within a cylindrical toroid cavity resonator to provide high-resolution nuclear magnetic resonance spectral information on electrolyte materials.

  8. Magnetic Resonant Coupling As a Potential Means for Wireless Power Transfer to Multiple Small Receivers

    E-Print Network [OSTI]

    Cannon, Benjamin Louis

    Wireless power transfer via magnetic resonant coupling is experimentally demonstrated in a system with a large source coil and either one or two small receivers. Resonance between source and load coils is achieved with ...

  9. Carbon-13 nuclear magnetic resonance studies of glycolysis in protozoa

    E-Print Network [OSTI]

    Rhoades, Teresa Ann

    1986-01-01T23:59:59.000Z

    in the ratio of 1:2:8:3. 17 ~ ~ CHg-COSH CHg-COSH CHg-CO)H ~ CH2-COSH ~ CHg-COSH HACH)-CO(H FIGURE 7. Simulated coupling patterns for the C-2 of succinate. (a) [1, 2- C]; (b) [U- C]; (c) [1, 2, 3- C]; (d) 1:1:1 addition of (a), (b), and (c); (e) 1... May 1986 Major Subject: Chemistry CARBON-13 NUCLEAR MAGNETIC RESONANCE STUDIES OF GLYCOLYSIS IN PROTOZOA A Thesis by TERESA ANN RHOADES Approved as to style and content by: A. I. Scott (Chair of Committee) Marvin W. Rowe (h1ember) Neil E...

  10. Array combination for parallel imaging in Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Spence, Dan Kenrick

    2007-09-17T23:59:59.000Z

    ......................................103 Figure 51. Diagram of geometry used...........................................................................104 Figure 52. 64 element 8x8 grid array SNR map using 64 receivers. ............................105 Figure 53. 64 element 8x8 grid...-factor maps for point combined array......................................................117 Figure 63. SENSE reconstructions using point combined array...................................118 Figure 64. Grid array geometry used for simulation...

  11. 3D and 4D magnetic susceptibility tomography based on complex MR images

    DOE Patents [OSTI]

    Chen, Zikuan; Calhoun, Vince D

    2014-11-11T23:59:59.000Z

    Magnetic susceptibility is the physical property for T2*-weighted magnetic resonance imaging (T2*MRI). The invention relates to methods for reconstructing an internal distribution (3D map) of magnetic susceptibility values, .chi. (x,y,z), of an object, from 3D T2*MRI phase images, by using Computed Inverse Magnetic Resonance Imaging (CIMRI) tomography. The CIMRI technique solves the inverse problem of the 3D convolution by executing a 3D Total Variation (TV) regularized iterative convolution scheme, using a split Bregman iteration algorithm. The reconstruction of .chi. (x,y,z) can be designed for low-pass, band-pass, and high-pass features by using a convolution kernel that is modified from the standard dipole kernel. Multiple reconstructions can be implemented in parallel, and averaging the reconstructions can suppress noise. 4D dynamic magnetic susceptibility tomography can be implemented by reconstructing a 3D susceptibility volume from a 3D phase volume by performing 3D CIMRI magnetic susceptibility tomography at each snapshot time.

  12. Molecular dynamics in liquid cyclopropane. Raman and magnetic nuclear resonance studies

    E-Print Network [OSTI]

    Boyer, Edmond

    723 Molecular dynamics in liquid cyclopropane. II. 2014 Raman and magnetic nuclear resonance as a function of temperature (155, 300 K) and pressure (up to 3 kilobars). 13C and 2H nuclear magnetic resonance experiments are performed in the same temperature range. The isotropic and anisotropic Raman profiles

  13. Ferromagnetic resonance and low-temperature magnetic tests for biogenic magnetite

    E-Print Network [OSTI]

    Weiss, Benjamin P.

    Ferromagnetic resonance and low-temperature magnetic tests for biogenic magnetite $ Benjamin P, Massachusetts Institute of Technology, Cambridge, MA 02139, USA c Jet Propulsion Laboratory, California two rock magnetic analyses--the low-temperature Moskowitz test and ferromagnetic resonance (FMR

  14. Plasmon Resonances in Nanoparticles, Their Applications to Magnetics and Relation to the Riemann Hypothesis

    E-Print Network [OSTI]

    Isaak D. Mayergoyz

    2011-07-18T23:59:59.000Z

    The review of the mathematical treatment of plasmon resonances as an eigenvalue problem for specific boundary integral equations is presented and general properties of plasmon spectrum are outlined. Promising applications of plasmon resonances to magnetics are described. Interesting relation of eigenvalue treatment of plasmon resonances to the Riemann hypothesis is discussed.

  15. Advances in Surface Plasmon Resonance Imaging Enable Quantitative Tracking of Nanoscale Changes in Thickness and

    E-Print Network [OSTI]

    Dutcher, John

    Advances in Surface Plasmon Resonance Imaging Enable Quantitative Tracking of Nanoscale Changes: To date, detailed studies of the thickness of coatings using surface plasmon resonance have been limited a significant improvement to surface plasmon resonance imaging (SPRi) that allows this sensitive technique

  16. Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement

    E-Print Network [OSTI]

    G. Pignol; S. Baessler; V. V. Nesvizhevsky; K. Protasov; D. Rebreyend; A. Yu. Voronin

    2014-08-05T23:59:59.000Z

    Gravitational resonance spectroscopy consists in measuring the energy spectrum of bouncing ultracold neutrons above a mirror by inducing resonant transitions between different discrete quantum levels. We discuss how to induce the resonances with a flow through arrangement in the GRANIT spectrometer, excited by an oscillating magnetic field gradient. The spectroscopy could be realized in two distinct modes (so called DC and AC) using the same device to produce the magnetic excitation. We present calculations demonstrating the feasibility of the newly proposed AC mode.

  17. Motion of free spins and NMR imaging without a radio-frequency magnetic field

    E-Print Network [OSTI]

    Kees van Schenk Brill; Jassem Lahfadi; Tarek Khalil; Daniel Grucker

    2015-04-19T23:59:59.000Z

    NMR imaging without any radio-frequency magnetic field is explained by a quantum treatment of independent spin~$\\tfrac 12$. The total magnetization is determined by means of their individual wave function. The theoretical treatment, based on fundamental axioms of quantum mechanics and solving explicitly the Schr\\"{o}dinger equation with the kinetic energy part which gives the motion of free spins, is recalled. It explains the phase shift of the spin noise spectrum with its amplitude compared to the conventional NMR spectrum. Moreover it explains also the relatively good signal to noise ratio of NMR images obtained without a RF pulse. This derivation should be helpful for new magnetic resonance imaging sequences or for developing quantum computing by NMR.

  18. Observations of Multi-Resonance Effect in ELM Control with Magnetic Perturbation Fields on the JET Tokamak

    E-Print Network [OSTI]

    Observations of Multi-Resonance Effect in ELM Control with Magnetic Perturbation Fields on the JET Tokamak

  19. Correlated Biofilm Imaging, Transport and Metabolism Measurements...

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

    Biofilm Imaging, Transport and Metabolism Measurements via Combined Nuclear Magnetic Resonance and Confocal Correlated Biofilm Imaging, Transport and Metabolism Measurements via...

  20. Magnetic Microscopy and Imaging II John Chapman, Chairman Study of in-plane magnetic domains with magnetic transmission

    E-Print Network [OSTI]

    Bayreuther, Günther

    with magnetic transmission x-ray microscopy P. Fischer,a) T. Eimu¨ller, and G. Schu¨tz University of Wu be designed by en- gaging, e.g., the different magnetic couplings between each layers. Due to a balanceMagnetic Microscopy and Imaging II John Chapman, Chairman Study of in-plane magnetic domains

  1. Wallerian degeneration demonstrated by magnetic resonance: spectroscopic measurements on peripheral nerve. [Rats

    SciTech Connect (OSTI)

    Jolesz, F.A.; Polak, J.F.; Ruenzel, P.W.; Adams, D.F.

    1984-07-01T23:59:59.000Z

    Wallerian degeneration of rat sciatic nerves was induced by nerve section. Fifteen days later the degenerated nerves were compared with the intact contralteral nerves from the same animal. Histological sections showed the changes typical of wallerian degeneration: axonal degeneration and secondary demyelination. The freshly dissected nerves were analyzed by magnetic resonance (MR) spectroscopy at 10 MHz, and the water content was determined by dehydration. In the degenerated nerves there was a marked prolongation of both T1 and T2 relaxation times, accompanied by an increase of water content. These results suggest that it should be possible to detect wallerian degeneration in MR images; this will have an important impact on neuropathological diagnosis of central and peripheral nervous system lesions.

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

    SciTech Connect (OSTI)

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

    2008-10-29T23:59:59.000Z

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

  3. Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance

    SciTech Connect (OSTI)

    Takahashi, Masato; Maeda, Hideaki [RIKEN Systems and Structural Biology Center, Yokohama, Kanagawa 230-0045 (Japan); Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045 (Japan); Ebisawa, Yusuke; Tennmei, Konosuke [Graduate School of Yokohama City University, Yokohama, Kanagawa 230-0045 (Japan); Yanagisawa, Yoshinori; Nakagome, Hideki [Graduate School of Chiba University, Chiba, Chiba 263-8522 (Japan); Hosono, Masami; Takasugi, Kenji [JEOL RESONANCE Inc., Akishima, Tokyo 196-8558 (Japan); Hase, Takashi; Miyazaki, Takayoshi [Kobe Steel, Ltd., Kobe, Hyogo 651-2271 (Japan); Fujito, Teruaki [Probe Laboratory Inc., Hamura, Tokyo 205-0021 (Japan); Kiyoshi, Tsukasa [Superconducting Wire Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0003 (Japan); Yamazaki, Toshio [RIKEN Systems and Structural Biology Center, Yokohama, Kanagawa 230-0045 (Japan)

    2012-10-15T23:59:59.000Z

    Achieving a higher magnetic field is important for solid-state nuclear magnetic resonance (NMR). But a conventional low temperature superconducting (LTS) magnet cannot exceed 1 GHz (23.5 T) due to the critical magnetic field. Thus, we started a project to replace the Nb{sub 3}Sn innermost coil of an existing 920 MHz NMR (21.6 T) with a Bi-2223 high temperature superconducting (HTS) innermost coil. Unfortunately, the HTS magnet cannot be operated in persistent current mode; an external dc power supply is required to operate the NMR magnet, causing magnetic field fluctuations. These fluctuations can be stabilized by a field-frequency lock system based on an external NMR detection coil. We demonstrate here such a field-frequency lock system in a 500 MHz LTS NMR magnet operated in an external current mode. The system uses a {sup 7}Li sample in a microcoil as external NMR detection system. The required field compensation is calculated from the frequency of the FID as measured with a frequency counter. The system detects the FID signal, determining the FID frequency, and calculates the required compensation coil current to stabilize the sample magnetic field. The magnetic field was stabilized at 0.05 ppm/3 h for magnetic field fluctuations of around 10 ppm. This method is especially effective for a magnet with large magnetic field fluctuations. The magnetic field of the compensation coil is relatively inhomogeneous in these cases and the inhomogeneity of the compensation coil can be taken into account.

  4. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    SciTech Connect (OSTI)

    Wang, Shuanhu

    1997-09-17T23:59:59.000Z

    This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.

  5. Multipole-multimode Floquet theory in nuclear magnetic resonance Ramesh Ramachandran and Robert G. Griffina

    E-Print Network [OSTI]

    Griffin, Robert G.

    Multipole-multimode Floquet theory in nuclear magnetic resonance Ramesh Ramachandran and Robert G. The approach, based on multimode Floquet theory, employs the multipole operator basis of Sanctuary for spin

  6. Implementation of State Transfer Hamiltonians in Spin Chains with Magnetic Resonance Techniques

    E-Print Network [OSTI]

    Cappellaro, Paola

    2014-01-01T23:59:59.000Z

    Nuclear spin systems and magnetic resonance techniques have provided a fertile platform for experimental investigation of quantum state transfer in spin chains. From the first observation of polarization transfer, predating ...

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

    E-Print Network [OSTI]

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

    2003-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Cox, James Calvin

    1993-01-01T23:59:59.000Z

    drive mechanism. This imbibition and induced solution gas drive study employed nuclear magnetic resonance (NMR) spectroscopy techniques to monitor and characterize the progress of oil recovery inside the rock sample core. A specially designed core...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...

  9. Optically detected magnetic resonance studies on {pi}-conjugate polymers and novel carbon allotropes

    SciTech Connect (OSTI)

    Partee, J.

    1999-02-12T23:59:59.000Z

    This report describes the following: introduction to photoluminescence detected magnetic resonance (PLDMR); introduction to {pi}-conjugated systems; PLDMR measurements on poly(p-phenylene)-type ladder polymers; PLMDR measurements on poly(p-phenylene ethylene); and PLDMR measurements on C{sub 70}, polythiophene, poly(p-phenylene vinylene) and Dan-40. Appendices to this report describe: Operation of ODMR (optically detected magnetic resonance) spectrometer; ODMR system parameters; and Special purpose circuitry.

  10. The study of skin permeation mechanism and terpene-skin lipid interaction via nuclear magnetic resonance

    E-Print Network [OSTI]

    Lim, P. F. C.; Liu, Xiang Yang; Huang, Meng; Ho, P. C. L.; Chan, S. Y.

    2006-10-27T23:59:59.000Z

    , lipid extraction, etc. In our case, the interaction between a terpene and a lipid was examinedwith nuclear magnetic resonance (NMR), which aims to provide some insight to enhancement in skin permeation. Palmitic acid (Fig 1), a 16-carbon fatty acid... and oxides were able to producea greater ??. National University of Singapore, 2006 PS77 -The Study of Skin Permeation Mechanism and Terpene-Lipid Interaction via Nuclear Magnetic Resonance Perry Fung Chye Lim a, Xiang Yang Liu b, Meng Huang a, Paul Chi...

  11. A METHODOLOGY TO INTEGRATE MAGNETIC RESONANCE AND ACOUSTIC MEASUREMENTS FOR RESERVOIR CHARACTERIZATION

    SciTech Connect (OSTI)

    Jorge O. Parra; Chris L. Hackert; Lorna L. Wilson

    2002-09-20T23:59:59.000Z

    The work reported herein represents the third year of development efforts on a methodology to interpret magnetic resonance and acoustic measurements for reservoir characterization. In this last phase of the project we characterize a vuggy carbonate aquifer in the Hillsboro Basin, Palm Beach County, South Florida, using two data sets--the first generated by velocity tomography and the second generated by reflection tomography. First, we integrate optical macroscopic (OM), scanning electron microscope (SEM) and x-ray computed tomography (CT) images, as well as petrography, as a first step in characterizing the aquifer pore system. This pore scale integration provides information with which to evaluate nuclear magnetic resonance (NMR) well log signatures for NMR well log calibration, interpret ultrasonic data, and characterize flow units at the field scale between two wells in the aquifer. Saturated and desaturated NMR core measurements estimate the irreducible water in the rock and the variable T{sub 2} cut-offs for the NMR well log calibration. These measurements establish empirical equations to extract permeability from NMR well logs. Velocity and NMR-derived permeability and porosity relationships integrated with velocity tomography (based on crosswell seismic measurements recorded between two wells 100 m apart) capture two flow units that are supported with pore scale integration results. Next, we establish a more detailed picture of the complex aquifer pore structures and the critical role they play in water movement, which aids in our ability to characterize not only carbonate aquifers, but reservoirs in general. We analyze petrography and cores to reveal relationships between the rock physical properties that control the compressional and shear wave velocities of the formation. A digital thin section analysis provides the pore size distributions of the rock matrix, which allows us to relate pore structure to permeability and to characterize flow units at the core and borehole scales. Vp, density, porosity, and permeability logs are integrated with crosswell reflection data to produce impedance, permeability, and porosity images. These images capture three flow units that are characterized at the pore and borehole scales. The upper flow units are thin, continuous beds, and the deeper flow unit is thicker and heterogeneous. NMR well log calibration data and thin section analysis demonstrate that interwell region permeability is controlled mainly by micropores and macropores, which represent the flow unit matrices of the confined aquifer. Reflection image-derived impedance provides lateral detail and the depth of the deeper confining unit. The permeable regions identified in both parts of this phase of the study are consistent with the hydrological results of high water production being monitored between two wells in the South Florida aquifer. Finally, we describe the two major methodologies developed to support the aquifer characterization efforts--(1) a method to estimate frequency-dependent scattering attenuation based on the volume fraction and typical size of vugs or karsts, and (2) a method to more accurately interpret NMR well logs by taking into account the diffusion of magnetization between large and small pores. For the first method, we take the exact vug structure from x-ray CT scans of two carbonate cores and use 3-D finite difference modeling to determine the P-wave scattering attenuation in these cores at ultrasonic frequencies. In spite of the sharp contrast in medium properties between cavity and rock and the violation of the small perturbation assumption, the computed scattering attenuation is roughly comparable to that predicted by various random medium scattering theories. For the second method, we investigate how the diffusion of magnetization between macropores and micropores influences NMR log interpretation through 2D simulation of magnetization diffusion in realistic macropore geometries derived from digital images of thin sections. In most cases, our simulations show that the resulting simulate

  12. Magnetic Resonant Wireless Power Delivery for Distributed Sensor and Wireless Systems

    E-Print Network [OSTI]

    Cervesato, Iliano

    Magnetic Resonant Wireless Power Delivery for Distributed Sensor and Wireless Systems Brian J. Lee, Pittsburgh, PA 15213 Abstract-- In this paper we report on a resonant wireless power delivery system using to loads distributed in the system. We experimentally map the power distribution for one and multiple loads

  13. Novel nuclear magnetic resonance techniques for studying biological molecules

    SciTech Connect (OSTI)

    Laws, David D.

    2000-06-01T23:59:59.000Z

    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.

  14. A personal computer-based nuclear magnetic resonance spectrometer Constantin Job

    E-Print Network [OSTI]

    Brown, Michael F.

    A personal computer-based nuclear magnetic resonance spectrometer Constantin Job Arizona Research of Arizona,, lkson, Arizona 85721 (Received 24 May 1994; accepted for publication 27 July 1994) Nuclear engineering, agriculture, geology, archaeology, and others have the possibility of utilizing magnetic

  15. Ferrite-ferroelectric layered structures for electrically and magnetically tunable microwave resonators

    E-Print Network [OSTI]

    Demokritov, S.O.

    Ferrite-ferroelectric layered structures for electrically and magnetically tunable microwave It is demonstrated experimentally that a layered structure consisting of ferrite and ferroelectric thin films can constant , and a bias magnetic field to the ferrite layer. The resonator having central frequency f0 5 GHz

  16. Development and applications of NMR (nuclear magnetic resonance) in low fields and zero field

    SciTech Connect (OSTI)

    Bielecki, A.

    1987-05-01T23:59:59.000Z

    This dissertation is about nuclear magnetic resonance (NMR) spectroscopy in the absence of applied magnetic fields. NMR is usually done in large magnetic fields, often as large as can be practically attained. The motivation for going the opposite way, toward zero field, is that for certain types of materials, particularly powdered or polycrystalline solids, the NMR spectra in zero field are easier to interpret than those obtained in high field. 92 refs., 60 figs., 1 tab.

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

    SciTech Connect (OSTI)

    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

    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.

  18. Direct Imaging of Asymmetric Magnetization Reversal

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

    new information storage and sensing devices. There are two basic energies involved in the manipulation and control of the magnetic properties of materials. Exchange controls...

  19. Resonant normal form and asymptotic normal form behavior in magnetic bottle Hamiltonians

    E-Print Network [OSTI]

    C. Efthymiopoulos; M. Harsoula; G. Contopoulos

    2015-01-28T23:59:59.000Z

    We consider normal forms in `magnetic bottle' type Hamiltonians of the form $H=\\frac{1}{2}(\\rho^2_\\rho+\\omega^2_1\\rho^2) +\\frac{1}{2}p^2_z+hot$ (second frequency $\\omega_2$ equal to zero in the lowest order). Our main results are: i) a novel method to construct the normal form in cases of resonance, and ii) a study of the asymptotic behavior of both the non-resonant and the resonant series. We find that, if we truncate the normal form series at order $r$, the series remainder in both constructions decreases with increasing $r$ down to a minimum, and then it increases with $r$. The computed minimum remainder turns to be exponentially small in $\\frac{1}{\\Delta E}$, where $\\Delta E$ is the mirror oscillation energy, while the optimal order scales as an inverse power of $\\Delta E$. We estimate numerically the exponents associated with the optimal order and the remainder's exponential asymptotic behavior. In the resonant case, our novel method allows to compute a `quasi-integral' (i.e. truncated formal integral) valid both for each particular resonance as well as away from all resonances. We applied these results to a specific magnetic bottle Hamiltonian. The non resonant normal form yields theorerical invariant curves on a surface of section which fit well the empirical curves away from resonances. On the other hand the resonant normal form fits very well both the invariant curves inside the islands of a particular resonance as well as the non-resonant invariant curves. Finally, we discuss how normal forms allow to compute a critical threshold for the onset of global chaos in the magnetic bottle.

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

    SciTech Connect (OSTI)

    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

    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.

  1. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in...

  2. High resolution detection and excitation of resonant magnetic perturbations in a wall-stabilized tokamak

    SciTech Connect (OSTI)

    Maurer, David A. [Physics Department, Auburn University, Auburn, Alabama 36849 (United States); Shiraki, Daisuke; Levesque, Jeffrey P.; Bialek, James; Angelini, Sarah; Byrne, Patrick; DeBono, Bryan; Hughes, Paul; Mauel, Michael E.; Navratil, Gerald A.; Peng Qian; Rhodes, Dov; Rath, Nickolaus; Stoafer, Christopher [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2012-05-15T23:59:59.000Z

    We report high-resolution detection of the 3D plasma magnetic response of wall-stabilized tokamak discharges in the High Beta Tokamak-Extended Pulse [T. H. Ivers et al., Phys. Plasmas 3, 1926 (1996)] device. A new adjustable conducting wall has been installed on HBT-EP made up of 20 independent, movable, wall segments instrumented with three distinct sets of 40 modular coils that can be independently driven to generate a wide variety of magnetic perturbations. High-resolution detection of the plasma response is made with 216 poloidal and radial magnetic sensors that have been located and calibrated with high-accuracy. Static and dynamic plasma responses to resonant and non-resonant magnetic perturbations are observed through measurement of the step-response following a rapid change in the toroidal phase of the applied perturbations. Biorthogonal decomposition of the full set of magnetic sensors clearly defines the structures of naturally occurring external kinks as being composed of independent m/n = 3/1 and 6/2 modes. Resonant magnetic perturbations were applied to discharges with pre-existing, saturated m/n = 3/1 external kink mode activity. This m/n = 3/1 kink mode was observed to lock to the applied perturbation field. During this kink mode locked period, the plasma resonant response is characterized by a linear, a saturated, and a disruptive plasma regime dependent on the magnitude of the applied field and value of the edge safety factor and plasma rotation.

  3. Neutrino spectral split in core-collapse supernovae: A magnetic resonance phenomenon

    SciTech Connect (OSTI)

    Galais, Sebastien; Volpe, Cristina [Institut de Physique Nucleaire Orsay, F-91406 Orsay cedex (France)

    2011-10-15T23:59:59.000Z

    A variety of neutrino flavor conversion phenomena occur in core-collapse supernova, due to the large neutrino density close to the neutrinosphere, and the importance of the neutrino-neutrino interaction. Three different regimes have been identified so far, usually called the synchronization, the bipolar oscillations, and the spectral split. Using the formalism of polarization vectors, within two flavors, we focus on the spectral split phenomenon and we show for the first time that the physical mechanism underlying the neutrino spectral split is a magnetic resonance phenomenon. In particular, we show that the precession frequencies fulfill the magnetic resonance conditions. Our numerical calculations show that the neutrino energies and the location at which the resonance takes place in the supernova coincide well with the neutrino energies at which a spectral swap occurs. The corresponding adiabaticity parameters present spikes at the resonance location.

  4. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Montoya, Cris; Geraci, Andrew A; Eardley, Matthew; Moreland, John; Hollberg, Leo; Kitching, John

    2015-01-01T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  5. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Cris Montoya; Jose Valencia; Andrew A. Geraci; Matthew Eardley; John Moreland; Leo Hollberg; John Kitching

    2015-03-26T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  6. Exciton-polaron complexes in pulsed electrically-detected magnetic resonance

    E-Print Network [OSTI]

    T. L. Keevers; W. J. Baker; D. R. McCamey

    2015-02-19T23:59:59.000Z

    Several microscopic pathways have been proposed to explain the large magnetic effects observed in organic semiconductors, but identifying and characterising which microscopic process actually influences the overall magnetic field response is challenging. Pulsed electrically-detected magnetic resonance provides an ideal platform for this task as it intrinsically monitors the charge carriers of interest and provides dynamical information which is inaccessible through conventional magnetoconductance measurements. Here we develop a general time domain theory to describe the spin-dependent reaction of exciton-charge complexes following the coherent manipulation of paramagnetic centers through electron spin resonance. A general Hamiltonian is treated, and it is shown that the transition frequencies and resonance positions of the exciton-polaron complex can be used to estimate inter-species coupling. This work also provides a general formalism for analysing multi-pulse experiments which can be used to extract relaxation and transport rates.

