National Library of Energy BETA

Sample records for magnetic resonance imaging

  1. Gradient characterization in magnetic resonance imaging

    E-Print Network [OSTI]

    Cheng, Joseph Yitan

    2007-01-01

    Special magnetic resonance (MR) scans, such as spiral imaging and echo-planar imaging, require speed and gradient accuracy while putting high demands on the MR gradient system that may cause gradient distortion. Additionally, ...

  2. Magnetic resonance imaging in cardiovascular disease 

    E-Print Network [OSTI]

    Richards, Jennifer Margaret Jane

    2013-07-06

    Background Superparamagnetic particles of iron oxide (SPIO) are part of a novel and exciting class of ‘smart’ magnetic resonance imaging (MRI) contrast agents that are taken up by inflammatory cells. Ultrasmall SPIO ...

  3. 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.

    1991-04-23

    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

  4. Array combination for parallel imaging in Magnetic Resonance Imaging 

    E-Print Network [OSTI]

    Spence, Dan Kenrick

    2007-09-17

    In Magnetic Resonance Imaging, the time required to generate an image is proportional to the number of steps used to encode the spatial information. In rapid imaging, an array of coil elements and receivers are used to reduce the number of encoding...

  5. Functional Magnetic Resonance Imaging of Motor Cortex Activation in Schizophrenia

    E-Print Network [OSTI]

    2015-01-01

    Magnetic Resonance Imaging of Motor Cortex Activation inBrain dysfunction during motor activation and corpus callo-Lee HJ, et al. • FMRI of Motor Cortex Activation in

  6. Methods for chemical exchange saturation transfer magnetic resonance imaging

    E-Print Network [OSTI]

    Scheidegger, Rachel Nora

    2013-01-01

    Chemical exchange saturation transfer (CEST) is a relatively new magnetic resonance imaging (MRI) acquisition technique that generates contrast dependent on tissue microenvironment, such as protein concentration and ...

  7. Magnetic resonance imaging of self-assembled biomaterial scaffolds

    DOE Patents [OSTI]

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

    2014-09-16

    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.

  8. Model-based reconstruction of magnetic resonance spectroscopic imaging

    E-Print Network [OSTI]

    Chatnuntawech, Itthi

    2013-01-01

    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 IMAGE VIEWING ``SCREEN REAL ESTATE'' PROBLEM

    E-Print Network [OSTI]

    Atkins, M. Stella

    MAGNETIC RESONANCE IMAGE VIEWING AND THE ``SCREEN REAL ESTATE'' PROBLEM By Johanna van der Heyden B Degree: Master of Science Title of thesis: Magnetic Resonance Image Viewing and the ``Screen Real Estate. These ``screen real estate'' issues are extensively explored in the literature but not consistently applied

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

    E-Print Network [OSTI]

    Gagoski, Borjan Aleksandar

    2011-01-01

    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 ...

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

    E-Print Network [OSTI]

    Anahtar, Melis Nuray

    2008-01-01

    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, ...

  12. The Future of Real-time Cardiac Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Southern California, University of

    Address *Electrical Engineering-Systems, 3740 McClintock Avenue, EEB 406, University of Southern. These and other factors require real-time imaging. Magnetic resonance imaging (MRI) is a powerful and flexible with excellent image quality. In this article, the term real-time refers to imaging sys- tems that acquire

  13. Magnetic resonance imaging contrast agents for chemical sensing

    E-Print Network [OSTI]

    Liu, Vincent Hok

    2014-01-01

    Magnetic resonance imaging (MRI) is frequently used for examining the human body. MRI contrast agents currently used in the clinic assist physicians in locating problematic areas, but other tools are needed to interrogate ...

  14. Design algorithms for parallel transmission in magnetic resonance imaging

    E-Print Network [OSTI]

    Setsompop, Kawin

    2008-01-01

    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 ...

  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. Wavelets and functional magnetic resonance imaging of the human brain

    E-Print Network [OSTI]

    Breakspear, Michael

    Wavelets and functional magnetic resonance imaging of the human brain Ed Bullmore,a,* Jalal Fadili Breakspeare a Brain Mapping Unit and Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke of Psychiatry (King's College), London, UK e Brain Dynamics Centre (Westmead Hospital) and School of Physics

  17. Nuclear magnetic resonance imaging with hyper-polarized noble gases

    SciTech Connect (OSTI)

    Schmidt, D.M.; George, J.S.; Penttila, S.I.; Caprihan, A.

    1997-10-01

    This is the final report of a six-month, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The nuclei of noble gases can be hyper polarized through a laser-driven spin exchange to a degree many orders of magnitude larger than that attainable by thermal polarization without requiring a strong magnetic field. The increased polarization from the laser pumping enables a good nuclear magnetic resonance (NMR) signal from a gas. The main goal of this project was to demonstrate diffusion-weighted imaging of such hyper-polarized noble gas with magnetic resonance imaging (MRI). Possible applications include characterizing porosity of materials and dynamically imaging pressure distributions in biological or acoustical systems.

  18. Chromatic Light Adaptation Measured using Functional Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Wandell, Brian A.

    Chromatic Light Adaptation Measured using Functional Magnetic Resonance Imaging Alex R. Wade- nisms within cone photoreceptor classes. Key words: fMRI; light adaptation; cones; simulation; V1; Naka regulation is part of a process called light adaptation. Light adaptation is an important computational step

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

    E-Print Network [OSTI]

    Alenezy, Mohammed D.

    2009-04-17

    A two-parameter computational model is proposed for the study of the regional motion of the left ventricle (LV) wall using tagged magnetic resonance imaging (tMRI) data. In this model, the LV wall motion is mathematically decomposed into two...

  20. Original Research In Vivo Magnetic Resonance Imaging of the Human

    E-Print Network [OSTI]

    Gorassini, Monica

    Original Research In Vivo Magnetic Resonance Imaging of the Human Cervical Spinal Cord at 3 Tesla is feasible at 3 T. Key Words: MRI; 3 Tesla; cervical spinal cord; gradient echo; gray matter; white matter J, and pulsatile flow (9,10). Deficits in motor and sensory function from damage to the spinal cord are mainly due

  1. Method for nuclear magnetic resonance imaging

    DOE Patents [OSTI]

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

    1988-05-26

    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.

  2. Parallel magnetic resonance imaging: characterization and comparison 

    E-Print Network [OSTI]

    Rane, Swati Dnyandeo

    2005-11-01

    coil configuration, k-space subsampling factor, k-space coverage in the imaging environment, there is a critical need to find the method giving the best results under certain imaging conditions. The tools developed in this research help the selection...

  3. Spectrally Resolved Magnetic Resonance Imaging of the XenonBiosensor

    SciTech Connect (OSTI)

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

    2005-07-15

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

  4. Instrumentation for parallel magnetic resonance imaging 

    E-Print Network [OSTI]

    Brown, David Gerald

    2007-04-25

    FIGURE 1 An example of a 2D Fourier encoded pulse sequence for MR imaging ..............20 2 Block diagram for an ideal analog mixer with an output bandpass filter ............28 3 Undersampling of a bandpass signal...

  5. Bayesian Optimization of Magnetic Resonance Imaging Sequences

    E-Print Network [OSTI]

    Seeger, Matthias

    Imaging 2 Bayesian Experimental Design 3 Scalable Approximate Inference 4 Experiments Seeger (MMCI Healthcare: Growing number of MRI diagnoses Brain research: Ethical human subject studies Seeger (MMCI Extremely versatile Noninvasive, no ionizing radiation Seeger (MMCI) Bayesian MRI Optimization 28 November

  6. Portable low-cost magnetic resonance imaging

    E-Print Network [OSTI]

    Cooley, Clarissa Zimmerman

    2014-01-01

    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 ...

  7. Single echo acquisition magnetic resonance imaging 

    E-Print Network [OSTI]

    McDougall, Mary Preston

    2006-04-12

    limitations are already being approached. Parallel imaging methods (using multiple receiver coils to partially encode k-space) have offered some relief in the efforts and are rapidly becoming the focus of current endeavors to decrease scan time. Ideally...

  8. 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

    2009-05-15

    Emerging technologies in parallel magnetic resonance imaging (MRI) with massive receiver arrays have paved the way for ultra-fast imaging at increasingly high frame rates. With the increase in the number of receiver channels ...

  9. 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

  10. 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

    2013-10-29

    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.

  11. 2007 Nature Publishing Group Nuclear magnetic resonance imaging

    E-Print Network [OSTI]

    Leonardo, Degiorgi

    to sense the magnetic force generated between the tip and spins in a sample. Magnetic resonance is used for the present work is the development of magnetic tips that generate magnetic field gradients as high as 1 of the technique on a patterned CaF2 test object. Unlike the permanent magnet tips previously used for

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

    E-Print Network [OSTI]

    Neumaier, Arnold

    by the uniformity of the magnetic field generated by this magnet, in that, the more uniform is the magnetic field a low field dedicated magnet is that of using permanent magnets surrounded by an iron yoke to amplifyMagnetic Resonance Imaging 1 A new global optimization algorithm and its application to a Magnetic

  13. On the dynamics of magnetic fluids in magnetic resonance imaging

    E-Print Network [OSTI]

    Cantillon-Murphy, Pádraig J

    2008-01-01

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

  14. Application of Parallel Imaging to Murine Magnetic Resonance Imaging 

    E-Print Network [OSTI]

    Chang, Chieh-Wei 1980-

    2012-09-21

    . 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...

  15. 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

    2014-01-21

    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.

  16. 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)

    2010-03-30

    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.

  17. 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

  18. Registration and Analysis of Myocardial Perfusion Magnetic Resonance Images

    E-Print Network [OSTI]

    - imum upslope, peak and time-to-peak. Qualitative and quantitative validation is carried out of Denmark, DTU #12;2 #12;3 Preface This thesis is based on five months work at the section for Image This thesis presents the registration and analysis of myocardial perfusion mag- netic resonance images

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

    E-Print Network [OSTI]

    Lebsack, Eliot Todd

    1999-01-01

    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...

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

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01

    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 imaging frequency...

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

    E-Print Network [OSTI]

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

    2005-01-01

    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 ...

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

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20

    A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

  3. Phase-based regional oxygen metabolism in magnetic resonance imaging at high field

    E-Print Network [OSTI]

    Fan, Audrey Peiwen

    2010-01-01

    Venous oxygen saturation (Yv) in cerebral veins and the cerebral metabolic rate of oxygen (CMRO?) are important indicators for brain function and disease. Phase-susceptibility measurements in magnetic resonance imaging ...

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

    E-Print Network [OSTI]

    Uh, Jinsoo

    2007-04-25

    Advanced nuclear magnetic resonance (NMR) imaging methodologies have been developed to determine porous media properties associated with fluid flow processes. This dissertation presents the development of NMR experimental and analysis methodologies...

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

    E-Print Network [OSTI]

    2010-09-24

    2008, 453:940-943. doi:10.1038/nrc2289 Cite this article as: Brindle: Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging. BMC Proceedings 2010 4(Suppl 2):O24. Correspondence: kmb1001@cam... Detecting tumor responses to treatment using hyperpolarized 13C magnetic resonance spectroscopic imaging Kevin M Brindle From 16th International Charles Heidelberger Symposium on Cancer Research Coimbra, Portugal. 26–28 September 2010 Patients with similar...

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

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16

    ? ?= (2.1) where ? is the gyromagnetic ratio. For 1H, ? = 42.58MHz/Tesla. 5 Figure 2.1. Precession of a nuclear spin about an external magnetic field. The imaging of an object relies on the bulk precession of the hydrogen spins in water...

  7. Detection of Tumors in Dynamic Magnetic Resonance Images using Principal Component Analysis

    E-Print Network [OSTI]

    Detection of Tumors in Dynamic Magnetic Resonance Images using Principal Component Analysis David Alberg Holm (1-2), Thomas Bøvith (2), Cecilia Cappellin (3) (1) Danish Research Centre for Magnetic different tissue classes. For this purpose, two methods were developed and combined. Data Eight mice bearing

  8. 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

  9. Wavelets and statistical analysis of functional magnetic resonance images of the human brain

    E-Print Network [OSTI]

    Breakspear, Michael

    Wavelets and statistical analysis of functional magnetic resonance images of the human brain Ed Bullmore Brain Mapping Unit and Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke CNRS UMR 6072, Caen, France, Michael Breakspear Brain Dynamics Centre (Westmead Hospital) and School

  10. 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)

    2011-07-01

    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.

  11. Bistable illusory rebound motion: Event-related functional magnetic resonance imaging of perceptual states and switches

    E-Print Network [OSTI]

    Bucci, David J.

    Bistable illusory rebound motion: Event-related functional magnetic resonance imaging of perceptual of a recently discovered visual illusion that we call Fillusory rebound motion_ (IRM) are described. This illusion is remarkable because motion is perceived in the absence of any net motion energy in the stimulus

  12. Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual processing

    E-Print Network [OSTI]

    Event-related single-shot volumetric functional magnetic resonance inverse imaging of visual head coil array data and then apply inverse reconstruction methods to obtain volumetric fMRI estimates-related brain activity. We demonstrate the sensitivity and inter-subject reliability of volumetric InI using

  13. 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)

    2009-08-11

    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.

  14. 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 ...

  15. Bioengineering 208: Magnetic Resonance Imaging Laboratory Winter 2007

    E-Print Network [OSTI]

    California at San Diego, University of

    velocity well. b. Acquire a 3D TOF image of the vessel, with the location of the 2D PC image the (volts/amps) scale labeled on the gradient amp test point, and a scaling of 4G/cm at 250A. Turn where all the major vessels going in and out of the head are clear and appear to be flowing straight

  16. Bioengineering 208: Magnetic Resonance Imaging Laboratory Winter 2008

    E-Print Network [OSTI]

    California at San Diego, University of

    velocity well. b. Acquire a 3D TOF image of the vessel, with the location of the 2D PC image the (volts/amps) scale labeled on the gradient amp test point, and a scaling of 4G/cm at 250A. Turn where all the major vessels going in and out of the head are clear and appear to be flowing straight

  17. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

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

    1997-12-30

    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.

  18. Nuclear magnetic resonance contrast agents

    DOE Patents [OSTI]

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

    1997-01-01

    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.

  19. 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 ...

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

    SciTech Connect (OSTI)

    Howison, Mark; Wes Bethel, E.

    2014-05-29

    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.

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

    E-Print Network [OSTI]

    Dabirzadeh, Arash

    2009-05-15

    Magnetic Resonance Spectroscopy is known as a valuable diagnostic tool for physicians as well as a research tool for biochemists. In addition to hydrogen (which is the most abundant atom with nuclear magnetic resonance capability), other species...

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

    E-Print Network [OSTI]

    Fjell, Anders M.

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

  3. 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)

    2014-09-15

    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.

  4. Method and apparatus for magnetic resonance imaging and spectroscopy using microstrip transmission line coils

    DOE Patents [OSTI]

    Zhang, Xiaoliang; Ugurbil, Kamil; Chen, Wei

    2006-04-04

    Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways. Further, while the MTL coils of the present invention work well at high field strengths and frequencies, they also work at low frequencies and in low field strengths as well.

  5. Lensless Imaging of Magnetic Nanostructures

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

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

  6. 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.

    1994-04-01

    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.

  7. 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

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

    SciTech Connect (OSTI)

    Barbaro, Brunella; Vitale, Renata; Valentini, Vincenzo; Illuminati, Sonia; Vecchio, Fabio M.; Rizzo, Gianluca; Gambacorta, Maria Antonietta; Coco, Claudio; Crucitti, Antonio; Persiani, Roberto; Sofo, Luigi; Bonomo, Lorenzo

    2012-06-01

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

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

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    MAGNETIC RESONANCE ELECTRICAL IMPEDANCE TOMOGRAPHY (MR-EIT): A new technique for high resolution are measured by using conventional electrical impedance tomography techniques and high resolution magnetic and the point spread function is not space invariant. On the other hand, magnetic field and electrical current

  10. In vivo chlorine-35, sodium-23 and proton magnetic resonance imaging of the rat brain , M. Augath2

    E-Print Network [OSTI]

    In vivo chlorine-35, sodium-23 and proton magnetic resonance imaging of the rat brain S. Kirsch1 of the cytoplasm and the volume of cells [1]. In order to investigate the feasibility of combined in vivo 35 Cl, 23 Na and 1 H MRI we developed a rf coil setup to measure 35 Cl, 23 Na and 1 H signals in one scanning

  11. Design and Simulation of Coils for High Field Magnetic Resonance Imaging and Spectroscopy 

    E-Print Network [OSTI]

    Rispoli, Joseph V

    2015-06-05

    The growing availability of high-field magnetic resonance (MR) scanners has reignited interest in the in vivo investigation of metabolics in the body. In particular, multinuclear MR spectroscopy (MRS) data reveal physiological details inaccessible...

  12. Evaluation of the Prostate Bed for Local Recurrence After Radical Prostatectomy Using Endorectal Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation Oncology, University of Chicago, Chicago, Illinois (United States); Pitroda, Sean P. [Department of Radiation Oncology, University of Chicago, Chicago, Illinois (United States)] [Department of Radiation Oncology, University of Chicago, Chicago, Illinois (United States); Eggener, Scott E. [Department of Urology, University of Chicago, Chicago, Illinois (United States)] [Department of Urology, University of Chicago, Chicago, Illinois (United States); Stadler, Walter M. [Department of Medical Oncology, University of Chicago, Chicago, Illinois (United States)] [Department of Medical Oncology, University of Chicago, Chicago, Illinois (United States); Pelizzari, Charles A. [Department of Radiation Oncology, University of Chicago, Chicago, Illinois (United States)] [Department of Radiation Oncology, University of Chicago, Chicago, Illinois (United States); Vannier, Michael W.; Oto, Aytek [Department of Radiology, University of Chicago, Chicago, Illinois (United States)] [Department of Radiology, University of Chicago, Chicago, Illinois (United States)

    2013-02-01

    Purpose: To summarize the results of a 4-year period in which endorectal magnetic resonance imaging (MRI) was considered for all men referred for salvage radiation therapy (RT) at a single academic center; to describe the incidence and location of locally recurrent disease in a contemporary cohort of men with biochemical failure after radical prostatectomy (RP), and to identify prognostic variables associated with MRI findings in order to define which patients may have the highest yield of the study. Methods and Materials: Between 2007 and 2011, 88 men without clinically palpable disease underwent eMRI for detectable prostate-specific antigen (PSA) after RP. The median interval between RP and eMRI was 32 months (interquartile range, 14-57 months), and the median PSA level was 0.30 ng/mL (interquartile range, 0.19-0.72 ng/mL). Magnetic resonance imaging scans consisting of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging were evaluated for features consistent with local recurrence. The prostate bed was scored from 0-4, whereby 0 was definitely normal, 1 probably normal, 2 indeterminate, 3 probably abnormal, and 4 definitely abnormal. Local recurrence was defined as having a score of 3-4. Results: Local recurrence was identified in 21 men (24%). Abnormalities were best appreciated on T2-weighted axial images (90%) as focal hypointense lesions. Recurrence locations were perianastomotic (67%) or retrovesical (33%). The only risk factor associated with local recurrence was PSA; recurrence was seen in 37% of men with PSA >0.3 ng/mL vs 13% if PSA {<=}0.3 ng/mL (P<.01). The median volume of recurrence was 0.26 cm{sup 3} and was directly associated with PSA (r=0.5, P=.02). The correlation between MRI-based tumor volume and PSA was even stronger in men with positive margins (r=0.8, P<.01). Conclusions: Endorectal MRI can define areas of local recurrence after RP in a minority of men without clinical evidence of disease, with yield related to PSA. Further study is necessary to determine whether eMRI can improve patient selection and success of salvage RT.

  13. 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)

    2012-12-15

    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.

  14. 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)

    1986-01-01

    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.

  15. Simulation of High-Resolution Magnetic Resonance Images on the IBM Blue Gene/L Supercomputer Using SIMRI

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

    Baum, K. G.; Menezes, G.; Helguera, M.

    2011-01-01

    Medical imaging system simulators are tools that provide a means to evaluate system architecture and create artificial image sets that are appropriate for specific applications. We have modified SIMRI, a Bloch equation-based magnetic resonance image simulator, in order to successfully generate high-resolution 3D MR images of the Montreal brain phantom using Blue Gene/L systems. Results show that redistribution of the workload allows an anatomically accurate 256 3 voxel spin-echo simulation in less than 5 hours when executed on an 8192-node partition of a Blue Gene/L system.