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

    SciTech Connect (OSTI)

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

    2011-08-24T23:59:59.000Z

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

  8. Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective

    E-Print Network [OSTI]

    Zare, Richard N.

    Surface Plasmon Resonance Imaging Using a High Numerical Aperture Microscope Objective Bo Huang-5080 We designed, constructed, and tested a surface plasmon resonance (SPR) microscope using a high, combined with various methods to shorten the surface plasmon propaga- tion length, achieves diffraction

  9. Detection of magnetic resonance signals using a magnetoresistive sensor

    DOE Patents [OSTI]

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

    2013-10-01T23:59:59.000Z

    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.

  10. Particle transport as a result of resonant magnetic perturbations

    E-Print Network [OSTI]

    Mordijck, Saskia

    2011-01-01T23:59:59.000Z

    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,

  11. arch magnetic resonance: Topics by E-print Network

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

    created by the spins in the sample Cai, Long 2 Laboratory Simulation of Arched Magnetic Flux Rope Eruptions in the Solar Atmosphere S. K. P. Tripathi* and W. Gekelman Plasma...

  12. Low-field classroom nuclear magnetic resonance system

    E-Print Network [OSTI]

    Zimmerman, Clarissa Lynette

    2010-01-01T23:59:59.000Z

    The goal of this research was to develop a Low-field Classroom NMR system that will enable hands-on learning of NMR and MRI concepts in a Biological-Engineering laboratory course. A permanent magnet system, designed using ...

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

    SciTech Connect (OSTI)

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

    2012-05-01T23:59:59.000Z

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

  14. Probing Water Phases in Cement Blends using 1 Magnetic Resonance Relaxometry

    E-Print Network [OSTI]

    Sheffield, University of

    Probing Water Phases in Cement Blends using 1 H Nuclear Magnetic Resonance Relaxometry Jean)114 222 5973 Fax: +44 (0)114 222 5943 E-Mail: j.gorce@sheffield.ac.uk Extended Abstract: Cement and Concrete Science, Warwick, 16th + 17th September 2004 Introduction The nuclear industry uses blended cement

  15. Solid State Nuclear Magnetic Resonance 29 (2006) 105117 Electron-nuclear cross polarization

    E-Print Network [OSTI]

    Griffin, Robert G.

    2006-01-01T23:59:59.000Z

    Solid State Nuclear Magnetic Resonance 29 (2006) 105­117 Electron-nuclear cross polarization V from an unpaired electron to neighboring nuclei via electron-nuclear cross polarization (e­Hahn cross polarization (CP) process introduced by Pines et al., that is widely used in solid-state nuclear

  16. JOURNAL OF MAGNETIC RESONANCE 75, 509-5 12 ( 1987) Recursive Evaluation of Interaction Pictures

    E-Print Network [OSTI]

    Suter, Dieter

    JOURNAL OF MAGNETIC RESONANCE 75, 509-5 12 ( 1987) Recursive Evaluation of Interaction Pictures D quadratically with the number of pulsesin the sequence.In addition, the apparent time reversal in 161,together with the lack of a recursion formula, makes the values of k(t) in the different windows appear to be unrelated

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

    E-Print Network [OSTI]

    Fiber-Optic Stethoscope: A Cardiac Monitoring and Gating System for Magnetic Resonance Microscopy monitoring and gating purposes. The fiber-optic stethoscope system offers a novel approach to measuring cardiac activity that, unlike the ECG, is immune to electromagnetic effects. The fiber-optic stethoscope

  18. A GLRT AND BOOTSTRAP APPROACH TO DETECTION IN MAGNETIC RESONANCE FORCE MICROSCOPY

    E-Print Network [OSTI]

    Moura, José

    A GLRT AND BOOTSTRAP APPROACH TO DETECTION IN MAGNETIC RESONANCE FORCE MICROSCOPY Pei­Jung Chung a model that, although simplistic, captures the features of the problem. We present a GLRT and bootstrap based on the gen- eralized likelihood ratio test (GLRT), and bootstrap. The GLRT is used because besides

  19. Solid-State Nuclear Magnetic Resonance Measurements of HIV Fusion Peptide 13

    E-Print Network [OSTI]

    Weliky, David

    Solid-State Nuclear Magnetic Resonance Measurements of HIV Fusion Peptide 13 CO to Lipid 31 P ABSTRACT: Fusion of the human immunodeficiency virus (HIV) membrane and the host cell membrane is an initial step of infection of the host cell. Fusion is catalyzed by gp41, which is an integral membrane

  20. Surface Plasmon Resonance of Nanoparticles and Applications in Imaging

    E-Print Network [OSTI]

    Habib Ammari; Youjun Deng; Pierre Millien

    2014-12-11T23:59:59.000Z

    In this paper we provide a mathematical framework for localized plasmon resonance of nanoparticles. Using layer potential techniques associated with the full Maxwell equations, we derive small-volume expansions for the electromagnetic fields, which are uniformly valid with respect to the nanoparticle's bulk electron relaxation rate. Then, we discuss the scattering and absorption enhancements by plasmon resonant nanoparticles. We study both the cases of a single and multiple nanoparticles. We present numerical simulations of the localized surface plasmonic resonances associated to multiple particles in terms of their separation distance.

  1. Frequency stabilization of spin-torque-driven oscillations by coupling with a magnetic nonlinear resonator

    SciTech Connect (OSTI)

    Kudo, Kiwamu, E-mail: kiwamu.kudo@toshiba.co.jp; Suto, Hirofumi; Nagasawa, Tazumi; Mizushima, Koichi; Sato, Rie [Corporate Research and Development Center, Toshiba Corporation, Kawasaki 212–8582 (Japan)

    2014-10-28T23:59:59.000Z

    The fundamental function of any oscillator is to produce a waveform with a stable frequency. Here, we show a method of frequency stabilization for spin-torque nano-oscillators (STNOs) that relies on coupling with an adjacent nanomagnet through the magnetic dipole–dipole interaction. It is numerically demonstrated that highly stable oscillations occur as a result of mutual feedback between an STNO and a nanomagnet. The nanomagnet acts as a nonlinear resonator for the STNO. This method is based on the nonlinear behavior of the resonator and can be considered as a magnetic analogue of an optimization scheme in nanoelectromechanical systems. The oscillation frequency is most stabilized when the nanomagnet is driven at a special feedback point at which the feedback noise between the STNO and resonator is completely eliminated.

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

    E-Print Network [OSTI]

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

    2014-04-04T23:59:59.000Z

    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.

  3. A numerical approach : broadband technologies for efficient Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Mitsouras, Dimitrios, 1976-

    2004-01-01T23:59:59.000Z

    (cont.) independent receiver coils in parallel or time-axis compression, can be cast as complementary to broadband MRI encoding. This affords broadband non-Fourier MRI with time efficiencies over current fast MRI methods. ...

  4. Bayesian Experimental Design of Magnetic Resonance Imaging Sequences

    E-Print Network [OSTI]

    Seeger, Matthias

    Nickisch, Rolf Pohmann and Bernhard Sch¨olkopf Max Planck Institute for Biological Cybernetics research of the brain. Without applying any harmful ioniz- ing radiation, this technique stands out by its

  5. Direct Imaging of Asymmetric Magnetization Reversal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: PotentialFederal Financial InterventionsDirect Imaging of

  6. Direct Imaging of Asymmetric Magnetization Reversal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: PotentialFederal Financial InterventionsDirect Imaging

  7. Direct Imaging of Asymmetric Magnetization Reversal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign: PotentialFederal Financial InterventionsDirect ImagingDirect

  8. Resonant mechanism of axion photoproduction in a magnetized electron gas

    SciTech Connect (OSTI)

    Skobelev, V. V. [Moscow State Industrial University (Russian Federation)], E-mail: V.Skobelev@inbox.ru

    2007-11-15T23:59:59.000Z

    It was shown that the contribution of diagrams with electron-positron vacuum excitation in a strong magnetic field B >> B{sub 0} = m{sup 2}/e = 4.41 x 10{sup 13} G in the Compton mechanism of axion production {gamma}e {sup {yields}} ae at temperatures on the order of the axion mass exceeds the contribution of the 'simple' Compton diagram and the contribution of the neutrino production {gamma}e {sup {yields}} ({nu}{nu}-bar)e to the radiation power by many orders of magnitude. The conclusion is made on the probable axionic nature of the cold hidden mass of the Universe.

  9. Magnetism studies using resonant, coherent, x-ray scattering | Stanford

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your Home and It'll Love YouTokamak|MagneticSynchrotron

  10. Soft x-ray microscopy - a powerful analytical tool to image magnetism down to fundamental length and times scales

    E-Print Network [OSTI]

    Fischer, Peter

    2008-01-01T23:59:59.000Z

    analytical tool to image magnetism down to fundamentalmicroscopies Research of magnetism in low dimensions has notnanoscience [3]. Solid state magnetism is also a showcase in

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

    DOE Patents [OSTI]

    Fan, N.Q.; Clarke, J.

    1993-10-19T23:59:59.000Z

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

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

    DOE Patents [OSTI]

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

    1993-01-01T23:59:59.000Z

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

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP7-0973ManagedStrategic|Aljazeera story onImaging (MRI)

  14. Slew-rate dependence of tracer magnetization response in magnetic particle imaging

    SciTech Connect (OSTI)

    Shah, Saqlain A.; Krishnan, K. M., E-mail: kannanmk@uw.edu [Materials Science and Engineering, University of Washington, Seattle, Washington 98195 (United States); Ferguson, R. M. [LodeSpin Labs, P.O. Box 95632, Seattle, Washington 98145 (United States)

    2014-10-28T23:59:59.000Z

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25?kHz and 20?mT/?{sub 0} excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (H{sub o}) and frequency (?). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2?kHz, with field amplitudes ranging from 7 to 52?mT/?{sub 0}. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (?H{sub o}) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories.

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2003-11-25T23:59:59.000Z

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

  16. Method of using a nuclear magnetic resonance spectroscopy standard

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

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

  17. Method of using a nuclear magnetic resonance spectroscopy standard

    SciTech Connect (OSTI)

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

    1985-07-16T23:59:59.000Z

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

  18. Spin counting in electrically detected magnetic resonance via low-field defect state mixing

    SciTech Connect (OSTI)

    Cochrane, Corey J.; Lenahan, Patrick M. [The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2014-03-03T23:59:59.000Z

    The work herein describes a method that allows one to measure paramagnetic defect densities in semiconductor and insulator based devices with electrically detected magnetic resonance (EDMR). The method is based upon the mixing of defect states which results from the dipolar coupling of paramagnetic sites at low magnetic fields. We demonstrate the measurement method with spin dependent tunneling in thin film dielectrics; however, the method should be equally applicable to paramagnetic defect density measurements in semiconductors via the more commonly utilized EDMR technique called spin dependent recombination.

  19. Micro-coil detection of Nuclear Magnetic Resonance for nanofluidic samples

    E-Print Network [OSTI]

    Shibahara, Aya; Lusher, Chris; Saunders, John; Aßmann, Cornelia; Schurig, Thomas; Drung, Dietmar

    2013-01-01T23:59:59.000Z

    We have developed a novel dc SQUID system with a micro-coil input circuit to act as a local probe of quantum matter and nanosystems. The planar niobium micro-coil pickup loop is located remotely from the SQUID, coupled through a superconducting twisted pair, enabling the sample to be at microkelvin temperatures. A high degree of coupling between the coil and the region of interest of similar dimensions (up to ~ 100 microns) can be achieved. We report nuclear magnetic resonance (NMR) measurements to characterise the sensitivity of these coils to 3He in the gas phase at 4.2 K in a 30 mT magnetic field.

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

    SciTech Connect (OSTI)

    Wu, Xi.

    1990-09-21T23:59:59.000Z

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

  1. Optically Detected Magnetic Resonance and Thermal Activation Spectroscopy Study of Organic Semiconductors

    SciTech Connect (OSTI)

    Chang-Hwan Kim

    2003-12-12T23:59:59.000Z

    Organic electronic materials are a new class of emerging materials. Organic light emitting devices (OLEDs) are the most promising candidates for future flat panel display technologies. The photophysical characterization is the basic research step one must follow to understand this new class of materials and devices. The light emission properties are closely related to the transport properties of these materials. The objective of this dissertation is to probe the relation between transport and photophysical properties of organic semiconductors. The transport characteristics were evaluated by using thermally stimulated current and thermally stimulated luminescence techniques. The photoluminescence detected magnetic resonance and photoluminescence quantum yield studies provide valuable photophysical information on this class of materials. OLEDs are already in the market. However, detailed studies on the degradation mechanisms are still lacking. Since both optically detected magnetic resonance and thermal activation spectroscopy probe long-lived defect-related states in organic semiconductors, the combined study generates new insight on the OLED operation and degradation mechanisms.

  2. Circularly polarized microwaves for magnetic resonance study in the GHz range: application to nitrogen-vacancy in diamonds

    E-Print Network [OSTI]

    Mrozek, Mariusz; Rudnicki, Daniel S; Gawlik, Wojciech

    2015-01-01T23:59:59.000Z

    The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85% it is possible to address the specific spin states of a diamond sample using a low power microwave generator.

  3. Influence of Cobalt Nanoparticles' Incorporation on the Magnetic Properties of the Nickel Nanofibers: Cobalt-Doped Nickel Nanofibers Prepared by Electrospinning

    E-Print Network [OSTI]

    Kim, Bongsoo

    , magnetic refrigeration systems, and contrast enhancement in magnetic resonance imaging carriers for drugsInfluence of Cobalt Nanoparticles' Incorporation on the Magnetic Properties of the Nickel, 2009 Among the common ferromagnetic metals, cobalt has distinct magnetic properties, so incorporation

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

    E-Print Network [OSTI]

    Jaroniec, Christopher P

    2003-01-01T23:59:59.000Z

    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 ...

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

    E-Print Network [OSTI]

    Genty, Coralie

    2006-10-30T23:59:59.000Z

    patterns. This study integrates data from thin sections and core analyses with measurements of Nuclear Magnetic Resonance (NMR) T2 relaxation times. It exposes a novel approach to the use of NMR by applying geological and statistical analysis to define...

  6. Nuclear magnetic resonance-based study of ordered layering on the surface of alumina nanoparticles in water

    E-Print Network [OSTI]

    Gerardi, Craig

    Layering of water molecules on the surface of alumina nanoparticles in an alumina/water nanofluid is studied using nuclear magnetic resonance (NMR). The data suggest that a thin ordered layer ( ? 1.4?nm) of water molecules ...

  7. Ultra-fast Imaging of Two-Phase Flow in Structured Monolith Reactors; Techniques and Data Analysis

    E-Print Network [OSTI]

    Heras, Jonathan Jaime

    This thesis will address the use of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) techniques to probe the “monolith reactor”, which consists of a structured catalyst over which reactions may occur. This reactor has emerged...

  8. Evaluation of brain edema using magnetic resonance proton relaxation times

    SciTech Connect (OSTI)

    Fu, Y.; Tanaka, K.; Nishimura, S. (Baba Memorial Hospital, Osaka (Japan))

    1990-01-01T23:59:59.000Z

    Experimental and clinical studies on the evaluation of water content in cases of brain edema were performed in vivo, using MR proton relaxation times (longitudinal relaxation time, T1; transverse relaxation time, T2). Brain edema was produced in the white matter of cats by the direct infusion method. The correlations between proton relaxation times obtained from MR images and the water content of white matter were studied both in autoserum-infused cats and in saline-infused cats. The correlations between T1 as well as T2 and the water content in human vasogenic brain edema were also examined and compared with the data obtained from the serum group. T1 and T2 showed good correlations with the water content of white matter not only in the experimental animals but also in the clinical cases. The quality of the edema fluid did not influence relaxation time and T1 seemed to represent almost solely the water content of the tissue. T2, however, was affected by the nature of existence of water and was more sensitive than T1 in detecting extravasated edema fluid. It seems feasible therefore to evaluate the water content of brain edema on the basis of T1 values.

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

    E-Print Network [OSTI]

    O'Brien, Patrick William

    1966-01-01T23:59:59.000Z

    NUCLEAR MAGNETIC RESONANCE (N. M. R. ) STUDIES OF ALKYL FORMATES AND OF ALCOHOL-WATER AZEOTROPES A Thesis By PATRICK WILLIAM O' BRIEN Submitted to the Graduate College of the Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE January 1966 Major Subject: Chemistry NUCLEAR MAGNETIC RESONANCE (N. M. R. ) STUDIES OF ALKYL FORMATES AND OF ALCOHOL-WATER AZEOTROPES A Thesis By PATRICK WILLIAM O' BRIEN Approved as to style and content by...

  10. Satellite Magnetic Resonances of a Bound Pair of Half-Quantum Vortices in Rotating Superfluid He-3-a

    E-Print Network [OSTI]

    Hu, Chia-Ren; MAKI, K.

    1987-01-01T23:59:59.000Z

    PHYSICAL REVIE%' B VOLUME 36, NUMBER 13 1 NOVEMBER 1987 Satellite magnetic resonances of a bound pair of half-quantum vortices in rotating superfluid He- A Chia-Ren Hu Center for Theoretical Physics, Department of Physics, Texas A&M University..., College Station, Texas 77843-4242 Kazumi Maki Department of Physics, University of Southern California, Los Angeles, California 90089-0484 (Received 29 December 1986) The transverse magnetic resonance satellite frequency and intensity associated with a...

  11. PUBLISHED ONLINE: 6 APRIL 2009 | DOI: 10.1038/NPHYS1232 Control of a magnetic Feshbach resonance

    E-Print Network [OSTI]

    Loss, Daniel

    with ultracold gases. Magnetic Feshbach resonances1,2 are widely harnessed for this purpose, but future an optical Feshbach resonance. Using light to change the s-wave scattering length a in ultracold gases offers, Germany. *e-mail: stephan.duerr@mpq.mpg.de. Energy Internuclear distance Laser |g |a |e Figure 1 | Level

  12. Superconducting magnet performance for 28 GHz electron cyclotron resonance ion source developed at the Korea Basic Science Institute

    SciTech Connect (OSTI)

    Park, Jin Yong [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of) [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); Pusan National University, Busan (Korea, Republic of); Choi, Seyong; Lee, Byoung-Seob; Yoon, Jang-Hee; Ok, Jung-Woo; Shin, Chang Seouk; Won, Mi-Sook, E-mail: mswon@kbsi.re.kr [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)] [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); Kim, Byoung Chul [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)] [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Ahn, Jung Keun [Pusan National University, Busan (Korea, Republic of)] [Pusan National University, Busan (Korea, Republic of)

    2014-02-15T23:59:59.000Z

    A superconducting magnet for use in an electron cyclotron resonance ion source was developed at the Korea Basic Science Institute. The superconducting magnet is comprised of three solenoids and a hexapole magnet. According to the design value, the solenoid magnets can generate a mirror field, resulting in axial magnetic fields of 3.6 T at the injection area and 2.2 T at the extraction region. A radial field strength of 2.1 T can also be achieved by hexapole magnet on the plasma chamber wall. NbTi superconducting wire was used in the winding process following appropriate techniques for magnet structure. The final assembly of the each magnet involved it being vertically inserted into the cryostat to cool down the temperature using liquid helium. The performance of each solenoid and hexapole magnet was separately verified experimentally. The construction of the superconducting coil, the entire magnet assembly for performance testing and experimental results are reported herein.

  13. Effect of Island Overlap on ELM Suppression by Resonant Magnetic Perturbations in DIII-D

    SciTech Connect (OSTI)

    Fenstermacher, M E; Evans, T E; Osborne, T H; Schaffer, M J; Aldan, M P; deGrassie, J S; Gohil, P; Joseph, I; Moyer, R A; Snyder, P B; Groebner, R J; Jakubowski, M; Leonard, A W; Schmitz, O

    2007-11-08T23:59:59.000Z

    Recent DIII-D [J.L. Luxon, et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap of magnetic islands induced in the edge plasma by perturbation coils and complete suppression of Type-I edge localized modes (ELMs) in plasmas with ITER-like electron pedestal collisionality {nu}*{sub e} {approx} 0.1, flux surface shape and low edge safety factor (q{sub 95} {approx} 3.6). With fixed n = 3 resonant magnetic perturbation (RMP) strength, ELM suppression is obtained only in a finite window in the edge safety factor (q{sub 95}) consistent with maximizing the resonant component of the applied helical field. ELM suppression is obtained over an increasing range of q{sub 95} by either increasing the n = 3 RMP strength, or by adding n = 1 perturbations to 'fill in' gaps between islands across the edge plasma. The suppression of Type-I ELMs correlates with a minimum width of the edge region having magnetic islands with Chirikov parameter >1.0, based on vacuum calculations of RMP mode components excluding the plasma response or rotational shielding. The fraction of vacuum magnetic field lines that are lost from the plasma, with connection length to the divertor targets comparable to an electron-ion collisional mean free path, increases throughout the island overlap region in the ELM suppressed case compared with the ELMing case.

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

    SciTech Connect (OSTI)

    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

    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.

  15. Self-consistent magnetic properties of magnetite tracers optimized for magnetic particle imaging measured by ac susceptometry,

    E-Print Network [OSTI]

    Krishnan, Kannan M.

    Self-consistent magnetic properties of magnetite tracers optimized for magnetic particle imaging measured by ac susceptometry, magnetorelaxometry and magnetic particle spectroscopy Frank Ludwig a , Hilke. Krishnan b,n a Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig

  16. Effect of ellipticity on Hanle electromagnetically induced absorption and transparency resonances with longitudinal and transverse magnetic fields

    SciTech Connect (OSTI)

    Ram, Nibedita; Pattabiraman, M.; Vijayan, C. [Department of Physics, Indian Institute of Technology, Madras, Chennai 600036 (India)

    2010-09-15T23:59:59.000Z

    The effect of incident light field ellipticity on the electromagnetically induced absorption (EIA) and electromagnetically induced transparency (EIT) resonances has been studied experimentally and computationally in Hanle configuration with longitudinal and transverse magnetic fields. We identify the Zeeman coherences that influence the resonance profile and study the role of coherence-transfer from excited to ground state via spontaneous emission as a function of ellipticity for the F{sub g}=2{yields}F{sub e}=3 transition of {sup 87}Rb. The EIT resonance observed with the light field locked on the F{sub g}=1{yields}F{sub e}=2 transition of {sup 87}Rb is an influence of the nearby F{sub g}=1{yields}F{sub e}=0 closed and F{sub g}=1{yields}F{sub e}=1 open transitions. With increase in ellipticity the observed EIA and EIT resonances diminish in amplitude for a longitudinal magnetic field and are enhanced for a transverse magnetic field. We computationally account for these observations and discuss the factors that influence the EIA and EIT resonance amplitudes as a function of ellipticity and show that for a transverse field scan the ellipticity dependence of the EIA resonance amplitude can be accounted for without invoking the Doppler effect unlike for a longitudinal field scan. We also show that the maximum in the EIA resonance amplitude obtained for nonzero ellipticities with a longitudinal magnetic field depends on the closedness of the atomic system.

  17. MRI Magnetic Signature Imaging, Tracking and Navigation for Targeted Micro/Nano-capsule Therapeutics

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - back for the microdevice and a propulsion sequence to enable interleaved magnetic propulsionMRI Magnetic Signature Imaging, Tracking and Navigation for Targeted Micro J. Nelson, Antoine Ferreira and Sergej Fatikow Abstract-- The propulsion of nano

  18. Measurement of Untruncated Nuclear Spin Interactions via Zero- to Ultra-Low-Field Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    John W. Blanchard; Tobias F. Sjolander; Jonathan P. King; Micah P. Ledbetter; Emma H. Levine; Vikram S. Bajaj; Dmitry Budker; Alexander Pines

    2015-07-09T23:59:59.000Z

    Zero- to ultra-low-field nuclear magnetic resonance (ZULF NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the coupling averages to zero under isotropic molecular tumbling. Under partial alignment, this information is retained in the form of so-called residual dipolar couplings. We report zero- to ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole coupling Hamiltonian that are invisible in conventional high-field NMR. This technique expands the capabilities of zero- to ultra-low-field NMR and may have applications in precision measurement of subtle physical interactions, chemical analysis, and characterization of local mesoscale structure in materials.

  19. Residual Dipolar Couplings in Zero-to-Ultra-Low-Field Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Blanchard, John W; King, Jonathan P; Ledbetter, Micah P; Levine, Emma H; Bajaj, Vikram S; Budker, Dmitry; Pines, Alexander

    2015-01-01T23:59:59.000Z

    Zero-to-ultra-low-field nuclear magnetic resonance (ZULF-NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the interaction averages to zero under isotropic molecular tumbling. Under partial orientational ordering, this information is retained in the form of so-called residual dipolar couplings. We report zero-to-ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole c...

  20. Development of advanced magnetic resonance sensor for industrial applications. Final report

    SciTech Connect (OSTI)

    De Los Santos, A.

    1997-06-01T23:59:59.000Z

    Southwest Research Institute (SwRI) and various subcontractors, in a cooperative agreement with the DOE, have developed and tested an advanced magnetic resonance (MR) sensor for several industrial applications and made various market surveys. The original goal of the program was to develop an advanced moisture sensor to allow more precise and rapid control of drying processes so that energy and/or product would not be wasted. Over the course of the program, it was shown that energy savings were achievable but in many processes the return in investment did not justify the cost of a magnetic resonance sensor. However, in many processes, particularly chemical, petrochemical, paper and others, the return in investment can be very high as to easily justify the cost of a magnetic resonance sensor. In these industries, substantial improvements in product yield, quality, and efficiency in production can cause substantial energy savings and reductions in product wastage with substantial environmental effects. The initial applications selected for this program included measurement of corn gluten at three different points and corn germ at one point in an American Maize corn processing plant. During the initial phases (I and II) of this program, SwRI developed a prototype advanced moisture sensor utilizing NMR technology capable of accurately and reliably measuring moisture in industrial applications and tested the sensor in the laboratory under conditions simulating on-line products in the corn wet milling industry. The objective of Phase III was to test the prototype sensor in the plant environment to determine robustness, reliability and long term stability. Meeting these objectives would permit extended field testing to improve the statistical database used to calibrate the sensor and subject the sensor to true variations in operating conditions encountered in the process rather than those which could only be simulated in the laboratory.

  1. Coaxial probe for nuclear magnetic resonance diffusion and relaxation correlation experiments

    SciTech Connect (OSTI)

    Tang, Yiqiao; Hürlimann, Martin; Mandal, Soumyajit; Paulsen, Jeffrey; Song, Yi-Qiao, E-mail: ysong@slb.com [Schlumberger-Doll Research, 1 Hampshire Street, Cambridge, Massachusetts 02139 (United States)

    2014-02-21T23:59:59.000Z

    A coaxial nuclear magnetic resonance (NMR) probe is built to measure diffusion and relaxation properties of liquid samples. In particular, we demonstrate the acquisition of two-dimensional (2D) distribution functions (T{sub 1}-T{sub 2} and diffusion–T{sub 2}), essential for fluids characterization. The compact design holds promise for miniaturization, thus enabling the measurement of molecular diffusion that is inaccessible to conventional micro-NMR setups. Potential applications range from crude oil characterization to biomolecular screening and detections.

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

    SciTech Connect (OSTI)

    Casadei, Cecilia

    2012-05-09T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    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

    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.

  4. THERMAL IMAGING OF ACTIVE MAGNETIC REGERNERATOR MCE MATERIALS DURING OPERATION

    SciTech Connect (OSTI)

    Shassere, Benjamin [ORNL] [ORNL; West, David L [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Evans III, Boyd Mccutchen [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    An active magnetic regenerator (AMR) prototype was constructed that incorporates a Gd sheet into the regenerator wall to enable visualization of the system s thermal transients. In this experiment, the thermal conditions inside the AMR are observed under a variety of operating conditions. An infrared (IR) camera is employed to visualize the thermal transients within the AMR. The IR camera is used to visually and quantitatively evaluate the temperature difference and thus giving means to calculate the performance of the system under the various operating conditions. Thermal imaging results are presented for two differing experimental test runs. Real time imaging of the thermal state of the AMR has been conducted while operating the system over a range of conditions. A 1 Tesla twin-coil electromagnet (situated on a C frame base) is used for this experiment such that all components are stationary during testing. A modular, linear reciprocating system has been realized in which the effects of regenerator porosity and utilization factor can be investigated. To evaluate the performance variation in porosity and utilization factor the AMR housing was constructed such that the plate spacing of the Gd sheets may be varied. Each Gd sheet has dimensions of 38 mm wide and 66 mm long with a thickness of 1 mm and the regenerator can hold a maximum of 29 plates with a spacing of 0.25 mm. Quantitative and thermal imaging results are presented for several regenerator configurations.

  5. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    SciTech Connect (OSTI)

    Urban, Jeffry Todd

    2004-12-21T23:59:59.000Z

    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.

  6. In Vivo Imaging with a Cell-Permeable Porphyrin-Based MRI Contrast

    E-Print Network [OSTI]

    Lee, Taekwan

    Magnetic resonance imaging (MRI) with molecular probes offers the potential to monitor physiological parameters with comparatively high spatial and temporal resolution in living subjects. For detection of intracellular ...

  7. In vivo imaging with a cell-permeable porphyrin-based MRI contrast agent

    E-Print Network [OSTI]

    Lee, Taekwan

    Magnetic resonance imaging (MRI) with molecular probes offers the potential to monitor physiological parameters with comparatively high spatial and temporal resolution in living subjects. For detection of intracellular ...

  8. Solid-State Nuclear Magnetic Resonance Evidence for an Extended Strand Conformation of the Membrane-Bound HIV-1 Fusion Peptide

    E-Print Network [OSTI]

    Weliky, David

    Solid-State Nuclear Magnetic Resonance Evidence for an Extended Strand Conformation of the Membrane-Bound HIV-1 Fusion Peptide Jun Yang, Charles M. Gabrys, and David P. Weliky* Department of ChemistryVed May 4, 2001 ABSTRACT: Solid-state nuclear magnetic resonance (NMR) spectroscopy was applied

  9. Acute Cardiac Impairment Associated With Concurrent Chemoradiotherapy for Esophageal Cancer: Magnetic Resonance Evaluation

    SciTech Connect (OSTI)

    Hatakenaka, Masamitsu, E-mail: mhatakenaka@sapmed.ac.jp [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Department of Diagnostic Radiology, School of Medicine, Sapporo Medical University, Sapporo (Japan); Yonezawa, Masato; Nonoshita, Takeshi; Nakamura, Katsumasa [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Yabuuchi, Hidetake [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Shioyama, Yoshiyuki [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Nagao, Michinobu [Department of Molecular Imaging and Diagnostic Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Matsuo, Yoshio; Kamitani, Takeshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Higo, Taiki [Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Nishikawa, Kei [Radiology Center, Kyushu University Hospital, Kyushu University, Fukuoka (Japan); Setoguchi, Taro [Department of Radiology, National Hospital Organization, Kokura Medical Center, Fukuoka (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2012-05-01T23:59:59.000Z

    Purpose: To evaluate acute cardiac effects of concurrent chemoradiotherapy (CCRT) for esophageal cancer. Methods and Materials: This prospective study was approved by the institutional review board, and written informed consent was obtained from all participants. The left ventricular function (LVF) of 31 patients with esophageal cancer who received cisplatin and 5-fluorouracil-based CCRT was evaluated using cardiac cine magnetic resonance imaging. The patients were classified into two groups according to mean LV dose. The parameters related to LVF were compared between before and during (40 Gy) or between before and after CCRT using a Wilcoxon matched-pairs single rank test, and parameter ratios (during/before CCRT, after/before CCRT) were also compared between the groups with a t test. Data were expressed as mean {+-} SE. Results: In the low LV-dose group (n = 10; mean LV dose <0.6 Gy), LV ejection fraction decreased significantly (before vs. during vs. after CCRT; 62.7% {+-} 2.98% vs. 59.8% {+-} 2.56% vs. 60.6% {+-} 3.89%; p < 0.05). In the high LV-dose group (n = 21; mean LV dose of 3.6-41.2 Gy), LV end-diastolic volume index (before vs. after CCRT; 69.1 {+-} 2.93 vs. 57.0 {+-} 3.23 mL/m{sup 2}), LV stroke volume index (38.6 {+-} 1.56 vs. 29.9 {+-} 1.60 mL/m{sup 2}), and LV ejection fraction (56.9% {+-} 1.79% vs. 52.8% {+-} 1.15%) decreased significantly (p < 0.05) after CCRT. Heart rate increased significantly (before vs. during vs. after CCRT; 66.8 {+-} 3.05 vs. 72.4 {+-} 4.04 vs. 85.4 {+-} 3.75 beats per minute, p < 0.01). Left ventricle wall motion decreased significantly (p < 0.05) in segments 8 (before vs. during vs. after CCRT; 6.64 {+-} 0.54 vs. 4.78 {+-} 0.43 vs. 4.79 {+-} 0.50 mm), 9 (6.88 {+-} 0.45 vs. 5.04 {+-} 0.38 vs. 5.27 {+-} 0.47 mm), and 10 (9.22 {+-} 0.48 vs. 8.08 {+-} 0.34 vs. 8.19 {+-} 0.56 mm). The parameter ratios of LV end-diastolic volume index, stroke volume index, wall motion in segment 9, and heart rate showed significant difference (p < 0.05) after CCRT between the groups. Conclusions: Concurrent chemoradiotherapy for esophageal cancer impairs LVF from an early treatment stage. This impairment is prominent in patients with high LV dose.

  10. Controlled-Resonant Surface Tapping-Mode Scanning Probe Electrospray Ionization Mass Spectrometry Imaging

    SciTech Connect (OSTI)

    Lorenz, Matthias [ORNL] [ORNL; Ovchinnikova, Olga S [ORNL] [ORNL; Kertesz, Vilmos [ORNL] [ORNL; Van Berkel, Gary J [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    This paper reports on the advancement of a controlled-resonance surface tapping-mode single capillary liquid junction extraction/ESI emitter for mass spectrometry imaging. The basic instrumental setup and the general operation of the system were discussed and optimized performance metrics were presented. The ability to spot sample, lane scan and chemically image in an automated and controlled fashion were demonstrated. Rapid, automated spot sampling was demonstrated for a variety of compound types including the cationic dye basic blue 7, the oligosaccharide cellopentaose, and the protein equine heart cytochrome c. The system was used for lane scanning and chemical imaging of the cationic dye crystal violet in inked lines on glass and for lipid distributions in mouse brain thin tissue sections. Imaging of the lipids in mouse brain tissue under optimized conditions provided a spatial resolution of approximately 35 m based on the ability to distinguish between features observed both in the optical and mass spectral chemical images. The sampling spatial resolution of this system was comparable to the best resolution that has been reported for other types of atmospheric pressure liquid extraction-based surface sampling/ionization techniques used for mass spectrometry imaging.

  11. Numerical procedure for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors

    E-Print Network [OSTI]

    Wang, Q.; Hu, Chia-Ren.

    2004-01-01T23:59:59.000Z

    Numerical procedure is developed for analyzing impurity-induced resonant-state STM images observed in high-T-c superconductors, and is applied to three sets of higher resolution data provided to us by J. C. Seamus Davis and E. W. Hudson. Each image...

  12. Upgrade of the extraction system of permanent magnet electron cyclotron resonance ion source

    SciTech Connect (OSTI)

    Zhang, M.; Peng, S. X.; Song, Z. Z.; Yuan, Z. X.; Zhou, Q. F.; Lu, P. N.; Xu, R.; Zhao, J.; Yu, J. X.; Chen, J. E.; Guo, Z. Y.; Lu, Y. R. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Ren, H. T. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)

    2010-02-15T23:59:59.000Z

    A set of new ion extraction electrodes have been designed for the permanent magnetic electron cyclotron resonance ion source at Peking University to improve beam quality and transmission. PBGUNS has been used to optimize the extraction electrodes and simulate the beam behavior at the extraction region. The experiments showed that with the new system, the beam half divergence angle can be less than 40 mrad and the normalized rms emittance is about 0.13{pi} mm mrad when the extracted current is 100 mA at 50 keV in pulse mode. The voltage of the suppression electrode has great effect on beam divergence. The effect of the microwave power and gas flow is also studied.

  13. Exhibition of the periodicity of Quantum Fourier Transformation in Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Xinhua Peng; Xiwen Zhu; Ximing Fang; Mang Feng; Xiaodong Yang; Maili Liu; Kelin Gao

    2002-02-01T23:59:59.000Z

    The remarkable capability of quantum Fourier transformation (QFT) to extract the periodicity of a given periodic function has been exhibited by using nuclear magnetic resonance (NMR) techniques. Two separate sets of experiments were performed. In a full QFT, the periodicity were validated with state tomography and fidelity measurements. For a simplified QFT, the three-qubit pseudo-pure state was created by introducting an additional observer spin, and the spectra recorded on the observer spin showed intuitively the power of QFT\\ to find the periodicity. Experimentally realizing the QFT provides a critical step to implement the renowned Shor's quantum factoring algorithm and many other algorithms. Moveover, it can be applied to the study of quantum chaos and other quantum information processing.

  14. Exhibition of the periodicity of Quantum Fourier Transformation in Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Peng, X; Fang, X; Feng, M; Yang, X; Liu, M; Gao, K; Peng, Xinhua; Zhu, Xiwen; Fang, Ximing; Feng, Mang; Yang, Xiaodong; Liu, Maili; Gao, Kelin

    2002-01-01T23:59:59.000Z

    The remarkable capability of quantum Fourier transformation (QFT) to extract the periodicity of a given periodic function has been exhibited by using nuclear magnetic resonance (NMR) techniques. Two separate sets of experiments were performed. In a full QFT, the periodicity were validated with state tomography and fidelity measurements. For a simplified QFT, the three-qubit pseudo-pure state was created by introducting an additional observer spin, and the spectra recorded on the observer spin showed intuitively the power of QFT\\ to find the periodicity. Experimentally realizing the QFT provides a critical step to implement the renowned Shor's quantum factoring algorithm and many other algorithms. Moveover, it can be applied to the study of quantum chaos and other quantum information processing.

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

    SciTech Connect (OSTI)

    Mamone, Salvatore, E-mail: s.mamone@soton.ac.uk; Concistrè, 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

    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.

  16. Fluorocarbon-23 measure of cat cerebral blood flow by nuclear magnetic resonance

    SciTech Connect (OSTI)

    Ewing, J.R.; Branch, C.A.; Fagan, S.C.; Helpern, J.A.; Simkins, R.T.; Butt, S.M.; Welch, K.M. (Henry Ford Hospital, Detroit, MI (USA))

    1990-01-01T23:59:59.000Z

    We employed fluorocarbon-23 (trifluoromethane) as a nuclear magnetic resonance gaseous indicator of cerebral blood flow in seven cats. Pulsed inhalation of this indicator and switching between two coils allowed the acquisition of both an arterial input and a cerebral response function, making possible multicompartmental curve fits to cerebral uptake and clearance data. The brain:blood partition coefficient for trifluoromethane was 0.9 for both gray and white matter. Fast-compartment blood flows were normal and showed appropriate CO{sub 2} reactivity. Slow-compartment blood flows did not demonstrate CO{sub 2} reactivity, probably because cranial as well as white-matter blood flows were lumped together in the slow compartment. Although cerebral blood flow was stable during administration of 60% trifluoromethane, the compound did prove to be a mild cardiac sensitizer to epinephrine in five cats.

  17. Simulation of magnetic island dynamics under resonant magnetic perturbation with the TEAR code and validation of the results on T-10 tokamak data

    SciTech Connect (OSTI)

    Ivanov, N. V.; Kakurin, A. M. [National Research Centre “Kurchatov Institute,” 123182 Moscow (Russian Federation)

    2014-10-15T23:59:59.000Z

    Simulation of the magnetic island evolution under Resonant Magnetic Perturbation (RMP) in rotating T-10 tokamak plasma is presented with intent of TEAR code experimental validation. In the T-10 experiment chosen for simulation, the RMP consists of a stationary error field, a magnetic field of the eddy current in the resistive vacuum vessel and magnetic field of the externally applied controlled halo current in the plasma scrape-off layer (SOL). The halo-current loop consists of a rail limiter, plasma SOL, vacuum vessel, and external part of the circuit. Effects of plasma resistivity, viscosity, and RMP are taken into account in the TEAR code based on the two-fluid MHD approximation. Radial distribution of the magnetic flux perturbation is calculated with account of the externally applied RMP. A good agreement is obtained between the simulation results and experimental data for the cases of preprogrammed and feedback-controlled halo current in the plasma SOL.

  18. Clustering Dynamics in Water/Methanol Mixtures: A Nuclear Magnetic Resonance Study at 205 K < T < 295 K

    E-Print Network [OSTI]

    Stanley, H. Eugene

    Clustering Dynamics in Water/Methanol Mixtures: A Nuclear Magnetic Resonance Study at 205 K functional groups in water/methanol mixtures at different methanol molar fractions (XMeOH ) 0, 0.04, 0.1, 0 in the mixtures, at all the methanol molar fractions, are faster than those of pure water and methanol because

  19. A biofilm microreactor system for simultaneous electrochemical and nuclear magnetic resonance techniques

    SciTech Connect (OSTI)

    Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.; Mehta, Hardeep S.; Ewing, R. James; Ewing, Thomas; Mueller, Karl T.; Beyenal, Haluk

    2014-01-30T23:59:59.000Z

    In order to fully understand electrochemically active biofilms and the limitations to their scale-up in industrial biofilm reactors, a complete picture of the microenvironments inside the biofilm is needed. Nuclear magnetic resonance (NMR) techniques are ideally suited for the study of biofilms and for probing their microenvironments because these techniques allow for non-invasive interrogation and in situ monitoring with high resolution. By combining NMR with simultaneous electrochemical techniques, it is possible to sustain and study live electrochemically active biofilms. Here, we introduce a novel biofilm microreactor system that allows for simultaneous electrochemical and NMR techniques (EC-NMR) at the microscale. Microreactors were designed with custom radiofrequency resonator coils, which allowed for NMR measurements of biofilms growing on polarized gold electrodes. For an example application of this system, we grew Geobacter sulfurreducens biofilms. NMR was used to investigate growth media flow velocities, which were compared to simulated laminar flow, and electron donor concentrations inside the biofilms. We use Monte Carlo error analysis to estimate standard deviations of the electron donor concentration measurements within the biofilm. The EC-NMR biofilm microreactor system can ultimately be used to correlate extracellular electron transfer rates with metabolic reactions and explore extracellular electron transfer mechanisms.

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

    SciTech Connect (OSTI)

    Anderson, D.L.

    1980-03-01T23:59:59.000Z

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

  1. Development of integrated imaging techniques for investigating biomarkers in glioblastoma

    E-Print Network [OSTI]

    Kim, Heisoog

    2011-01-01T23:59:59.000Z

    Cancer is a diverse disease with many manifestations. Various imaging modalities including magnetic resonance imaging (MRI) and positron emission tomography (PET) have been used to study human cancer. In this study, we ...

  2. Simultaneous PET/fMRI for imaging neuroreceptor dynamics

    E-Print Network [OSTI]

    Sander, Christin Y. (Christin Yen-Ming)

    2014-01-01T23:59:59.000Z

    Whole-brain neuroimaging is a key technique for studying brain function and connectivity. Recent advances in combining two imaging modalities - magnetic resonance imaging (MRI) and positron emission tomography (PET) - into ...

  3. Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a PenningMalmberg trap used for antihydrogen trapping

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a Penning­Malmberg trap of the antiprotons around the trap axis to pass through zero. In the presence of a transverse magnetic multipole into the trap wall when the trap also employs a magnetic multipole. The multipole's function is to confine H

  4. The Magnetic Resonance Force Microscope P. Chris Hammel and Denis V. Pelekhov

    E-Print Network [OSTI]

    Hammel, P. Chris

    , Zhang, Moore and Roukes, 1995; Bruland et al., 1998) and ferromagnetic resonance (FMR) experiments

  5. Optical imaging correlates with magnetic resonance imaging breast density and reveals composition changes during neoadjuvant chemotherapy

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    index that corresponds to increased vascu- lar density [32]. DOSI scanning is performed without compression

  6. Efficient MR image reconstruction for compressed MR imaging Junzhou Huang

    E-Print Network [OSTI]

    Huang, Junzhou

    to be very powerful for the MR image reconstruction. First, we decompose the original problem into L1 and TV.V. All rights reserved. 1. Introduction Magnetic Resonance (MR) imaging has been widely used in medical. Computation became the bottleneck that prevented this good model (1) from being used in practical MR image

  7. Efficient MR Image Reconstruction for Compressed MR Imaging

    E-Print Network [OSTI]

    Huang, Junzhou

    demonstrate the superior performance of the proposed algorithm for com- pressed MR image reconstruction. 1 [1][2] show that it is possi- ble to accurately reconstruct the Magnetic Resonance (MR) images from for real MR images. Computation became the bottleneck that prevented this good model (1) from being used

  8. Detection of electron energy distribution function anisotropy in a magnetized electron cyclotron resonance plasma by using a directional Langmuir probe

    SciTech Connect (OSTI)

    Shikama, T., E-mail: shikama@me.kyoto-u.ac.jp; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan); Kitaoka, H. [Faculty of Engineering, Undergraduate School of Engineering Science, Kyoto University, Kyoto 615-8540 (Japan)

    2014-07-15T23:59:59.000Z

    Anisotropy in the electron energy distribution function (EEDF) in an electron cyclotron resonance plasma with magnetized electrons and weakly magnetized ions is experimentally investigated using a directional Langmuir probe. Under an assumption of independent EEDFs in the directions parallel and perpendicular to the magnetic field, the directional variation of the EEDF is evaluated. In the measured EEDFs, a significantly large population density of electrons with energies larger than 30?eV is found in one of the cross-field directions depending on the magnetic field direction. With the aid of an electron trajectory calculation, it is suggested that the observed anisotropic electrons originate from the EEDF anisotropy and the cross-field electron drift.

  9. Plasma studies of the permanent magnet electron cyclotron resonance ion source at Peking University

    SciTech Connect (OSTI)

    Ren, H. T.; Peng, S. X., E-mail: sxpeng@pku.edu.cn; Xu, Y.; Zhao, J.; Lu, P. N.; Chen, J.; Zhang, A. L.; Zhang, T.; Guo, Z. Y.; Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China)

    2014-02-15T23:59:59.000Z

    At Peking University (PKU) we have developed several 2.45 GHz Permanent Magnet Electron Cyclotron Resonance ion sources for PKUNIFTY, SFRFQ, Coupled RFQ and SFRFQ, and Dielectric-Wall Accelerator (DWA) projects (respectively, 50 mA of D{sup +}, 10 mA of O{sup +}, 10 mA of He{sup +}, and 50 mA of H{sup +}). In order to improve performance of these ion sources, it is necessary to better understand the principal factors that influence the plasma density and the atomic ion fraction. Theoretical analysis about microwave transmission and cut-off inside the discharge chamber were carried out to study the influence of the discharge chamber diameters. As a consequence, experimental studies on plasma density and ion fraction with different discharge chamber sizes have been carried out. Due to the difficulties in measuring plasma density inside the discharge chamber, the output beam current was measured to reflect the plasma density. Experimental results show that the plasma density increases to the maximum and then decreases significantly as the diameter changed from 64 mm to 30 mm, and the atomic ion fraction has the same tendency. The maximum beam intensity was obtained with the diameter of 35 mm, but the maximum atomic ion fraction with a diameter of 40 mm. The experimental results are basically accordant with the theoretical calculation. Details are presented in this paper.

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

    SciTech Connect (OSTI)

    Kong, Zueqian

    2010-03-15T23:59:59.000Z

    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.

  11. A nuclear magnetic resonance study of hydrogen in battery and chemically prepared material

    SciTech Connect (OSTI)

    Hill, R.J.; Jessel, A.M.

    1987-06-01T23:59:59.000Z

    Solid-state magic-angle-spinning nuclear magnetic resonance studies have been undertaken on positive plate material from lead-acid batteries and on samples of both pure ..cap alpha..-PbO/sub 2/ and pure ..beta..-PbO/sub 2/ prepared by nonelectrochemical methods. Battery positive plate samples contain protons in two different surface and near surface configurations. One of these proton species is associated with mobile, isolated, adsorbed hydroxyl groups, and/or water molecules that can be removed by outgassing. The other proton species is not removed by outgassing; it probably corresponds to water molecules and/of closely spaced hydroxyl groups trapped on internal crystal surfaces. The proton species present in fresh (uncycled) positive plate material are not significantly different in either configuration or abundance from those in extensively cycled samples. Thus, it is unlikely that decline in battery capacity with cycling service is associated with a change in the hydrogen content of PbO/sub 2/.