  16. Identification of breast contour for nipple segmentation in breast magnetic resonance images

    SciTech Connect (OSTI)

    Gwo, Chih-Ying [Department of Information Management, Chien Hsin University of Science and Technology, Taoyuan 320, Taiwan (China)] [Department of Information Management, Chien Hsin University of Science and Technology, Taoyuan 320, Taiwan (China); Gwo, Allen [Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712 (United States); Wei, Chia-Hung, E-mail: rogerwei@uch.edu.tw [Department of Information Management, Chien Hsin University of Science and Technology, Taoyuan 320, Taiwan and Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei 110, Taiwan (China)] [Department of Information Management, Chien Hsin University of Science and Technology, Taoyuan 320, Taiwan and Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei 110, Taiwan (China); Huang, Pai Jung [Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei 110, Taiwan and Comprehensive Breast Health Center, Taipei Medical University Hospital, Taipei 110, Taiwan (China)] [Graduate Institute of Biomedical Informatics, Taipei Medical University, Taipei 110, Taiwan and Comprehensive Breast Health Center, Taipei Medical University Hospital, Taipei 110, Taiwan (China)

    2014-02-15

    Purpose: The purpose of this study is to develop a method to simulate the breast contour and segment the nipple in breast magnetic resonance images. Methods: This study first identifies the chest wall and removes the chest part from the breast MR images. Subsequently, the cleavage and its motion artifacts are removed, distinguishing the separate breasts, where the edge points are sampled for curve fitting. Next, a region growing method is applied to find the potential nipple region. Finally, the potential nipple region above the simulated curve can be removed in order to retain the original smooth contour. Results: The simulation methods can achieve the least root mean square error (RMSE) for certain cases. The proposed YBnd and (Dmin+Dmax)/2 methods are significant due toP = 0.000. The breast contour curve detected by the two proposed methods is closer than that determined by the edge detection method. The (Dmin+Dmax)/2 method can achieve the lowest RMSE of 1.1029 on average, while the edge detection method results in the highest RMSE of 6.5655. This is only slighter better than the comparison methods, which implies that the performance of these methods depends upon the conditions of the cases themselves. Under this method, the maximal Dice coefficient is 0.881, and the centroid difference is 0.36 pixels. Conclusions: The contributions of this study are twofold. First, a method was proposed to identify and segment the nipple in breast MR images. Second, a curve-fitting method was used to simulate the breast contour, allowing the breast to retain its original smooth shape.

  17. 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)

    2009-05-19

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

  18. 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.

    2006-01-24

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

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

    SciTech Connect (OSTI)

    Gazdzinski, Lisa M.; Cormier, Kyle; Lu, Fred G.; Lerch, Jason P.; Department of Medical Biophysics, University of Toronto, Toronto ; Wong, C. Shun; Department of Medical Biophysics, University of Toronto, Toronto; Department of Radiation Oncology, University of Toronto, Toronto ; Nieman, Brian J.

    2012-12-01

    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.

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

    SciTech Connect (OSTI)

    Cao Yue; Wang Hesheng; Johnson, Timothy D.; Pan, Charlie; Hussain, Hero; Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary

    2013-01-01

    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.

  1. Magnetic Resonance Imaging of Therapy-Induced Necrosis Using Gadolinium-Chelated Polyglutamic Acids

    SciTech Connect (OSTI)

    Jackson, Edward F.; Esparza-Coss, Emilio; Wen Xiaoxia; Ng, Chaan S.; Daniel, Sherita L.; Price, Roger E.; Rivera, Belinda; Charnsangavej, Chusilp; Gelovani, Juri G.; Li Chun . E-mail: cli@di.mdacc.tmc.edu

    2007-07-01

    Purpose: Necrosis is the most common morphologic alteration found in tumors and surrounding normal tissues after radiation therapy or chemotherapy. Accurate measurement of necrosis may provide an early indication of treatment efficacy or associated toxicity. The purpose of this report is to evaluate the selective accumulation of polymeric paramagnetic magnetic resonance (MR) contrast agents-gadolinium p-aminobenzyl-diethylenetriaminepentaacetic acid-poly(glutamic acid) (L-PG-DTPA-Gd and D-PG-DTPA-Gd)-in necrotic tissue. Methods and Materials: Two different solid tumor models, human Colo-205 xenograft and syngeneic murine OCA-1 ovarian tumors, were used in this study. Necrotic response was induced by treatment with poly(L-glutamic acid)-paclitaxel conjugate (PG-TXL). T{sub 1}-weighted spin-echo images were obtained immediately and up to 4 days after contrast injection and compared with corresponding histologic specimens. Two low-molecular-weight contrast agents, DTPA-Gd and oligomeric(L-glutamic acid)-DTPA-Gd, were used as nonspecific controls. Results: Initially, there was minimal tumor enhancement after injection of either L-PG-DTPA-Gd or D-PG-DTPA-Gd, but rapid enhancement after injection of low-molecular-weight agents. However, polymeric contrast agents, but not low-molecular-weight contrast agents, caused sustained enhancement in regions of tumor necrosis in both tumors treated with PG-TXL and untreated tumors. These data indicate that high molecular weight, rather than in vivo biodegradation, is necessary for the specific localization of polymeric MR contrast agents to necrotic tissue. Moreover, biotinylated L-PG-DTPA-Gd colocalized with macrophages in the tumor necrotic areas, suggesting that selective accumulation of L- and D-PG-DTPA-Gd in necrotic tissue was mediated through residing macrophages. Conclusions: Our data suggest that MR imaging with PG-DTPA-Gd may be a useful technique for noninvasive characterization of treatment-induced necrosis.

  2. Evaluation of Angiographic and Technical Aspects of Carotid Stenting with Diffusion-Weighted Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Blasel, Stella, E-mail: Stella.Blasel@kgu.de; Hattingen, Elke; Berkefeld, Joachim; Kurre, Wiebke [University of Frankfurt, Institute of Neuroradiology (Germany); Morawe, Gerald [University of Frankfurt, Department of Biomathematics (Germany); Zanella, Friedhelm; Rochemont, Richard Du Mesnil de [University of Frankfurt, Institute of Neuroradiology (Germany)

    2009-07-15

    The detection of clinically silent ischemic lesions on postprocedural diffusion-weighted magnetic resonance images has become a preferred method for the description of embolic risks. The purpose of this single-center study was to evaluate whether diffusion-weighted imaging (DWI) could determine material related or technical risk factors of filter-protected carotid stenting. Eighty-four patients with symptomatic severe ({>=}60%) carotid artery stenoses received filter-protected carotid stenting. Standard DWI (b = 1000) was performed within 48 h before and after carotid stenting. The occurrence and load of new postinterventional DWI lesions were assessed. Multivariate analysis was performed to determine risk factors associated with DWI lesions, with emphasis on technical factors such as use of different access devices (guiding catheter method vs. long carotid sheath method), type of stent (open-cell nitinol stent vs. closed-cell Wallstent), and protective device (filters with 80-{mu}m vs. 110-120-{mu}m pore size). Markers for generalized atherosclerosis and for degree and site of stenosis were assessed to allow comparison of adequate risk profiles. Access, protective device, and stent type were not significantly associated with new embolic DWI lesions when we compared patients with equivalent risk profiles (long carotid sheath method 48% [11 of 23] vs. guiding catheter method 44% [27 of 61], Wallstent 47% [15 of 32] vs. nitinol stent 44% [23 of 52], and small pore size filter 61% [11 of 18] vs. large pore size filter 41% [27 of 66]). Single-center DWI studies with a moderate number of cases are inadequate for proper assessment of the embolic risk of technical- or material-related risk factors in carotid stenting. Larger multicenter studies with more cases are needed.

  3. Pulsed Gradient Spin Echo Nuclear Magnetic Resonance Imaging of Diffusion in Granular Flow

    SciTech Connect (OSTI)

    Seymour, Joseph D.; Caprihan, Arvind; Altobelli, Stephen A.; Fukushima, Eiichi

    2000-01-10

    We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. (c) 2000 The American Physical Society.

  4. Lensless Imaging of Magnetic Nanostructures

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

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

  5. High-resolution magnetic resonance imaging and diffusion tensor imaging of the porcine temporomandibular joint disc

    E-Print Network [OSTI]

    Benavides, E.; Bilgen, M.; Al-Hafez, B.; Alrefae, T.; Wang, Y; Spencer, Paulette

    2014-01-28

    scanned on a 9.4?Tesla horizontal bore MRI scanner using an inductively coupled surface coil. High-resolution gradient-echo and diffusion-weighted spin-echo based images were obtained. The mean diffusivity and fractional anisotropy (FA) were computed...

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

    SciTech Connect (OSTI)

    Seymour, Joseph D.

    2005-06-01

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

  7. 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

    2009-07-09

    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.

  8. Resonant and non-resonant magnetic scattering

    SciTech Connect (OSTI)

    McWhan, D.B.; Hastings, J.B.; Kao, C.C.; Siddons, D.P.

    1991-12-31

    The tunability and the polarization of synchrotron radiation open upon new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and thy fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation.

  9. Resonant and non-resonant magnetic scattering

    SciTech Connect (OSTI)

    McWhan, D.B.; Hastings, J.B.; Kao, C.C.; Siddons, D.P.

    1991-01-01

    The tunability and the polarization of synchrotron radiation open upon new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and thy fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation.

  10. 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: drGraf@t-online.de; Clasen, Stephan

    2014-06-15

    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.

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

    E-Print Network [OSTI]

    Halpern-Manners, Nicholas Wm

    2011-01-01

    field and an oscillating magnetic field in the sample and,static and oscillating magnetic fields when consideringthe sample produce oscillating magnetic fields that can be

  12. Magnetic Resonance Facility (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-03-01

    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.

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

    SciTech Connect (OSTI)

    Kowalchik, Kristin V.; Vallow, Laura A.; McDonough, Michelle; Thomas, Colleen S.; Heckman, Michael G.; Peterson, Jennifer L.; Adkisson, Cameron D.; Serago, Christopher; McLaughlin, Sarah A.

    2013-09-01

    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.

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

    E-Print Network [OSTI]

    Halpern-Manners, Nicholas Wm

    2011-01-01

    and biomarker screening. Analytical Chemistry 78, 15 (2006),by remote detection. Analytical Chemistry 77, [96] Menon, R.resonance spectroscopy. Analytical Chemistry 79, 7 (2007),

  15. 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...

  16. 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.

    1984-01-01

    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.

  17. 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 ...

  18. 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)

    2012-02-15

    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.

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

    E-Print Network [OSTI]

    Son, Jong Bum

    2009-05-15

    as the resonance frequency (w0) of interested protons, 11 00w= ?B [2.1] where ? is the gyromagnetic ratio of a proton. MRI is primarily dependant on signals from the hydrogen proton (? = 2??42.5759 radians / Tesla) due to its...

  20. Design and Simulation of Coils for High Field Magnetic Resonance Imaging and Spectroscopy 

    E-Print Network [OSTI]

    Rispoli, Joseph V

    2015-06-05

    radiative losses and becomes increasingly compelling at higher fields (38). Adriany et al. characterized the performance of a variety of 7T surface coils with conventional shielding, reporting appreciable benefits over unshielded versions... Alternating current ACR American College of Radiology AP Anterior–posterior AWG American wire gauge B0 Static magnetic flux density B1 RF magnetic flux density B1 - Circularly-polarized receive B1 B1 + Circularly-polarized transmit B1 B2 Proton...

  1. 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)

    1990-01-01

    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.

  2. Bioengineered Probes for Molecular Magnetic Resonance Imaging in the Nervous System

    E-Print Network [OSTI]

    Hsieh, Vivian

    The development of molecular imaging probes has changed the nature of neurobiological research. Some of the most notable successes have involved the use of biological engineering techniques for the creation of fluorescent ...

  3. 1,2-Hydroxypyridonates as Contrast Agents for Magnetic ResonanceImaging: TREN-1,2-HOPO

    SciTech Connect (OSTI)

    Jocher, Christoph J.; Moore, Evan G.; Xu, Jide; Avedano, Stefano; Botta, Mauro; Aime, Silvio; Raymond, Kenneth N.

    2007-05-08

    1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for Magnetic Resonance Imaging (MRI). X-ray diffraction of single crystals established that the solid state structures of the Eu(III) and the previously reported [Inorg. Chem. 2004, 43, 5452] Gd(III) complex are identical. The recently discovered sensitizing properties of 1,2-HOPO chelates for Eu(III) luminescence allow direct measurement of the number if water molecules in the metal complex. Fluorescence measurements of the Eu(III) complex corroborate that in solution two water molecules coordinate the lanthanide (q = 2) as proposed from the analysis of NMRD profiles. In addition, fluorescence measurements have verified the anion binding interactions of lanthanide TREN-1,2-HOPO complexes in solution, studied by relaxivity, revealing only very weak oxalate binding (K{sub A} = 82.7 {+-} 6.5 M{sup -1}). Solution thermodynamic studies of the metal complex and free ligand have been carried out using potentiometry, spectrophotometry and fluorescence spectroscopy. The metal ion selectivity of TREN-1,2-HOPO supports the feasibility of using 1,2-HOPO ligands for selective lanthanide binding [pGd = 19.3 (2); pZn = 15.2 (2), pCa = 8.8 (3)].

  4. 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)

    2012-06-15

    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.

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

    E-Print Network [OSTI]

    By, Samantha

    2014-04-01

    , this will enable the ability to acquire images with higher resolution than could be achieved at 3T or 1.5T in clinically standard scan times. This has the potential to improve the morphological characterization of tumors and their involvement in the surrounding...

  6. Development of a 0.014-inch Magnetic Resonance Imaging Guidewire

    E-Print Network [OSTI]

    Atalar, Ergin

    . The conductors were made of superelastic, nonmagnetic, biocompatible mate- rials, Nitinol or MP35N. Then, such as balloon angioplasty and stent placement (4). Currently, the MR imaging-guidewire is made of Nitinol, 0 can construct a 0.014-inch MRIG with superelastic materials, such as Nitinol and MP35N, similar

  7. A Prospective Study of the Utility of Magnetic Resonance Imaging in Determining Candidacy for Partial Breast Irradiation

    SciTech Connect (OSTI)

    Dorn, Paige L.; Al-Hallaq, Hania A.; Haq, Farah; Goldberg, Mira; Abe, Hiroyuki; Hasan, Yasmin; Chmura, Steven J.

    2013-03-01

    Purpose: Retrospective data have demonstrated that breast magnetic resonance imaging (MRI) may change a patient's eligibility for partial breast irradiation (PBI) by identifying multicentric, multifocal, or contralateral disease. The objective of the current study was to prospectively determine the frequency with which MRI identifies occult disease and to establish clinical factors associated with a higher likelihood of MRI prompting changes in PBI eligibility. Methods and Materials: At The University of Chicago, women with breast cancer uniformly undergo MRI in addition to mammography and ultrasonography. From June 2009 through May 2011, all patients were screened prospectively in a multidisciplinary conference for PBI eligibility based on standard imaging, and the impact of MRI on PBI eligibility according to National Surgical Adjuvant Breast and Bowel Project protocol B-39/Radiation Therapy Oncology Group protocol 0413 entry criteria was recorded. Univariable analysis was performed using clinical characteristics in both the prospective cohort and in a separate cohort of retrospectively identified patients. Pooled analysis was used to derive a scoring index predictive of the risk that MRI would identify additional disease. Results: A total of 521 patients were screened for PBI eligibility, and 124 (23.8%) patients were deemed eligible for PBI based on standard imaging. MRI findings changed PBI eligibility in 12.9% of patients. In the pooled univariable analysis, tumor size ?2 cm on mammography or ultrasonography (P=.02), age <50 years (P=.01), invasive lobular histology (P=.01), and HER-2/neu amplification (P=.01) were associated with a higher likelihood of MRI changing PBI eligibility. A predictive score was generated by summing the number of significant risk factors. Patients with a score of 0, 1, 2, and 3 had changes to eligibility based on MRI findings in 2.8%, 13.2%, 38.1%, and 100%, respectively (P<.0001). Conclusions: MRI identified additional disease in a significant number of patients eligible for PBI, based on standard imaging. Clinical characteristics may be useful in directing implementation of MRI in the staging of PBI candidates.

  8. Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: A postmortem study

    SciTech Connect (OSTI)

    Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q.; Ducote, Justin L.; Su, Min-Ying; Molloi, Sabee

    2013-12-15

    Purpose: Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. Methods: T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left–right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson'sr, was used to evaluate the two image segmentation algorithms and the effect of bias field. Results: The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left–right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left–right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson'sr increased from 0.86 to 0.92 with the bias field correction. Conclusions: The investigated CLIC method significantly increased the precision and accuracy of breast density quantification using breast MRI images by effectively correcting the bias field. It is expected that a fully automated computerized algorithm for breast density quantification may have great potential in clinical MRI applications.

  9. Nuclear magnetic resonance readable sensors

    E-Print Network [OSTI]

    Ling, Yibo

    2010-01-01

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

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

    E-Print Network [OSTI]

    Mandava, Shanthi Sree

    1991-01-01

    and resolution of those saturations were developed with regards to the imaging method employed. The estimates so developed show that MRI can effectively monitor dynamic displacements for quantitative property estimation. An NMR spin-echo technique... in porous media was conducted with NMR Spectroscopy. A study of the effect of surrounding physical barriers on the diffusion of fluids in porous media was attempted. A Pulsed Gradient Spin-Echo sequence was developed to determine apparent self...

  11. Repeated exposure of the developing rat brain to magnetic resonance imaging did not affect neurogenesis, cell death or memory function

    SciTech Connect (OSTI)

    Zhu, Changlian [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden) [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Gao, Jianfeng [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden) [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Department of Physiology, Henan Traditional Medical University (China); Li, Qian; Huang, Zhiheng; Zhang, Yu; Li, Hongfu [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden) [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Kuhn, Hans-Georg [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden)] [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Blomgren, Klas, E-mail: klas.blomgren@neuro.gu.se [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden) [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatric Oncology, The Queen Silvia Children's Hospital, Gothenburg (Sweden)

    2011-01-07

    Research highlights: {yields} The effect of MRI on the developing brain is a matter of debate. {yields} Repeated exposure to MRI did not affect neurogenesis. {yields} Memory function was not affected by repeated MRI during development. {yields} Neither late gestation nor young postnatal brains were affected by MRI. {yields} Repeated MRI did not cause cell death in the neurogenic region of the hippocampus. -- Abstract: The effect of magnetic fields on the brain is a matter of debate. The objective of this study was to investigate whether repeated exposure to strong magnetic fields, such as during magnetic resonance imaging (MRI), could elicit changes in the developing rat brain. Embryonic day 15 (E15) and postnatal day 14 (P14) rats were exposed to MRI using a 7.05 T MR system. The animals were anesthetized and exposed for 35 min per day for 4 successive days. Control animals were anesthetized but no MRI was performed. Body temperature was maintained at 37 {sup o}C. BrdU was injected after each session (50 mg/kg). One month later, cell proliferation, neurogenesis and astrogenesis in the dentate gyrus were evaluated, revealing no effects of MRI, neither in the E15, nor in the P14 group. DNA damage in the dentate gyrus in the P14 group was evaluated on P18, 1 day after the last session, using TUNEL staining. There was no difference in the number of TUNEL-positive cells after MRI compared with controls, neither in mature neurons, nor in newborn progenitors (BrdU/TUNEL double-labeled cells). Novel object recognition was performed to assess memory function 1 month after MRI. There was no difference in the recognition index observed after MRI compared with the control rats, neither for the E15, nor for the P14 group. In conclusion, repeated exposure to MRI did not appear to affect neurogenesis, cell death or memory function in rats, neither in late gestation (E15-E18) nor in young postnatal (P14-P17) rats.

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

    E-Print Network [OSTI]

    Kremkus, Mark Christian

    2013-02-22

    . . Expenmentation. 27 RESULTS AND DISCUSSION . 29 CONCLUSIONS . REFERENCES. APPENDIX A ? FUNDAMENTALS OF MRI . . 32 33 Resolut&on and F&eld of Viev . Contrast Rad&t&-frequencf Coils. Cirad&ent Coils . . 41 . . 42 . . . 44 . . 43 APPENDIX B - BURST... Coil Lavout 14 F&sure 3 2 Field along x &n lmag&ng Re ion for N 15 F&gure 3. 3 F&eld ulon . r in Imagmg Reg&on fi&r &V=6 . . Figure 3 4 I icld along i. &n Imaging Reg&on for N= J(&0 Figure 3 5 I'ield Strength vs. L Figure 3 6 Fiekl Pattern Along x...