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

    SciTech Connect (OSTI)

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

    1998-04-01T23:59:59.000Z

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

  13. Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for Vanadium Redox Flow Battery

    SciTech Connect (OSTI)

    Vijayakumar, M.; Burton, Sarah D.; Huang, Cheng; Li, Liyu; Yang, Zhenguo; Graff, Gordon L.; Liu, Jun; Hu, Jian Z.; Skyllas-Kazacos, Maria

    2010-11-15T23:59:59.000Z

    The vanadium (IV) electrolyte solutions with various vanadium concentrations are studied by variable temperature 1H and 17O Nuclear Magnetic Resonance (NMR) spectroscopy. The structure and kinetics of vanadium (IV) species in the electrolyte solutions are explored with respect to vanadium concentration and temperature. It was found that the vanadium (IV) species exist as hydrated vanadyl ion, i.e. [VO(H2O)5]2+ forming an octahedral coordination with vanadyl oxygen in the axial position and the remaining positions occupied by water molecules. This hydrated vanadyl ion structure is stable in vanadium concentrations up to 3M and in the temperature range of 240 to 340 K. The sulfate anions in the electrolyte solutions are found to be weekly bound to this hydrated vanadyl ion and occupies its second coordination sphere. The possible effects of these sulfate anions in proton and water exchange between vanadyl ion and solvent molecules are discussed based on 1H and 17O NMR results.

  14. Isotopic imaging via nuclear resonance fluorescence with laser-based Thomson radiation

    DOE Patents [OSTI]

    Barty, Christopher P. J. (Hayward, CA); Hartemann, Frederic V. (San Ramon, CA); McNabb, Dennis P. (Alameda, CA); Pruet, Jason A. (Brentwood, CA)

    2009-07-21T23:59:59.000Z

    The present invention utilizes novel laser-based, high-brightness, high-spatial-resolution, pencil-beam sources of spectrally pure hard x-ray and gamma-ray radiation to induce resonant scattering in specific nuclei, i.e., nuclear resonance fluorescence. By monitoring such fluorescence as a function of beam position, it is possible to image in either two dimensions or three dimensions, the position and concentration of individual isotopes in a specific material configuration. Such methods of the present invention material identification, spatial resolution of material location and ability to locate and identify materials shielded by other materials, such as, for example, behind a lead wall. The foundation of the present invention is the generation of quasimonochromatic high-energy x-ray (100's of keV) and gamma-ray (greater than about 1 MeV) radiation via the collision of intense laser pulses from relativistic electrons. Such a process as utilized herein, i.e., Thomson scattering or inverse-Compton scattering, produces beams having diameters from about 1 micron to about 100 microns of high-energy photons with a bandwidth of .DELTA.E/E of approximately 10E.sup.-3.

  15. Magnetic Resonance Angiography of the Peripheral Vessels in Patients with Peripheral Arterial Occlusive Disease: When Is an Additional Conventional Angiography Required?

    SciTech Connect (OSTI)

    Janka, R., E-mail: rolf.janka@idr.imed.uni-erlangen.de; Wenkel, E. [Friedrich-Alexander-University, Institute of Radiology (Germany); Fellner, C. [Institute of Radiology, Friedrich-Alexander-University Erlangen-Nuernberg (Germany); Lang, W. [Friedrich-Alexander-University Erlangen-Nuernberg, Vascular Surgery, Department of Surgery (Germany); Bautz, W.; Uder, M. [Friedrich-Alexander-University, Institute of Radiology (Germany)

    2006-04-15T23:59:59.000Z

    The purpose of this work was to find out how often the clinician asks for a conventional angiography (CA) in patients with peripheral arterial occlusive disease (PAOD) after a magnetic resonance angiography (MRA) has been performed and how often the CA reveals additional information for therapy planning. Quality criteria for the MRA were defined and tested to see whether they can predict the need for an additional CA. In this prospective study, 81 patients suffering from PAOD (Fontaine classification IIa, n = 13; IIb, n = 33; III, n = 10; IV, n = 25) were examined with a 1.5-T MR-scanner with dedicated coils using a step-by-step technique. The vascular surgeon decided whether he could plan the therapy on the basis of the MRA or if he needed an additional CA. The MRA was assessed in terms of the image quality of the MRA and regarding therapeutic management of the patient in a two-grade scale: sufficient and insufficient. In 27/81 (33%) patients, the clinician asked for a CA, which revealed new information in only 11 patients. The relative number of MRAs with insufficient image quality was significantly higher (p < 0.01) in the group with additional information on CA (8/11) compared to the group without additional information (0/16). The assessment of an MRA based on image quality and regarding therapeutic management of the patient might reduce the number of CAs for therapy planning in patients with PAOD.

  16. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

    E-Print Network [OSTI]

    Ferracin, P.

    2011-01-01T23:59:59.000Z

    the design of a N b S n superconducting magnet system for aNbjSn superconducting magnets for electron cyclotron5 C H 1 1 2 3 1 . Nb Sn superconducting magnets for electron

  17. Knowledge discovery using data mined from Nuclear Magnetic

    E-Print Network [OSTI]

    Narasayya, Vivek

    Knowledge discovery using data mined from Nuclear Magnetic Resonance spectral images William J cyberinfrastructure · Method ­ Solid State ab initio calculations ­ Nuclear Magnetic Resonance (NMR) ­ Support Vector refined (and/or relaxed) structure, perform Self-Consistent Field calculation for electronic structure

  18. Femtosecond Single-Shot Imaging of Nanoscale Ferromagnetic Order in Co/Pd Multilayers using Resonant X-ray Holography

    SciTech Connect (OSTI)

    Wang, Tianhan; Zhu, Diling; Benny Wu,; Graves, Catherine; Schaffert, Stefan; Rander, Torbjorn; Muller, leonard; Vodungbo, Boris; Baumier, Cedric; Bernstein, David P.; Brauer, Bjorn; Cros, Vincent; Jong, Sanne de; Delaunay, Renaud; Fognini, Andreas; Kukreja, Roopali; Lee, Sooheyong; Lopez-Flores, Victor; Mohanty, Jyoti; Pfau, Bastian; Popescu, 5 Horia

    2012-05-15T23:59:59.000Z

    We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm{sup 2}. Employing resonant spatially-muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm{sup 2}. Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.

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

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

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

  20. Determining diffusion coefficients of ionic liquids by means of field cycling nuclear magnetic resonance relaxometry

    SciTech Connect (OSTI)

    Kruk, D. [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, S?oneczna 54, PL-10710 Olsztyn (Poland); Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Meier, R.; Rössler, E. A. [Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Rachocki, A. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Pozna? (Poland); Korpa?a, A. [Department of Biophysics, Jagiellonian University Medical College, ?azarza 16, 31-530 Kraków, Poland and Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków (Poland); Singh, R. K. [Ionic Liquid and Solid State Ionics Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221 005 (India)

    2014-06-28T23:59:59.000Z

    Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxation studies are reported for three ionic liquids: 1-ethyl-3- methylimidazolium thiocyanate (EMIM-SCN, 220–258 K), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF{sub 4}, 243–318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF{sub 6}, 258–323 K). The dispersion of {sup 1}H spin-lattice relaxation rate R{sub 1}(?) is measured in the frequency range of 10 kHz–20 MHz, and the studies are complemented by {sup 19}F spin-lattice relaxation measurements on BMIM-PF{sub 6} in the corresponding frequency range. From the {sup 1}H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF{sub 4}, and BMIM-PF{sub 6} are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the {sup 1}H spin-lattice relaxation as well as by benefiting from the universal low-frequency dispersion law characteristic of Fickian diffusion which yields, at low frequencies, a linear dependence of R{sub 1} on square root of frequency. From the {sup 19}F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF{sub 6}. The diffusion coefficients obtained from FC NMR relaxometry are in good agreement with results reported from pulsed- field-gradient NMR. This shows that NMR relaxometry can be considered as an alternative route of determining diffusion coefficients of both cations and anions in ionic liquids.

  1. A New Type of Resonant Neutrino Conversions Induced by Magnetic Fields

    E-Print Network [OSTI]

    S. Sahu; V. B. Semikoz; J. W. F. Valle

    1995-12-21T23:59:59.000Z

    We consider resonant neutrino conversions in magnetised matter, such as a degenerate electron gas. We show how magnetisation effects caused by axial vector interactions of neutrinos with the charged leptons in the medium can induce a new type of resonant neutrino conversion which may occur even in situations where the MSW effect does not occur, such as the case of degenerate or inverted neutrino mass spectra. Our new resonance may simultaneously affect anti-neutrino $\\bar{\

  2. First test of the Siberian snake magnet arrangement to overcome depolarizing resonances in a circular accelerator

    SciTech Connect (OSTI)

    Krisch, A.D.; Mane, S.R.; Raymond, R.S.; Roser, T.; Stewart, J.A.; Terwilliger, K.M.; Vuaridel, B. (Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (US)); Goodwin, J.E.; Meyer, H.; Minty, M.G.; and others

    1989-09-11T23:59:59.000Z

    We studied the {ital G}{gamma}=2 imperfection depolarizing resonance at 108 MeV, both with and without a Siberian snake, by varying the resonance strength while storing beams of 104- and 120-MeV polarized protons at the Indiana University Cooler Ring. We used a cylindrically symmetric polarimeter to simultaneously study the effect of a depolarizing resonance on both the vertical and radial components of the polarization. AT 104 MeV we found that the Siberian snake eliminated the effect of the nearby {ital G}{gamma}=2 depolarizing resonance.

  3. angio-magnetic resonance finding: Topics by E-print Network

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

    of an order of magnitude and the corresponding lifetime of about seven decades. R. Yamapi; G. Filatrella 2014-06-24 367 Electromagnetic Excitation of Nucleon Resonances Nuclear...

  4. Image Fusion for MR Bias Stochastic Systems Group

    E-Print Network [OSTI]

    Willsky, Alan S.

    We can target T1 and T2 through appropriate selection of TE and TR. #12;Image Reconstruction The MRImage Fusion for MR Bias Correction Ayres Fan Stochastic Systems Group Joint work with W. Wells, J. Fisher, M. Cetin, S. Haker, A. Willsky, B. Mulkern #12;Magnetic Resonance The magnetic resonance (MR

  5. Magnetic charge crystals imaged in artificial spin ice

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your Home and It'll Love YouTokamak| NationalMagneticMagnetic

  6. Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals: Evidence of image potential resonance and pseudogap

    SciTech Connect (OSTI)

    Maniraj, M [UGC-DAE Confortium for Scientific Research; Rai, Abhishek [UGC-DAE Confortium for Scientific Research; Barman, S R [UGC-DAE Confortium for Scientific Research; Krajci, M [Slovak Academy of Sciences; Schlagel, Deborah L [Ames Laboratory; Lograsso, Thomas A [Ames Laboratory; Horn, K [Fritz-Haber-Institut der Max-Planck-Gesellschaft

    2014-09-01T23:59:59.000Z

    We study the unoccupied region of the electronic structure of the fivefold symmetric surface of an icosahedral (i) Al-Pd-Mn quasicrystal. A feature that exhibits parabolic dispersion with an effective mass of (1.15±0.1)me and tracks the change in the work function is assigned to an image potential resonance because our density functional calculation shows an absence of band gap in the respective energy region. We show that Sn grows pseudomorphically on i?Al?Pd?Mn as predicted by density functional theory calculations, and the energy of the image potential resonance tracks the change in the work function with Sn coverage. The image potential resonance appears much weaker in the spectrum from the related crystalline Al-Pd-Mn surface, demonstrating that its strength is related to the compatibility of the quasiperiodic wave functions in i?Al?Pd?Mn with the free-electron-like image potential states. Our investigation of the energy region immediately above EF provides unambiguous evidence for the presence of a pseudogap, in agreement with our density functional theory calculations.

  7. X-ray imaging of extended magnetic domain walls in Ni80Fe20 wires

    SciTech Connect (OSTI)

    Basu, S.; Fry, P. W.; Allwood, D. A.; Bryan, M. T.; Gibbs, M. R. J.; Schrefl, T.; Im, M.-Y.; Fischer, P.

    2009-06-20T23:59:59.000Z

    We have used magnetic transmission X-ray microscopy to image magnetization configurations in 700 nm wide Ni{sub 80}Fe{sub 20} planar wires attached to 'nucleation' pads Domain walls were observed to inject only across half of the wire width but extend to several micrometers in length. Magnetostatic interactions with adjacent wires caused further unusual domain wall behavior. Micromagnetic modeling suggests the extended walls have Neel-like structure along their length and indicates weaker exchange coupling than is often assumed. These observations explain previous measurements of domain wall injection and demonstrate that magnetic domain walls in larger nanowires cannot always be considered as localized entities.

  8. Extreme Ultraviolet Imaging of Three-dimensional Magnetic Reconnection in a Solar Eruption

    E-Print Network [OSTI]

    Sun, J Q; Ding, M D; Guo, Y; Priest, E R; Parnell, C E; Edwards, S J; Zhang, J; Chen, P F; Fang, C

    2015-01-01T23:59:59.000Z

    Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively. It is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions (3D) using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet (EUV) images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from $\\sim$1 to $\\ge$5 MK. Shortly afterwards, warm flare loops ($\\sim$3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magneti...

  9. Ultrahigh-Resolution Magnetic Resonance in Inhomogeneous Magnetic Fields: Two-Dimensional Long-Lived-Coherence Correlation Spectroscopy

    E-Print Network [OSTI]

    sophisticated gradient switching or frequency-modulated pulses. Applications to in-cell NMR and to magnetic, metabolism, blood flow, diffusion, and brain activity. Most applications to inanimate samples and living

  10. The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Magnetohydrodynamics Simulation Module for the Global Solar Corona

    E-Print Network [OSTI]

    Hayashi, Keiji; Liu, Yang; Bobra, Monica G; Sun, Xudong D; Norton, Aimee A

    2015-01-01T23:59:59.000Z

    Time-dependent three-dimensional magnetohydrodynamics (MHD) simulation modules are implemented at the Joint Science Operation Center (JSOC) of Solar Dynamics Observatory (SDO). The modules regularly produce three-dimensional data of the time-relaxed minimum-energy state of the solar corona using global solar-surface magnetic-field maps created from Helioseismic Magnetic Imager (HMI) full-disk magnetogram data. With the assumption of polytropic gas with specific heat ratio of 1.05, three types of simulation products are currently generated: i) simulation data with medium spatial resolution using the definitive calibrated synoptic map of the magnetic field with a cadence of one Carrington rotation, ii) data with low spatial resolution using the definitive version of the synchronic frame format of the magnetic field, with a cadence of one day, and iii) low-resolution data using near-real-time (NRT) synchronic format of the magnetic field on daily basis. The MHD data available in the JSOC database are three-dimen...

  11. 128 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 25, NO. 1, JANUARY 2006 Unwrapping of MR Phase Images Using a

    E-Print Network [OSTI]

    Koetter, Ralf

    128 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 25, NO. 1, JANUARY 2006 Unwrapping of MR Phase of blood flow [1], [2]. Extracting the phase image from its measured complex MR image is nontrivial because, phase unwrapping. I. INTRODUCTION A. Background Magnetic resonance (MR) phase images often contain

  12. 106 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 29, NO. 1, JANUARY 2010 Feature Based Nonrigid Brain MR Image Registration

    E-Print Network [OSTI]

    Chung, Albert C. S.

    106 IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 29, NO. 1, JANUARY 2010 Feature Based Nonrigid Brain MR Image Registration With Symmetric Alpha Stable Filters Shu Liao* and Albert C. S. Chung Abstract--A new feature based nonrigid image registration method for magnetic resonance (MR) brain images

  13. Layer resolved magnetic domain imaging of epitaxial heterostructures in large applied magnetic fields

    E-Print Network [OSTI]

    Zohar, S.; Choi, Y.; Love, D. M.; Mansell, R.; Barnes, C. H. W.; Keavney, D. J.; Rosenberg, R. A.

    2015-02-19T23:59:59.000Z

    We use X-ray Excited Luminescence Microscopy to investigate the elemental and layer resolved magnetic reversal in an interlayer exchange coupled (IEC) epitaxial Fe/Cr wedge/Co heterostructure. The transition from strongly coupled parallel Co...

  14. Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter

    E-Print Network [OSTI]

    Vaisman, G; Shavit, R

    2015-01-01T23:59:59.000Z

    Study of interaction between high absorption matter and microwave radiated energy is a subject of great importance. Especially, this concerns microwave spectroscopic characterization of biological liquids. Use of effective testing methods to obtain information about physical properties of different liquids on the molecular level is one of the most important problems in biophysics. However, the standard methods based on the microwave resonant techniques are not sufficiently suitable for biological liquids because the resonance peak in a resonator with high-loss liquids is so broad that the material parameters cannot be measured correctly. Although molecular vibrations of biomolecules may have microwave frequencies, it is not thought that such resonant coupling is significant due to their low energy compared with thermal energy and the strongly dampening aqueous environment. This paper presents an innovative microwave sensing technique for different types of lossy materials, including biological liquids. The te...

  15. Origin of the resonant dependence of the instability current in a magnetic field

    SciTech Connect (OSTI)

    Nevirkovets, I.P.; Rudenko, E.M.

    1985-05-01T23:59:59.000Z

    The instability current in the case of Sn--I--Sn tunnel junctions in weak magnetic fields is investigated in detail. (AIP)

  16. Fructose-induced aberration of metabolism in familial gout identified by sup 31 P magnetic resonance spectroscopy

    SciTech Connect (OSTI)

    Seegmiller, J.E. (John Radcliffe Hospital, Oxford (England) Univ. of California, San Diego (United States)); Dixon, R.M.; Kemp, G.J.; Rajagopalan, B.; Radda, G.K. (John Radcliffe Hospital, Oxford (England)); Angus, P.W. (John Radcliffe Hospital, Oxford (England) Austin Hospital, Heidelburg, Victoria (Australia)); McAlindon, T.E.; Dieppe, P. (Univ. of Bristol (England))

    1990-11-01T23:59:59.000Z

    The hyperuricemia responsible for the development of gouty arthritis results from a wide range of environmental factors and underlying genetically determined aberrations of metabolism. {sup 31}P magnetic resonance spectroscopy studies of children with hereditary fructose intolerance revealed a readily detectable rise in phosphomonoesters with a marked fall in inorganic phosphate in their liver in vivo and a rise in serum urate in response to very low doses of oral fructose. Parents and some family members heterozygous for this enzyme deficiency showed a similar pattern when given a substantially larger dose of fructose. Three of the nine heterozygotes thus identified also had clinical gout, suggesting the possibility of this defect being a fairly common cause of gout. In the present study this same noninvasive technology was used to identify the same spectral pattern in 2 of the 11 families studied with hereditary gout. In one family, the index patient's three brothers and his mother all showed the fructose-induced abnormality of metabolism, in agreement with the maternal inheritance of metabolism, in agreement with the maternal inheritance of the gout in this family group. The test dose of fructose used produced a significantly larger increment in the concentration of serum urate in the patients showing the changes in {sup 31}P magnetic resonance spectra than in the other patients with familial gout or in nonaffected members, thus suggesting a simpler method for initial screening for the defect.

  17. Evaluation of the toroidal torque driven by external non-resonant non-axisymmetric magnetic field perturbations in a tokamak

    SciTech Connect (OSTI)

    Kasilov, Sergei V. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität 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); Kernbichler, Winfried; Martitsch, Andreas F.; Heyn, Martin F. [Fusion@ÖAW, Institut für Theoretische Physik—Computational Physics, Technische Universität Graz Petersgasse 16, A–8010 Graz (Austria); Maassberg, Henning [Max-Planck Institut für Plasmaphysik, D-17491 Greifswald (Germany)

    2014-09-15T23:59:59.000Z

    The toroidal torque driven by external non-resonant magnetic perturbations (neoclassical toroidal viscosity) is an important momentum source affecting the toroidal plasma rotation in tokamaks. The well-known force-flux relation directly links this torque to the non-ambipolar neoclassical particle fluxes arising due to the violation of the toroidal symmetry of the magnetic field. Here, a quasilinear approach for the numerical computation of these fluxes is described, which reduces the dimension of a standard neoclassical transport problem by one without model simplifications of the linearized drift kinetic equation. The only limiting condition is that the non-axisymmetric perturbation field is small enough such that the effect of the perturbation field on particle motion within the flux surface is negligible. Therefore, in addition to most of the transport regimes described by the banana (bounce averaged) kinetic equation also such regimes as, e.g., ripple-plateau and resonant diffusion regimes are naturally included in this approach. Based on this approach, a quasilinear version of the code NEO-2 [W. Kernbichler et al., Plasma Fusion Res. 3, S1061 (2008).] has been developed and benchmarked against a few analytical and numerical models. Results from NEO-2 stay in good agreement with results from these models in their pertinent range of validity.

  18. A practical acceleration algorithm for real-time imaging

    E-Print Network [OSTI]

    Sumbul, Uygar

    A practical acceleration algorithm for real-time magnetic resonance imaging (MRI) is presented. Neither separate training scans nor embedded training samples are used. The Kalman filter based algorithm provides a fast and ...

  19. Novel Hall sensors developed for magnetic field imaging systems.

    SciTech Connect (OSTI)

    Cambel, V.; Karapetrov, G.; Novosad, V.; Bartolome, E.; Gregusova, D.; Fedor, J.; Kudela, R.; Soltys, J.; Materials Science Division; Slovak Academy of Sciences; Univ. Autonoma de Barcelona

    2007-09-01T23:59:59.000Z

    We report here on the fabrication and application of novel planar Hall sensors based on shallow InGaP/AlGaAs/GaAs heterostructure with a two-dimensional electron gas (2DEG) as an active layer. The sensors are developed for two kinds of experiments. In the first one, magnetic samples are placed directly on the Hall sensor. Room temperature experiments of permalloy objects evaporated onto the sensor are presented. In the second experiment, the sensor scans close over a multigranular superconducting sample prepared on a YBCO thin film. Large-area and high-resolution scanning experiments were performed at 4.2 K with the Hall probe scanning system in a liquid helium flow cryostat.

  20. Human Brain Glutamate, Glutamine, ?-Aminobutyric Acid Proton Magnetic Resonance Spectral Quantification with the Fast Pade Transform

    E-Print Network [OSTI]

    Zhang, Jingjing Michele

    2013-01-01T23:59:59.000Z

    27 Figure 2-8: Pulse sequence diagram of 2D PEPSISpectroscopic Imaging (PEPSI) in Adolescents with xv  acquisition. However, PEPSI sequence provides considerable

  1. High field nuclear magnetic resonance in transition metal substituted BaFe{sub 2}As{sub 2}

    SciTech Connect (OSTI)

    Garitezi, T. M., E-mail: thalesmg@ifi.unicamp.br; Lesseux, G. G.; Rosa, P. F. S.; Adriano, C.; Pagliuso, P. G.; Urbano, R. R. [Instituto de Física “Gleb Wataghin,” UNICAMP, Campinas, SP 13083-859 (Brazil); Reyes, A. P.; Kuhns, P. L. [National High Magnetic Field Laboratory, FSU, Tallahassee, Florida 32306-4005 (United States)

    2014-05-07T23:59:59.000Z

    We report high field {sup 75}As nuclear magnetic resonance (NMR) measurements on Co and Cu substituted BaFe{sub 2}As{sub 2} single crystals displaying same structural/magnetic transition T{sub 0}?128??K. From our anisotropy studies in the paramagnetic state, we strikingly found virtually identical quadrupolar splitting and consequently the quadrupole frequency ?{sub Q}?2.57(1)??MHz for both compounds, despite the claim that each Cu delivers 2 extra 3d electrons in BaFe{sub 2}As{sub 2} compared to Co substitution. These results allow us to conclude that a subtle change in the crystallographic structure, particularly in the Fe–As tetrahedra, must be the most probable tuning parameter to determine T{sub 0} in this class of superconductors rather than electronic doping. Furthermore, our NMR data around T{sub 0} suggest coexistence of tetragonal/paramagnetic and orthorhombic/antiferromagnetic phases between the structural and the spin density wave magnetic phase transitions, similarly to what was reported for K-doped BaFe{sub 2}As{sub 2} [Urbano et al., Phys. Rev. Lett. 105, 107001 (2010)].

  2. Magnetic and microwave properties of U-type hexaferrite films with high remanence and low ferromagnetic resonance linewidth

    SciTech Connect (OSTI)

    Su, Zhijuan; Bennett, Steven; Hu, Bolin; Chen, Yajie, E-mail: y.chen@neu.edu; Harris, Vincent G. [Center for Microwave Magnetic Materials and Integrated Circuits, Northeastern University, Boston, Massachusetts 02115, USA and The Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States)

    2014-05-07T23:59:59.000Z

    U-type barium hexaferrite films (Ba{sub 4}Ni{sub 1.4}Co{sub 0.6}Fe{sub 36}O{sub 60}) were deposited on (0001) sapphire substrates by pulsed laser deposition. Microstructure and magnetic properties of the films were characterized by X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry. Ferromagnetic resonance (FMR) measurements were performed at X-band. The results indicate an anisotropy field of ?8 kOe, and the saturation magnetization (4?M{sub s}) of ?3.6 kG. An optimal post-deposition annealing of films results in a strong (0 0?n) crystallographic texture and a high hysteresis loop squareness (M{sub r}/M{sub s}?=?92%) leading to self biased properties. Furthermore, the highly self-biased ferrite films exhibited an FMR linewidth of ?200?Oe. The U-type hexaferrite films having low microwave loss, low magnetic anisotropy field, and high squareness are a suitable alternative to Sc or In doped BaM ferrites that have been the choice material for self-biased microwave devices at X-band frequencies.