  13. Difference between healthy children and ADHD based on wavelet spectral analysis of nuclear magnetic resonance images

    SciTech Connect (OSTI)

    González Gómez Dulce, I. E-mail: emoreno@fcfm.buap.mx E-mail: joserm84@gmail.com; Moreno Barbosa, E. E-mail: emoreno@fcfm.buap.mx E-mail: joserm84@gmail.com; Hernández, Mario Iván Martínez E-mail: emoreno@fcfm.buap.mx E-mail: joserm84@gmail.com; Méndez, José Ramos E-mail: emoreno@fcfm.buap.mx E-mail: joserm84@gmail.com; Silvia, Hidalgo Tobón; Pilar, Dies Suarez E-mail: neurodoc@prodigy.net.mx; Eduardo, Barragán Pérez E-mail: neurodoc@prodigy.net.mx; Benito, De Celis Alonso

    2014-11-07

    The main goal of this project was to create a computer algorithm based on wavelet analysis of region of homogeneity images obtained during resting state studies. Ideally it would automatically diagnose ADHD. Because the cerebellum is an area known to be affected by ADHD, this study specifically analysed this region. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Statistical differences between the values of the absolute integrated wavelet spectrum were found and showed significant differences (p<0.0015) between groups. This difference might help in the future to distinguish healthy from ADHD patients and therefore diagnose ADHD. Even if results were statistically significant, the small size of the sample limits the applicability of this methods as it is presented here, and further work with larger samples and using freely available datasets must be done.

  14. Direct Numerical Simulation of Pore-Scale Flow in a Bead Pack: Comparison with Magnetic Resonance Imaging Observations

    SciTech Connect (OSTI)

    Yang, Xiaofan; Scheibe, Timothy D.; Richmond, Marshall C.; Perkins, William A.; Vogt, Sarah J.; Codd, Sarah L.; Seymour, Joseph D.; Mckinley, Matthew I.

    2013-04-01

    A significant body of current research is aimed at developing methods for numerical simulation of flow and transport in porous media that explicitly resolve complex pore and solid geometries, and at utilizing such models to study the relationships between fundamental pore-scale processes and macroscopic manifestations at larger (i.e., Darcy) scales. A number of different numerical methods for pore-scale simulation have been developed, and have been extensively tested and validated for simplified geometries. However, validation of pore-scale simulations of fluid velocity for complex, three-dimensional (3D) pore geometries that are representative of natural porous media is challenging due to our limited ability to measure pore-scale velocity in such systems. Recent advances in magnetic resonance imaging (MRI) offer the opportunity to measure not only the pore geometry, but also local fluid velocities under steady-state flow conditions in 3D and with high spatial resolution. In this paper, we present a 3D velocity field measured at sub-pore resolution (tens of micrometers) over a centimeter-scale 3D domain using MRI methods. We have utilized the measured pore geometry to perform 3D simulations of Navier-Stokes flow over the same domain using direct numerical simulation techniques. We present a comparison of the numerical simulation results with the measured velocity field. It is shown that the numerical results match the observed velocity patterns well overall except for a variance and small systematic scaling which can be attributed to the known experimental error in the MRI measurements. The comparisons presented here provide strong validation of the pore-scale simulation methods and new insights for interpretation of uncertainty in MRI measurements of pore-scale velocity. This study also provides a potential benchmark for future comparison of other pore-scale simulation methods.

  15. Noble gas magnetic resonator

    DOE Patents [OSTI]

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

    2014-04-15

    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.

  16. Optically Detected Magnetic Resonance Studies on ?-conjugated...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: Optically Detected Magnetic Resonance Studies on -conjugated semiconductor systems Citation Details In-Document Search Title: Optically Detected Magnetic...

  17. Magnetic resonance apparatus

    DOE Patents [OSTI]

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

    1980-10-10

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

  18. Edward Purcell and Nuclear Magnetic Resonance (NMR)

    Office of Scientific and Technical Information (OSTI)

    Edward Mills Purcell and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Edward M. Purcell was awarded the 1952 Nobel Prize in Physics for his "development...

  19. Reciprocity and gyrotropism in magnetic resonance transduction

    SciTech Connect (OSTI)

    Tropp, James

    2006-12-15

    We give formulas for transduction in magnetic resonance - i.e., the appearance of an emf due to Larmor precession of spins - based upon the modified Lorentz reciprocity principle for gyrotropic (also called 'nonreciprocal') media, i.e., in which a susceptibility tensor is carried to its transpose by reversal of an external static field [cf., R. F. Harrington and A. T. Villeneuve IRE Trans. Microwave Theory and Technique MTT6, 308 (1958)]. Prior applications of reciprocity to magnetic resonance, despite much success, have ignored the gyrotropism which necessarily arises due to nuclear and/or unpaired electronic spins. For detection with linearly polarized fields, oscillating at the Larmor frequency, the emf is written in terms of a volume integral containing a product of two factors which we define as the antenna patterns, i.e. (H{sub 1x}{+-}iH{sub 1y}), where, e.g., for a single transceive antenna, the H's are just the spatially dependent oscillatory magnetic field strengths, per the application of some reference current at the antenna terminals, with the negative sign obtaining for transmission, and the positive for reception. Similar expressions hold for separate transmit and receive antennas; expressions are also given for circular polarization of the fields. We then exhibit a receive-only array antenna of two elements for magnetic resonance imaging of protons, which, due an intensity artifact arising from stray reactive coupling of the elements, produces, despite its own bilateral symmetry, asymmetric proton NMR images of a symmetric cylindrical phantom containing aqueous saline solution [J. Tropp and T. Schirmer, J. Magn. Reson. 151, 146 (2001)]. Modification of this two-port antenna, to function in transmit-receive mode, allows us to demonstrate highly nonreciprocal behavior: that is, to record images (of cylindrical test phantoms containing aqueous saline solution) whose appearance dramatically changes, when the roles of transmission and reception are swapped between the two antenna ports--giving in one instance a signal intensity pattern whose form resembles an umbrella (i.e., with a central column of moderate intensity surmounted by a bright canopy), and in the other, a distorted oval with slight concavities at its horizontal extremes, whose outline suggests that of a cat's eye. The relation between image patterns and drive scheme can be shown to reverse if the static polarizing field is reversed. Electromagnetic and circuit calculations, together with the modified reciprocity principle, allow us to reproduce these pattern changes in numerical simulations, closely and convincingly. Although the imaging experiments are performed at a static field of 3.0 T, and consequently a Larmor frequency of 128 MHz, the nonreciprocal effects are not related to the shortness of the wavelength in aqueous medium, but appear equally in simulations based in either the quasistatic or full electromagnetic regimes. Finally, we show that although antenna patterns for transmission and reception are swapped with reversal of the polarizing field, meaning that the receive pattern equals the transmit pattern with the field reversed, this in no way invalidates the familiar rotating wave model of spin dynamics in magnetic resonance.

  20. Three-Dimensional Mapping of Ozone-Induced Injury in the Nasal Airways of Monkeys Using Magnetic Resonance Imaging and Morphometric Techniques

    SciTech Connect (OSTI)

    Carey, Stephen A.; Minard, Kevin R.; Trease, Lynn L.; Wagner, James G.; Garcia, Guilherme M.; Ballinger, Carol A.; Kimbell, Julia; Plopper, Charles G.; Corley, Rick A.; Postlewait, Ed; Harkema, Jack R.

    2007-03-01

    ABSTRACT Age-related changes in gross and microscopic structure of the nasal cavity can alter local tissue susceptibility as well as the dose of inhaled toxicant delivered to susceptible sites. This article describes a novel method for the use of magnetic resonance imaging, 3-dimensional airway modeling, and morphometric techniques to characterize the distribution and magnitude of ozone-induced nasal injury in infant monkeys. Using this method, we are able to generate age-specific, 3-dimensional, epithelial maps of the nasal airways of infant Rhesus macaques. The principal nasal lesions observed in this primate model of ozone-induced nasal toxicology were neutrophilic rhinitis, along with necrosis and exfoliation of the epithelium lining the anterior maxilloturbinate. These lesions, induced by acute or cyclic (episodic) exposures, were examined by light microscopy, quantified by morphometric techniques, and mapped on 3-dimensional models of the nasal airways. Here, we describe the histopathologic, imaging, and computational biology methods developed to efficiently characterize, localize, quantify, and map these nasal lesions. By combining these techniques, the location and severity of the nasal epithelial injury were correlated with epithelial type, nasal airway geometry, and local biochemical and molecular changes on an individual animal basis. These correlations are critical for accurate predictive modeling of exposure-dose-response relationships in the nasal airways, and subsequent extrapolation of nasal findings in animals to humans for developing risk assessment.

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

    SciTech Connect (OSTI)

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

    2013-02-15

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

  2. 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

    2007-04-25

    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 µm and the length was 580 µm. The coil... microspec- troscopy. Liquid samples were loaded into a fused silica capillary positioned 50 µm 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...

  3. Design of multi-channel radio-frequency front-end for 200mhz parallel magnetic resonance imaging 

    E-Print Network [OSTI]

    Liu, Xiaoqun

    2009-05-15

    ) which also acts as a variable gain amplifier (VGA). The quadrature image rejection downconverter consists of a quadrature generator, a passive mixer with a transimpedance amplifier which converts the output current signal of the passive mixer...

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

    E-Print Network [OSTI]

    Glover, Gary H.

    and becomes a larger fraction of the total noise at 3.0 T. Activation of the primary motor and visual cortex a magnetic field strength of 1.5 Tesla (T) seems to represent a good compromise. Functional MRI (f

  5. Differences in span task performance recorded in a functional magnetic resonance imaging (fMRI) simulator compared to a standard laboratory condition 

    E-Print Network [OSTI]

    Harcourt-Brown, Sally

    2006-01-01

    Forty-eight participants completed a working memory span task in a functional magnetic imaging (fMRI) simulator and laboratory. Differences in performance between the two conditions were investigated. The trends in the ...

  6. Noninvasive Monitoring of Microvascular Changes With Partial Irradiation Using Dynamic Contrast-Enhanced and Blood Oxygen Level-Dependent Magnetic Resonance Imaging

    SciTech Connect (OSTI)

    Lin, Yu-Chun [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Electrical Engineering, Chang Gung University, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Jiun-Jie [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Hong, Ji-Hong [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lin, Yi-Ping [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)] [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Wai, Yau-Yau; Ng, Shu-Hang; Wu, Yi-Ming [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China) [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Chun-Chieh, E-mail: jjwang@adm.cgmh.org.tw [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China) [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)

    2013-04-01

    Purpose: The microvasculature of a tumor plays an important role in its response to radiation therapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and blood oxygen level-dependent (BOLD) MRI are both sensitive to vascular characteristics. The present study proposed a partial irradiation approach to a xenograft tumor to investigate the intratumoral response to radiation therapy using DCE and BOLD MRI. Methods and Materials: TRAMP-C1 tumors were grown in C57BL/6J mice. Partial irradiation was performed on the distal half of the tumor with a single dose of 15 Gy. DCE MRI was performed to derive the endothelium transfer constant, K{sup trans}, using pharmacokinetic analysis. BOLD MRI was performed using quantitative R2* measurements with carbogen breathing. The histology of the tumor was analyzed using hematoxylin and eosin staining and CD31 staining to detect endothelial cells. The differences between the irradiated and nonirradiated regions of the tumor were assessed using K{sup trans} values, ?R2* values in response to carbogen and microvascular density (MVD) measurements. Results: A significantly increased K{sup trans} and reduced BOLD response to carbogen were found in the irradiated region of the tumor compared with the nonirradiated region (P<.05). Histologic analysis showed a significant aggregation of giant cells and a reduced MVD in the irradiated region of the tumor. The radiation-induced difference in the BOLD response was associated with differences in MVD and K{sup trans}. Conclusions: We demonstrated that DCE MRI and carbogen-challenge BOLD MRI can detect differential responses within a tumor that may potentially serve as noninvasive imaging biomarkers to detect microvascular changes in response to radiation therapy.

  7. Velocity and concentration studies of flowing suspensions by nuclear magnetic resonance imaging. Technical progress report, April--June 1996

    SciTech Connect (OSTI)

    1997-05-01

    Our search for a suitable combination of imageable particles in a carrier liquid which will not dissolve the particles has led us to try pharmaceutical particles in silicon oil. This combination doses not seem to last long enough for adequate NMR measurements. Results are discussed.

  8. Enhancement of artificial magnetism via resonant bianisotropy

    E-Print Network [OSTI]

    Markovich, Dmitry; Shalin, Alexander; Samusev, Anton; Krasnok, Alexander; Belov, Pavel; Ginzburg, Pavel

    2015-01-01

    All-dielectric "magnetic light" nanophotonics based on high refractive index nanoparticles allows controlling magnetic component of light at nanoscale without having high dissipative losses. The artificial magnetic optical response of such nanoparticles originates from circular displacement currents excited inside those structures and strongly depends on geometry and dispersion of optical materials. Here a new approach for increasing magnetic response via resonant bianisotropy effect is proposed and analyzed. The key mechanism of enhancement is based on electric-magnetic interaction between two electrically and magnetically resonant nanoparticles of all-dielectric dimer nanoantenna. It was shown that proper geometrical arrangement of the dimer in respect to the incident illumination direction allows flexible control over all vectorial components of magnetic polarizability, tailoring the later in the dynamical range of 100 % and enhancement up to 36 % relative to performances of standalone spherical particles....

  9. A finite elements method to solve the Bloch–Torrey equation applied to diffusion magnetic resonance imaging

    SciTech Connect (OSTI)

    Nguyen, Dang Van; Li, Jing-Rebecca; Grebenkov, Denis; Le Bihan, Denis

    2014-04-15

    The complex transverse water proton magnetization subject to diffusion-encoding magnetic field gradient pulses in a heterogeneous medium can be modeled by the multiple compartment Bloch–Torrey partial differential equation (PDE). In addition, steady-state Laplace PDEs can be formulated to produce the homogenized diffusion tensor that describes the diffusion characteristics of the medium in the long time limit. In spatial domains that model biological tissues at the cellular level, these two types of PDEs have to be completed with permeability conditions on the cellular interfaces. To solve these PDEs, we implemented a finite elements method that allows jumps in the solution at the cell interfaces by using double nodes. Using a transformation of the Bloch–Torrey PDE we reduced oscillations in the searched-for solution and simplified the implementation of the boundary conditions. The spatial discretization was then coupled to the adaptive explicit Runge–Kutta–Chebyshev time-stepping method. Our proposed method is second order accurate in space and second order accurate in time. We implemented this method on the FEniCS C++ platform and show time and spatial convergence results. Finally, this method is applied to study some relevant questions in diffusion MRI.

  10. Physical Background OfPhysical Background Of Nuclear Magnetic ResonanceNuclear Magnetic Resonance

    E-Print Network [OSTI]

    Olszewski Jr., Edward A.

    Physical Background OfPhysical Background Of Nuclear Magnetic ResonanceNuclear Magnetic Resonance SpectroscopySpectroscopy Michael McClellan Spring 2009 Department of Physics and Physical Oceanography Theoretically the nucleus can have any of these allowed spins #12;General Characteristics of Nuclear Spin

  11. Modifications in Dynamic Contrast-Enhanced Magnetic Resonance Imaging Parameters After ?-Particle-Emitting {sup 227}Th-trastuzumab Therapy of HER2-Expressing Ovarian Cancer Xenografts

    SciTech Connect (OSTI)

    Heyerdahl, Helen; Røe, Kathrine; Brevik, Ellen Mengshoel; Dahle, Jostein

    2013-09-01

    Purpose: The purpose of this study was to investigate the effect of ?-particle-emitting {sup 227}Th-trastuzumab radioimmunotherapy on tumor vasculature to increase the knowledge about the mechanisms of action of {sup 227}Th-trastuzumab. Methods and Materials: Human HER2-expressing SKOV-3 ovarian cancer xenografts were grown bilaterally in athymic nude mice. Mice with tumor volumes 253 ± 36 mm{sup 3} (mean ± SEM) were treated with a single injection of either {sup 227}Th-trastuzumab at a dose of 1000 kBq/kg body weight (treated group, n=14 tumors) or 0.9% NaCl (control group, n=10 tumors). Dynamic T1-weighted contrast-enhanced magnetic resonance imaging (DCEMRI) was used to study the effect of {sup 227}Th-trastuzumab on tumor vasculature. DCEMRI was performed before treatment and 1, 2, and 3 weeks after therapy. Tumor contrast-enhancement curves were extracted voxel by voxel and fitted to the Brix pharmacokinetic model. Pharmacokinetic parameters for the tumors that underwent radioimmunotherapy were compared with the corresponding parameters of control tumors. Results: Significant increases of k{sub ep}, the rate constant of diffusion from the extravascular extracellular space to the plasma (P<.05), and k{sub el,} the rate of clearance of contrast agent from the plasma (P<.01), were seen in the radioimmunotherapy group 2 and 3 weeks after injection, compared with the control group. The product of k{sub ep} and the amplitude parameter A, associated with increased vessel permeability and perfusion, was also significantly increased in the radioimmunotherapy group 2 and 3 weeks after injection (P<.01). Conclusions: Pharmacokinetic modeling of MRI contrast-enhancement curves evidenced significant alterations in parameters associated with increased tumor vessel permeability and tumor perfusion after {sup 227}Th-trastuzumab treatment of HER2-expressing ovarian cancer xenografts.

  12. Magnetic resonance imaging and computational fluid dynamics (CFD) simulations of rabbit nasal airflows for the development of hybrid CFD/PBPK models

    SciTech Connect (OSTI)

    Corley, Richard A.; Minard, Kevin R.; Kabilan, Senthil; Einstein, Daniel R.; Kuprat, Andrew P.; harkema, J. R.; Kimbell, Julia; Gargas, M. L.; Kinzell, John H.

    2009-06-01

    The percentages of total air?ows over the nasal respiratory and olfactory epithelium of female rabbits were cal-culated from computational ?uid dynamics (CFD) simulations of steady-state inhalation. These air?ow calcula-tions, along with nasal airway geometry determinations, are critical parameters for hybrid CFD/physiologically based pharmacokinetic models that describe the nasal dosimetry of water-soluble or reactive gases and vapors in rabbits. CFD simulations were based upon three-dimensional computational meshes derived from magnetic resonance images of three adult female New Zealand White (NZW) rabbits. In the anterior portion of the nose, the maxillary turbinates of rabbits are considerably more complex than comparable regions in rats, mice, mon-keys, or humans. This leads to a greater surface area to volume ratio in this region and thus the potential for increased extraction of water soluble or reactive gases and vapors in the anterior portion of the nose compared to many other species. Although there was considerable interanimal variability in the ?ne structures of the nasal turbinates and air?ows in the anterior portions of the nose, there was remarkable consistency between rabbits in the percentage of total inspired air?ows that reached the ethmoid turbinate region (~50%) that is presumably lined with olfactory epithelium. These latter results (air?ows reaching the ethmoid turbinate region) were higher than previous published estimates for the male F344 rat (19%) and human (7%). These di?erences in regional air?ows can have signi?cant implications in interspecies extrapolations of nasal dosimetry.

  13. 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...

  14. 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)

    2012-05-01

    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.

  15. 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

  16. Magnetic Resonance Imaging of concrete

    E-Print Network [OSTI]

    Burgoyne, Chris

    it for babies, why not for concrete? #12;2 Non-destructive-testing Methods for Concrete Structures. Irie et al structure · In both cases procedure is destructive Systems to monitor concrete modulus · Ultra-sonic pulse and examined under microscope Limited number of sections can be obtained and only after unloading Destructive

  17. Performing temperature feedback controlled tissue photo-coagulation using magnetic resonance thermometry 

    E-Print Network [OSTI]

    Sampath, Smita

    1999-01-01

    controlled photo-coagulation using magnetic resonance imaging as the non-invasive means of temperature feedback. The desired coagulation depth was controlled at a constant temperature of 40 degrees for different amounts of time and the actual coagulation...

  18. 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)

    2011-11-22

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

  19. Magnetic and electric excitations in split ring resonators

    E-Print Network [OSTI]

    Magnetic and electric excitations in split ring resonators Jiangfeng Zhou1,2,, Thomas Koschny1 studied the electric and magnetic resonances of U-shaped SRRs. We showed that higher order excitation modes exist in both of the electric and magnetic resonances. The nodes in the current distribution were

  20. 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)

    2014-07-14

    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.

  1. JOURNAL OF MAGNETIC RESONANCE 63, 622-628 (1985) An Efficient, Highly Hokogeneous RadiofrequencyCoil

    E-Print Network [OSTI]

    California at San Diego, University of

    1985-01-01

    that of a saddle coil or slotted tube resonator. The improved Br homogeneity is needed to generate accurateJOURNAL OF MAGNETIC RESONANCE 63, 622-628 (1985) An Efficient, Highly Hokogeneous RadiofrequencyCoil have developed radiofrequency coils for high-field head and whole-body imaging which achieve near

  2. Electro-Mechanical Resonant Magnetic Field Sensor

    E-Print Network [OSTI]

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

    2002-01-01

    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 ...

  3. 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

  4. Molecular structure and motion in zero field magnetic resonance

    SciTech Connect (OSTI)

    Jarvie, T.P.

    1989-10-01

    Zero field magnetic resonance is well suited for the determination of molecular structure and the study of motion in disordered materials. Experiments performed in zero applied magnetic field avoid the anisotropic broadening in high field nuclear magnetic resonance (NMR) experiments. As a result, molecular structure and subtle effects of motion are more readily observed.

  5. 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

  6. Solid State Nuclear Magnetic Resonance 29 (2006) 5265 Dynamic nuclear polarization and nuclear magnetic resonance in the

    E-Print Network [OSTI]

    Gusev, Guennady

    2006-01-01

    Solid State Nuclear Magnetic Resonance 29 (2006) 52­65 Dynamic nuclear polarization and nuclear Nuclear magnetic resonance is detected via the in-plane conductivity of a two-dimensional electron system edge states at the perimeter of the 2DES. Interpretation of the electron-nuclear double resonance

  7. 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

  8. 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

  9. Nuclear magnetic Trond Saue (LCPQ, Toulouse) Nuclear magnetic resonance Virginia Tech 2015 1 / 51

    E-Print Network [OSTI]

    Crawford, T. Daniel

    Nuclear magnetic resonance Trond Saue Trond Saue (LCPQ, Toulouse) Nuclear magnetic resonance Virginia Tech 2015 1 / 51 #12;Nuclear spin The atomic nucleus is a composite particle built from Z protons (LCPQ, Toulouse) Nuclear magnetic resonance Virginia Tech 2015 1 / 51 #12;Gyromagnetic ratio: classical

  10. Science Drivers and Technical Challenges for Advanced Magnetic Resonance

    SciTech Connect (OSTI)

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

    2013-03-07

    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.

  11. Abstract-A novel imaging method for electrical impedance tomography is implemented. In this method, the magnetic flux

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    - electrical impedance tomography, magnetic resonance imaging. I. INTRODUCTION Electrical impedance tomography conductivity images [11]. Both of these techniques can be named as magnetic resonance-electrical impedanceAbstract- A novel imaging method for electrical impedance tomography is implemented. In this method

  12. Novel nuclear magnetic resonance techniques for studying biological molecules

    E-Print Network [OSTI]

    Laws, David D.

    2010-01-01

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

  13. MRI Magnet Design: Search Space Analysis, EDAs and a Real-World Problem with Significant Dependencies

    E-Print Network [OSTI]

    Gallagher, Marcus

    of superconductive magnet configurations in Magnetic Resonance Imaging (MRI) systems as a challenging real

  14. 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.; Schoeder, Heiko; Lee, Nancy Y.; Stambuk, Hilda E.; Wang Ya; Fury, Matthew G.; Patel, Senehal G.; Pfister, David G.; Shah, Jatin P.; Koutcher, Jason A.; Shukla-Dave, Amita

    2012-01-01

    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.

  15. General classical and quantum-mechanical description of magnetic resonance

    E-Print Network [OSTI]

    Alexander J. Silenko

    2015-08-04

    A general theoretical description of the magnetic resonance is given. General formulas describing a behavior of all components of the polarization vector at the magnetic resonance are derived in the case of an arbitrary initial polarization. The equations obtained are exact on condition that the nonresonance rotating field is neglected. The spin dynamics is also calculated at frequencies far from resonance without neglecting the above-mentioned field. A quantum-mechanical analysis of the spin evolution at the magnetic resonance is fulfilled and the full agreement between the classical and quantum-mechanical approaches is proven. Distinguishing features of magnetic and quasimagnetic resonances for nuclei and particles moving in accelerators and storage rings which include resonances caused by the electric dipole moment are considered.

  16. General classical and quantum-mechanical description of magnetic resonance

    E-Print Network [OSTI]

    Silenko, Alexander J

    2015-01-01

    A general theoretical description of the magnetic resonance is given. General formulas describing a behavior of all components of the polarization vector at the magnetic resonance are derived in the case of an arbitrary initial polarization. The equations obtained are exact on condition that the nonresonance rotating field is neglected. The spin dynamics is also calculated at frequencies far from resonance without neglecting the above-mentioned field. A quantum-mechanical analysis of the spin evolution at the magnetic resonance is fulfilled and the full agreement between the classical and quantum-mechanical approaches is proven. Distinguishing features of magnetic and quasimagnetic resonances for nuclei and particles moving in accelerators and storage rings which include resonances caused by the electric dipole moment are considered.

  17. Selectivity in multiple quantum nuclear magnetic resonance

    SciTech Connect (OSTI)

    Warren, W.S.

    1980-11-01

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible.

  18. IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 44, NO. 6, JUNE 2009 1805 A Spectral-Scanning Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Hajimiri, Ali

    resonance detection and analysis is tunable from 1 kHz to 37 MHz, corresponding to 0­0.9 T magnetization- troscopy, magnetic resonance imaging (MRI), coherent detection, Torrey-Bloch equation, nuclear magnetic keeping the sensitivity, detection time, spectral resolution, and the relative-to-sample-size spatial res

  19. Resonant x-ray magnetic scattering in holmium

    SciTech Connect (OSTI)

    Gibbs, D.

    1991-01-01

    We review the results of resonant x-ray magnetic scattering experiments on the rare earth metal holmium. When the incident incident x-ray energy is tuned near the L{sub III} absorption edge, large resonant enhancements of the magnetic scattering and resonant integer harmonics are observed. These results are analyzed within the theory of x-ray resonance exchange scattering assuming electric dipole (2p {yields} 5d) and quadrupole (2p {yields} 4f) transitions among atomic orbitals. 30 refs., 5 figs.

  20. Sensitive magnetic force detection with a carbon nanotube resonator

    SciTech Connect (OSTI)

    Willick, Kyle; Haapamaki, Chris; Baugh, Jonathan

    2014-03-21

    We propose a technique for sensitive magnetic point force detection using a suspended carbon nanotube (CNT) mechanical resonator combined with a magnetic field gradient generated by a ferromagnetic gate electrode. Numerical calculations of the mechanical resonance frequency show that single Bohr magneton changes in the magnetic state of an individual magnetic molecule grafted to the CNT can translate to detectable frequency shifts, on the order of a few kHz. The dependences of the resonator response to device parameters such as length, tension, CNT diameter, and gate voltage are explored and optimal operating conditions are identified. A signal-to-noise analysis shows that, in principle, magnetic switching at the level of a single Bohr magneton can be read out in a single shot on timescales as short as 10??s. This force sensor should enable new studies of spin dynamics in isolated single molecule magnets, free from the crystalline or ensemble settings typically studied.

  1. Investigation of Peptide Folding by Nuclear Magnetic Resonance Spectroscopy 

    E-Print Network [OSTI]

    Hwang, SoYoun

    2012-07-16

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

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2004-12-28

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

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2003-12-30

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

  4. Threshold Doses for Focal Liver Reaction After Stereotactic Ablative Body Radiation Therapy for Small Hepatocellular Carcinoma Depend on Liver Function: Evaluation on Magnetic Resonance Imaging With Gd-EOB-DTPA

    SciTech Connect (OSTI)

    Sanuki, Naoko; Takeda, Atsuya; Oku, Yohei; Eriguchi, Takahisa; Nishimura, Shuichi; Aoki, Yosuke; Mizuno, Tomikazu; Iwabuchi, Shogo; Kunieda, Etsuo

    2014-02-01

    Purpose: Focal liver reaction (FLR) appears on radiographic images after stereotactic ablative body radiation therapy (SABR) in patients with hepatocellular carcinoma (HCC) and chronic liver disease. We investigated the threshold dose (TD) of FLR and possible factors affecting the TD on gadoxetate acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI). Methods and Materials: In 50 patients who were treated with SABR for small HCC and followed up by MRI for >6 months, FLR, seen as a hypointense area, was evaluated on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI. The follow-up MRI with the largest extent of FLR was fused to the planning computed tomography (CT) image, and patients with good image fusion concordance were eligible. After delineating the border of the FLR manually, a dose–volume histogram was used to identify the TD for the FLR. Clinical and volumetric factors were analyzed for correlation with the TD. Results: A total of 45 patients were eligible for analysis with a median image fusion concordance of 84.9% (range, 71.6-95.4%). The median duration between SABR and subsequent hepatobiliary phase MRI with the largest extent of FLR was 3 months (range, 1-6 months). The median TD for FLR was 28.0 Gy (range, 22.3-36.4 Gy). On univariate analysis, pre-treatment Child-Pugh (CP) score and platelet count were significantly correlated with the TD. On multiple linear regression analysis, CP score was the only parameter that predicted TD. Median TDs were 30.5 Gy (range, 26.2.3-36.4 Gy) and 25.2 Gy (range, 22.3-27.5 Gy) for patients with CP-A and CP-B disease, respectively. Conclusion: The TD was significantly correlated with baseline liver function. We propose 30 Gy for CP-A disease and 25 Gy for CP-B disease in 5 fractions as TDs for FLR after SABR for patients with HCC and chronic liver disease. Use of these TDs will help to predict potential loss of liver tissue after SABR.

  5. 232 OPTICS LETTERS / Vol. 29, No. 3 / February 1, 2004 Off-resonant defocus-contrast imaging of cold atoms

    E-Print Network [OSTI]

    Scholten, Robert

    of column-density images of cold atoms, using a noninterferometric phase- recovery technique based prospects for simple, nondestructive imaging of atoms in magnetic and optical traps and condensates. © 2004 is predominant, despite its limited dynamic range and recoil heating. Off-resonant phase-imaging tech- niques

  6. Molecular imaging by optically-detected electron spin resonance of nitrogen-vacancies in nanodiamond

    E-Print Network [OSTI]

    Alex Hegyi; Eli Yablonovitch

    2012-12-11

    Molecular imaging refers to a class of noninvasive biomedical imaging techniques with the sensitivity and specificity to image biochemical variations in-vivo. An ideal molecular imaging technique visualizes a biochemical target according to a range of criteria, including high spatial and temporal resolution, high contrast relative to non-targeted tissues, depth-independent penetration into tissue, lack of harm to the organism under study, and low cost. Because no existing molecular imaging modality is ideal for all purposes, new imaging approaches are needed. Here we demonstrate a novel molecular imaging approach, called nanodiamond imaging, that uses nanodiamonds containing nitrogen-vacancy (NV) color centers as an imaging agent, and image nanodiamond targets in pieces of chicken breast. Nanodiamonds can be tagged with biologically active molecules so they bind to specific receptors; their distribution can then be quantified in-vivo via optically-detected magnetic resonance of the NVs. In effect, we are demonstrating Optically-Detected Functional-Electron-Spin-Resonance-Imaging, OD-f-ESRI. By combining optical detection with magnetic resonance, nanodiamond imaging achieves high sensitivity and high spatial resolution. It is absent of the complications of ionizing radiation, and the cost should be similar to all-optical imaging. Because nanodiamond imaging is limited by the depth of optical penetration into tissue to depths of a few cm, nanodiamond imaging should open up new avenues of investigation for applications where high depth penetration is not required, such as in small-animal imaging, tumor margin imaging, sentinel lymph node mapping, and perhaps mammography.

  7. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2010-06-29

    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.

  8. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2009-11-10

    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.

  9. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2007-12-11

    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.

  10. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2009-10-27

    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.

  11. Spin microscope based on optically detected magnetic resonance

    DOE Patents [OSTI]

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

    2010-07-13

    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.

  12. Molecular imaging by optically-detected electron spin resonance of nitrogen-vacancies in nanodiamond

    E-Print Network [OSTI]

    Hegyi, Alex

    2012-01-01

    Molecular imaging refers to a class of noninvasive biomedical imaging techniques with the sensitivity and specificity to image biochemical variations in-vivo. An ideal molecular imaging technique visualizes a biochemical target according to a range of criteria, including high spatial and temporal resolution, high contrast relative to non-targeted tissues, depth-independent penetration into tissue, lack of harm to the organism under study, and low cost. Because no existing molecular imaging modality is ideal for all purposes, new imaging approaches are needed. Here we demonstrate a novel molecular imaging approach, called nanodiamond imaging, that uses nanodiamonds containing nitrogen-vacancy (NV) color centers as an imaging agent, and image nanodiamond targets in pieces of chicken breast. Nanodiamonds can be tagged with biologically active molecules so they bind to specific receptors; their distribution can then be quantified in-vivo via optically-detected magnetic resonance of the NVs. In effect, we are demo...

  13. 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

  14. 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

  15. 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; Sadeghi, Mahdi; Mahdavi, Seied Rabie; Babapour Mofrad, Farshid; Astarakee, Mahdi; Khaledi, Navid; Fadavi, Pedram

    2013-09-01

    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.

  16. 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)

    2014-07-15

    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})

  17. FY08 Annual Report for Nuclear Resonance Fluorescence Imaging

    SciTech Connect (OSTI)

    Warren, Glen A.; Caggiano, Joseph A.

    2009-01-06

    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.

  18. Next Generation Magnetic Resonance Imaging Contrast Agents

    E-Print Network [OSTI]

    Klemm, Piper Julia

    2012-01-01

    Meade, T. J. Gd(III)-Nanodiamond conjugates for MRI contrastMeade, T. J. Gd(III)-Nanodiamond conjugates for MRI contrastMeade, T. J. Gd(III)-Nanodiamond conjugates for MRI contrast

  19. Next Generation Magnetic Resonance Imaging Contrast Agents

    E-Print Network [OSTI]

    Klemm, Piper Julia

    2012-01-01

    and environmental impact of Fe make it a promising candidate for more sustainable contrast agent development.

  20. Next Generation Magnetic Resonance Imaging Contrast Agents

    E-Print Network [OSTI]

    Klemm, Piper Julia

    2012-01-01

    were filtered over 0.45 ! m PTFE filters to remove dust andsolids through a 0.45 ! m PTFE filter the red solution wasand filtered over a 0.45 ! m PTFE filter. After evaporation

  1. Magnetic resonance imaging of plantar plate rupture

    E-Print Network [OSTI]

    Yao, L; Cracchiolo, A; Farahani, K; Seeger, LL

    1996-01-01

    had an ipsilateral hallux valgus, and five had a hammertoe8), and an ipsilateral hallux valgus (6 of 8). Patients with

  2. 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

  3. Amyloid Oligomer Formation Probed by Water Proton Magnetic Resonance Spectroscopy

    E-Print Network [OSTI]

    Berry, R. Stephen

    Amyloid Oligomer Formation Probed by Water Proton Magnetic Resonance Spectroscopy J. H. Walton, R, Chicago, Illinois; and § Department of Pharmacology, University of California, Davis, California ABSTRACT Formation of amyloid oligomers, the most toxic species of amyloids in degenerative diseases, is critically

  4. Edge stability and transport control with resonant magnetic perturbations in

    E-Print Network [OSTI]

    Loss, Daniel

    ARTICLES Edge stability and transport control with resonant magnetic perturbations in collisionless, California 92186-5608, USA 2 University of California, San Diego, California 92093-0417, USA 3 Lawrence Livermore National Laboratory, Livermore, California 94551-0808, USA 4 Association EURATOM-CEA, CEA

  5. Magneto-optical imaging of thin magnetic films using spins in diamond

    E-Print Network [OSTI]

    David A. Simpson; Jean-Philippe Tetienne; Julia McCoey; Kumaravelu Ganesan; Liam T. Hall; Steven Petrou; Robert E. Scholten; Lloyd C. L. Hollenberg

    2015-08-10

    Imaging the fields of magnetic materials provides crucial insight into the physical and chemical processes surrounding magnetism, and has been a key ingredient in the spectacular development of magnetic data storage. Existing approaches using the magneto-optic Kerr effect (MOKE), x-ray and electron microscopy have limitations that constrain further development, and there is increasing demand for imaging and characterisation of magnetic phenomena in real time with high spatial resolution. In this work, we show how the magneto-optical response of an array of negatively-charged nitrogen-vacancy spins in diamond can be used to image and map the sub-micron stray magnetic field patterns from thin ferromagnetic films. Using optically detected magnetic resonance, we demonstrate wide-field magnetic imaging over 100x100 {\\mu}m^2 with a diffraction-limited spatial resolution of 440 nm at video frame rates, under ambient conditions. We demonstrate a novel all-optical spin relaxation contrast imaging approach which can image magnetic structures in the absence of an applied microwave field. Straightforward extensions promise imaging with sub-{\\mu}T sensitivity and sub-optical spatial and millisecond temporal resolution. This work establishes practical diamond-based wide-field microscopy for rapid high-sensitivity characterisation and imaging of magnetic samples, with the capability for investigating magnetic phenomena such as domain wall and skyrmion dynamics and the spin Hall effect in metals.

  6. 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

    2015-03-13

    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 (fields of 3 T. In addition, we demonstrate coherent control of single nuclear spins under these conditions. Furthermore, our results extend the applicable magnetic field range of a single spin magnetic field 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.

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

    SciTech Connect (OSTI)

    Parra, J.O.

    2001-01-26

    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.

  8. 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)

    2014-06-15

    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.

  9. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse Bergkamp GraduateResidential EnergyOrganizationLecturersLending aImaging

  10. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogo and-E C H N I C AFAQLensless Imaging of

  11. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogo and-E C H N I C AFAQLensless Imaging

  12. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverseIMPACTThousand CubicResourcelogo and-E C H N I C AFAQLensless ImagingLensless

  13. Contributed Review: Nuclear magnetic resonance core analysis at 0.3 T

    SciTech Connect (OSTI)

    Mitchell, Jonathan Fordham, Edmund J.

    2014-11-15

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  14. Instruments High-resolution imaging of

    E-Print Network [OSTI]

    Boppart, Stephen

    Instruments & Methods High-resolution imaging of gynecologic neoplasms using optical coherence and Gynecologists.) Diagnostic imaging methods available to gynecologists include magnetic resonance imaging (MRI

  15. Electrically driven nuclear spin resonance in a single-molecule magnet

    E-Print Network [OSTI]

    Vallette, Bruno

    Electrically driven nuclear spin resonance in a single-molecule magnet Institut Néel : Nanospin Institut Néel, CNRS-UJF, Grenoble NanoSpin #12;· Molecular magnets are characterised by : a magnetic moment a strong uniaxial anisotropy Mn12 Molecular magnets Fe8 #12;· Molecular magnets are characterised

  16. 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 ...

  17. Resonances and spectral shift function for a magnetic Schroedinger operator

    SciTech Connect (OSTI)

    Khochman, Abdallah

    2009-04-15

    We consider the three-dimensional Schroedinger operator H{sub 0} with a constant magnetic field and subject to an electric potential v{sub 0} depending only on the variable along the magnetic field x{sub 3}. The operator H{sub 0} has infinitely many eigenvalues of infinite multiplicity embedded in its continuous spectrum. We perturb H{sub 0} by smooth scalar potentials V=O(<(x{sub 1},x{sub 2})>{sup -{delta}{sub perpendicular}}{sup -{delta}{sub ||}}), {delta}{sub perpendicular}>2, {delta}{sub ||}>1. We assume also that V and v{sub 0} have an analytic continuation, in the magnetic field direction, in a complex sector outside a compact set. We define the resonances of H=H{sub 0}+V as the eigenvalues of the nonself-adjoint operator obtained from H by analytic distortions of R{sub x{sub 3}}. We study their distribution near any fixed real eigenvalue of H{sub 0}, 2bq+{lambda} for q is an element of N. In a ring centered at 2bq+{lambda} with radii (r,2r), we establish an upper bound, as r tends to 0, of the number of resonances. This upper bound depends on the decay of V at infinity only in the directions (x{sub 1},x{sub 2}). Finally, we deduce a representation of the derivative of the spectral shift function for the operator pair (H{sub 0},H) in terms of resonances. This representation justifies the Breit-Wigner approximation and implies a local trace formula.

  18. A Magnetic Resonance Realization of Decoherence-Free Quantum Computation

    E-Print Network [OSTI]

    Jason E. Ollerenshaw; Daniel A. Lidar; Lewis E. Kay

    2003-09-24

    We report the realization, using nuclear magnetic resonance techniques, of the first quantum computer that reliably executes an algorithm in the presence of strong decoherence. The computer is based on a quantum error avoidance code that protects against a class of multiple-qubit errors. The code stores two decoherence-free logical qubits in four noisy physical qubits. The computer successfully executes Grover's search algorithm in the presence of arbitrarily strong engineered decoherence. A control computer with no decoherence protection consistently fails under the same conditions.

  19. 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)

    2000-01-01

    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.