  3. Development of a microwave ion and plasma source immersed in a multicusp electron-cyclotron-resonant magnetic field

    SciTech Connect (OSTI)

    Dahimene, M.

    1987-01-01T23:59:59.000Z

    Experimental development and test of an electrodeless microwave (2.45 GHz)-generated plasma and ion source in a discharge pressure range of 6 x 10 /sup -4/-5 x 10/sup -1/ Torr and relatively low power (80-350 W CW) are presented. Also presented is a semi-empirical model applicable to low-pressure microwave discharges with no static magnetic field. Initial experiments studied the properties of variable diffusion length (0.43-1.22 cm) disk-shaped discharges generated and maintained in a cylindrical microwave resonant-cavity applicator for argon and oxygen gases without a static magnetic field. These discharges were characterized by measuring plasma densities and electron temperatures using a Langmuir double probe for different experimental conditions. The measured plasma densities and electron temperatures ranged for 8 x 10/sup 10/ to 5 x 10 /sup 11/ cm/sup -3/ and 2 x 10/sup 4/ to 8 x 10/sup 4/ /sup 0/K, respectively. The ion temperature was less than 500 /sup 0/K. Ion beams were extracted from these discharges using single and double grids. Argon ion-beam currents densities were measured to be 3.0 mA/cm/sup 2/ for the single grid and 5.8 mA/cm/sup 2/ for the double grids with a maximum extraction voltage of 1.7 kV. This applicator was then retrofitted with magnets to study the effect of a multicusp static magnetic field. Using this concept, a new cylindrical microwave applicator was designed and tested.

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

    SciTech Connect (OSTI)

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

    2002-01-29T23:59:59.000Z

    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.

  5. Two-dimensional resonant magnetic excitation in BaFe1.84Co0.16As2

    SciTech Connect (OSTI)

    Lumsden, Mark D [ORNL; Christianson, Andrew D [ORNL; Parshall, Daniel [ORNL; Stone, Matthew B [ORNL; Nagler, Stephen E [ORNL; Mook Jr, Herbert A [ORNL; Lokshin, Konstantin A [ORNL; Egami, Takeshi [ORNL; Abernathy, Douglas L [ORNL; Goremychkin, E. A. [ISIS Facility, Rutherford Appleton Laboratory; Osborn, R. [Argonne National Laboratory (ANL); McGuire, Michael A [ORNL; Safa-Sefat, Athena [ORNL; Jin, Rongying [ORNL; Sales, Brian C [ORNL; Mandrus, David [ORNL

    2009-01-01T23:59:59.000Z

    Inelastic neutron scattering measurements on single crystals of superconducting BaFe1.84Co0.16As2 clearly reveal a magnetic excitation located at wavevectors (1/2 1/2 L) in tetragonal notation. The scattering is much broader in L than are spin waves observed in the parent compound BaFe2As2 indicating that the excitations in the superconducting material are more two-dimensional in nature. The excitation appears gapless for T > TC and becomes gapped on cooling below TC. The observed gap energy is approximately 9.6 meV corresponding to 5 kBTC which is remarkably similar to the canonical value for the resonance energy in the cuprates.

  6. Multi-rank nuclear magnetic resonance studies of half-integer quadrupolar nuclei in solids by three-dimensional dynamic-angle

    E-Print Network [OSTI]

    Frydman, Lucio

    orientations of the shielding and quadrupolar interactions. A method for extracting the 3D spectral minerals, structural ceramics, semiconductors, glasses and catalysts, the nuclear magnetic resonance NMR can prevent the extraction of chemically useful information from powder NMR spectra, most cases

  7. Solid-State Nuclear Magnetic Resonance Evidence for Parallel and Antiparallel Strand Arrangements in the Membrane-Associated HIV-1 Fusion Peptide

    E-Print Network [OSTI]

    Weliky, David

    Solid-State Nuclear Magnetic Resonance Evidence for Parallel and Antiparallel Strand Arrangements in the Membrane-Associated HIV-1 Fusion Peptide Jun Yang and David P. Weliky* Department of Chemistry, Michigan 7, 2003 ABSTRACT: The HIV-1 fusion peptide serves as a useful model system for understanding viral

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

    SciTech Connect (OSTI)

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

    2012-11-28T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Chi, Ji

    2009-05-15T23:59:59.000Z

    Al-rich Fe-Al systems (FeAl2, Fe2 Al5 and Fe4Al13) and Al20V2Eu have complicated structures with quasicrystal-like features making these materials potentially of interest for magnetic behavior. However, there is not much work on these materials...

  10. Electron spin resonance and magnetic characterization of the Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88}

    SciTech Connect (OSTI)

    Pires, M.J.M.; Carvalho, A. Magnus G.; Gama, S.; Silva, E.C. da; Coelho, A.A.; Mansanares, A.M. [Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, Unicamp, Cx. P. 6165, 13083-970, Campinas, Sao Paulo (Brazil)

    2005-12-01T23:59:59.000Z

    Electron spin resonance was applied on samples of Gd{sub 5.09}Ge{sub 2.03}Si{sub 1.88}. The results are discussed under the scope of magnetization measurements, optical metallography, and wavelength dispersive spectroscopy. Polycrystalline arc-melted samples submitted to different heat treatments were investigated. The correlation of the electron spin resonance and magnetization results permitted a characterization of the present phases and their transitions. Two coexisting phases in the temperature range between two phase transitions have been identified and associated to distinct crystallographic phases. Additionally, the magnetic moment at high temperatures has been estimated from the measured effective g factor. A peak value of 21.5 J/kg K for the magnetocaloric effect was obtained for a sample heat treated at 1500 deg. C for 16 h.

  11. Proton magnetic resonance studies of the chemical shifts occurring in propionic acid-dioxane solutions

    E-Print Network [OSTI]

    Oldham, William J. Bryan

    1958-01-01T23:59:59.000Z

    , Nxperimentaliy Gutowsky 1'ound S to be a linear function of Pl, Howevers Bhar end Lindstrom(I~ found deviations from the linear de- pendence g1ven in Gutowsky's report, These deviat1ons occur in the range of 5Q of acid by volume. The shift does not decrease... lines are displayed as the f10IlL is swept through 'the resonant value Since it was desire4 to find if the cheaical shift is tesperature de pendent~ 1t vas decided to neasure the shift at two tenperatures, One of those vas to be roc' tenperatuze...

  12. Proton magnetic resonance studies of the chemical shifts occurring in propionic acid-dioxane solutions 

    E-Print Network [OSTI]

    Oldham, William J. Bryan

    1958-01-01T23:59:59.000Z

    , Nxperimentaliy Gutowsky 1'ound S to be a linear function of Pl, Howevers Bhar end Lindstrom(I~ found deviations from the linear de- pendence g1ven in Gutowsky's report, These deviat1ons occur in the range of 5Q of acid by volume. The shift does not decrease... lines are displayed as the f10IlL is swept through 'the resonant value Since it was desire4 to find if the cheaical shift is tesperature de pendent~ 1t vas decided to neasure the shift at two tenperatures, One of those vas to be roc' tenperatuze...

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

    E-Print Network [OSTI]

    Chi, Ji

    2009-05-15T23:59:59.000Z

    and electronic properties. There has been more and more interest in intermetallic compounds containing rare-earth and transition metals, in cases of weak magnetic behavior resulting in variety of characteristics including spin and valence fluctuations, spin... and charge orderings, heavy Fermion behavior and Kondo insulators. Kondo insulators are 3d, 4f and 5f intermetallic compounds. At high temperatures, they behave like metals. But as temperature is reduced, an energy gap opens in the conduction band...

  14. Nanoscale Diffusion Studies of Lipid Membranes National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Magnetic Resonance Imaging & Spectroscopy User Facility, University of Florida Chemical Engineering We haveNanoscale Diffusion Studies of Lipid Membranes National High Magnetic Field Laboratory Advanced for the facility's future use. This will serve to enhance infrastructure for research and education at the Magnet

  15. Quantitative Assessment of Myocardial Microstructural Remodeling Using Diffusion Tensor Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Kung, Geoffrey

    2013-01-01T23:59:59.000Z

    death in the United States affecting 5.1 million Americans in 2013 with a 50% mortality ratedeath in the United States affecting 5.1 million Americans in 2013 with a 50% mortality ratedeath in the United States affecting 7.6 million Americans as of 2013 with a 15% mortality rate

  16. Abstract--Magnetic Resonance Imaging (MRI) guided prostate biopsy and brachytherapy has been introduced in

    E-Print Network [OSTI]

    Camesano, Terri

    is a major health concern in the United States. In 2009, an estimate of 192280 new cases and 27360 deaths%) for men. In the last two decades, however, the death rate is decreasing, which largely reflects are reported, which are the largest number of male cancer (25%) and the second largest cause of cancer death (9

  17. Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device

    E-Print Network [OSTI]

    Myers, Whittier R.

    2006-01-01T23:59:59.000Z

    Cooling techniques.J = NI/A C . 5.1.2. Cooling techniques The first polarizingI call this technique internal cooling as opposed to

  18. Rf coil design for multi-frequency magnetic resonance imaging & spectroscopy

    E-Print Network [OSTI]

    Dabirzadeh, Arash

    2009-05-15T23:59:59.000Z

    using inductor-capacitor (LC) trap circuits on a 31P coil. The method can be easily applied to other nuclei. The main advantage of this trapping method is the enabling design of second-nuclei coils that are insertable into standard proton coils...

  19. T? tunable porous silicon iron oxide nanocomposites for magnetic resonance imaging guided drug delivey

    E-Print Network [OSTI]

    Ananda Yogendran, Shalini

    2012-01-01T23:59:59.000Z

    > y) & (0 z)) if (sqrt(pwr(x-xpos[sphere],2) + pwr (y-ypos[sphere],2)+pwr( z-zpos[sphere], 2)) <=sphere_radius) { int

  20. Quantitative Assessment of Myocardial Microstructural Remodeling Using Diffusion Tensor Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Kung, Geoffrey

    2013-01-01T23:59:59.000Z

    fluid (Fomblin Y-LVAC 6-06, Solvay Solexis, West Deptford,fluid (Fomblin Y-LVAC 6-06, Solvay Solexis, West Deptford,fluid (Fomblin Y-LVAC 6-06, Solvay Solexis, West Deptford,

  1. Near-infrared frequency-domain optical spectroscopy and magnetic resonance imaging: a combined

    E-Print Network [OSTI]

    for measurements in all neonates. Positron emission tomogra- phy PET studies in humans have shown regional changes of glucose utilization, oxygen consumption, and blood flow with brain maturation.2­7 However, because

  2. Analysis, design, and application of circularly polarized RF receiver antennas for magnetic resonance imaging

    E-Print Network [OSTI]

    Usey, Michael Christopher

    1995-01-01T23:59:59.000Z

    , an example coil will be designed for significantly improved SNR over the spine, with a minimum of added cost and complexity. The receiver antenna will be evaluated in both lab and clinical environments, with the results presented in this thesis. Further MRI...

  3. Quadrature Rotating-Frame Gradient Fields for Ultra-Low Field Nuclear Magnetic Resonance and Imaging

    E-Print Network [OSTI]

    Bouchard, Louis-Serge

    2005-01-01T23:59:59.000Z

    Frame Gradient Fields For Ultra-Low Field Nuclear Magneticslow, as in the limit of ultra-low ?elds. In the ?rst case,B. Slice selection in ultra-low ?elds We ?rst examine the

  4. Applications of Magnetic Resonance to Current Detection and Microscale Flow Imaging

    E-Print Network [OSTI]

    Halpern-Manners, Nicholas Wm

    2011-01-01T23:59:59.000Z

    for Reversible Hydrogen Storage. Chemistry of Materials 18,F. Nanoporous Polymers for Hydrogen Storage. Small 5, 10 (136] as well as hydrogen storage [36][35]. The development

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

    E-Print Network [OSTI]

    Uh, Jinsoo

    2007-04-25T23:59:59.000Z

    heterogeneous porous media. The permeability distributions are determined by solving the inverse problem formulated in terms of flow models and the velocity data. We present new experimental designs associated with flow conditions to enhance the accuracy...

  6. Clinical Application of Magnetic Resonance Imaging in Management of Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

    E-Print Network [OSTI]

    Chen, Jeon-Hor; Su, Min-Ying

    2013-01-01T23:59:59.000Z

    in MR mammography,” Radiologia Medica, vol. 115, no. 3, pp.molecular subtypes,” Radiologia, vol. 54, no. 5, pp. 442–

  7. Functional Connectivity Magnetic Resonance Imaging Reveals Cortical Functional Connectivity in the Developing Brain

    E-Print Network [OSTI]

    Utah, University of

    in the Developing Brain Weili Lin, Ph.D.^1 , Quan Zhu, M.S.^ 2 , Wei Gao, M.S.^ 3 , Yasheng Chen, D.Sc.^ 1 , Cheng was utilized to depict brain regions exhibiting temporal synchronization, also known as resting brain pixel-by-pixel throughout the entire brain, identifying regions with high temporal correlation. Results

  8. Magnetic Resonance - Ultrasound Fusion of the Prostate: Imaging for Cancer Diagnosis

    E-Print Network [OSTI]

    Natarajan, Shyam

    2012-01-01T23:59:59.000Z

    testing using polyimide-based TUUS array . . . . . . . . . .characterization of polyimide-based TUUS transducer . . .transducer with flexible polyimide joints,” in Ultrasonics

  9. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    . The channel numbers were marked out on modules A and B. The RF input jack was connected to the input of the power splitter. Eight coaxial cables of increasing length were used to connect the power splitter outputs to the inputs of the attenuator...

  10. Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device

    E-Print Network [OSTI]

    Myers, Whittier R.

    2006-01-01T23:59:59.000Z

    MRI system were wound on wooden coil forms. Figure 1.12copper wire wound on wooden coil forms. As in the first-MRI system. We wound these coils on a two circular forms cut

  11. In vivo magnetic resonance imaging and spectroscopy identifies oncolytic adenovirus responders

    E-Print Network [OSTI]

    Hemminki, Akseli

    and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland 7 NMR Metabolomics Laboratory, School of Pharmacy, University of Eastern Finland, Joensuu, Finland 8 Docrates Cancer Center, Helsinki, Finland 9 Laboratory of Immunovirotherapy, Division of Biopharmaceutics and Pharmacokinetics, Faculty of Pharmacy

  12. Magnetic Resonance - Ultrasound Fusion of the Prostate: Imaging for Cancer Diagnosis

    E-Print Network [OSTI]

    Natarajan, Shyam

    2012-01-01T23:59:59.000Z

    The roles of PET and PET/CT in the diagnosis and managementPolydimethylsiloxane PET-CT Positron Emission Tomography /computed tomography (PET-CT) of the prostate, metabolic

  13. Visualization of flow structures in Fontan patients using 3-dimensional phase contrast magnetic resonance imaging

    E-Print Network [OSTI]

    Pekkan, Kerem

    D,a Lakshmi P. Dasi, PhD,b Kerem Pekkan, PhD,c David H. Frakes, PhD,d Andrew J. Powell, MD,e Kirk R. Kanter

  14. Magnetic Resonance Imaging Indicates Decreased Choroidal and Retinal Blood Flow in the DBA/2J Mouse

    E-Print Network [OSTI]

    Duong, Timothy Q.

    proteins: tyrosinase-related protein 1 (Tyrp1), which causes iris stromal atrophy,6 and glycoprotein

  15. Function Biomedical Informatics Research Network Recommendations for Prospective Multi-Center Functional Magnetic Resonance Imaging Studies

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    V, Preda A, Keator D, O'Leary DS, Lim KO, Glover G, PotkinHJ, Clark VP, Lauriello J, O'Leary D, Mueller BA, Lim KO,DH, Gollub R, Lauriello J, O'Leary D, van Erp TG, Toga AW,

  16. SURFACE AND VOLUME REGISTRATION OF BRAIN MAGNETIC RESONANCE IMAGES Natasha Lepore1

    E-Print Network [OSTI]

    Leahy, Richard M.

    . Joshi1 , Richard Leahy2 , Caroline Brun1 , Yi-Yu Chou1 , Xavier Pennec3 , Agatha D. Lee1 , Marina Barysheva1 , Greig I. de Zubicaray4 , Margaret Wright5 , Katie McMahon4 , Arthur W. Toga1 , Paul M. Thompson

  17. 1,2-Hydroxypyridonates as Contrast Agents for Magnetic Resonance Imaging: TREN-1,2-HOPO

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    Hydroxypyridonate, Gadolinium, Europium, MRI, Fluorescence,was added a solution of europium chloride hexahydrate (36with the formation of europium hydroxide. 30 The competition

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

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurTheBrookhaven NationalRegionalsResearchIdahoKansasLawrenceof Science (SC)

  19. Proton Dynamics in ZnO Nanorods Quantified by In Situ Solid-State 1H Nuclear Magnetic Resonance

    SciTech Connect (OSTI)

    Wang, Li Q.; Zhou, Xiao Dong; Exarhos, Gregory J.; Pederson, Larry R.; Wang, Chong M.; Windisch, Charles F.; Yao, Chunhua

    2007-10-22T23:59:59.000Z

    Zinc oxide (ZnO) adopts wurtzite structure and possesses a direct wide band gap (Eg ~ 3.3 eV at 300 K), similar to that of GaN (Eg ~ 3.4 eV at 300 K), which enables ZnO as an alternative candidate to replace GaN for use in optoelectronic devices. The present controversy is centered at the microscopic origin of the “native donors”, particularly after ab initio calculations by Van de Walle, which indicate that hydrogen is soluble in ZnO at the interstitial sites, effectively forming a donor level just below the conduction band in ZnO. Hence, the origin of n type conductivity in ZnO is proposed due to the presence of hydrogen. Electron paramagnetic resonance and spectroscopic observations of muons provide experimental evidence of hydrogen presence in ZnO. Whereas, Look et al. suggests that the complex of zinc interstitial and nitrogen defect is a stronger candidate for donor than hydrogen interstitials under N ambient. Hydrogen-oxygen complex is claimed to be stable even at T > 1000°C in the hydrothermally synthesized ZnO. Therefore, the thermodynamic nature of hydrogen characteristics remains controversial, particularly its role on resident defects. In this letter, in situ temperature dependent solid state 1H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy is employed to probe the local chemical environments of hydrogen in ZnO nanorods. To best knowledge of ours, this is the first time that the presence of hydrogen, its concentration, and local transport dynamics are directly chemically determined. Moreover, in situ NMR allows a new approach to investigate the absorption and desorption of protons from different sites on the ZnO nanorods, thus study of site-specific proton dynamics in ZnO becomes feasible.

  20. Noise-Produced Patterns in Images Constructed from Magnetic Flux Leakage Data

    E-Print Network [OSTI]

    Pimenova, Anastasiya V; Levesley, Jeremy; Elkington, Peter; Bacciarelli, Mark

    2015-01-01T23:59:59.000Z

    Magnetic flux leakage measurements help identify the position, size and shape of corrosion-related defects in steel casings used to protect boreholes drilled into oil and gas reservoirs. Images constructed from magnetic flux leakage data contain patterns related to noise inherent in the method. We investigate the patterns and their scaling properties for the case of delta-correlated input noise, and consider the implications for the method's ability to resolve defects. The analytical evaluation of the noise-produced patterns is made possible by model reduction facilitated by large-scale approximation. With appropriate modification, the approach can be employed to analyze noise-produced patterns in other situations where the data of interest are not measured directly, but are related to the measured data by a complex linear transform involving integrations with respect to spatial coordinates.

  1. X-ray resonant magnetic scattering and x-ray magnetic circular dichroism branching ratios, L[subscript 3] / L[subscript 2], for heavy rare earths

    SciTech Connect (OSTI)

    Lee, Yongbin; Kim, Jong-Woo; Goldman, Alan I.; Harmon, Bruce N. (Iowa State)

    2010-07-19T23:59:59.000Z

    In this study we have used first principles electronic structure methods to investigate the detailed contributions to the L{sub 3}/L{sub 2} branching ratio in the heavy rare earth elements. The calculations use the full potential, relativistic, linear augmented plane wave method with the LSDA+U approach for consideration of the local 4f electronic orbitals. With no spin orbit coupling (SOC) in the conducting bands, and with the same radial function for the 2p{sub 3/2} and 2p{sub 1/2} core states, the branching ratio (BR) is exactly 1:-1 for the x-ray magnetic circular dichroism spectra of the ferromagnetic heavy rare earth metals. However, with full SOC the BR ranges from 1.5 to 6.0 in going from Gd to Er. The energy and spin dependence of the 5d radial functions are important. The results point to problems with modified atomic models which have been proposed to explain the BR. Recent x-ray resonant magentic scattering experiments on (Gd,Tb,Dy,Ho,Er,Tm)Ni{sub 2}Ge{sub 2} are discussed.

  2. Pellet fuelling of plasmas with ELM mitigation by resonant magnetic perturbations in MAST

    E-Print Network [OSTI]

    Valovic, M; Garzotti, L; Gurl, C; Kirk, A; Naylor, G; Patel, A; Scannell, R; Thornton, A J

    2013-01-01T23:59:59.000Z

    Shallow fuelling pellets are injected from the high field side into plasmas in which ELMs have been mitigated using external magnetic perturbation coils. The data are compared with ideal assumptions in the ITER fuelling model, namely that mitigated ELMs are not affected by fuelling pellets. Firstly it is shown that during the pellet evaporation an ELM is triggered, during which the amount particle loss could be larger (factor ~1.5) than the particle loss during an ELM which was not induced by pellet. Secondly, a favourable example is shown in which post-pellet particle losses due to mitigated ELMs are similar to the non-pellet case, however unfavourable counter-examples also exist.

  3. Imaging and spectroscopic observations of magnetic reconnection and chromospheric evaporation in a solar flare

    E-Print Network [OSTI]

    Tian, Hui; Reeves, Katharine K; Raymond, John C; Guo, Fan; Liu, Wei; Chen, Bin; Murphy, Nicholas A

    2014-01-01T23:59:59.000Z

    Magnetic reconnection is believed to be the dominant energy release mechanism in solar flares. The standard flare model predicts both downward and upward outflow plasmas with speeds close to the coronal Alfv\\'{e}n speed. Yet, spectroscopic observations of such outflows, especially the downflows, are extremely rare. With observations of the newly launched Interface Region Imaging Spectrograph (IRIS), we report the detection of greatly redshifted ($\\sim$125 km s$^{-1}$ along line of sight) Fe {\\sc{xxi}} 1354.08\\AA{} emission line with a $\\sim$100 km s$^{-1}$ nonthermal width at the reconnection site of a flare. The redshifted Fe {\\sc{xxi}} feature coincides spatially with the loop-top X-Ray source observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). We interpret this large redshift as the signature of downward-moving reconnection outflow/hot retracting loops. Imaging observations from both IRIS and the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) also...

  4. Performance of a static-anode/flat-panel x-ray fluoroscopy system in a diagnostic strength magnetic field: A truly hybrid x-ray/MR imaging system

    SciTech Connect (OSTI)

    Fahrig, R.; Wen, Z.; Ganguly, A.; DeCrescenzo, G.; Rowlands, J.A.; Stevens, G.M.; Saunders, R.F.; Pelc, N.J. [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Radiology and Department of Physics, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States); Sunnybrook and Women's Health Sciences Center and Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); GE Healthcare, Schenectady, Wisconsin (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States)

    2005-06-15T23:59:59.000Z

    Minimally invasive procedures are increasing in variety and frequency, facilitated by advances in imaging technology. Our hybrid imaging system (GE Apollo{sup TM} flat panel, custom Brand x-ray static anode x-ray tube, GE Lunar high-frequency power supply and 0.5 T Signa SP{sup TM}) provides both x-ray and MR imaging capability to guide complex procedures without requiring motion of the patient between two distant gantries. The performance of the x-ray tube in this closely integrated system was evaluated by modeling and measuring both the response of the filament to an externally applied field and the behavior of the electron beam for field strengths and geometries of interest. The performance of the detector was assessed by measuring the slanted-edge modulation transfer function (MTF) and when placed at zero field and at 0.5 T. Measured resonant frequencies of filaments can be approximated using a modified vibrating beam model, and were at frequencies well below the 25 kHz frequency of our generator for our filament geometry. The amplitude of vibration was not sufficient to cause shorting of the filament during operation within the magnetic field. A simple model of electrons in uniform electric and magnetic fields can be used to estimate the deflection of the electron beam on the anode for the fields of interest between 0.2 and 0.5 T. The MTF measured at the detector and the DQE showed no significant difference inside and outside of the magnetic field. With the proper modifications, an x-ray system can be fully integrated with a MR system, with minimal loss of image quality. Any x-ray tube can be assessed for compatibility when placed at a particular location within the field using the models. We have also concluded that a-Si electronics are robust against magnetic fields. Detailed knowledge of the x-ray system installation is required to provide estimates of system operation.

  5. Nuclear magnetic resonance studies of phenylalanine analog interactions with normal and sicklen hemoglobin

    SciTech Connect (OSTI)

    Lee, Y.H.

    1985-01-01T23:59:59.000Z

    Several phenylalanine derivatives have been found to inhibit the gelation of deoxygenated sickle hemoglobin (deoxy HbS). Proton and /sup 19/F-NMR techniques were used to monitor the interaction of selected phenylalanine derivatives with the Hb molecule by using fluorine containing phenylalanine derivatives, Hb labeled at the ..beta..93 position with N-(2,2,2-trifluoroethyl) iodoacetamide (IA-F/sub 3/), and by monitoring the relaxation rates of the C2 and C4 histidine protons. The results show that the /sup 19/F spin-spin relaxation times of L-phenylalanin-4-fluorobenzylamide (PheNBz1-F), which has a deoxy HbS antigelling activity comparable to that of the amino acid, tryptophan, are affected much more strongly by interaction with Hb than are those of glycin-4-fluorobenzylamide (GlyNBz1-F). In contrast, it is shown that N-(2,2,5,5-tetramethylpyrrolidin-1-oxy-3-carboxyl)-L-phenylalanine t-butyl ester (SL-Phe) exhibits specific binding to Hb, and an antigelling activity more than two orders of magnitude greater than that of phenylalanine. These results indicate that the fluorine nuclei strongly influenced by the presence of spin label nitroxide are located in a conformation within a few angstroms of the SL-Phe binding site. Proton NMR relaxation measurements of the C2 and C4 proton resonances from the ..beta..2, 4b143 and ..beta..146 histidine residues show significant and selective effects from the binding of SL-Phe to Hb, indicating that the SL-Phe binding site must be close to the side chains of these three residues. The strong antigelation activity of SL-Phe suggests that this binding site may be one of the intermolecular contact sites of importance to the deoxy HbS aggregation process.

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

    SciTech Connect (OSTI)

    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

    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.

  7. Characterization of the testicular cell types present in the rat by in vivo 31P magnetic resonance spectroscopy

    SciTech Connect (OSTI)

    van der Grond, J.; Van Pelt, A.M.; van Echteld, C.J.; Dijkstra, G.; Grootegoed, J.A.; de Rooij, D.G.; Mali, W.P. (Department of Radiodiagnosis, University of Utrecht (Netherlands))

    1991-07-01T23:59:59.000Z

    Testes of vitamin A-deficient Wistar rats before and after vitamin A replacement, of rats irradiated in utero, and of control rats were investigated by in vivo 31P magnetic resonance (MR) spectroscopy. The testicular phosphomonoester/ATP (PM/ATP) ratio ranged from 0.79 {plus minus} 0.05 for testes that contained only interstitial tissue and Sertoli cells to 1.64 {plus minus} 0.04 for testes in which spermatocytes were the most advanced cell types present. When new generations of spermatids entered the seminiferous epithelium, this ratio decreased. The testicular phosphodiester/ATP (PD/ATP) ratio amounted to 0.16 {plus minus} 0.06 for testes in which Sertoli cells, spermatogonia, or spermatocytes were the most advanced cell type present. When new generations of spermatids entered the seminiferous epithelium, the PD/ATP ratio rapidly increased and finally reached a value of 0.71 {plus minus} 0.06 for fully developed testes. Taken together, specific patterns of the PM/ATP ratio, the PD/ATP ratio, and pH were obtained that were correlated to the presence of spermatogonia, spermatocytes, round spermatids, and elongated spermatids or to the absence of spermatogenic cells. Hence, a good impression of the status of the seminiferous epithelium in the rat can be obtained by in vivo 31P MR spectroscopy.

  8. 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)

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

    2012-01-01T23:59:59.000Z

    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 formore »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.« less

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

    SciTech Connect (OSTI)

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

    2012-01-07T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    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

    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.

  11. 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)

    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). Environmental Molecular Sciences Lab.

    2012-01-01T23:59:59.000Z

    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.

  12. Controlled manipulation of elastomers with radiation: Insights from multiquantum nuclear-magnetic-resonance data and mechanical measurements

    SciTech Connect (OSTI)

    Maiti, A.; Weisgraber, T.; Dinh, L. N.; Gee, R. H.; Wilson, T.; Chinn, S.; Maxwell, R. S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2011-03-15T23:59:59.000Z

    Filled and cross-linked elastomeric rubbers are versatile network materials with a multitude of applications ranging from artificial organs and biomedical devices to cushions, coatings, adhesives, interconnects, and seismic-isolation, thermal, and electrical barriers. External factors such as mechanical stress, temperature fluctuations, or radiation are known to create chemical changes in such materials that can directly affect the molecular weight distribution (MWD) of the polymer between cross-links and alter the structural and mechanical properties. From a materials science point of view it is highly desirable to understand, affect, and manipulate such property changes in a controlled manner. Unfortunately, that has not yet been possible due to the lack of experimental characterization of such networks under controlled environments. In this work we expose a known rubber material to controlled dosages of {gamma} radiation and utilize a newly developed multiquantum nuclear-magnetic-resonance technique to characterize the MWD as a function of radiation. We show that such data along with mechanical stress-strain measurements are amenable to accurate analysis by simple network models and yield important insights into radiation-induced molecular-level processes.

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

    E-Print Network [OSTI]

    I. A. Shkrob

    2006-07-25T23:59:59.000Z

    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.

  14. Electron nuclear double resonance study of photostimulated luminescence active centers in CsBr:Eu{sup 2+} medical imaging plates

    SciTech Connect (OSTI)

    Vrielinck, H.; Loncke, F.; Matthys, P.; Callens, F. [Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, B-9000 Gent (Belgium); Tahon, J.-P.; Leblans, P. [Agfa HealthCare NV, Septestraat 27, B-2640 Mortsel (Belgium)

    2011-02-01T23:59:59.000Z

    CsBr:Eu{sup 2+} needle image plates exhibit an electron-paramagnetic-resonance (EPR) spectrum at room temperature (RT), whose intensity is correlated with the photostimulated luminescence sensitivity of the plate. This EPR spectrum shows a strong temperature dependence: At RT it is owing to a single Eu{sup 2+} (S =7/2) center with axial symmetry, whereas at T<35 K the spectra can only be explained when two distinct centers are assumed to be present, a minority axial center and a majority center with nearly extremely rhombic symmetry. In this paper these low-temperature centers are studied with electron nuclear double resonance (ENDOR) spectroscopy, which reveals the presence of {sup 1}H nuclei close to the central Eu{sup 2+} ions in the centers. Analysis of the angular dependence of the ENDOR spectra allows to propose models for these centers, providing an explanation for the observed difference in intensity between the spectral components and for their temperature dependence.

  15. Magnetic Resonance in Medicine 63:15371547 (2010) Feasibility of In Vivo Measurement of Carotid Wall Shear

    E-Print Network [OSTI]

    Carvalho, João Luiz

    2010-01-01T23:59:59.000Z

    /vessel wall interface, using a method developed by Frayne and Rutt (Magn Reson Med 1995;34:378­ 387

  16. Whole-Body Magnetic Resonance Angiography with Additional Steady-State Acquisition of the Infragenicular Arteries in Patients with Peripheral Arterial Disease

    SciTech Connect (OSTI)

    Nielsen, Yousef W., E-mail: yujwni01@heh.regionh.d [University Hospital at Herlev, Department of Radiology (Denmark); Eiberg, Jonas P. [Rigshospitalet, Department of Vascular Surgery (Denmark); Logager, Vibeke B. [University Hospital at Herlev, Department of Radiology (Denmark); Just, Sven [University Hospital at Gentofte, Department of Radiology (Denmark); Schroeder, Torben V. [Rigshospitalet, Department of Vascular Surgery (Denmark); Thomsen, Henrik S. [University Hospital at Herlev, Department of Radiology (Denmark)

    2010-06-15T23:59:59.000Z

    The purpose of this investigation was to determine if addition of infragenicular steady-state (SS) magnetic resonance angiography (MRA) to first-pass imaging improves diagnostic performance compared with first-pass imaging alone in patients with peripheral arterial disease (PAD) undergoing whole-body (WB) MRA. Twenty consecutive patients with PAD referred to digital-subtraction angiography (DSA) underwent WB-MRA. Using a bolus-chase technique, first-pass WB-MRA was performed from the supra-aortic vessels to the ankles. The blood-pool contrast agent gadofosveset trisodium was used at a dose of 0.03 mmol/kg body weight. Ten minutes after injection of the contrast agent, high-resolution (0.7-mm isotropic voxels) SS-MRA of the infragenicular arteries was performed. Using DSA as the 'gold standard,' sensitivities and specificities for detecting significant arterial stenoses ({>=}50% luminal narrowing) with first-pass WB-MRA, SS-MRA, and combined first-pass and SS-MRA were calculated. Kappa statistics were used to determine intermodality agreement between MRA and DSA. Overall sensitivity and specificity for detecting significant arterial stenoses with first-pass WB-MRA was 0.70 (95% confidence interval 0.61 to 0.78) and 0.97 (0.94 to 0.99), respectively. In first-pass WB-MRA, the lowest sensitivity was in the infragenicular region, with a value of 0.42 (0.23 to 0.63). Combined analysis of first-pass WB-MRA and SS-MRA increased sensitivity to 0.81 (0.60 to 0.93) in the infragenicular region, with specificity of 0.94 (0.88 to 0.97). Sensitivity and specificity for detecting significant arterial stenoses with isolated infragenicular SS-MRA was 0.47 (0.27 to 0.69) and 0.86 (0.78 to 0.91), respectively. Intermodality agreement between MRA and DSA in the infragenicular region was moderate for first-pass WB-MRA ({kappa} = 0.49), fair for SS-MRA ({kappa} = 0.31), and good for combined first-pass/SS-MRA ({kappa} = 0.71). Addition of infragenicular SS-MRA to first-pass WB MRA improves diagnostic performance.

  17. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    SciTech Connect (OSTI)

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio, E-mail: lucio.frydman@weizmann.ac.il [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)] [Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2014-02-28T23:59:59.000Z

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out “intrinsic” T{sub 1} and T{sub 2} weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  18. Integrating an automatic classification method into the medical image retrieval process

    E-Print Network [OSTI]

    Ruiz, Miguel E.

    the performance of the University at Buffalo Medical Text and Images Retrieval System (UBMedTIRS). This paper classification process was performed using the Image Retrieval for Medical Application (IRMA) codes3 employed to acquire the image such as x-ray, ultrasound, magnetic resonance measurement, nuclear medicine

  19. Dynamic Surface Reconstruction from 4D-MR Images Matthias Fenchel1

    E-Print Network [OSTI]

    Gumhold, Stefan

    Dynamic Surface Reconstruction from 4D-MR Images Matthias Fenchel1 , Stefan Gumhold2 , Hans approach is applied to 4D-MR images of a human heart in motion. 1 Introduction Image segmentation-Peter Seidel3 1 Siemens AG Medical Solutions, Magnetic Resonance, Karl-Schall-Str. 4, 91052 Erlangen 2 TU

  20. Image-based fluidstructure interaction model of the human mitral valve Xingshuang Ma a

    E-Print Network [OSTI]

    Luo, Xiaoyu

    Image-based fluid­structure interaction model of the human mitral valve Xingshuang Ma a , Hao Gao Available online 15 November 2012 Keywords: Human mitral valve Clinical imaging Magnetic resonance imaging Fluid­structure interaction Immersed boundary method a b s t r a c t The mitral valve (MV) is one

  1. Advances in the Understanding of ELM Suppression by Resonant Magnetic Perturbations (RMPs) in DIII-D and Implications for ITER

    SciTech Connect (OSTI)

    Nazikian, R. [PPPL

    2014-09-01T23:59:59.000Z

    Experiments on DIII-D have expanding the operating window for RMP ELM suppression to higher q95 with dominant electron heating and fully non-inductive current drive relevant to advanced modes of ITER operation. Robust ELM suppression has also been obtained with a reduced coil set, mitigating the risk of coil failure in maintaining ELM suppression in ITER. These results significantly expand the operating space and reduce risk for obtaining RMP ELM suppression in ITER. Efforts have also been made to search for 3D cause of ELM suppression. No internal non-axisymmetric structure is detected at the top of the pedestal, indicating that the dominant effect of the RMP is to produce an n=0 transport modification of the profiles. Linear two fluid MHD simulations using M3D-C1 indicate resonant field penetration and significant magnetic stochasticity at the top of the pedestal, consistent with the absence of detectable 3D structure in that region. A profile database was developed to compare the scaling of the pedestal and global confinement with the applied 3D field strength in ELM suppressed and ELM mitigated plasmas. The EPED pedestal model accurately predicts the measured pedestal pressure at the threshold of ELM suppression, increasing confidence in theoretical projections to ITER pedestal conditions. Both the H-factor (H(sub)98y2) and thermal energy confinement time do not degrade substantially with applied RMP fields near the threshold of ELM suppression, enhancing confidence in the compatibility of ITER high performance operation with RMP ELM suppression.

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

    SciTech Connect (OSTI)

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

    2012-12-01T23:59:59.000Z

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

  3. Solar nebula magnetic fields recorded in the Semarkona meteorite

    E-Print Network [OSTI]

    Fu, Roger R.; Weiss, Benjamin P.; Lima, Eduardo A.; Harrison, Richard J.; Bai, Xue-Ning; Desch, Steven J.; Ebel, Denton S.; Suavet, Clement; Wang, Huapei; Glenn, David; Le Sage, David; Kasama, Takeshi; Walsworth, Ronald L.; Kuan, Aaron T.

    2014-11-13T23:59:59.000Z

    images of all three vector 492   components of the magnetic field produced by the sample in the plane of NV sensors using 493   optically-detected magnetic resonance (ODMR) spectroscopy. In this technique, described by 494   Le Sage et al. (74...   Figure 1. Dusty olivine-bearing chondrules from the Semarkona meteorite. (A) Optical 224   photomicrograph of chondrule DOC4 showing the location of dusty olivine grains. Image taken 225   in reflected light with crossed polarizers. (B) Annular...

  4. Image Fusion and Registration a Variational Bernd Fischer1

    E-Print Network [OSTI]

    Modersitzki, Jan

    Image Fusion and Registration ­ a Variational Approach Bernd Fischer1 and Jan Modersitzki1 Institute of Mathematics, Wallstra�e 40, D-23560 L¨ubeck, Germany fischer@math.uni-luebeck.de, modersitzki, including the registration of magnetic resonance images of a female breast subject to some volume preserving

  5. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  6. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology] Note: Admission to the program is required to enroll in RIS courses RIS 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2

  7. Prediction-Based Compression Ratio Boundaries for Medical Images

    E-Print Network [OSTI]

    Qi, Xiaojun

    Prediction-Based Compression Ratio Boundaries for Medical Images Xiaojun Qi Computer Science present prediction-based image compression techniques take advantage of either intra- or inter function. The prediction-based compression technique has been applied on some magnetic resonance (MR) brain

  8. X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er)

    SciTech Connect (OSTI)

    Nandi, Shibabrata

    2009-12-19T23:59:59.000Z

    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.

  9. Platinum dendritic nanoparticles with magnetic behavior

    SciTech Connect (OSTI)

    Li, Wenxian, E-mail: wl240@uowmail.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Solar Energy Technologies, School of Computing, Engineering, and Mathematics, University of Western Sydney, Penrith NSW 2751 (Australia); Sun, Ziqi; Nevirkovets, Ivan P.; Dou, Shi-Xue [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia); Tian, Dongliang [Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, School of Chemistry and the Environment, Beihang University, Beijing 100191 (China)

    2014-07-21T23:59:59.000Z

    Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ?4?nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a mixed paramagnetic and ferromagnetic state, originating from the core and surface, respectively. The 3D nanodendrite structure is suitable for surface modification and high amounts of drug loading if the transition temperature was enhanced to room temperature properly.

  10. Performance Analysis between Two Sparsity Constrained MRI Methods: Highly Constrained Backprojection(HYPR) and Compressed Sensing(CS) for Dynamic Imaging 

    E-Print Network [OSTI]

    Arzouni, Nibal

    2012-10-19T23:59:59.000Z

    One of the most important challenges in dynamic magnetic resonance imaging (MRI) is to achieve high spatial and temporal resolution when it is limited by system performance. It is desirable to acquire data fast enough to capture the dynamics...

  11. 740 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 12, NO. 1, MARCH 2002 High-Resolution Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Wider, Gerhard

    740 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 12, NO. 1, MARCH 2002 High research depend on high- field superconducting magnets with outstanding homogeneity and excellent long term, superconducting magnets, TROSY. I. INTRODUCTION IN THE half century since its discovery, nuclear magnetic

  12. Video Toroid Cavity Imager

    DOE Patents [OSTI]

    Gerald, Rex E. II; Sanchez, Jairo; Rathke, Jerome W.

    2004-08-10T23:59:59.000Z

    A video toroid cavity imager for in situ measurement of electrochemical properties of an electrolytic material sample includes a cylindrical toroid cavity resonator containing the sample and employs NMR and video imaging for providing high-resolution spectral and visual information of molecular characteristics of the sample on a real-time basis. A large magnetic field is applied to the sample under controlled temperature and pressure conditions to simultaneously provide NMR spectroscopy and video imaging capabilities for investigating electrochemical transformations of materials or the evolution of long-range molecular aggregation during cooling of hydrocarbon melts. The video toroid cavity imager includes a miniature commercial video camera with an adjustable lens, a modified compression coin cell imager with a fiat circular principal detector element, and a sample mounted on a transparent circular glass disk, and provides NMR information as well as a video image of a sample, such as a polymer film, with micrometer resolution.

  13. Whole-Body Magnetic Resonance Angiography at 3 Tesla Using a Hybrid Protocol in Patients with Peripheral Arterial Disease

    SciTech Connect (OSTI)

    Nielsen, Yousef W., E-mail: yujwni01@heh.regionh.d [University Hospital at Herlev, Department of Radiology (Denmark); Eiberg, Jonas P., E-mail: Eiberg@dadlnet.d [Rigshospitalet, Department of Vascular Surgery (Denmark); Logager, Vibeke B., E-mail: viloe@heh.regionh.d [University Hospital at Herlev, Department of Radiology (Denmark); Schroeder, Torben V., E-mail: tvs@dadlnet.d [Rigshospitalet, Department of Vascular Surgery (Denmark); Just, Sven, E-mail: svju@geh.regionh.d [University Hospital at Gentofte, Department of Radiology (Denmark); Thomsen, Henrik S., E-mail: hentho01@heh.regionh.d [University Hospital at Herlev, Department of Radiology (Denmark)

    2009-09-15T23:59:59.000Z

    The purpose of this study was to determine the diagnostic performance of 3T whole-body magnetic resonance angiography (WB-MRA) using a hybrid protocol in comparison with a standard protocol in patients with peripheral arterial disease (PAD). In 26 consecutive patients with PAD two different protocols were used for WB-MRA: a standard sequential protocol (n = 13) and a hybrid protocol (n = 13). WB-MRA was performed using a gradient echo sequence, body coil for signal reception, and gadoterate meglumine as contrast agent (0.3 mmol/kg body weight). Two blinded observers evaluated all WB-MRA examinations with regard to presence of stenoses, as well as diagnostic quality and degree of venous contamination in each of the four stations used in WB-MRA. Digital subtraction angiography served as the method of reference. Sensitivity for detecting significant arterial disease (luminal narrowing {>=} 50%) using standard-protocol WB-MRA for the two observers was 0.63 (95%CI: 0.51-0.73) and 0.66 (0.58-0.78). Specificities were 0.94 (0.91-0.97) and 0.96 (0.92-0.98), respectively. In the hybrid protocol WB-MRA sensitivities were 0.75 (0.64-0.84) and 0.70 (0.58-0.8), respectively. Specificities were 0.93 (0.88-0.96) and 0.95 (0.91-0.97). Interobserver agreement was good using both the standard and the hybrid protocol, with {kappa} = 0.62 (0.44-0.67) and {kappa} = 0.70 (0.59-0.79), respectively. WB-MRA quality scores were significantly higher in the lower leg using the hybrid protocol compared to standard protocol (p = 0.003 and p = 0.03, observers 1 and 2). Distal venous contamination scores were significantly lower with the hybrid protocol (p = 0.02 and p = 0.01, observers 1 and 2). In conclusion, hybrid-protocol WB-MRA shows a better diagnostic performance than standard protocol WB-MRA at 3 T in patients with PAD.

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

    SciTech Connect (OSTI)

    Cai, Min

    2011-11-30T23:59:59.000Z

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

  15. Parity violation in nuclear magnetic resonance frequencies of chiral tetrahedral tungsten complexes NWXYZ (X, Y, Z = H, F, Cl, Br or I)

    SciTech Connect (OSTI)

    Nahrwold, Sophie, E-mail: nahrwold@fias.uni-frankfurt.de; Berger, Robert, E-mail: r.berger@fias.uni-frankfurt.de [Frankfurt Institute for Advanced Studies, Goethe-University Frankfurt am Main, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany) [Frankfurt Institute for Advanced Studies, Goethe-University Frankfurt am Main, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Clemens-Schöpf-Institute, Technical University Darmstadt, Petersenstr. 22, D-64287 Darmstadt (Germany); Schwerdtfeger, Peter, E-mail: p.a.schwerdtfeger@massey.ac.nz [Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study, Massey University Albany, Private Bag 102904, North Shore City, Auckland 0745 (New Zealand) [Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study, Massey University Albany, Private Bag 102904, North Shore City, Auckland 0745 (New Zealand); Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str., D-35032 Marburg (Germany)

    2014-01-14T23:59:59.000Z

    Density functional theory within the two-component quasi-relativistic zeroth-order regular approximation (ZORA) is used to predict parity violation shifts in {sup 183}W nuclear magnetic resonance shielding tensors of chiral, tetrahedrally bonded tungsten complexes of the form NWXYZ (X, Y, Z = H, F, Cl, Br or I), as well as for the heavier systems NWHAtF and NWH(117)F for comparison. The calculations reveal that sub-mHz accuracy is required to detect such tiny effects in this class of compounds, and that parity violation effects are very sensitive to the choice of ligands.

  16. Adjustable permanent magnet assembly for NMR and MRI

    DOE Patents [OSTI]

    Pines, Alexander; Paulsen, Jeffrey; Bouchard, Louis S; Blumich, Bernhard

    2013-10-29T23:59:59.000Z

    System and methods for designing and using single-sided magnet assemblies for magnetic resonance imaging (MRI) are disclosed. The single-sided magnet assemblies can include an array of permanent magnets disposed at selected positions. At least one of the permanent magnets can be configured to rotate about an axis of rotation in the range of at least +/-10 degrees and can include a magnetization having a vector component perpendicular to the axis of rotation. The single-sided magnet assemblies can further include a magnet frame that is configured to hold the permanent magnets in place while allowing the at least one of the permanent magnets to rotate about the axis of rotation.

  17. Plant root system analysis from MRI images Hannes Schulz1, Johannes A. Postma2, Dagmar van Dusschoten2,

    E-Print Network [OSTI]

    Behnke, Sven

    voxel to the base of the plant root, weighing the Euclidean distance measure by a multi-scale vesselness test this method using both virtually generated MRI images of Maize and real MRI images of Barley roots (Ferreira et al., 2010; Nakanishi et al., 2003; Pierret et al., 2003) and Nuclear Magnetic Resonance Imaging

  18. Type-I superconductor pick-up coil in superconducting quantum interference device-based ultra-low field nuclear magnetic resonance

    SciTech Connect (OSTI)

    Hwang, Seong-min, E-mail: smhwang@kriss.re.kr; Kim, Kiwoong; Kyu Yu, Kwon; Lee, Seong-Joo; Hyun Shim, Jeong [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Körber, Rainer [Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin (Germany); Magnicon GmbH, Division Berlin, Abbestraße 2-12, D-10587 Berlin (Germany); Burghoff, Martin [Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin (Germany)

    2014-02-10T23:59:59.000Z

    In ultra-low field nuclear magnetic resonance (ULF-NMR) with strong prepolarization field (B{sub p}), type-II superconducting pick-up coils may be vulnerable to flux pinning from the strong B{sub p}. Pick-up coils made of NbTi, Nb, and Pb were evaluated in terms of acquired NMR signal quality. The type-II pick-up coils showed degraded signals above 61?mT maximum exposure, while the Pb pick-up coil exhibited no such degradation. Furthermore, a negative counter pulse following a strong B{sub p} was shown to follow magnetic hysteresis loop to unpin the trapped flux in the type-II pick-up coil and restore the NMR signal.