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

    E-Print Network [OSTI]

    Firpo, Marie-Christine; 10.1063/1.3562493

    2011-01-01

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

  1. Improved evolution equations for magnetic island chains in toroidal pinch plasmas subject to externally applied resonant magnetic perturbations

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    inside the plasma. Such island chains degrade plasma confinement be- cause both heat and particlesImproved evolution equations for magnetic island chains in toroidal pinch plasmas subject nonlinear dynamics of magnetic islands due to resonant magnetic perturbations Phys. Plasmas 21, 122502 (2014

  2. 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

  3. Ultrafast-based projection-reconstruction three-dimensional nuclear magnetic resonance spectroscopy

    E-Print Network [OSTI]

    Frydman, Lucio

    Ultrafast-based projection-reconstruction three-dimensional nuclear magnetic resonance spectroscopy Eriks Kupce Varian Ltd., 28 Manor Road, Walton-on-Thames, Surrey KT12 2QF, United Kingdom Lucio Frydmana the accelerated acquisition of multidimensional nuclear magnetic resonance nD NMR spectra. Among the methods

  4. Second harmonic generation with plasmonic metasurfaces: direct comparison of electric and magnetic resonances

    E-Print Network [OSTI]

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

    2015-01-01

    Plasmonic resonances in metallic nanostructures have been shown to drastically enhance local electromagnetic fields, and thereby increase the efficiency of nonlinear optical phenomena, such as second harmonic generation (SHG). While it has been experimentally observed that enhanced fields can significantly boost SHG, to date it proved difficult to probe electrical and magnetic resonances in one and the same nanostructure. This however is necessary to directly compare relative contributions of electrical and magnetic components of SHG enhancement. In this paper we report an experimental study of a metasurface capable of providing electrical and magnetic resonant SHG enhancement for TM polarization. Our metasurface could be engineered such that the peak frequencies of electrical and magnetic resonances could be adjusted independently. We used this feature to distinguish their relative contributions. Experimentally it was observed that the magnetic resonance provides only 50% as much enhancement to SHG as compar...

  5. Nuclear Magnetic Resonance Quantum Computing Using Liquid Crystal Solvents

    E-Print Network [OSTI]

    Costantino S. Yannoni; Mark H. Sherwood; Lieven M. K. Vandersypen; Dolores C. Miller; Mark G. Kubinec; Isaac L. Chuang

    1999-12-12

    Liquid crystals offer several advantages as solvents for molecules used for nuclear magnetic resonance quantum computing (NMRQC). The dipolar coupling between nuclear spins manifest in the NMR spectra of molecules oriented by a liquid crystal permits a significant increase in clock frequency, while short spin-lattice relaxation times permit fast recycling of algorithms, and save time in calibration and signal-enhancement experiments. Furthermore, the use of liquid crystal solvents offers scalability in the form of an expanded library of spin-bearing molecules suitable for NMRQC. These ideas are demonstrated with the successful execution of a 2-qubit Grover search using a molecule ($^{13}$C$^{1}$HCl$_3$) oriented in a liquid crystal and a clock speed eight times greater than in an isotropic solvent. Perhaps more importantly, five times as many logic operations can be executed within the coherence time using the liquid crystal solvent.

  6. Nuclear magnetic resonance spectroscopy of single subnanoliter ova

    E-Print Network [OSTI]

    Grisi, Marco; Guidetti, Roberto; Harris, Nicola; Boero, Giovanni

    2015-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is, in principle, a promising candidate to study the intracellular chemistry of single microscopic living entities. However, due to sensitivity limitations, NMR experiments were reported only on very few and relatively large single cells down to a minimum volume of 10 nl. Here we show NMR spectroscopy of single ova at volume scales (0.1 and 0.5 nl) where life development begins for a broad variety of animals, humans included. We demonstrate that the sensitivity achieved by miniaturized inductive NMR probes (few pmol of 1H nuclei in some hours at 7 T) is sufficient to observe chemical heterogeneities among subnanoliter ova of tardigrades. Such sensitivities should allow to non-invasively monitor variations of concentrated intracellular compounds, such as glutathione, in single mammalian zygotes.

  7. 3D and 4D magnetic susceptibility tomography based on complex MR images

    DOE Patents [OSTI]

    Chen, Zikuan; Calhoun, Vince D

    2014-11-11

    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.

  8. 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

    2014-08-05

    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.

  9. 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

  10. 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

    2015-04-19

    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.

  11. Inversion of surface nuclear magnetic resonance data by an adapted Monte Carlo method applied to water resource characterization

    E-Print Network [OSTI]

    Sailhac, Pascal

    Inversion of surface nuclear magnetic resonance data by an adapted Monte Carlo method applied, France Abstract Inversion of surface nuclear magnetic resonance (SNMR) provides important information Science B.V. All rights reserved. Keywords: Inversion; Surface nuclear magnetic resonance; Monte Carlo 1

  12. Resonances Width in Crossed Electric and Magnetic Christian Ferrari a and Hynek Kova r k b

    E-Print Network [OSTI]

    Resonances Width in Crossed Electric and Magnetic Fields Christian Ferrari a and Hynek Kova#20;r#19 con#12;ned to a two- dimensional plane and submitted to homogeneous magnetic and electric #12;elds dimensions in the presence of crossed magnetic and electric #12;elds and a potential type perturbation. We

  13. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    SciTech Connect (OSTI)

    Heaney, M.B. . Dept. of Physics Lawrence Berkeley Lab., CA )

    1990-11-01

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

  14. 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

  15. Direct imaging of nanoscale magnetic interactions in minerals

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Direct imaging of nanoscale magnetic interactions in minerals Richard J. Harrison*, Rafal E. Dunin. Magnetite is the most strongly magnetic mineral in nature. Small particles of magnetite in single-domain (SD and pseudo-SD particles (1). In most igneous rocks, the grain size of primary magnetic minerals exceeds

  16. Direct Imaging of Asymmetric Magnetization Reversal

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

    storage density. However, it remains poorly understood, and even the fundamental mechanism of magnetic reversal for exchange-biased systems in changing magnetic fields is...

  17. Advances in Zero-Field Nuclear Magnetic Resonance Spectroscopy

    E-Print Network [OSTI]

    Theis, Thomas

    2012-01-01

    in order to apply oscillating magnetic fields (test signals)x field, an oscillating magnetic field in the z direction isused to apply an oscillating magnetic field ranging from 2

  18. Tunable multiple Fano resonances in magnetic single-layered core-shell particles

    E-Print Network [OSTI]

    Arruda, Tiago Jose; Pinheiro, Felipe Arruda

    2015-01-01

    We investigate multiple Fano, comblike scattering resonances in single-layered, concentric core-shell nanoparticles composed of magnetic materials. Using the Lorenz-Mie theory, we derive, in the long-wavelength limit, an analytical condition for the occurrence of comblike resonances in the single scattering by coated spheres. This condition establishes that comblike scattering response uniquely depends on material parameters and thickness of the shell, provided that it is magnetic and thin compared to the scatterer radius. We also demonstrate that comblike scattering response shows up beyond the long-wavelength limit and it is robust against absorption. Since multiple Fano resonances are shown to depend explicitly on the magnetic permeability of the shell, we argue that both the position and profile of the comblike, morphology-dependent resonances could be externally tuned by exploiting the properties of engineered magnetic materials.

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

    E-Print Network [OSTI]

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

    2003-01-01

    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 ...

  20. Rapid Determination of Moisture and Fat in Meats By Microwave And Nuclear Magnetic Resonance Analysis 

    E-Print Network [OSTI]

    Claflin, Amy Elizabeth

    2013-08-30

    methods that require less time, labor, skill, and cost. Microwave drying and nuclear magnetic resonance technologies for the determination of moisture and fat in meat products, respectively, have been incorporated into the CEM Smart Trac 5 System...

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

    E-Print Network [OSTI]

    Cappellaro, Paola

    2014-01-01

    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 ...

  2. Two Phase Flow Measurements by Nuclear Magnetic Resonance (NMR)

    SciTech Connect (OSTI)

    Altobelli, Stephen A; Fukushima, Eiichi

    2006-08-14

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

  3. Fast Algorithms for Image Reconstruction with Application to Partially Parallel MR Imaging

    E-Print Network [OSTI]

    Yin, Wotao

    Fast Algorithms for Image Reconstruction with Application to Partially Parallel MR Imaging Yunmei. Key words. Image reconstruction, Variable splitting, TV denoising, Nonlinear optimization 1 from an emerging magnetic resonance (MR) medical imaging technique known as partially parallel imaging

  4. 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, Andrew Hillenius and David S. Ricketts Electrical & Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 Abstract-- In this paper we report on a resonant wireless power delivery system using

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

    SciTech Connect (OSTI)

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

    2002-09-20

    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

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

    SciTech Connect (OSTI)

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

    2011-03-15

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

  7. Surface plasmon resonance imaging of the enzymatic degradation of cellulose microfibrils

    E-Print Network [OSTI]

    Dutcher, John

    Surface plasmon resonance imaging of the enzymatic degradation of cellulose microfibrils Scott G with cellulose microfibrils using surface plasmon resonance (SPR) imaging. The cellulose microfibrils, obtained of the enzymes onto both the cellulose microfibrils and the bare surface, and the subsequent degradation

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

    E-Print Network [OSTI]

    Loss, Daniel

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

  9. Magnetically tunable resonance frequency beam utilizing a stress-sensitive film

    DOE Patents [OSTI]

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

    2001-01-01

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

  10. 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)

    2013-09-15

    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.

  11. Latest Developments in Image Processing Methods and Technologies for Magnetic Confinement Nuclear Fusion

    E-Print Network [OSTI]

    Latest Developments in Image Processing Methods and Technologies for Magnetic Confinement Nuclear Fusion

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

    DOE Patents [OSTI]

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

    2013-03-05

    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.

  13. 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

    2015-01-01

    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.

  14. 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

    2015-03-26

    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.

  15. Sub-natural $N$-type Resonance in Cesium Atomic Vapor: splitting in magnetic fields

    E-Print Network [OSTI]

    Slavov, D; Sarkisyan, D; Mirzoyan, R; Krasteva, A; Wilson-Gordon, A D; Cartaleva, S

    2013-01-01

    The sub-natural-width $N$-type resonance in {\\Lambda}-system, on the $D_2$ line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow band diode lasers. $L$ = 1 cm long cell is used to investigate $N$-type process. The $N$-type resonance in a magnetic field for $^{133}$Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that levels $F_g$ = 3, 4 are initial and final in the N resonance formation. The experimental results with magnetic field agree well with the theoretical curves.

  16. Rest period duration of the coronary arteries: Implications for magnetic resonance coronary angiography

    SciTech Connect (OSTI)

    Shechter, Guy; Resar, Jon R.; McVeigh, Elliot R. [Lab of Cardiac Energetics, NHLBI, NIH Building 10, Room B1D-412, msc-1061, Bethesda, Maryland 20892-1061 (United States); Division of Cardiology, Department of Medicine, Johns Hopkins University, 600 North Wolfe Street, Blalock 524B, Baltimore, Maryland 21287 (United States); Lab of Cardiac Energetics, NHLBI, NIH Building 10, Room B1D-412, msc-1061, Bethesda, Maryland 20892-1061 (United States)

    2005-01-01

    Magnetic resonance (MR) and computed tomography coronary imaging is susceptible to artifacts caused by motion of the heart. The presence of rest periods during the cardiac and respiratory cycles suggests that images free of motion artifacts could be acquired. In this paper, we studied the rest period (RP) duration of the coronary arteries during a cardiac contraction and a tidal respiratory cycle. We also studied whether three MR motion correction methods could be used to increase the respiratory RP duration. Free breathing x-ray coronary angiograms were acquired in ten patients. The three-dimensional (3D) structure of the coronary arteries was reconstructed from a biplane acquisition using stereo reconstruction methods. The 3D motion of the arterial model was then recovered using an automatic motion tracking algorithm. The motion field was then decomposed into separate cardiac and respiratory components using a cardiac respiratory parametric model. For the proximal-to-middle segments of the right coronary artery (RCA), a cardiac RP (<1 mm 3D displacement) of 76{+-}34 ms was measured at end systole (ES), and 65{+-}42 ms in mid-diastole (MD). The cardiac RP was 80{+-}25 ms at ES and 112{+-}42 ms at MD for the proximal 5 cm of the left coronary tree. At end expiration, the respiratory RP (in percent of the respiratory period) was 26{+-}8% for the RCA and 27{+-}17% for the left coronary tree. Left coronary respiratory RP (<0.5 mm 3D displacement) increased with translation (32% of the respiratory period), rigid body (51%), and affine (79%) motion correction. The RCA respiratory RP using translational (27%) and rigid body (33%) motion correction were not statistically different from each other. Measurements of the cardiac and respiratory rest periods will improve our understanding of the temporal and spatial resolution constraints for coronary imaging.

  17. Raman spectroscopy of graphite in high magnetic fields: Electron-phonon coupling and magnetophonon resonance

    SciTech Connect (OSTI)

    Kim, Younghee; Smirnov, Dmitry; Kalugin, Nikolai G.; Lombardo, Antonio; Ferrari, Andrea C.

    2013-12-04

    The magneto-Raman measurements of graphite were performed in a back-scattering Faraday geometry at temperature 10 K in magnetic fields up to 45 T. The experimental data reveal the rich structure of Raman-active excitations dominated by K-point massive electrons. At high magnetic fields the graphite E{sub 2g} Raman line shows complex multi- component behavior interpreted as magnetophonon resonance coupled electron-phonon modes at graphite’s K-point. Also we found the clear signature of the fundamental, strongly dumped, n=0 magnetophonon resonance associated with H point massless holes.

  18. Characterization of polyxylylenes with solid state {sup 13}C nuclear magnetic resonance spectroscopy

    SciTech Connect (OSTI)

    Schneider, D.A.; Loy, D.A.; Assink, R.A. [Sandia National Labs., Albuquerque, NM (United States)] [and others

    1996-10-01

    Polyxylylenes are an important class of thermoplastics that are readily prepared by thermolysis of [2.2]paracyclophane or xylene precursors to afford xylylene monomers that condense and polymerize on solid surfaces to give polymer films. As most polyxylylenes are insoluble due to a high degree of crystallinity, characterization by solid state nuclear magnetic resonance spectroscopic techniques is necessary. In this paper we describe the preparation of polyxylylene, poly-2-ethylxylylene, poly-2-chloroxylylene, poly-2, 3-dichloroxylylene, and poly({alpha}, {alpha}, {alpha}{prime}, {alpha}{prime}-tetrafluoroxylylene) and their characterization using solid state {sup 13}C Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance (CP MAS NMR) spectroscopy.

  19. 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

    2013-10-01

    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.

  20. Low-field classroom nuclear magnetic resonance system

    E-Print Network [OSTI]

    Zimmerman, Clarissa Lynette

    2010-01-01

    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 ...

  1. In Situ Root System Architecture Extraction from Magnetic Resonance

    E-Print Network [OSTI]

    Behnke, Sven

    using SmartRoot (Lobet et al., 2011). It is tested on the basis of a MRI image of a 25 days old lupin was inspired by methods for blood vessel detection in MRI images. It describes the root system). Both systems work well and allow for continuous water flow. Slight differences in the connectivity

  2. Current-induced torque driven ferromagnetic resonance in magnetic microstructures

    E-Print Network [OSTI]

    Fang, Dong

    2011-03-15

    of this Thesis a b Figure 1.2: An illustration of the spin-transfer torque effect in spin-valve device structures, adapted from [36]. a, A single magnetic layer with a spin- polarised electron passing through it. The magnet transmits and scatters the collinear... when an electric current passes through the pinned layer of a spin-valve, which can then act on the magnetisation in the free layer. 5 1.2 Context of this Thesis The current-induced torque in uniform ferromagnets has its origin in two quantum mechanical...

  3. 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

  4. 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

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

    SciTech Connect (OSTI)

    Pankin, Alexei Y.; Kritz, Arnold H.

    2011-07-19

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

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

    E-Print Network [OSTI]

    Griffin, Robert G.

    2006-01-01

    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

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

    E-Print Network [OSTI]

    Alexander J. Silenko

    2007-10-02

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

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

    SciTech Connect (OSTI)

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

    2013-07-15

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

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

    E-Print Network [OSTI]

    Koo, Chiwan

    2013-08-09

    -cooling microfluidic channel layer (d-f), and the final assembly and tubing insertion (g). (a) Negative photoresist (NR2-20000P) patterning on a thin PMMA substrate with Cr/Cu as seed layers. (b) Cu electroplating to 25 ?m height and removal of the photoresist... and Cr/Cu seed layers. (c) Thin PDMS coating. (d) SU-8 mold fabrication on Si substrate. (e) PDMS casting on the master mold for liquid nitrogen channel layer fabrication. (f) PDMS channel layer releasing and hole punching for tubing insertion. (g...

  10. Adaptive alternating minimization for fitting magnetic resonance spectroscopic imaging

    E-Print Network [OSTI]

    constraints and to use good starting values in the nonconvex metabolite quantification optimization problems. In partic- ular, we focus on the spatial smoothness of the nonlinear model parameters across the MRSI grid

  11. SQUID-Detected Magnetic Resonance Imaging in Microtesla Fields

    E-Print Network [OSTI]

    Moessle, Michael; Hatridge, Michael; Clarke, John

    2008-01-01

    System for prostate brachytherapy and biopsy in a standardprostate tumors (brachytherapy) (54). Cryosurgery involves

  12. 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

  13. Safety Guidelines for Conducting Magnetic Resonance Imaging (MRI) Experiments Involving

    E-Print Network [OSTI]

    California at San Diego, University of

    & an approved Informed Consent form. For animal studies, provide the Center with approval letter from the UCSD Institutional Animal Care and Use Committee. (4) Establish an experimenter research file and subject screening (MRI) center is dedicated solely for research. It is not a medical facility. The center houses three

  14. Genetically encoded reporters for hyperpolarized xenon magnetic resonance imaging

    E-Print Network [OSTI]

    experiments performed on living cells. G enetically encoded optical reporters, such as the green fluor- escent

  15. Bioengineering/Radiology 278: Magnetic Resonance Imaging Laboratory Winter 2011

    E-Print Network [OSTI]

    California at San Diego, University of

    Design and implement a 2D RF pulse 7 RF coil design Quadrature Detection Classes of coils Design criteria

  16. A Spectral-Scanning Magnetic Resonance Imaging (MRI) Integrated System

    E-Print Network [OSTI]

    Hajimiri, Ali

    , detection time, spectral resolution, and the spatial resolution (relative to the sample size) equivalent that the electromotive force (emf) voltage induced in the coils of the MR system, )(tE , is describe by [ ] -= V n d

  17. Measurement of brain temperature using magnetic resonance spectroscopic imaging 

    E-Print Network [OSTI]

    Parikh, Jehill

    2013-07-06

    The study of brain temperature is important for a number of clinical conditions such as stroke, traumatic brain injury, schizophrenia and birth asphyxia (for neonates). A direct method to estimate brain temperature ...

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

    E-Print Network [OSTI]

    Mitsouras, Dimitrios, 1976-

    2004-01-01

    (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. ...

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

    E-Print Network [OSTI]

    Li, Feng

    1992-01-01

    and the pirani gauge respectively. Gs is a pressure gauge used to monitor the pressure in the standard volume. has a field homogeneity of 0. 7 ppm for a sample 1 cm in diameter and 1 cm long in the center of the magnet. The maximum field strength is 4. 7 Tesla... in this study was approximately 0. 7 Tesla. Pulse sequences were generated by an Interface Technology timing simulator which could produce pulses from 50 nano-seconds to 1 second on 8 output channels. The timing simulator could be programmed either manually...

  20. A nuclear magnetic resonance probe of group IV clathrates 

    E-Print Network [OSTI]

    Gou, Weiping

    2008-10-10

    (NMR) technique. NMR is a local probe, which can tell us local electronic and magnetic information. The long coherence times allow NMR to be used to study relatively low-frequency atomic dynamics. 13 CHAPTER II INTRODUCTION TO SOLID STATE NMR Nuclear... University, China; M.S., Academy of Science of China; M.S., Texas A&M University Chair of Advisory Committee: Dr. Joseph H. Ross, Jr. The clathrates feature large cages of silicon, germanium, or tin, with guest atoms in the cage centers. The group IV...