  19. Global analysis of Fo rster resonance energy transfer in live cells measured by fluorescence lifetime imaging microscopy exploiting

    E-Print Network [OSTI]

    van Stokkum, Ivo

    Global analysis of Fo¨ rster resonance energy transfer in live cells measured by fluorescence of Fo¨ rster resonance energy transfer (FRET) in live cells using the rise time of acceptor fluorescence those molecules that are involved in the energy-transfer process are monitored. This contrasts

  20. DERIVATION OF THE MAGNETIC FIELD IN A CORONAL MASS EJECTION CORE VIA MULTI-FREQUENCY RADIO IMAGING

    SciTech Connect (OSTI)

    Tun, Samuel D. [The Naval Research Laboratory, Washington, DC 20375 (United States)] [The Naval Research Laboratory, Washington, DC 20375 (United States); Vourlidas, A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)] [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2013-04-01T23:59:59.000Z

    The magnetic field within the core of a coronal mass ejection (CME) on 2010 August 14 is derived from analysis of multi-wavelength radio imaging data. This CME's core was found to be the source of a moving type IV radio burst, whose emission is here determined to arise from the gyrosynchrotron process. The CME core's true trajectory, electron density, and line-of-sight depth are derived from stereoscopic observations, constraining these parameters in the radio emission models. We find that the CME carries a substantial amount of mildly relativistic electrons (E < 100 keV) in a strong magnetic field (B < 15 G), and that the spectra at lower heights are preferentially suppressed at lower frequencies through absorption from thermal electrons. We discuss the results in light of previous moving type IV burst studies, and outline a plan for the eventual use of radio methods for CME magnetic field diagnostics.

  1. Revisiting the Rigidly Rotating Magnetosphere model for $\\sigma$ Ori E - II. Magnetic Doppler imaging, arbitrary field RRM, and light variability

    E-Print Network [OSTI]

    Oksala, M E; Krticka, J; Townsend, R H D; Wade, G A; Prvak, M; Mikulasek, Z; Silvester, J; Owocki, S P

    2015-01-01T23:59:59.000Z

    The initial success of the Rigidly Rotating Magnetosphere (RRM) model application to the B2Vp star sigma OriE by Townsend, Owocki & Groote (2005) triggered a renewed era of observational monitoring of this archetypal object. We utilize high-resolution spectropolarimetry and the magnetic Doppler imaging (MDI) technique to simultaneously determine the magnetic configuration, which is predominately dipolar, with a polar strength Bd = 7.3-7.8 kG and a smaller non-axisymmetric quadrupolar contribution, as well as the surface distribution of abundance of He, Fe, C, and Si. We describe a revised RRM model that now accepts an arbitrary surface magnetic field configuration, with the field topology from the MDI models used as input. The resulting synthetic Ha emission and broadband photometric observations generally agree with observations, however, several features are poorly fit. To explore the possibility of a photospheric contribution to the observed photometric variability, the MDI abundance maps were used to ...

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

    SciTech Connect (OSTI)

    Lizhi Tan

    2008-08-18T23:59:59.000Z

    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.

  3. Magnetic Imaging of Micrometer and Nanometer-size Magnetic Structures and Their Flux-Pinning Effects on Superconducting Thin Films

    E-Print Network [OSTI]

    Ozmetin, Ali E.

    2010-07-14T23:59:59.000Z

    to various ferromagnetic structures. These magnetic structures include: (i) alternating iron-brass shims of 275 mu m period, (ii) an array of 4 mu m wide Co stripes with smaller period (9 mu m), (iii) a square array of 50nm diameter, high aspect ratio (5...

  4. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOE Patents [OSTI]

    Campbell, Ann. N. (13170-B Central SE #188, Albuquerque, NM 87123); Anderson, Richard E. (2800 Tennessee NE, Albuquerque, NM 87110); Cole, Jr., Edward I. (2116 White Cloud NE, Albuquerque, NM 87112)

    1995-01-01T23:59:59.000Z

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

  5. Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

    DOE Patents [OSTI]

    Skeist, S. Merrill; Baker, Richard H.

    2006-01-10T23:59:59.000Z

    An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

  6. Semi-resonant operation of a fiber-cantilever piezotube scanner for stable optical coherence tomography endoscope imaging

    E-Print Network [OSTI]

    Moon, Sucbei; Lee, Sang-Won; Rubinstein, Marc; Wong, Brian J. F; Chen, Zhongping

    2010-01-01T23:59:59.000Z

    in-phase driving signals can be described as a line with aline were added for comparing the two in each column. Drivingdriving axes (X and Y) in the vicinity of their lowest resonance peaks. Solid lines

  7. AN APPROACH FOR INTERSUBJECT ANALYSIS OF 3D BRAIN IMAGES BASED ON CONFORMAL GEOMETRY

    E-Print Network [OSTI]

    Hua, Jing

    ABSTRACT Recent advances in imaging technologies, such as Magnetic Resonance Imaging (MRI), Positron technologies have accelerated brain research in many aspects [10, 12, 13]. In order to enable comparison that it minimizes the landmark mismatch energy [4] and Wang et al. introduced the application of compound energy

  8. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2 C RIS 44025 Computed Tomography Clinical Education I 3 C RIS 44030

  9. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  10. 3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data

    E-Print Network [OSTI]

    Thompson, Paul

    3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data Yalin Wang1 , Xianfeng Gu2 , Paul algorithm finds a harmonic map from a 3-manifold to a 3D solid sphere and the second is a novel sphere of magnetic resonance images (MRI). A heat flow method is used to solve the volumetric harmonic mapping

  11. High-energy magnetic excitations in overdoped La 2 - x Sr x CuO 4 studied by neutron and resonant inelastic x-ray scattering

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

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, L. M.; Granroth, G. E.

    2015-05-01T23:59:59.000Z

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L? edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO? with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (?,?) direction agree with the dispersion relation of the spin wave in the nondoped La?CuO? (LCO), which is consistent with the previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L? edge, we have measured the dispersion relations of the so-called paramagnon mode along both (?,?) and (?,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (?,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (?,?) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (?/2,?/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (?,?) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (?,?) direction as detected by the x-ray scattering.

  12. High-energy magnetic excitations in overdoped La 2 - x Sr x CuO 4 studied by neutron and resonant inelastic x-ray scattering

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

    Wakimoto, S.; Ishii, K.; Kimura, H.; Fujita, M.; Dellea, G.; Kummer, K.; Braicovich, L.; Ghiringhelli, G.; Debeer-Schmitt, L. M.; Granroth, G. E.

    2015-05-01T23:59:59.000Z

    We have performed neutron inelastic scattering and resonant inelastic x-ray scattering (RIXS) at the Cu-L? edge to study high-energy magnetic excitations at energy transfers of more than 100 meV for overdoped La2-xSrxCuO? with x=0.25 (Tc=15 K) and x=0.30 (nonsuperconducting) using identical single-crystal samples for the two techniques. From constant-energy slices of neutron-scattering cross sections, we have identified magnetic excitations up to ~250 meV for x=0.25. Although the width in the momentum direction is large, the peak positions along the (?,?) direction agree with the dispersion relation of the spin wave in the nondoped La?CuO? (LCO), which is consistent with themore »previous RIXS results of cuprate superconductors. Using RIXS at the Cu-L? edge, we have measured the dispersion relations of the so-called paramagnon mode along both (?,?) and (?,0) directions. Although in both directions the neutron and RIXS data connect with each other and the paramagnon along (?,0) agrees well with the LCO spin-wave dispersion, the paramagnon in the (?,?) direction probed by RIXS appears to be less dispersive and the excitation energy is lower than the spin wave of LCO near (?/2,?/2). Thus, our results indicate consistency between neutron inelastic scattering and RIXS, and elucidate the entire magnetic excitation in the (?,?) direction by the complementary use of two probes. The polarization dependence of the RIXS profiles indicates that appreciable charge excitations exist in the same energy range of magnetic excitations, reflecting the itinerant character of the overdoped sample. A possible anisotropy in the charge excitation intensity might explain the apparent differences in the paramagnon dispersion in the (?,?) direction as detected by the x-ray scattering.« less

  13. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source

    SciTech Connect (OSTI)

    Yoshida, Ken-ichi, E-mail: yoshida.kennichi71@jaea.go.jp; Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)] [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-02-15T23:59:59.000Z

    A flat distribution of the minimum magnetic field (flat-B{sub min}) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical B{sub min}. To form a flat-B{sub min} structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-B{sub min} structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  14. "Spectral Implementation" for creating a labeled pseudo-pure state and the Bernstein-Vazirani's algorithm in a four-qubit nuclear magnetic resonance quantum processor

    E-Print Network [OSTI]

    Xinhua Peng; Xiwen Zhu; Ximing Fang; Mang Feng; Maili Liu; Kelin Gao

    2004-02-23T23:59:59.000Z

    A quantum circuit is introducted to describe the preparation of a labeled pseudo-pure state by mutiplet-component excitation scheme which has been experimentally implemented on a 4-qubit nuclear magnetic resonance quantum processor. Meanwhile, we theoretically analyze and numerically inverstigate the low-power selective single-pulse implementation of a controlled-rotation gate, which manifests its validity in our experiment. Based on the labeled pseudo-pure state prepared, a 3-qubit Bernstein-Vazirani algorithm has been experimentally demonstrated by spectral implementation. The "answers" of the computations are indentified from the split speak positions in the spectra of the observer spin, which are equivalent to projective measurements required by the algorithms.

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

    SciTech Connect (OSTI)

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

    2010-08-15T23:59:59.000Z

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

  16. Journal of Superconductivity: Incorporating Novel Magnetism, Vol. 16, No. 2, April 2003 ( C 2003) Theory of Cyclotron Resonance and Magneto-Optics

    E-Print Network [OSTI]

    Kono, Junichiro

    magnetic semiconductors; ultra-high magnetic fields. 1. INTRODUCTION Dilute magnetic semiconductor alloys- gap In1-xMnxAs dilute magnetic semiconductor (DMS) alloys in an ultra-high magnetic field, B, ori

  17. Systemic, local, and imaging biomarkers of brain injury: more needed, and better use of those already established?

    E-Print Network [OSTI]

    Carpenter, Keri L. H.; Czosnyka, Marek; Jalloh, Ibrahim; Newcombe, Virginia F. J.; Helmy, Adel; Shannon, Richard J.; Budohoski, Karol P.; Kolias, Angelos G.; Kirkpatrick, Peter J.; Carpenter, Thomas Adrian; Menon, David K.; Hutchinson, Peter J.

    2015-02-18T23:59:59.000Z

    anisotropy; FDG, 18F-fluorodeoxyglucose; FLAIR, fluid-attenuated inversion recovery; GABA, gamma-aminobutyric acid; GCS, Glas- gow coma scale score; GFAP, glial fibrillary acidic protein; GOS, Glasgow outcome scale score; GE, gradient echo; GRE, gradient... dehydrogenase; LPR, lac- tate/pyruvate ratio; MMP, matrix metalloprotease; MRI, magnetic resonance imag- ing; MRS, magnetic resonance spectroscopy; NAA, N -acetylaspartate; NAAG, N - acetylaspartylglutamate; NAD+, nicotine adenine dinucleotide (oxidized form...

  18. Imaging and Spectroscopic Diagnostics on the Formation of Two Magnetic Flux Ropes Revealed by SDO/AIA and IRIS

    E-Print Network [OSTI]

    Cheng, X; Fang, C

    2015-01-01T23:59:59.000Z

    Helical magnetic flux rope (MFR) is a fundamental structure of corona mass ejections (CMEs) and has been discovered recently to exist as a sigmoidal channel structure prior to its eruption in the extreme ultraviolet (EUV) high temperature passbands of the Atmospheric Imaging Assembly (AIA). However, when and where the MFR is built up are still elusive. In this paper, we investigate two MFRs (MFR1 and MFR2) in detail, whose eruptions produced two energetic solar flares and CMEs on 2014 April 18 and 2014 September 10, respectively. The AIA EUV images reveal that for a long time prior to their eruption, both MFR1 and MFR2 are under formation, which is probably through magnetic reconnection between two groups of sheared arcades driven by the shearing and converging flows in the photosphere near the polarity inversion line. At the footpoints of the MFR1, the \\textit{Interface Region Imaging Spectrograph} Si IV, C II, and Mg II lines exhibit weak to moderate redshifts and a non-thermal broadening in the pre-flare p...

  19. Fast radio-frequency amplitude modulation in multiple-quantum magic-angle-spinning nuclear magnetic resonance: Theory and experiments

    E-Print Network [OSTI]

    Frydman, Lucio

    Fast radio-frequency amplitude modulation in multiple-quantum magic-angle-spinning nuclear magnetic of this experiment has been the poor efficiency of the radio-frequency pulses used in converting multiple-modulated radio-frequency pulses, and which can yield substantial signal and even resolution enhancements over

  20. Images of Vega Dust Ring at 350 and 450 microns: New Clues to the Trapping of Multiple-Sized Dust Particles in Planetary Resonances

    E-Print Network [OSTI]

    K. A. Marsh; C. D. Dowell; T. Velusamy; K. Grogan; C. A. Beichman

    2006-06-14T23:59:59.000Z

    We have used the SHARC II camera at Caltech Submillimeter Observatory to make 350 and 450 micron images of the Vega dust disk at spatial resolutions (FWHM) of 9.7" and 11.1", respectively. The images show a ring-like morphology (radius \\~ 100 AU) with inhomogeneous structure that is qualitatively different from that previously reported at 850 microns and longer wavelengths. We attribute the 350/450 micron emission to a grain population whose characteristic size (~ 1 mm) is intermediate between that of the cm-sized grains responsible for emission longward of 850 microns and the much smaller grains (< 18 microns) in the extensive halo, visible at 70 microns, discussed by Su et al. (2005). We have combined our submillimeter images with Spitzer data at 70 microns to produce 2-d maps of line-of-sight optical depth (relative column density). These "tau maps" suggest that the mm-sized grains are located preferentially in three symmetrically-located concentrations. If so, then this structure could be understood in terms of the Wyatt (2003) model in which planetesimals are trapped in the mean motion resonances of a Neptune-mass planet at 65 AU, provided allowance is made for the spatial distribution of dust grains to differ from that of the parent planetesimals. The peaks of the tau maps are, in fact, located near the expected positions corresponding to the 4:3 resonance. If this identification is confirmed by future observations, it would resolve an ambiguity with regard to the location of the planet.

  1. Imaging Agents DOI: 10.1002/anie.201301135

    E-Print Network [OSTI]

    Gao, Jinming

    Takahashi, A. Dean Sherry, and Jinming Gao* Magnetic resonance imaging (MRI) is a powerful non- invasive a "reverse" pH gradient across the cell membrane is observed in cancer cells compared to normal cells.[11 19 F signal. b) Structural formula of three representative diblock copolymers containing different p

  2. Nanoscale magnetic field mapping with a single spin scanning probe magnetometer

    SciTech Connect (OSTI)

    Rondin, L.; Tetienne, J.-P.; Spinicelli, P.; Roch, J.-F.; Jacques, V. [Laboratoire de Photonique Quantique et Moleculaire, Ecole Normale Superieure de Cachan and CNRS UMR 8537, 94235 Cachan Cedex (France); Dal Savio, C.; Karrai, K. [Attocube systems AG, Koeniginstrasse 11A RGB, Munich 80539 (Germany); Dantelle, G. [Laboratoire de Physique de la Matiere Condensee, Ecole Polytechnique and CNRS UMR 7643, 91128 Palaiseau (France); Thiaville, A.; Rohart, S. [Laboratoire de Physique des Solides, Universite Paris-Sud and CNRS UMR 8502, 91405 Orsay (France)

    2012-04-09T23:59:59.000Z

    We demonstrate quantitative magnetic field mapping with nanoscale resolution, by applying a lock-in technique on the electron spin resonance frequency of a single nitrogen-vacancy defect placed at the apex of an atomic force microscope tip. In addition, we report an all-optical magnetic imaging technique which is sensitive to large off-axis magnetic fields, thus extending the operation range of diamond-based magnetometry. Both techniques are illustrated by using a magnetic hard disk as a test sample. Owing to the non-perturbing and quantitative nature of the magnetic probe, this work should open up numerous perspectives in nanomagnetism and spintronics.

  3. Injection-controlled laser resonator

    DOE Patents [OSTI]

    Chang, J.J.

    1995-07-18T23:59:59.000Z

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

  4. Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

    DOE Patents [OSTI]

    Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

    2000-12-19T23:59:59.000Z

    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.

  5. Nuclear magnetic resonance: Its role as a microscopic probe of the electronic and magnetic properties of High-{Tc} superconductors and related materials

    SciTech Connect (OSTI)

    Suh, Byoung Jin

    1995-12-27T23:59:59.000Z

    NMR experiments are reported for Sr{sub 2}CuO{sub 2}Cl{sub 2}, HgBa{sub 2}CuO{sub 4+d}, YNi{sub 2}B{sub 2}C and YBa{sub 2}Cu{sub 3}O{sub 7}. NMR studies typify three different aspects of microscopic properties of HTSC. In non-superconducting antiferromagnetic (AF) prototype Sr{sub 2}CuO{sub 2}Cl{sub 2}, we used NMR to investigate Cu{sup 2+} correlated spin dynamics and AF phase transition in CuO2 layers. In the superconductors, we used NMR both to investigate the electronic properties of the Fermi-liquid in normal and superconducting states and to investigate flux lattice and flux-line dynamics in the superconducting state in presence of magnetic field. A summary of each study is given: {sup 35}Cl NMR was measured in Sr{sub 2}CuO{sub 2}Cl{sub 2} single crystals with T{sub N}=257K. {sub 35}Cl NMR relaxation rates showed crossover of Cu{sup 2+} spin dynamics from Heisenberg to XY-like correlation at 290 K well above T{sub N}. A field-dependent T{sub N} for H{perpendicular}c was observed and explained by a field-induced Ising-like anisotropy in ab plane. {sup 199}Hg NMR was measured in HgBa{sub 2}CuO{sub 4+d}. Properties of the Fermi-liquid are characterized by a single-spin fluid picture and opening of a spin pseudo-gap at q=0 above {Tc}. Below {Tc}, spin component of Knight shift decreases rapidly in agreement with prediction for d-wave pairing scheme. {sup 11}B and {sup 89}Y NMR/magnetization were measured in YNi{sub 2}B{sub 2}C. Temperature dependence of {sup 11}B Knight shift and of the NSLR gave a normal state which agrees with the Korringa relation, indicating that the AF fluctuations on the Ni sublattice are negligible. Opening of the superconducting gap obeys BCS. A NMR approach to investigate vortex thermal motion in HTSC is presented, based on contribution of thermal flux-lines motion to both T{sub 2}{sup {minus}1} and T{sub 1}{sup {minus}1}. Effects are demonstrated in YBa{sub 2}Cu{sub 3}O{sub 7} and HgBa{sub 2}CuO{sub 4+d}.

  6. Magnetic Materials Group

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

    for magnetic circular dichroism (XMCD) and magnetic scattering experiments. Sunset Yellow 6-ID-B: Resonant and In-Field Scattering Beamline 6-ID-B,C is the primary beamline on...

  7. Local determination of the constitutive law of a dense suspension of noncolloidal particles through magnetic resonance imaging

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    industrial processes (coal slurries transport, sewage sludge application, foodstuff transport...), natural

  8. Robust inference of baseline optical properties of the human head with 3D segmentation from magnetic resonance imaging

    E-Print Network [OSTI]

    Barnett, Alex

    and voltage-sensitive dyes [4]. By relying on photon transport through tis- sue, DOT also accesses spatial, measuring both total hemoglobin concentration and oxygenation. Optical con- trast can also arise from cellMRI). In addition to sensitivity to ab- sorbing chromophores, DOT can be sensitive to cellular scattering changes

  9. Computer Aided Segmentation and Early Therapeutic Response Classification (CADrx) for Glioblastoma Multiforme (GBM) Brain Tumors with Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Huo, Jing

    2012-01-01T23:59:59.000Z

    discriminate classifier (LDC) [DHS00] to differentiate tumortumor voxels. We used the LDC classifier implementation inapply the machine learned LDC classifier on the new test

  10. Computer Aided Segmentation and Early Therapeutic Response Classification (CADrx) for Glioblastoma Multiforme (GBM) Brain Tumors with Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Huo, Jing

    2012-01-01T23:59:59.000Z

    all 1.5T GE and all 1.5T Siemens scanners: (A) Brain WM ROIfield strength for all Siemens scanners: (A) Brain WM ROIincluded two 3T scan- ners (Siemens TrioTim at two sites)

  11. FRPRCS-8 University of Patras, Patras, Greece, July 16-18, 2007 MAGNETIC RESONANCE IMAGING OF CONCRETE WITH FRP

    E-Print Network [OSTI]

    Burgoyne, Chris

    the mobility of the water molecules and thereby to characterise the pore structure of the matrix material-dimensional (3D) assessment can be made. The signal is also affected by the mobility of the hydrogen nuclei. Consequently, the observation of the different internal structures inside an object depends not only

  12. Assessment of Alzheimer's disease risk with structural and functional magnetic resonance imaging : an arterial spin labeling study

    E-Print Network [OSTI]

    Bangen, Katherine J.

    2010-01-01T23:59:59.000Z

    Framingham Stroke Risk Pro?le (FSRP; D’Agostino, et al. ,1994). The FSRP is a validated scale that was developed torisk burden. The FSRP provides gender-corrected scores based

  13. Design of multi-channel radio-frequency front-end for 200mhz parallel magnetic resonance imaging

    E-Print Network [OSTI]

    Liu, Xiaoqun

    2009-05-15T23:59:59.000Z

    increases to 64 or even 128, the traditional method of stacking the same number of radio-frequency (RF) receivers with very low level of integration becomes expensive and cumbersome. However, the cost, size, power consumption of the Parallel MRI receivers...

  14. Magnetic resonance imaging demonstrates long-term changes in brain structure in children born preterm and exposed to chorioamnionitis.

    E-Print Network [OSTI]

    Hatfield, Tamera; Wing, Deborah A; Buss, Claudia; Head, Kevin; Muftuler, L Tugan; Davis, Elysia Poggi

    2011-01-01T23:59:59.000Z

    11035896] 12. Davis EP, Buss C, Muftuler T, et al. Children’A. Wing, MD 1 , Claudia Buss, PhD 2,4 , Kevin Head, BS 2 ,

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

    DOE Patents [OSTI]

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

    1983-05-09T23:59:59.000Z

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

  16. Scales in the fine structure of the magnetic dipole resonance: A wavelet approach to the shell model

    SciTech Connect (OSTI)

    Petermann, I.; Langanke, K. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Martinez-Pinedo, G. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany); Neumann-Cosel, P. von [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Nowacki, F. [Institute Pluridisciplinaire Hubert Curien, F-67037 Strasbourg (France); Richter, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); ECT, Villa Tambosi, I-38050 Villazano, Trento (Italy)

    2010-01-15T23:59:59.000Z

    Wavelet analysis is applied as a tool for the examination of magnetic dipole (M1) strength distributions in pf-shell nuclei by the extraction of wavelet scales. Results from the analysis of theoretical M1 strength distributions calculated with the KB3G interaction are compared to experimental data from (e,e{sup '}) experiments and good agreement of the deduced wavelet scales is observed. This provides further insight into the nature of the scales from the model results. The influence of the number of Lanczos iterations on the development and stability of scales and the role of the model space in terms of the truncation level are studied. Moreover, differences in the scales of spin and orbital parts of the M1 strength are investigated, as is the use of different effective interactions (KB3G, GXPF1, and FPD6).

  17. A triple-resonant RF coil setup for 1H, 23Na and 39K MR imaging of the rat brain at 9.4T M. A. Augath1,2

    E-Print Network [OSTI]

    A triple-resonant RF coil setup for 1H, 23Na and 39K MR imaging of the rat brain at 9.4T M. A. Augath1,2 , P. Heiler1 , S. Kirsch1 , and L. R. Schad1 1 Computer Assisted Clinical Medicine, Faculty concentrations of 23 Na and 39 K offers a very promising approach in clinical diagnostics. For MR imaging of both

  18. Rapid prediction of various physical properties for middle distillate fuel utilizing directly coupled liquid chromatography//sup 1/H nuclear magnetic resonance

    SciTech Connect (OSTI)

    Caswell, K.A.; Glass, T.E.; Swann, M.; Dorn, H.C.