  1. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse BergkampCentermillion toMSDS on the internetMagnetic

  2. Resonant absorption of kink MHD waves by magnetic twist in coronal loops

    E-Print Network [OSTI]

    Ebrahimi, Z

    2015-01-01

    There is ample evidences of twisted magnetic structures in the corona. This motivates us to consider the magnetic twist as the cause of Alfven frequency continuum in coronal loops, which can support the resonant absorption as the rapid damping mechanism for the observed coronal kink MHD oscillations. For a straight cylindrical compressible zero-beta thin flux tube with a magnetic twist in a thin boundary and straight magnetic field in the interior and exterior regions as well as a step-like radial density profile, we derive the dispersion relation and solve it analytically. Consequently, we obtain the frequencies and damping rates of the fundamental (l=1) and first/second overtones (l=2,3) kink (m=1) MHD modes. We conclude that the resonant absorption by the magnetic twist can justify the rapid damping of kink MHD waves observed in coronal loops. Furthermore, the magnetic twist in the inhomogeneous layer can achieve deviations from P_1/P_2=2 and P_1/P_3=3 of the same order of magnitude as in the observations.

  3. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirect ImagingDirect

  4. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirect ImagingDirectDirect

  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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirect 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit theCovalent BondingMeetingDifferences BetweenDiracDirectDirect 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HAB PacketDiesel prices continueDileep Singh GroupDiracDirect Imaging

  8. McCausland Center For Brain Imaging

    E-Print Network [OSTI]

    Almor, Amit

    .mricro.com). he Siemens 3-Tesla Magnetic Resonance Imag- ing system at the McCausland Center for Brain Imaging the Palmetto Richland Memorial Hospi- tal. The Siemens 3-Tesla magnetic resonance imag- ing system is fitted brain remains one of the great scientific challenges of our generation. With approximately 100 billion

  9. Convective radial energy flux due to resonant magnetic perturbations and magnetic curvature at the tokamak plasma edge

    E-Print Network [OSTI]

    Marcus, F A; Fuhr, G; Monnier, A; Benkadda, S

    2014-01-01

    With the resonant magnetic perturbations (RMPs) consolidating as an important tool to control the transport barrier relaxation, the mechanism on how they work is still a subject to be clearly understood. In this work we investigate the equilibrium states in the presence of RMPs for a reduced MHD model using 3D electromagnetic fluid numerical code (EMEDGE3D) with a single harmonic RMP (single magnetic island chain) and multiple harmonics RMPs in cylindrical and toroidal geometry. Two different equilibrium states were found in the presence of the RMPs with different characteristics for each of the geometries used. For the cylindrical geometry in the presence of a single RMP, the equilibrium state is characterized by a strong convective radial thermal flux and the generation of a mean poloidal velocity shear. In contrast, for toroidal geometry the thermal flux is dominated by the magnetic flutter. For multiple RMPs, the high amplitude of the convective flux and poloidal rotation are basically the same in cylindr...

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

    DOE Patents [OSTI]

    Fan, N.Q.; Clarke, J.

    1993-10-19

    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.

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

    Office of Scientific and Technical Information (OSTI)

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report: Achievements of structural genomics CitationImaging (MRI) Allan M.

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

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2003-11-25

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

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

    SciTech Connect (OSTI)

    Chang-Hwan Kim

    2003-12-12

    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.

  14. Origin of the positive spin- 12 photoluminescence-detected magnetic resonance in ?-conjugated materials and devices

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

    Chen, Ying; Cai, Min; Hellerich, Emily; Shinar, Ruth; Shinar, Joseph

    2015-09-02

    The spin-1/2 single-modulation (SM) and double-modulation (DM) photoluminescence (PL) detected magnetic resonance (PLDMR) in poly(2-methoxy-5-(2'-ethyl)–hexoxy-1,4- phenylene vinylene) (MEH-PPV) films and poly(3-hexylthiophene) (P3HT) films is described, analyzed, and discussed. In particular, the models based on spin-dependent recombination of charge pairs (SDR) and triplet-polaron quenching (TPQ) are evaluated. By analyzing the dependence of the resonance amplitude on the microwave chopping (modulation) frequency using rate equations, it is demonstrated that the TPQ model can well explain the observed resonance behavior, while SDR model cannot reproduce the results of the observed DM-PLDMR. As a result, the observed spin-1/2 PLDMR is assigned to TPQ rathermore »than SDR, even though the latter may also be present.« less

  15. Electronic and magnetic properties of manganite thin films with different compositions and its correlation with transport properties: An X-ray resonant magnetic scattering study

    SciTech Connect (OSTI)

    Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

    2014-12-14

    Here, we present x-ray resonant magnetic dichroism and x-ray resonant magnetic scattering measurements of the temperature dependence of magnetism in Pr-doped La-Ca-Mn-O films grown on (110) NdGaO{sub 3} substrates. We observed thermal hysteresis of the ferromagnetism in one film that also showed large thermal hysteresis of ?18?K in transport measurements. While in a second film of a different nominal chemistry, which showed very small thermal hysteresis ?3?K in transport measurements, no thermal hysteresis of the ferromagnetism was observed. These macroscopic properties are correlated with evolution of surface magnetization across metal insulator transition for these films as observed by soft x-ray resonant magnetic scattering measurements.

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

    E-Print Network [OSTI]

    Jaroniec, Christopher P

    2003-01-01

    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 ...

  17. Imaging transport resonances in the quantum Hall effect

    E-Print Network [OSTI]

    Steele, Gary Alexander

    2006-01-01

    We image charge transport in the quantum Hall effect using a scanning charge accumulation microscope. Applying a DC bias voltage to the tip induces a highly resistive ring-shaped incompressible strip (IS) in a very high ...

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

    SciTech Connect (OSTI)

    Tamaru, S. Kubota, H.; Yakushiji, K.; Konoto, M.; Nozaki, T.; Fukushima, A.; Imamura, H.; Taniguchi, T.; Arai, H.; Tsunegi, S.; Yuasa, S.; Suzuki, Y.

    2014-05-07

    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.

  19. Superconducting quantum interference device microsusceptometer balanced over a wide bandwidth for nuclear magnetic resonance applications

    SciTech Connect (OSTI)

    Vinante, A. Falferi, P.; Mezzena, R.

    2014-10-15

    Superconducting Quantum Interference Device (SQUID) microsusceptometers have been widely used to study magnetic properties of materials at microscale. As intrinsically balanced devices, they could also be exploited for direct SQUID-detection of nuclear magnetic resonance (NMR) from micron sized samples, or for SQUID readout of mechanically detected NMR from submicron sized samples. Here, we demonstrate a double balancing technique that enables achievement of very low residual imbalance of a SQUID microsusceptometer over a wide bandwidth. In particular, we can generate ac magnetic fields within the SQUID loop as large as 1 mT, for frequencies ranging from dc up to a few MHz. As an application, we demonstrate direct detection of NMR from {sup 1}H spins in a glycerol droplet placed directly on top of the 20 ?m SQUID loops.

  20. Acoustic resonances in microfluidic chips: full-image micro-PIV experiments and numerical simulations

    E-Print Network [OSTI]

    of the corresponding acoustic wave equation. 1. Introduction For the typical dimensions of microfluidic structures and small 1 mm particles can be understood in terms of the acoustic eigenmodes or standing ultra-sound wavesAcoustic resonances in microfluidic chips: full-image micro-PIV experiments and numerical

  1. MHD Field Line Resonances and Global Modes in Three-Dimensional Magnetic Fields

    SciTech Connect (OSTI)

    C.Z. Cheng

    2002-05-30

    By assuming a general isotropic pressure distribution P = P (y,a), where y and a are three-dimensional scalar functions labeling the field lines with B = -y x -a, we have derived a set of MHD eigenmode equations for both global MHD modes and field line resonances (FLR). Past MHD theories are restricted to isotropic pressures with P = P (y only). The present formulation also allows the plasma mass density to vary along the field line. The linearized ideal-MHD equations are cast into a set of global differential equations from which the field line resonance equations of the shear Alfvin waves and slow magnetosonic modes are naturally obtained for general three-dimensional magnetic field geometries with flux surfaces. Several new terms associated with the partial derivative of P with respect to alpha are obtained. In the FLR equations, a new term is found in the shear Alfvin FLR equation due to the geodesic curvature and the pressure gradient in the poloidal flux surface. The coupling between the shear Alfvin waves and the magnetosonic waves is through the combined effects of geodesic magnetic field curvature and plasma pressure as previously derived. The properties of the FLR eigenfunctions at the resonance field lines are investigated, and the behavior of the FLR wave solutions near the FLR surface are derived. Numerical solutions of the FLR equations for three-dimensional magnetospheric fields in equilibrium with high plasma pressure will be presented in a future publication.

  2. High-sensitivity cooled coil system for nuclear magnetic resonance in kHz range

    SciTech Connect (OSTI)

    Lin, Tingting; Zhao, Jing; Zhang, Yi; Krause, Hans-Joachim; Lee, Yong-Ho; Lin, Jun

    2014-11-15

    In several low-field Nuclear Magnetic Resonance (LF-NMR) and surface nuclear magnetic resonance applications, i.e., in the frequency range of kHz, high sensitivity magnetic field detectors are needed. Usually, low-T{sub c} superconducting quantum interference devices (SQUIDs) with a high field sensitivity of about 1 fT/Hz{sup 1/2} are employed as detectors. Considering the flux trapping and operational difficulties associated with low-T{sub c} SQUIDs, we designed and fabricated liquid-nitrogen-cooled Cu coils for NMR detection in the kHz range. A cooled coil system consisting of a 9-cm diameter Cu coil and a low noise preamplifier was systematically investigated and reached a sensitivity of 2 fT/Hz{sup 1/2} at 77 K, which is 3 times better compared to the sensitivity at 300 K. A Q-switch circuit as an essential element for damping the ringing effects of the pickup coil was developed to acquire free induction decay signals of a water sample with minimum loss of signal. Our studies demonstrate that cooled Cu coils, if designed properly, can provide a comparable sensitivity to low-T{sub c} SQUIDs.

  3. 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

    2015-07-09

    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.

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

    SciTech Connect (OSTI)

    Casadei, Cecilia

    2012-05-09

    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.

  5. 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

  6. 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

    2014-02-21

    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.

  7. Electrically detected magnetic resonance modeling and fitting: An equivalent circuit approach

    SciTech Connect (OSTI)

    Leite, D. M. G.; Batagin-Neto, A.; Nunes-Neto, O.; Gómez, J. A.; Graeff, C. F. O.

    2014-01-21

    The physics of electrically detected magnetic resonance (EDMR) quadrature spectra is investigated. An equivalent circuit model is proposed in order to retrieve crucial information in a variety of different situations. This model allows the discrimination and determination of spectroscopic parameters associated to distinct resonant spin lines responsible for the total signal. The model considers not just the electrical response of the sample but also features of the measuring circuit and their influence on the resulting spectral lines. As a consequence, from our model, it is possible to separate different regimes, which depend basically on the modulation frequency and the RC constant of the circuit. In what is called the high frequency regime, it is shown that the sign of the signal can be determined. Recent EDMR spectra from Alq{sub 3} based organic light emitting diodes, as well as from a-Si:H reported in the literature, were successfully fitted by the model. Accurate values of g-factor and linewidth of the resonant lines were obtained.

  8. Method and apparatus for molecular imaging using X-rays at resonance wavelengths

    DOE Patents [OSTI]

    Chapline, Jr., George F. (Alamo, CA)

    1985-01-01

    Holographic X-ray images are produced representing the molecular structure of a microscopic object, such as a living cell, by directing a beam of coherent X-rays upon the object to produce scattering of the X-rays by the object, producing interference on a recording medium between the scattered X-rays from the object and unscattered coherent X-rays and thereby producing holograms on the recording surface, and establishing the wavelength of the coherent X-rays to correspond with a molecular resonance of a constituent of such object and thereby greatly improving the contrast, sensitivity and resolution of the holograms as representations of molecular structures involving such constituent. For example, the coherent X-rays may be adjusted to the molecular resonant absorption line of nitrogen at about 401.3 eV to produce holographic images featuring molecular structures involving nitrogen.

  9. 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

    2012-01-01

    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.

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

    SciTech Connect (OSTI)

    Urban, Jeffry Todd

    2004-12-21

    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.

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

    E-Print Network [OSTI]

    M. H. Mohammady

    2013-05-04

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

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

    SciTech Connect (OSTI)

    M. H. Wilson

    2009-10-02

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

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

    SciTech Connect (OSTI)

    Mamone, Salvatore Concistrè, Maria; Carignani, Elisa; Meier, Benno; Krachmalnicoff, Andrea; Johannessen, Ole G.; Denning, Mark; Carravetta, Marina; Whitby, Richard J.; Levitt, Malcolm H.; Lei, Xuegong; Li, Yongjun; Goh, Kelvin; Horsewill, Anthony J.

    2014-05-21

    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.

  14. 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 ...

  15. 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 ...

  16. Effect of a high-frequency magnetic field on the resonant behavior displayed by a spin-$1/2$ particle under the influence of a rotating magnetic field

    E-Print Network [OSTI]

    Jesús Casado-Pascual

    2010-07-29

    In this paper, we investigate the role of a high-frequency magnetic field in the resonant behavior displayed by a spin-$1/2$ particle under the influence of a rotating magnetic field. We propose two alternative methods for analyzing the system dynamics, namely, the averaging method and the multiple scale method. The analytical results achieved by applying these two methods are compared with those obtained from the numerical solution of the Schr\\"odinger equation. This comparison leads to the conclusion that the multiple scale method provides a better understanding of the system dynamics than the averaging method. In particular, the averaging method predicts the complete destruction of the resonant behavior by an appropriate choice of the parameter values of the high-frequency magnetic field. This conclusion is disproved both by the numerical results, and also by the results obtained from the multiple scale method.

  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)

    2014-10-15

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

    SciTech Connect (OSTI)

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

    2014-01-01

    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.

  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

    2014-03-01

    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. Parametric Resonance Amplification of Neutrino Oscillations in Electromagnetic Wave with Varying Amplitude and "Castle Wall" Magnetic Field

    E-Print Network [OSTI]

    M. S. Dvornikov; A. I. Studenikin

    2001-07-10

    Within the Lorentz invariant formalizm for description of neutrino evolution in electromagnetic fields and matter we consider neutrino spin oscillations in the electromagnetic wave with varying amplitude and in "castle wall" magnetic field. It is shown for the first time that the parametric resonances of neutrino oscillations in such systems can occur.

  1. 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

  2. High-frequency and high-field optically detected magnetic resonance of nitrogen-vacancy centers in diamond

    E-Print Network [OSTI]

    Viktor Stepanov; Franklin H. Cho; Chathuranga Abeywardana; Susumu Takahashi

    2015-02-11

    We present the development of an optically detected magnetic resonance (ODMR) system, which enables us to perform the ODMR measurements of a single defect in solids at high frequencies and high magnetic fields. Using the high-frequency and high-field ODMR system, we demonstrate 115 GHz continuous-wave and pulsed ODMR measurements of a single nitrogen-vacancy (NV) center in a diamond crystal at the magnetic field of 4.2 Tesla as well as investigation of field dependence ($0-8$ Tesla) of the longitudinal relaxation time ($T_1$) of NV centers in nanodiamonds.

  3. Using co-cultures expressing fluorescence resonance energy transfer based protein biosensors to simultaneously image caspase-3 and Ca2+

    E-Print Network [OSTI]

    Using co-cultures expressing fluorescence resonance energy transfer based protein biosensors received: 8 June 2005; Accepted 11 June 2005 Key words: biosensor, fluorescence imaging, fluorescence)-based protein biosensors allow the spatial and temporal imaging of signaling events in living cells. However

  4. Magnetic defects in chemically converted graphene nanoribbons: electron spin resonance investigation

    SciTech Connect (OSTI)

    Singamaneni, Srinivasa Rao; Stesmans, Andre; Tol, Johan van; Kosynkin, D. V.; Tour, James M.; Department of Mechanical Engineering and Materials Science, Smalley Institute for Nanoscale Science and Technology, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005; Smalley Institute for Nanoscale Science and Technology, Rice University, MS-222, 6100 Main Street, Houston, Texas 77005, USA.

    2014-04-15

    Electronic spin transport properties of graphene nanoribbons (GNRs) are influenced by the presence of adatoms, adsorbates and edge functionalization. To improve the understanding of the factors that influence the spin properties of GNRs, local (element) spin-sensitive techniques such as electron spin resonance (ESR) spectroscopy are important for spintronics applications. Here, we present results of multi-frequency continuous wave (CW), pulse and hyperfine sublevel correlation (HYSCORE) ESR spectroscopy measurements performed on oxidatively unzipped graphene nanoribbons (GNRs), which were subsequently chemically converted (CCGNRs) with hydrazine. ESR spectra at 336 GHz reveal an isotropic ESR signal from the CCGNRs, of which the temperature dependence of its line width indicates the presence of localized unpaired electronic states. Upon functionalization of CCGNRs with 4-nitrobenzene diazonium tetrafluoroborate, the ESR signal is found to be 2 times narrower than that of pristine ribbons. NH{sub 3} adsorption/desorption on CCGNRs is shown to narrow the signal, while retaining the signal intensity and g value. The electron spin-spin relaxation process at 10 K is found to be characterized by slow (163 ns) and fast (39 ns) components. HYSCORE ESR data demonstrate the explicit presence of protons and {sup 13}C atoms. With the provided identification of intrinsic point magnetic defects such as proton and {sup 13}C has been reported, which are roadblocks to spin travel in graphene-based materials, this work could help in advancing the present fundamental understanding on the edge-spin (or magnetic)-based transport properties of CCGNRs.

  5. Methods for functional brain imaging

    E-Print Network [OSTI]

    Witzel, Thomas, Ph. D. Massachusetts Institute of Technology

    2011-01-01

    Magnetic resonance imaging (MRI) has demonstrated the potential for non-invasive mapping of structure and function (fMRI) in the human brain. In this thesis, we propose a series of methodological developments towards ...

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

    SciTech Connect (OSTI)

    Einstein, Douglas B.; Wessels, Barry; Bangert, Barbara; Fu, Pingfu; Nelson, A. Dennis; Cohen, Mark; Sagar, Stephen; Lewin, Jonathan; Sloan, Andrew; Zheng Yiran; Williams, Jordonna; Colussi, Valdir; Vinkler, Robert; Maciunas, Robert

    2012-11-01

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

  7. Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using Electronic Spins in Diamond

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    1 Fourier Magnetic Imaging with Nanoscale Resolution and Compressed Sensing Speed-up using imaging.12 Here we introduce an alternative technique of Fourier magnetic imaging using NV Fourier transform to yield real-space images with nanoscale resolution, wide field-of-view (FOV

  8. Simultaneous PET/fMRI for imaging neuroreceptor dynamics

    E-Print Network [OSTI]

    Sander, Christin Y. (Christin Yen-Ming)

    2014-01-01

    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 ...

  9. Advancements in branched bottlebrush polymers for responsive, targeted imaging

    E-Print Network [OSTI]

    Sowers, Molly A. (Molly Ann)

    2015-01-01

    Multi-modality and stimuli responsive nanoparticles are promising platform materials for medical imaging and diagnostics. Specifically magnetic resonance imaging (MRI) and nearinfrared (NIR) fluorescent probes can be used ...

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

    E-Print Network [OSTI]

    Kim, Heisoog

    2011-01-01

    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 ...

  11. Narrowband and x-Space Magnetic Particle Imaging

    E-Print Network [OSTI]

    Goodwill, Patrick

    2010-01-01

    mT peak-to-peak oscillating magnetic field at 6.23 kHz. ThemT peak-to-peak oscillating magnetic field at 6.23 kHz. Theone or more oscillating magnetic fields to measure the mass

  12. Z-STEM Imaging of Chemical Ordering in FePt Magnetic Nanoparticles

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

    Z-STEM Imaging of Chemical Ordering in FePt Magnetic Nanoparticles J.E. Wittig, M.S. Wellons and C.M. Lukehart, Vanderbilt University J. Bentley and L.F. Allard, Oak Ridge National...

  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

    2010-11-15

    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. Accelerated 2D magnetic resonance spectroscopy of single spins using matrix completion

    E-Print Network [OSTI]

    Jochen Scheuer; Alexander Stark; Matthias Kost; Martin B. Plenio; Boris Naydenov; Fedor Jelezko

    2015-07-14

    Two dimensional nuclear magnetic resonance (NMR) spectroscopy is one of the major tools for analysing the chemical structure of organic molecules and proteins. Despite its power, this technique requires long measurement times, which, particularly in the recently emerging diamond based single molecule NMR, limits its application to stable samples. Here we demonstrate a method which allows to obtain the spectrum by collecting only a small fraction of the experimental data. Our method is based on matrix completion which can recover the full spectral information from randomly sampled data points. We confirm experimentally the applicability of this technique by performing two dimensional electron spin echo envelope modulation (ESEEM) experiments on a two spin system consisting of a single nitrogen vacancy (NV) centre in diamond coupled to a single 13C nuclear spin. We show that the main peaks in the spectrum can be obtained with only 10 % of the total number of the data points. We believe that our results reported here can find an application in all types of two dimensional spectroscopy, as long as the measured matrices have a low rank.

  15. H-1 Nuclear Magnetic Resonance Metabolomics Analysis Identifies Novel Urinary Biomarkers for Lung Function

    SciTech Connect (OSTI)

    MCClay, Joseph L.; Adkins, Daniel E.; Isern, Nancy G.; O'Connell, Thomas M.; Wooten, Jan B.; Zedler, Barbara K.; Dasika, Madhukar S.; Webb, B. T.; Webb-Robertson, Bobbie-Jo M.; Pounds, Joel G.; Murrelle, Edward L.; Leppert, Mark F.; van den Oord, Edwin J.

    2010-06-04

    Chronic obstructive pulmonary disease (COPD), characterized by chronic airflow limitation, is a serious and growing public health concern. The major environmental risk factor for COPD is tobacco smoking, but the biological mechanisms underlying COPD are not well understood. In this study, we used proton nuclear magnetic resonance (1H-NMR) spectroscopy to identify and quantify metabolites associated with lung function in COPD. Plasma and urine were collected from 197 adults with COPD and from 195 adults without COPD. Samples were assayed using a 600 MHz NMR spectrometer, and the resulting spectra were analyzed against quantitative spirometric measures of lung function. After correcting for false discoveries and adjusting for covariates (sex, age, smoking) several spectral regions in urine were found to be significantly associated with baseline lung function. These regions correspond to the metabolites trigonelline, hippurate and formate. Concentrations of each metabolite, standardized to urinary creatinine, were associated with baseline lung function (minimum p-value = 0.0002 for trigonelline). No significant associations were found with plasma metabolites. Two of the three urinary metabolites positively associated with baseline lung function, i.e. hippurate and formate, are often related to gut microflora. This suggests that the microbiome composition is variable between individuals with different lung function. Alternatively, the nature and origins of all three associated metabolites may reflect lifestyle differences affecting overall health. Our results will require replication and validation, but demonstrate the utility of NMR metabolomics as a screening tool for identifying novel biomarkers of lung disease or disease risk.

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

    SciTech Connect (OSTI)

    Kong, Zueqian

    2010-03-15

    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.

  17. Electrically detected magnetic resonance in a W-band microwave cavity

    E-Print Network [OSTI]

    Lang, V.

    2012-01-01

    resonance in a W-band microwave cavity V. Lang, 1, ? C. C.resonant W-band (94 GHz) microwave cavity. The advantages ofmagnetic ?elds and high microwave frequencies is therefore a

  18. Two-fluid magnetic island dynamics in slab geometry. II. Islands interacting with resistive walls or resonant magnetic perturbations

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    magnetic islands. Such islands degrade plasma confinement because heat and particles are able to travelTwo-fluid magnetic island dynamics in slab geometry. II. Islands interacting with resistive walls-fluid magnetic island dynamics in slab geometry: Determination of the island phase velocity Phys. Plasmas 12

  19. JOURNAL OF MAGNETIC RESONANCE 81,2 12-2 16(1989) Three-Dimensional Homonuclear Hartmann-Hahn-Nuclear

    E-Print Network [OSTI]

    Clore, G. Marius

    1989-01-01

    JOURNAL OF MAGNETIC RESONANCE 81,2 12-2 16(1989) Three-Dimensional Homonuclear Hartmann)-homonuclear Hartmann-Hahn (HOHAHA) spectrum of the protein (Ye-purothionin in 90% H20. In this particular sequence

  20. 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

  1. 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)

    2009-07-21

    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.

  2. Magnetic soft x-ray microscopy-imaging fast spin dynamics in magnetic nanostructures

    E-Print Network [OSTI]

    Fischer, Peter; Kim, Dong-Hyun; Mesler, Brooke L.; Chao, Weilun; Sakdinawat, Anne E.; Anderson, Erik H.

    2007-01-01

    concepts such as spintronics, where in addition to theLogical elements for spintronics, non-volatile magnetic

  3. Feshbach resonances, weakly bound states and coupled-channel potentials for cesium molecules at high magnetic field

    E-Print Network [OSTI]

    Berninger, Martin; Huang, Bo; Harm, Walter; Nägerl, Hanns-Christoph; Ferlaino, Francesca; Grimm, Rudolf; Julienne, Paul S; Hutson, Jeremy M

    2012-01-01

    We explore the scattering properties of ultracold ground-state Cs atoms at magnetic fields between 450 G (45 mT) and 1000 G. We identify 17 new Feshbach resonances, including two very broad ones near 549 G and 787 G. We measure the binding energies of several different dimer states by magnetic field modulation spectroscopy. We use least-squares fitting to these experimental results, together with previous measurements at lower field, to determine a new 6-parameter model of the long-range interaction potential, designated M2012. Coupled-channels calculations using M2012 provide an accurate mapping between the s-wave scattering length and the magnetic field over the entire range of fields considered. This mapping is crucial for experiments that rely on precise tuning of the scattering length, such as those on Efimov physics.

  4. NEAR-IR IMAGING POLARIMETRY TOWARD A BRIGHT-RIMMED CLOUD: MAGNETIC FIELD IN SFO 74

    SciTech Connect (OSTI)

    Kusune, Takayoshi; Sugitani, Koji [Graduate School of Natural Sciences, Nagoya City University, Mizuho-ku, Nagoya 467-8501 (Japan); Miao, Jingqi [Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NR (United Kingdom); Tamura, Motohide; Kwon, Jungmi [Department of Astronomy, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Sato, Yaeko [National Astronomical Observatory, 2-21-1 Osawa, Mikata, Tokyo 181-8588 (Japan); Watanabe, Makoto [Department of Cosmosciences, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Nishiyama, Shogo [Faculty of Education, Miyagi University of Education, Sendai 980-0845 (Japan); Nagayama, Takahiro [Department of Physics, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan); Sato, Shuji [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)

    2015-01-01

    We have made near-infrared (JHK {sub s}) imaging polarimetry of a bright-rimmed cloud (SFO 74). The polarization vector maps clearly show that the magnetic field in the layer just behind the bright rim is running along the rim, quite different from its ambient magnetic field. The direction of the magnetic field just behind the tip rim is almost perpendicular to that of the incident UV radiation, and the magnetic field configuration appears to be symmetric as a whole with respect to the cloud symmetry axis. We estimated the column and number densities in the two regions (just inside and far inside the tip rim) and then derived the magnetic field strength, applying the Chandrasekhar-Fermi method. The estimated magnetic field strength just inside the tip rim, ?90 ?G, is stronger than that far inside, ?30 ?G. This suggests that the magnetic field strength just inside the tip rim is enhanced by the UV-radiation-induced shock. The shock increases the density within the top layer around the tip and thus increases the strength of the magnetic field. The magnetic pressure seems to be comparable to the turbulent one just inside the tip rim, implying a significant contribution of the magnetic field to the total internal pressure. The mass-to-flux ratio was estimated to be close to the critical value just inside the tip rim. We speculate that the flat-topped bright rim of SFO 74 could be formed by the magnetic field effect.

  5. 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

    1989-09-11

    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.

  6. TEST OF THE HEMISPHERIC RULE OF MAGNETIC HELICITY IN THE SUN USING THE HELIOSEISMIC AND MAGNETIC IMAGER (HMI) DATA

    SciTech Connect (OSTI)

    Liu, Y.; Hoeksema, J. T.; Sun, X.

    2014-03-01

    Magnetic twist in solar active regions (ARs) has been found to have a hemispheric preference in sign (hemisphere rule): negative in the northern hemisphere and positive in the southern. The preference reported in previous studies ranges greatly, from ? 58% to 82%. In this study, we examine this hemispheric preference using vector magnetic field data taken by Helioseismic and Magnetic Imager and find that 75% ± 7% of 151 ARs studied obey the hemisphere rule, well within the preference range in previous studies. If the sample is divided into two groups—ARs having magnetic twist and writhe of the same sign and having opposite signs—the strength of the hemispheric preference differs substantially: 64% ± 11% for the former group and 87% ± 8% for the latter. This difference becomes even more significant in a sub-sample of 82 ARs having a simple bipole magnetic configuration: 56% ± 16% for the ARs having the same signs of twist and writhe, and 93% with lower and upper confidence bounds of 80% and 98% for the ARs having the opposite signs. The error reported here is a 95% confidence interval. This may suggest that, prior to emergence of magnetic tubes, either the sign of twist does not have a hemispheric preference or the twist is relatively weak.

  7. Novel mathematical modeling approaches to assess ischemic stroke lesion evolution on medical imaging 

    E-Print Network [OSTI]

    Rekik, Islem

    2014-11-28

    Stroke is a major cause of disability and death worldwide. Although different clinical studies and trials used Magnetic Resonance Imaging (MRI) to examine patterns of change in different imaging modalities (eg: perfusion ...

  8. Direct visualization of the perforant pathway in the human brain with ex vivo diffusion tensor imaging

    E-Print Network [OSTI]

    Augustinack, Jean

    Ex vivo magnetic resonance imaging yields high resolution images that reveal detailed cerebral anatomy and explicit cytoarchitecture in the cerebral cortex, subcortical structures, and white matter in the human brain. Our ...

  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. 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

  11. 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

    2015-01-01

    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...

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

    E-Print Network [OSTI]

    Vaisman, G; Shavit, R

    2015-01-01

    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...

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

    E-Print Network [OSTI]

    Willingham, Frank Phillip

    1988-01-01

    about one. The longitudinal relaxation time, Ti In a liquid macroscopic sample of nuclear dipoles at thermal equilibrium there is no preferred orientatiou of the dipoles vrhen there is no externally applied magnetic field. As discussed earlier, when... coherent precession of the magnetization about the magnetic field and introducing a "dephasing" effect among the dipoles. This de- phasing of the transverse component of M combined with the longitudinal relaxs. tion described above has been shown...

  14. Improved evolution equations for magnetic island chains in toroidal pinch plasmas subject to externally applied resonant magnetic perturbations

    E-Print Network [OSTI]

    Rossi, Enrico

    confinement be- cause both heat and particles are able to travel radially from one side of an island chainImproved evolution equations for magnetic island chains in toroidal pinch plasmas subject Received 1 May 2001; accepted 30 July 2001 An improved set of island evolution equations is derived

  15. Application of a single step temporal imaging of magnetic induction tomography for metal flow visualization

    E-Print Network [OSTI]

    Adler, Andy

    and sensing coils. MIT has potential in visualization of metal flow for continuous casting mainly because of spatio-temporal resolution using the real metal flow in continuous casting. Results are comparedApplication of a single step temporal imaging of magnetic induction tomography for metal flow

  16. Imaging exotic properties of nanoscale magnetic lattices | Argonne National

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (JournalvivoHighHusseinSOLICWfATION/MODIFICATlONImagingLaboratory Imaging

  17. Stellar magnetic field measurements Zeeman-Doppler imaging and magnetic-flux

    E-Print Network [OSTI]

    cool stars and solar-like stars Instrumentation The most successful spectrographs field measurements of the Herbig Ae stars HD 101412 (left panel) and HD 150193 (right panel) (FORS 2). Left panel: Phase diagram and residuals for the longitudinal magnetic field measurements of the Cephei

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

    E-Print Network [OSTI]

    Goodson, B.M.

    2010-01-01

    ized helium gas at such low fields. CONVENTIONAL DETECTION jDETECTION optical pumping. Following respiration of laser-polarized heliumand helium at low magnetic fields. 9.3. SQUID DETECTION OF

  19. 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)

    2014-05-07

    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.

  20. Noise temperature improvement for magnetic fusion plasma millimeter wave imaging systems

    SciTech Connect (OSTI)

    Lai, J.; Domier, C. W.; Luhmann, N. C.

    2014-03-15

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas [B. Tobias et al., Plasma Fusion Res. 6, 2106042 (2011)]. Of particular importance have been microwave electron cyclotron emission imaging and microwave imaging reflectometry systems for imaging T{sub e} and n{sub e} fluctuations. These instruments have employed heterodyne receiver arrays with Schottky diode mixer elements directly connected to individual antennas. Consequently, the noise temperature has been strongly determined by the conversion loss with typical noise temperatures of ?60?000 K. However, this can be significantly improved by making use of recent advances in Monolithic Microwave Integrated Circuit chip low noise amplifiers to insert a pre-amplifier in front of the Schottky diode mixer element. In a proof-of-principle design at V-Band (50–75 GHz), significant improvement of noise temperature from the current 60?000 K to measured 4000 K has been obtained.

  1. Heat flux modeling using ion drift effects in DIII-D H-mode plasmas with resonant magnetic perturbations

    SciTech Connect (OSTI)

    Wingen, A. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States) [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf (Germany); Schmitz, O. [Institut für Energie und Klimaforschung-Plasma Physik, Forschungszentrum Jülich, 52428 Jülich (Germany)] [Institut für Energie und Klimaforschung-Plasma Physik, Forschungszentrum Jülich, 52428 Jülich (Germany); Evans, T. E. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)] [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States); Spatschek, K. H. [Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf (Germany)] [Institut für Theoretische Physik, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf (Germany)

    2014-01-15

    The heat flux patterns measured in low-collisionality DIII-D H-mode plasmas strongly deviate from simultaneously measured CII emission patterns, used as indicator of particle flux, during applied resonant magnetic perturbations. While the CII emission clearly shows typical striations, which are similar to magnetic footprint patterns obtained from vacuum field line tracing, the heat flux is usually dominated by one large peak at the strike point position. The vacuum approximation, which only considers applied magnetic fields and neglects plasma response and plasma effects, cannot explain the shape of the observed heat flux pattern. One possible explanation is the effect of particle drifts. This is included in the field line equations and the results are discussed with reference to the measurement. Electrons and ions show different drift motions at thermal energy levels in a guiding center approximation. While electrons hardly deviate from the field lines, ions can drift several centimetres away from field line flux surfaces. A model is presented in which an ion heat flux, based on the ion drift motion from various kinetic energies as they contribute to a thermal Maxwellian distribution, is calculated. The simulated heat flux is directly compared to measurements with a varying edge safety factor q{sub 95}. This analysis provides evidence for the dominate effect of high-energy ions in carrying heat from the plasma inside the separatrix to the target. High-energy ions are deposited close to the unperturbed strike line, while low-energy ions can travel into the striated magnetic topology.

  2. Characterization of polyxylylenes with solid state {sup 13}C nuclear magnetic resonance spectroscopy

    SciTech Connect (OSTI)

    Loy, D.A.; Assink, R.A.; Jamison, G.M.; McNamara, W.F.; Schneider, D.A. [Sandia National Labs., Livermore, CA (United States); Prabakar, S. [New Mexico Univ., Albuquerque, NM (United States)

    1996-02-01

    Polyxylylenes are thermoplastics used as encapsulants for electronic devices. Five polyxylylenes were prepared by pyrolysis of [2.2]paracyclophanes and characterized by solid state {sup 13}C NMR spectroscopy. The chemical shift data, in combination with interrupted decoupling experiments, allowed assignment of resonances to their carbon sources in the polymers. This confirmed the integrity of the xylylene building block in the polymers and is consistent with linear polymers. No crosslinking could be detected within the NMR sensitivity limits. Residual paracyclophane was detected by {sup 13}C CP MAS NMR spectroscopy in the polyxylylene samples prepared at room temperature; however discrete {sup 13}C resonances due to amorphous and crystalline phases in the polymers were not resolved.

  3. 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

    2002-01-29

    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.

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

    SciTech Connect (OSTI)

    Lumsden, Mark D; Christianson, Andrew D; Parshall, Daniel; Stone, Matthew B; Nagler, Stephen E; Mook Jr, Herbert A; Lokshin, Konstantin A; Egami, Takeshi; Abernathy, Douglas L; Goremychkin, E. A.; Osborn, R.; McGuire, Michael A; Safa-Sefat, Athena; Jin, Rongying; Sales, Brian C; Mandrus, David

    2009-01-01

    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.

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

    SciTech Connect (OSTI)

    Lu Qing; Wei Daixu; Cheng Jiejun; Xu Jianrong; Zhu Jun

    2012-08-15

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

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

    SciTech Connect (OSTI)

    Raita, O.; Popa, A.; Toloman, D.; Stan, M.; Giurgiu, L. M.

    2013-11-13

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

  7. Resolving the Impact of Biological Processes on DNAPL Transport in Unsaturated Porous Media through Nuclear Magnetic Resonance Relaxation Time Measurements

    SciTech Connect (OSTI)

    Hertzog, Russel; Geesey, Gill G.; White, Timothy A.; Ho, Clifford K.; Straley, Christian; Bryar, Traci R.; Seymour, Joseph; Codd, Sarah L.; Oram, Libbie

    2003-06-01

    This research leads to a better understanding of how physical and biological properties of porous media influence water and dense non-aqueous phase liquid (DNAPL) distribution under saturated and unsaturated conditions. Knowing how environmental properties affect DNAPL solvent flow in the subsurface is essential for developing models of flow and transport that are needed for designing remediation and long-term stewardship strategies. This project investigates the capability and limitations of low-field nuclear magnetic resonance (NMR) relaxation decay-rate measurements for determining environmental properties affecting DNAPL solvent flow in the subsurface. For in-situ subsurface environmental applications, lowfield proton NMR measurements are preferred to the conventional high-field techniques commonly used to obtain chemical shift data, because the low field measurements are much less degraded by the magnetic susceptibility variations between the rock grains and the pore fluid s that significantly interfere with the high-field NMR measurements. Our research scope includes determining whether DNAPLs exist in water-wet or solvent-wet environments, the pore-size distribution of the soils containing DNAPLs, and the impact of biological processes on their transport mechanisms in porous media. Knowledge of the in situ flow properties and pore distributions of organic contaminants are critical to understanding where and when these fluids will enter subsurface aquifers.

  8. 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)

    2005-12-01

    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.

  9. Magnetic imaging of ion-irradiation patterned CoPt multilayers using complementary electron and photon probes

    E-Print Network [OSTI]

    Krishnan, Kannan M.

    Magnetic imaging of ion-irradiation patterned CoÕPt multilayers using complementary electron with perpendicular anisotropy were patterned by ion irradiation through a stencil mask to produce in-plane magnetization in the irradiated regions. The boundaries of the patterns, defined by the transition from out

  10. Asynchronous symmetry-based sequences for homonuclear dipolar recoupling in solid-state nuclear magnetic resonance

    SciTech Connect (OSTI)

    Tan, Kong Ooi; Ernst, Matthias E-mail: maer@ethz.ch; Rajeswari, M.; Madhu, P. K. E-mail: maer@ethz.ch

    2015-02-14

    We show a theoretical framework, based on triple-mode Floquet theory, to analyze recoupling sequences derived from symmetry-based pulse sequences, which have a non-vanishing effective field and are not rotor synchronized. We analyze the properties of one such sequence, a homonuclear double-quantum recoupling sequence derived from the C7{sub 2}{sup 1} sequence. The new asynchronous sequence outperforms the rotor-synchronized version for spin pairs with small dipolar couplings in the presence of large chemical-shift anisotropy. The resonance condition of the new sequence is analyzed using triple-mode Floquet theory. Analytical calculations of second-order effective Hamiltonian are performed to compare the efficiency in suppressing second-order cross terms. Experiments and numerical simulations are shown to corroborate the results of the theoretical analysis.

  11. Large-Scale Magnetic Field Re-generation by Resonant MHD Wave Interactions

    E-Print Network [OSTI]

    S. Galtier; S. Nazarenko

    2007-10-24

    We investigate numerically the long-time behavior of balanced Alfven wave turbulence forced at intermediate scales. Whereas the usual constant-flux solution is found at the smallest scales, two new scalings are obtained at the forcing scales and at the largest scales of the system. In the latter case we show, in particular, that the spectrum evolves first to a state determined by Loitsyansky invariant and later a state close to the thermodynamic equipartition solution predicted by wave turbulence. The astrophysical implications for galactic magnetic field generation are discussed.

  12. JOURNAL OF MAGNETIC RESONANCE, Series B 111, 204207 (1996) ARTICLE NO. 0084

    E-Print Network [OSTI]

    Walsworth, Ronald L.