    1989-02-01T23:59:59.000Z

    A group property approach has been developed to predict 17 physical properties of middle distillate (e.g., jet and diesel) fuels from experimentally derived liquid chromatography//sup 1/H nuclear magnetic resonance (LC//sup 1/H NMR) data. In the LC//sup 1/H NMR technique, the fuel is separated according to chemical class and the average molecular structure for each chemical class is then calculated. These average molecular structures form a basis set to predict the physical properties of the fuel. The physical properties that can be obtained in this manner are 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 the initial, 10%, 50%, 90%, and end boiling points. Fourteen of the correlation coefficients for the predictions are better than 0.90 with 11 of the predictions falling either within or approximately equal to the ASTM method reproducibility for the measurement of the fuel property. The present method also provides chemical insight concerning the influence of chemical structural changes on the physical properties of the fuel as well as requiring much less analysis time and sample volume than corresponding ASTM methods.

  19. Bruker 380E electron paramagnetic resonance | EMSL

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

    Computational and Magnetic Resonance Spectroscopy: A Case Study on Abstract: Redox flow battery (RFB) is a promising candidate for energy storage component in designing resilient...

  20. Use of diffusion tensor imaging to assess the impact of normobaric hyperoxia within at-risk pericontusional tissue after traumatic brain injury

    E-Print Network [OSTI]

    Veenith, Tonny V.; Carter, Eleanor L.; Grossac, Julia; Newcombe, Virginia F.; Outtrim, Joanne G.; Nallapareddy, Sridhar; Lupson, Victoria; Correia, Marta M.; Mada, Marius M.; Williams, Guy B.; Menon, David K.; Coles, Jonathan P.

    2014-07-09T23:59:59.000Z

    Glamorgan, Wales, UK). Diffusion tensor imaging was obtained at each level after an equilibration period of 15min to assess the impact of oxygen therapy on normal brain. Imaging All subjects were scanned using a 3T Siemens Verio magnetic resonance imaging... scanner (Siemens AG, Erlangen, Germany) within the Wolfson Brain Imaging Centre (WBIC), University of Cambridge. During the study period there were no major changes or upgrades to the scanner or software. The sequences obtained were structural sequences...

  1. Use of diffusion tensor imaging to assess the impact of normobaric hyperoxia within at-risk pericontusional tissue following traumatic brain injury

    E-Print Network [OSTI]

    Veenith, T.V.; Carter, E.L.; Grossac, J.; Newcombe, V.F.; Outtrim, J.G.; Nallapareddy, Sridhar; Lupson, Victoria; Correia, M.M.; Mada, Marius M.; Williams, Guy B.; Menon, David K.; Coles, J.P.

    2014-07-08T23:59:59.000Z

    Glamorgan, Wales, UK). Diffusion tensor imaging was obtained at each level after an equilibration period of 15min to assess the impact of oxygen therapy on normal brain. Imaging All subjects were scanned using a 3T Siemens Verio magnetic resonance imaging... scanner (Siemens AG, Erlangen, Germany) within the Wolfson Brain Imaging Centre (WBIC), University of Cambridge. During the study period there were no major changes or upgrades to the scanner or software. The sequences obtained were structural sequences...

  2. Copyright by SIAM. Unauthorized reproduction of this article is prohibited. SIAM J. IMAGING SCIENCES c 2010 Society for Industrial and Applied Mathematics

    E-Print Network [OSTI]

    Bertozzi, Andrea L.

    forces we use total variation­based inverse scale-space techniques on the input data. Furthermore, we use process is the external data, which can be images of any kind, such as photographs or magnetic resonance of California, Los Angeles, Los Angeles, CA 90095. Current address: Mental Images, Fasanenstr. 81, 10623 Berlin

  3. 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)

    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

    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.

  4. Lensless Imaging of Magnetic Nanostructures by X-ray Spectro-Holography

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5 -ofLearningLensless Imaging of4 J. Lüning, W.

  5. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-Ray Imaging of the

  6. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-Ray Imaging of

  7. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires may contribute more toConsensusX-RayX-Ray Imaging ofX-Ray

  8. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat isJoin theanniversaryI 1 0 3 P 0 d dX-Ray Imaging

  9. X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsingWhat isJoin theanniversaryI 1 0 3 P 0 dX-Ray Imaging

  10. X-Ray Diffraction Microscopy of Magnetic Structures

    SciTech Connect (OSTI)

    Turner, J.; Lima, E.; Huang, X.; Krupin, O.; Seu, K.; Parks, D.; Kevan, S.; Kisslinger, K.; McNulty, I.; Gambino, R.; Mangin, S.; Roy, S. and Fischer, P.

    2011-07-14T23:59:59.000Z

    We report the first proof-of-principle experiment of iterative phase retrieval from magnetic x-ray diffraction. By using the resonant x-ray excitation process and coherent x-ray scattering, we show that linearly polarized soft x rays can be used to image both the amplitude and the phase of magnetic domain structures. We recovered the magnetic structure of an amorphous terbium-cobalt thin film with a spatial resolution of about 75 nm at the Co L{sub 3} edge at 778 eV. In comparison with soft x-ray microscopy images recorded with Fresnel zone plate optics at better than 25 nm spatial resolution, we find qualitative agreement in the observed magnetic structure.

  11. Experimental determination of the radial dose distribution in high gradient regions around {sup 192}Ir wires: Comparison of electron paramagnetic resonance imaging, films, and Monte Carlo simulations

    SciTech Connect (OSTI)

    Kolbun, N.; Leveque, Ph.; Abboud, F.; Bol, A.; Vynckier, S.; Gallez, B. [Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Institute of Experimental and Clinical Research, Universite catholique de Louvain, Avenue Hippocrate 55, B-1200 Brussels (Belgium); Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium)

    2010-10-15T23:59:59.000Z

    Purpose: The experimental determination of doses at proximal distances from radioactive sources is difficult because of the steepness of the dose gradient. The goal of this study was to determine the relative radial dose distribution for a low dose rate {sup 192}Ir wire source using electron paramagnetic resonance imaging (EPRI) and to compare the results to those obtained using Gafchromic EBT film dosimetry and Monte Carlo (MC) simulations. Methods: Lithium formate and ammonium formate were chosen as the EPR dosimetric materials and were used to form cylindrical phantoms. The dose distribution of the stable radiation-induced free radicals in the lithium formate and ammonium formate phantoms was assessed by EPRI. EBT films were also inserted inside in ammonium formate phantoms for comparison. MC simulation was performed using the MCNP4C2 software code. Results: The radical signal in irradiated ammonium formate is contained in a single narrow EPR line, with an EPR peak-to-peak linewidth narrower than that of lithium formate ({approx}0.64 and 1.4 mT, respectively). The spatial resolution of EPR images was enhanced by a factor of 2.3 using ammonium formate compared to lithium formate because its linewidth is about 0.75 mT narrower than that of lithium formate. The EPRI results were consistent to within 1% with those of Gafchromic EBT films and MC simulations at distances from 1.0 to 2.9 mm. The radial dose values obtained by EPRI were about 4% lower at distances from 2.9 to 4.0 mm than those determined by MC simulation and EBT film dosimetry. Conclusions: Ammonium formate is a suitable material under certain conditions for use in brachytherapy dosimetry using EPRI. In this study, the authors demonstrated that the EPRI technique allows the estimation of the relative radial dose distribution at short distances for a {sup 192}Ir wire source.

  12. A novel strategy for surface modification of superparamagnetic iron oxide nanoparticles for lung cancer imaging

    E-Print Network [OSTI]

    Gao, Jinming

    A novel strategy for surface modification of superparamagnetic iron oxide nanoparticles for lung Superparamagnetic iron oxide (SPIO) nanoparticles are widely used in magnetic resonance imaging (MRI) as versatile-step procedure for the surface functionalization of SPIO nanoparticles with a lung cancer-targeting peptide

  13. NACoM2003 Extended Abstracts 1 --6 Fast image registration --a variational approach

    E-Print Network [OSTI]

    Modersitzki, Jan

    Fischer # and Jan Modersitzki Institute of Mathematics, University of LË?ubeck, D­23560 LË?ubeck, Germany#erent modalities, like for example computer tomography (CT) and magnetic resonance imaging (MRI). To be successful measure. For this type of problems, we provide a toolbox of registration routines which enables the user

  14. 3D RECONSTRUCTION OF PLANT ROOTS FROM MRI IMAGES Hannes Schulz1

    E-Print Network [OSTI]

    Behnke, Sven

    distance measure by a multi-scale vesselness measure. As a result, paths running within good root candidates are preferred over paths in bare soil. We test this method using both virtually generated MRI) and Nuclear Magnetic Resonance Imaging (MRI) (Brown et al., 1990; Jahnke et al., 2009; Southon and Jones, 1992

  15. Imaging and Radiography with Nuclear Resonance Fluorescence and Effective-Z (EZ-3D) Determination; SNM Detection Using Prompt Neutrons from Photon Induced Fission

    SciTech Connect (OSTI)

    Bertozzi, William; Hasty, Richard; Klimenko, Alexei; Korbly, Stephen E.; Ledoux, Robert J.; Park, William [Passport Systems, Inc., 70 Treble Cove Road, N. Billerica MA 01862 (United States)

    2009-03-10T23:59:59.000Z

    Four new technologies have been developed for use in non-intrusive inspection systems to detect nuclear materials, explosives and contraband. Nuclear Resonance Fluorescence (NRF) provides a three dimensional image of the isotopic content of a container. NRF determines the isotopic composition of a region and specifies the isotopic structure of the neighboring regions, thus providing the detailed isotopic composition of any threat. In transmission mode, NRF provides a two dimensional projection of the isotopic content of a container, much as standard X-ray radiography provides for density. The effective-Z method (EZ-3D) uses electromagnetic scattering processes to yield a three-dimensional map of the effective-Z and the density in a container. The EZ-3D method allows for a rapid discrimination based on effective Z and mass of materials such as those with high Z, as well as specifying regions of interest for other contraband. The energy spectrum of prompt neutrons from photon induced fission (PNPF) provides a unique identification of the presence of actinides and SNM. These four new technologies can be used independently or together to automatically determine the presence of hazardous materials or contraband. They can also be combined with other technologies to provide added specificity.

  16. 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)

    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

    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.

  17. Decay of an ultracold fermionic lithium gas near a Feshbach resonance The interactions between atoms can be strongly modified by tuning magnetic fields to

    E-Print Network [OSTI]

    Decay of an ultracold fermionic lithium gas near a Feshbach resonance The interactions between the interaction strength is crucial in the search for a superfluid phase transition. Otherwise, the phase lithium gas near a Feshbach resonance, Phys. Rev. Lett. 89, 203201 (2002). 2. K.M. O'Hara, S.L. Hemmer, S

  18. Bruker BioSpin EPR (Electron Paramagnetic Resonance) is a spectroscopic

    E-Print Network [OSTI]

    Niebur, Ernst

    might put on your refrigerator. When we supply an external magnetic field, the paramagnetic electrons is a magnetic resonance technique very similar to NMR (Nuclear Magnetic Resonance). However, instead in an applied magnetic field. Like a proton, the electron has "spin", which gives it a magnetic property known

  19. " Rotating, In Plane Magnetization and Magneto-Optic Imaging of Cracks in Thick-Section Steel Under Stainless-Steel Cladding".

    SciTech Connect (OSTI)

    Gerald Fitzpatrick & Richard Skaugset

    2000-10-13T23:59:59.000Z

    The nondestructive inspection (NDI) of thick-section steel nuclear reactor pressure vessels (RPV'S) is rendered difficult by rough stainless steel cladding. Because the cladding condition is poorly known in most RPV's, an NDI technique that is unaffected by cladding roughness would be a major advance. Magneto-optic imaging is one such technique. The purpose of this project was to develop a novel method to induce rotating, in-plane magnetization, and to combine this capability with magneto-optic imaging to produce a self-contained inspection system. Imaging of cracks under thick cladding (0.250 inches) was demonstrated using a system capable, in principle, of performing robotic inspections, both inside & outside a typical boiling water reactor (BWR) RPV. This report, together publications listed, constitutes a comprehensive account of this work.

  20. Imaging

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem NotEnergy,ARMFormsGasReleaseSpeechesHallNotSeventyTechnologiesfacilityImaging

  1. Imaging

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)Hydrogen StorageITERITERBuilding EnergyImaging Print The

  2. Imaging

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm)Hydrogen StorageITERITERBuilding EnergyImaging Print

  3. Dynamic control of spin states in interacting magnetic elements

    DOE Patents [OSTI]

    Jain, Shikha; Novosad, Valentyn

    2014-10-07T23:59:59.000Z

    A method for the control of the magnetic states of interacting magnetic elements comprising providing a magnetic structure with a plurality of interacting magnetic elements. The magnetic structure comprises a plurality of magnetic states based on the state of each interacting magnetic element. The desired magnetic state of the magnetic structure is determined. The active resonance frequency and amplitude curve of the desired magnetic state is determined. Each magnetic element of the magnetic structure is then subjected to an alternating magnetic field or electrical current having a frequency and amplitude below the active resonance frequency and amplitude curve of said desired magnetic state and above the active resonance frequency and amplitude curve of the current state of the magnetic structure until the magnetic state of the magnetic structure is at the desired magnetic state.

  4. Computer-aided detection of bladder tumors based on the thickness mapping of bladder wall in MR images

    E-Print Network [OSTI]

    deaths in the United States. Recent advances in medical imaging technologies, such as magnetic resonance in the United States, and early diagnosis of bladder abnormalities is crucial for effective treatment of bladder. INTRODUCTION According to American Cancer Society, bladder cancer is the fifth leading cause of cancer deaths

  5. Permanent magnet with MgB{sub 2} bulk superconductor

    SciTech Connect (OSTI)

    Yamamoto, Akiyasu, E-mail: yamamoto@appchem.t.u-tokyo.ac.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ishihara, Atsushi; Tomita, Masaru [Railway Technical Research Institute, 2-8-38 Hikari, Kokubunji, Tokyo 185-8540 (Japan); Kishio, Kohji [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    2014-07-21T23:59:59.000Z

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2?K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3?T at 20?K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulk magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.

  6. Appl. Magn. Reson. (2007) 32, 93112 DOI 10.1007/s00723-007-0002-7

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    2007-01-01T23:59:59.000Z

    Applied Magnetic Resonance Noninvasive Measurements of Gas Exchange in a Three- Dimensional Fluidized Bed 12 July 2006 © Springer-Verlag 2007 Abstract. We present a novel nuclear magnetic resonance (NMR of nuclear magnetic resonance (NMR) as a noninvasive tool for studying the dy- namics of the solid particles

  7. Imaging dirac-mass disorder from magnetic dopant-atoms in the ferromagnetic topological insulator Crx(Bi?.?Sb?.?)??xTe?

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

    Lee, Inhee [Brookhaven National Lab. (BNL), Upton, NY (United States); Kim, Chung Koo [Brookhaven National Lab. (BNL), Upton, NY (United States); Lee, Jinho [Brookhaven National Lab. (BNL), Upton, NY (United States); Seoul National Univ., Seoul (Korea); Billinge, Simon J. L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Columbia Univ., New York, NY (United States); Zhong, Ruidan D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Schneeloch, John A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Liu, Tiansheng S. [Brookhaven National Lab. (BNL), Upton, NY (United States); North Univ. of China, Shanxi (China); Valla, Tonica [Brookhaven National Lab. (BNL), Upton, NY (United States); Tranquada, John M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Davis, J. C. Seamus [Brookhaven National Lab. (BNL), Upton, NY (United States); Cornell Univ., Ithaca, NY (United States); Univ. of St. Andrews, Fife (Scotland)

    2015-02-03T23:59:59.000Z

    To achieve and use the most exotic electronic phenomena predicted for the surface states of 3D topological insulators (TIs), it is necessary to open a “Dirac-mass gap” in their spectrum by breaking time-reversal symmetry. Use of magnetic dopant atoms to generate a ferromagnetic state is the most widely applied approach. However, it is unknown how the spatial arrangements of the magnetic dopant atoms influence the Dirac-mass gap at the atomic scale or, conversely, whether the ferromagnetic interactions between dopant atoms are influenced by the topological surface states. Here we image the locations of the magnetic (Cr) dopant atoms in the ferromagnetic TI Cr?.??(Bi?.?Sb?.?)?.??Te?. Simultaneous visualization of the Dirac-mass gap ?(r) reveals its intense disorder, which we demonstrate is directly related to fluctuations in n(r), the Cr atom areal density in the termination layer. We find the relationship of surface-state Fermi wavevectors to the anisotropic structure of ?(r) not inconsistent with predictions for surface ferromagnetism mediated by those states. Moreover, despite the intense Dirac-mass disorder, the anticipated relationship ?(r)?n(r) is confirmed throughout and exhibits an electron–dopant interaction energy J* = 145 meV·nm². These observations reveal how magnetic dopant atoms actually generate the TI mass gap locally and that, to achieve the novel physics expected of time-reversal symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential.

  8. Imaging dirac-mass disorder from magnetic dopant-atoms in the ferromagnetic topological insulator Crx(Bi?.?Sb?.?)??xTe?

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

    Lee, Inhee; Kim, Chung Koo; Lee, Jinho; Billinge, Simon J. L.; Zhong, Ruidan D.; Schneeloch, John A.; Liu, Tiansheng S.; Valla, Tonica; Tranquada, John M.; Gu, Genda; et al

    2015-02-03T23:59:59.000Z

    To achieve and use the most exotic electronic phenomena predicted for the surface states of 3D topological insulators (TIs), it is necessary to open a “Dirac-mass gap” in their spectrum by breaking time-reversal symmetry. Use of magnetic dopant atoms to generate a ferromagnetic state is the most widely applied approach. However, it is unknown how the spatial arrangements of the magnetic dopant atoms influence the Dirac-mass gap at the atomic scale or, conversely, whether the ferromagnetic interactions between dopant atoms are influenced by the topological surface states. Here we image the locations of the magnetic (Cr) dopant atoms in themore »ferromagnetic TI Cr?.??(Bi?.?Sb?.?)?.??Te?. Simultaneous visualization of the Dirac-mass gap ?(r) reveals its intense disorder, which we demonstrate is directly related to fluctuations in n(r), the Cr atom areal density in the termination layer. We find the relationship of surface-state Fermi wavevectors to the anisotropic structure of ?(r) not inconsistent with predictions for surface ferromagnetism mediated by those states. Moreover, despite the intense Dirac-mass disorder, the anticipated relationship ?(r)?n(r) is confirmed throughout and exhibits an electron–dopant interaction energy J* = 145 meV·nm². These observations reveal how magnetic dopant atoms actually generate the TI mass gap locally and that, to achieve the novel physics expected of time-reversal symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential.« less

  9. Wavelets in medical imaging

    SciTech Connect (OSTI)

    Zahra, Noor e; Sevindir, Huliya A.; Aslan, Zafar; Siddiqi, A. H. [Sharda University, SET, Department of Electronics and Communication, Knowledge Park 3rd, Gr. Noida (India); University of Kocaeli, Department of Mathematics, 41380 Kocaeli (Turkey); Istanbul Aydin University, Department of Computer Engineering, 34295 Istanbul (Turkey); Sharda University, SET, Department of Mathematics, 32-34 Knowledge Park 3rd, Greater Noida (India)

    2012-07-17T23:59:59.000Z

    The aim of this study is to provide emerging applications of wavelet methods to medical signals and images, such as electrocardiogram, electroencephalogram, functional magnetic resonance imaging, computer tomography, X-ray and mammography. Interpretation of these signals and images are quite important. Nowadays wavelet methods have a significant impact on the science of medical imaging and the diagnosis of disease and screening protocols. Based on our initial investigations, future directions include neurosurgical planning and improved assessment of risk for individual patients, improved assessment and strategies for the treatment of chronic pain, improved seizure localization, and improved understanding of the physiology of neurological disorders. We look ahead to these and other emerging applications as the benefits of this technology become incorporated into current and future patient care. In this chapter by applying Fourier transform and wavelet transform, analysis and denoising of one of the important biomedical signals like EEG is carried out. The presence of rhythm, template matching, and correlation is discussed by various method. Energy of EEG signal is used to detect seizure in an epileptic patient. We have also performed denoising of EEG signals by SWT.

  10. Element-specific imaging of magnetic domains at 25 nm spatial resolution using soft x-ray microscopy

    E-Print Network [OSTI]

    Bayreuther, Günther

    magnetic transmission x-ray microscopy M-TXM . This was first demonstrated at the synchrotron facility BESSY I in Berlin.8­10 In this article experiments with M-TXM obtained at the XM-1 beamline

  11. V O L U M E 59, NU M B E R 1 P H Y S I C A L R E V I E W L E T T E R S Observation of Spin Diffusion in Zero-Field Magnetic Resonance

    E-Print Network [OSTI]

    Suter, Dieter

    zero-field magnetic resonance, namely the potential for structure determination in solids without for a time ft, after which one component is converted back into population by a second pulse. The remainin gcoherence s decay over a time of the order of the spin-spin relaxation time Tz. During the mixing time rm

  12. Resonant-cavity antenna for plasma heating

    DOE Patents [OSTI]

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

    1984-01-10T23:59:59.000Z

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

  13. Radio frequency quadrupole resonator for linear accelerator

    DOE Patents [OSTI]

    Moretti, Alfred (Downers Grove, IL)

    1985-01-01T23:59:59.000Z

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

  14. JOURNAL DE PHYSIQUE Colloque C5, supplkment au no 5, Tome 40, Mai 1979,page C5-184 Magnetic properties and resonance studies of some pseudobinary gadolinium

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . The results of experimental data are well described if we suppose that cobalt has a magnetic moment Mco (x = 1 ) if there are at least n, = 2 iron atoms as NN in 3m site or Mco (x = 0) if n,

  15. Magnetic Stereoscopy

    E-Print Network [OSTI]

    Thomas Wiegelmann; Bernd Inhester

    2006-12-21T23:59:59.000Z

    The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.

  16. Surface Plasmon Resonance (SPR) Reflectance Imaging: A Label-Free/Real-Time Mapping of Microscale Mixture Concentration Fields (Water+Ethanol)

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    Mixture Concentration Fields (Water+Ethanol) Iltai Kim and Kenneth D. Kihm Department of Mechanical (water+ethanol) concentration fields with surface plasmon resonance (SPR) reflectance technique based the refractive index and mixture concentration fields. The presented results show that ethanol penetrates

  17. Stability of the electron cyclotron resonance

    E-Print Network [OSTI]

    Joachim Asch; Olivier Bourget; Cédric Meresse

    2014-12-30T23:59:59.000Z

    We consider the magnetic AC Stark effect for the quantum dynamics of a single particle in the plane under the influence of an oscillating homogeneous electric and a constant perpendicular magnetic field. We prove that the electron cyclotron resonance is insensitive to impurity potentials.

  18. Instrument for in-situ orientation of superconducting thin-film resonators used for electron-spin resonance experiments

    E-Print Network [OSTI]

    Mowry, Andrew; Kuabsek, James; Friedman, Jonathan R

    2015-01-01T23:59:59.000Z

    When used in Electron-Spin Resonance (ESR) measurements, superconducting thin-film resonators must be precisely oriented relative to the external magnetic field in order to prevent the trapping of magnetic flux and the associated degradation of resonator performance. We present a compact design solution for this problem that allows in-situ control of the orientation of the resonator at cryogenic temperatures. Tests of the apparatus show that when proper alignment is achieved, there is almost no hysteresis in the field dependence of the resonant frequency.

  19. Revealing the Degree of Magnetic Frustration by Non-Magnetic Impurities

    SciTech Connect (OSTI)

    Not Available

    2011-08-12T23:59:59.000Z

    Imaging the magnetic fields around a non-magnetic impurity can provide a clear benchmark for quantifying the degree of magnetic frustration. Focusing on the strongly frustrated J{sub 1}-J{sub 2} model and the spatially anisotropic J{sub 1a}-J{sub 1b}-J{sub 2} model, very distinct low energy behaviors reflect different levels of magnetic frustration. In the J{sub 1}-J{sub 2} model, bound magnons appear trapped near the impurity in the ground state and strongly reduce the ordered moments for sites proximal to the impurity. In contrast, local moments in the J{sub 1a}-J{sub 1b}-J{sub 2} model are enhanced on the impurity neighboring sites. These theoretical predictions can be probed by experiments such as nuclear magnetic resonance and scanning tunneling microscopy, and the results can elucidate the role of frustration in antiferromagnets and help narrow the possible models to understand magnetism in the iron pnictdies.

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

    E-Print Network [OSTI]

    Burger, Anat

    2006-01-01T23:59:59.000Z

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