    1996-01-01

    ). There is considerable interest in extending the cell was fitted with high-vacuum O-ring valves and filled technique to physiological human imaging. As a step toward with 3 atm of natural xenon, 0.2 atm of nitrogen, and a small thisAsnique of noble-gas hyperpolarization, by collisional spin ex- diode laser array (FWHM É 1.5 nm

  13. Medical Imaging: ECE-4BF3 Winter 2012

    E-Print Network [OSTI]

    Haykin, Simon

    and formation; post-processing for magnetic resonance imaging and spectroscopy; comparisons to other medical with medical imaging technologies- both from a physics and engineering perspective through to a practical.). However, comparative applications with other imaging modalities (e.g. PET, SPECT, ultrasound, mammography

  14. Medical Imaging: Elec Eng -4BF3 Winter 2013

    E-Print Network [OSTI]

    Haykin, Simon

    image acquisition and formation; post-processing for magnetic resonance imaging and spectroscopy is designed to allow students to become familiar with medical imaging technologies- both from a physics modalities (e.g. PET, SPECT, ultrasound, mammography, CT, EEG, MEG) will be made where appropriate. Practical

  15. Medical Imaging: ECE-4BF3 Michael D. Noseworthy, Ph.D., P.Eng.

    E-Print Network [OSTI]

    Haykin, Simon

    ; post-processing for magnetic resonance imaging and spectroscopy; comparisons to other medical imaging This course is designed to allow students to become familiar with medical imaging technologies- both from imaging modalities (e.g. PET, SPECT, ultrasound, mammography, CT, EEG, MEG) will be made where appropriate

  16. Towards Systematic Exploration of Tradeoffs for Medical Image Registration on Heterogeneous Platforms

    E-Print Network [OSTI]

    Bhattacharyya, Shuvra S.

    . INTRODUCTION Advances in medical imaging technologies have enabled medical diagnoses and procedures simply of imaging modalities (e.g. computed tomography (CT), positron emission tomography (PET), magnetic resonance into one integrated view through a procedure called image registration. Image registration is the process

  17. Magnetic Resonance Imaging Analysis of Molecular Mobility during Dissolution of Poly(vinyl alcohol) in Water

    E-Print Network [OSTI]

    Peppas, Nicholas A.

    for recycling,4 the semiconductor industry,5 and packaging.6 The dissolution of a polymer in a solvent involves-dimensional water concentration profiles were measured as a function of distance from the polymer-solvent interface of the polymer. Self-diffusion coefficient values within the dissolving polymer increase with increasing

  18. 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

    2013-01-01

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

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

    E-Print Network [OSTI]

    Natarajan, Shyam

    2012-01-01

    fusion for prostate brachytherapy. Preliminary results,”Mri/trus data fusion for brachytherapy,” The Interna- tionalapplications in prostrate brachytherapy: analysis of phantom

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

    E-Print Network [OSTI]

    2012-01-01

    center studies on multiple sclerosis? Eur J Neurol. 2008;as stroke (14), multiple sclerosis (15– 17,18) and first-in patients with Multiple Sclerosis (15–18). Another large

  1. Skull-stripping magnetic resonance brain images using a model-based level set

    E-Print Network [OSTI]

    Zhuang, A H; Valentino, Daniel J; Toga, A W

    2006-01-01

    in relapsing-remitting multiple sclerosis. Neurologicalbrain atrophy in multiple sclerosis. Neurological SciencesWhole-brain atrophy in multiple sclerosis measured by two

  2. Functional Magnetic Resonance Imaging of Rats with Experimental Autoimmune Encephalomyelitis Reveals Brain Cortex Remodelling

    E-Print Network [OSTI]

    Tambalo, Stefano; Peruzzotti-Jametti, Luca; Rigolio, Roberta; Fiorini, Silvia; Bontempi, Pietro; Mallucci, Giulia; Balzarotti, Beatrice; Marmiroli, Paola; Sbarbati, Andrea; Cavaletti, Guido; Pluchino, Stefano; Marzola, Pasquina

    2015-01-01

    Cortical reorganization occurring in Multiple Sclerosis (MS) patients is thought to play a key role in limiting the impact of structural tissue damage. Conversely, its exhaustion may contribute to the irreversible disability that accumulates...

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

    E-Print Network [OSTI]

    Sherman, Byron Blake

    1991-01-01

    16 Calculated Pomsities and Experimental Errors: Trial 2 17 NMR Parameters for Trial 3 . . . 40 41 41 18 Observed Signal Intensities for Core KMS - TE=4: Trial 3 19 Observed Signal Intensities for Core AH8 ? TE=4; Trial 3 20 Observed Signal... Intensities for Core JCR2 - TE=4: Trial 3 . . . 42 . . . 43 Table 21 Observed Signal Intensities for Core AH5 - TE=4: Trial 3 22 Observed Signal Intensities for Glass Bead A: Trial 3 23 Observed Signal Intensities for Glass Bead B: Trial 3 24 Observed...

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

    E-Print Network [OSTI]

    Kischell, Eric Robert

    1993-01-01

    were obtained on a 0. 6 Tesla Technicare MRT50A machine. A double echo sequence with a repetition time (TR) of 3000 ms and echo times (TE) of 30 and 120 ms was used. An average of 20 coronal sec- tions, slice thickness of 7. 5 mm and separation of 1...

  5. Partial volume segmentation of brain magnetic resonance images based on maximum a posteriori probability

    E-Print Network [OSTI]

    was pioneered by Vannier et al.1 and has been widely adopted by other researchers. Noise, partial volume PV 2005; accepted for publication 9 May 2005; published 22 June 2005 Noise, partial volume PV effect of each voxel belonging to different tissues, which we call a mixture, is considered to address the PV

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

    E-Print Network [OSTI]

    Bouchard, Louis-Serge

    2005-01-01

    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

  7. Analysis of 4D Cardiac Magnetic Resonance Images Mikkel B. Stegmann

    E-Print Network [OSTI]

    fraction, related to the amount of blood pumped out at each heart beat and ii) estimation of regional-slice segmentation we use statistical models of shape and appearance, namely the deformable model: Active Appearance

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

    E-Print Network [OSTI]

    2012-01-01

    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,

  9. The Multisensory Attentional Consequences of Tool Use: A Functional Magnetic Resonance Imaging Study

    E-Print Network [OSTI]

    Miall, Chris

    , United Kingdom, 5 Warwick Manufacturing Group, International Manufacturing Centre, University of Warwick to the vibrotactile stimuli, and to maintain visual fixation centrally. In addition, the magnitude of multisensory

  10. Non-Contrast Enhanced Cardiovascular Magnetic Resonance Imaging for Characterizing Chronic Myocardial Infarctions

    E-Print Network [OSTI]

    Kali, Avinash

    2015-01-01

    of LV in Patients post-PCI . 142 7.4.3. Acuteis reduced in primary PCI-treated STEMI patients withon day 3 post-PCI. 123 Table 6.3:

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

    E-Print Network [OSTI]

    Natarajan, Shyam

    2012-01-01

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

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

    E-Print Network [OSTI]

    Ananda Yogendran, Shalini

    2012-01-01

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

  13. QUANTITATIVE EVALUATION OF LEFT VENTRICULAR ROTATIONAL MECHANICS USING MAGNETIC RESONANCE IMAGING

    E-Print Network [OSTI]

    Wang, Zhe

    2015-01-01

    qualitative and quantitative assessment of left ventricular (LV) myocardial deformation in both research and clinical settings. This thesis

  14. 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

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

    E-Print Network [OSTI]

    Moody, Katherine

    2014-08-11

    with the static field along the z-direction. The precession induces an electromotive force (EMF) in the RF coil (according to Faraday’s law of induction), which gives the detected signal in MR, but before the signal is measured, localization must occur...

  16. Responsive magnetic resonance imaging contrast agents as chemical sensors for metals in biology and medicine

    E-Print Network [OSTI]

    Glaser, Rainer

    and medicine Emily L. Quea and Christopher J. Chang*ab Received 22nd July 2009 First published as an Advance recognition to metals in biology and medicine. 1. Introduction Bioinorganic chemistry is a field therapeutics and diagnostics. An emerging intersection between metals in biology and metals in medicine

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

    E-Print Network [OSTI]

    2012-01-01

    10.1002/jmri.23572. Function Biomedical Informatics Researchstudy performed by Biomedical Informatics Research Network.of information in distributed biomedical collaboratories.

  18. Bayesian learning of continuous time dynamical systems with applications in functional magnetic resonance imaging 

    E-Print Network [OSTI]

    Murray, Lawrence

    2009-01-01

    Temporal phenomena in a range of disciplines are more naturally modelled in continuous-time than coerced into a discrete-time formulation. Differential systems form the mainstay of such modelling, in fields from physics ...

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

    E-Print Network [OSTI]

    Usey, Michael Christopher

    1995-01-01

    This thesis will develop methods for analyzing CP receiver coils for use in MRI. In addition, background, theory, and modeling information will be discussed in this thesis. Coil designs and implementations will be extensively described. Afterwards...

  20. Morphology and development of the human vocal tract: A study using magnetic resonance imaging

    E-Print Network [OSTI]

    Fitch, Tecumseh

    which have generally focused on bony struc- tures vertebral column, skull base, hyoid bone, etc. , MRI

  1. What Neural Correlates Underlie Successful Encoding and Retrieval? A Functional Magnetic Resonance Imaging Study

    E-Print Network [OSTI]

    Corkin, Suzanne

    Corkin1,2 1Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge al., 1996; Naveh-Benjamin et al., 2000a,b). Positron emission to- mography (PET) studies using versus the hard task because some encoding-related processes were not performed with concurrent

  2. Technical Note Graph-partitioned spatial priors for functional magnetic resonance images

    E-Print Network [OSTI]

    Penny, Will

    .M. Harrison a, , W. Penny a , G. Flandin a , C.C. Ruff a,b , N. Weiskopf a , K.J. Friston a a Wellcome Trust-univariate analyses. Recently diffusion-based spatial priors [Harrison, L.M., Penny, W., Daunizeau, J., and Friston, K neighbouring voxels (Flandin and Penny, 2007; Gossl et al., 2001; Penny et al., 2005; Woolrich et al., 2004

  3. Introduction The delivery and interactive rendering and segmentation of magnetic resonance imaging (MRI) data

    E-Print Network [OSTI]

    Linsen, Lars

    2003],which optimizes the XWindows protocol transparently by removing unnecessary round will concentrate on how to integrate these toolkits transparently into a web-based multi-user application framework.This is completely transparent to the application using VTK. We observed a considerable decrease in netload

  4. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe23-24, 2011 High EnergyJanuaryLawrenceof Science (SC)

  5. 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)

    2010-07-19

    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.

  6. One- and two-dimensional nuclear magnetic resonance spectroscopy with a diamond quantum sensor

    E-Print Network [OSTI]

    J. M. Boss; K. Chang; J. Armijo; K. Cujia; T. Rosskopf; J. R. Maze; C. L. Degen

    2015-12-10

    We report on Fourier spectroscopy experiments performed with near-surface nitrogen-vacancy centers in a diamond chip. By detecting the free precession of nuclear spins rather than applying a multipulse quantum sensing protocol, we are able to unambiguously identify the NMR species devoid of harmonics. We further show that by engineering different Hamiltonians during free precession, the hyperfine coupling parameters as well as the nuclear Larmor frequency can be selectively measured with high precision (here 5 digits). The protocols can be combined to demonstrate two-dimensional Fourier spectroscopy. The technique will be useful for mapping nuclear coordinates in molecules en route to imaging their atomic structure.

  7. 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

    2013-01-01

    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.

  8. VFISV: Very Fast Inversion of the Stokes Vector for the Helioseismic and Magnetic Imager

    E-Print Network [OSTI]

    Borrero, J M; Kubo, M; Socas-Navarro, H; Schou, J; Couvidat, S; Bogart, R

    2009-01-01

    In this paper we describe in detail the implementation and main properties of a new inversion code for the polarized radiative transfer equation (VFISV: Very Fast inversion of the Stokes vector). VFISV will routinely analyze pipeline data from the Helioseismic and Magnetic Imager (HMI) on-board of the Solar Dynamics Observatory (SDO). It will provide full-disk maps (4096$\\times$4096 pixels) of the magnetic field vector on the Solar Photosphere every 10 minutes. For this reason VFISV is optimized to achieve an inversion speed that will allow it to invert 16 million pixels every 10 minutes with a modest number (approx. 50) of CPUs. Here we focus on describing a number of important details, simplifications and tweaks that have allowed us to significantly speed up the inversion process. We also give details on tests performed with data from the spectropolarimeter on-board of the Hinode spacecraft.

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

    E-Print Network [OSTI]

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

    2015-01-01

    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.

  10. Vector Magnetic Fields and Electric Currents from the Imaging Vector Magnetograph

    E-Print Network [OSTI]

    Jing Li; A. A. van Ballegooijen; Don Mickey

    2008-11-01

    First, we describe a general procedure to produce high quality vector magnetograms using the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. At the spatial resolution 2"x2", the Stokes Q,U,V uncertainty reaches 0.001-0.0005 in time-averaged data over 1-hour in the quiet Sun. When vector magnetic fields are inferred from the time-averaged Stokes spectral images of FeI 6302.5A, the resulting uncertainties are on the order of 10 G for the longitudinal fields, 40 G for the transverse field strength and 9 degree for the magnetic azimuth. The magnetic field inversion used in this work is the "Triplet" code, which was developed and implemented in the IVM software package by the late Barry J. LaBonte. The inversion code is described in detail in the Appendix. Second, we solve for the absolute value of the vertical electric current density, |Jz|, accounting for the above IVM problems, for two different active regions. One is a single sunspot region (NOAA 10001 observed on 20 June 2002) while the other is a more complex, quadrupolar region (NOAA10030 observed on 15 July 2002). We use a calculation that does not require disambiguation of 180 degree in the transverse field directions. The |Jz| uncertainty is on the order of 7.0 mA m^-2. The vertical current density increases with increasing vertical magnetic field. The rate of increase is about 1 -2 times as large in the quadrupolar NOAA 10030 region as in the simple NOAA 10001, and it is more spatially variable over NOAA 10030 than over NOAA 10001.

  11. Phase-locking of magnetic islands diagnosed by ECE-imaging

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

    Tobias, B.; Grierson, B. A.; Muscatello, C. M.; Ren, X.; Domier, C. W.; Luhmann, N. C.; Zemedkun, S. E.; Munsat, T. L.; Classen, I. G. J.

    2014-08-13

    Millimeter-wave imaging diagnostics identify phase-locking and the satisfaction of 3-wave coupling selection criteria amongst multiple magnetic island chains by providing a localized, internal measurement of the 2D power spectral density, S(?, kpol). In high-confinement tokamak discharges, these interactions impact both plasma rotation and tearing stability. Nonlinear coupling amongst neoclassical tearing modes (NTMs) of different n-number, with islands not satisfying the poloidal mode number selection criterion {m, m ', m - m ' }, contributes to a reduction in core rotation and flow shear in the vicinity of the modes.

  12. 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). Environmental Molecular Sciences Lab.

    2012-01-01

    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.

  13. 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

    2010-09-14

    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.

  14. 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.

    2012-01-01

    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.

  15. A new combined nuclear magnetic resonance and Raman spectroscopic probe applied to in situ investigations of catalysts and catalytic processes

    SciTech Connect (OSTI)

    Camp, Jules C. J.; Mantle, Michael D.; York, Andrew P. E.; McGregor, James

    2014-06-15

    Both Raman and nuclear magnetic resonance (NMR) spectroscopies are valuable analytical techniques capable of providing mechanistic information and thereby providing insights into chemical processes, including catalytic reactions. Since both techniques are chemically sensitive, they yield not only structural information but also quantitative analysis. In this work, for the first time, the combination of the two techniques in a single experimental apparatus is reported. This entailed the design of a new experimental probe capable of recording simultaneous measurements on the same sample and/or system of interest. The individual datasets acquired by each spectroscopic method are compared to their unmodified, stand-alone equivalents on a single sample as a means to benchmark this novel piece of equipment. The application towards monitoring reaction progress is demonstrated through the evolution of the homogeneous catalysed metathesis of 1?hexene, with both experimental techniques able to detect reactant consumption and product evolution. This is extended by inclusion of magic angle spinning (MAS) NMR capabilities with a custom made MAS 7 mm rotor capable of spinning speeds up to 1600 Hz, quantified by analysis of the spinning sidebands of a sample of KBr. The value of this is demonstrated through an application involving heterogeneous catalysis, namely the metathesis of 2-pentene and ethene. This provides the added benefit of being able to monitor both the reaction progress (by NMR spectroscopy) and also the structure of the catalyst (by Raman spectroscopy) on the very same sample, facilitating the development of structure-performance relationships.

  16. Comparison of glucose fermentation by suspended and gel-entrapped yeast cells: An in vivo nuclear magnetic resonance study

    SciTech Connect (OSTI)

    Taipa, M.A.; Cabral, J.M.S. Inst. Superior Tecnico, Lisboa ); Santos, H. U.N.L., Monte de Caparica )

    1993-03-15

    Phosphorus-31 nuclear magnetic resonance ([sup 31]P NMR) was used to compare the anaerobic metabolism of glucose by suspended and gel-entrapped Saccaromyces bayanus cells. The fermentation of glucose was carried out in a reaction system with continuous circulation through the NMR sample tube. The intracellular pH and the levels of some phosphorylated compounds were noninvasively monitored by [sup 31]P NMR while glucose, fermentation products, and biomass were determined by analytical techniques. Qualitative comparisons showed that no significant differences are observed in the relative concentrations of the major phosphorylated metabolites in the spectra, but distinct profile for the variation of both intracellular and extracellular pH of immobilized cells is maintained at a constant value throughout the fermentation as opposed to freely suspended cells for which a steady decrease in the internal pH occurs. A faster and stronger acidification is also observed in the external medium of the assays with suspended cells. Furthermore, higher yields for ethanol and biomass production and lower yields of fermentation by-products are obtained with immobilized cells. It is concluded that the higher intracellular pH achieved in the presence of the gel matrix had a regulatory effect on the metabolism which favored the ethanol production pathway.

  17. 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.

    2012-01-06

    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

  18. Genetically engineered sensors for non-invasive molecular imaging using MRI

    E-Print Network [OSTI]

    Shapiro, Mikhail G

    2008-01-01

    Technologies that provide information about the concentrations or activities of specific molecules in living subjects have the potential to greatly advance science and medicine. Magnetic resonance imaging (MRI) is a tool ...

  19. Engineering genetically-encodable MRI contrast agents for in vivo imaging

    E-Print Network [OSTI]

    Matsumoto, Yuri, Ph. D. Massachusetts Institute of Technology

    2014-01-01

    Magnetic resonance imaging (MRI) is gaining recognition as a powerful tool in biological research, offering non-invasive access to anatomy and activity at high spatial and temporal resolution. However, the range of biological ...

  20. The feasibility of Quadrupole Dip Imaging with PMRI: focus on multiple sclerosis 

    E-Print Network [OSTI]

    Jeter, Edward Hilton

    2013-02-22

    Magnetic Resonance (MR) techniques provide valuable information for the diagnosis, monitoring, treatment, and study of many diseases. However, limitations on the sensitivity and specificity warrant the development of new imaging techniques...

  1. Medical Image Segmentation Xiaolei Huang

    E-Print Network [OSTI]

    Huang, Xiaolei

    . The National Electrical Manufacturers Association (NEMA) holds the copyright to the DICOM standard. Medical (CAT), Magnetic Resonance Imaging (MRI), Ultrasound, and X-Ray, in standard DICOM formats are often and Communications in Medicine (DICOM) standard is created as a cooperative international standard for communication

  2. Advances in the Understanding of ELM Suppression by Resonant Magnetic Perturbations (RMPs) in DIII-D and Implications for ITER

    SciTech Connect (OSTI)

    Nazikian, R.

    2014-09-01

    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.

  3. Sequence dependent structure and thermodynamics of DNA oligonucleotides and polynucleotides: uv melting and NMR (nuclear magnetic resonance) studies

    SciTech Connect (OSTI)

    Aboul-ela, F.M.

    1987-12-01

    Thermodynamic parameters for double strand formation have been measured for the twenty-five DNA double helices made by mixing deoxyoligonucleotides of the sequence dCA/sub 3/XA/sub 3/G with the complement dCT/sub 3/YT/sub 3/G. Each of the bases A, C, G, T, and I (I = hypoxanthine) have been substituted at the positions labeled X and Y. The results are analyzed in terms of nearest neighbors. At higher temperatures the sequences containing a G)centerreverse arrowdot)C base pair become more stable than those containing only A)centerreverse arrowdot)T. All molecules containing mismatcher are destabilized with respect to those with only Watson-Crick pairing, but there is a wide range of destabilization. Large neighboring base effects upon stability were observed. For example, when (X, Y) = (I, A), the duplex is eightfold more stable than when (X, Y) = (A, I). Independent of sequence effects the order of stabilities is: I)centerreverse arrowdot)C )succ) I)centerreverse arrowdot) A)succ) I)centerreverse arrowdot)T approx. I)centerreverse arrowdot)G. All of these results are discussed within the context of models for sequence dependent DNA secondary structure, replication fidelity and mechanisms of mismatch repair, and implications for probe design. The duplex deoxyoligonucleotide d(GGATGGGAG))centerreverse arrowdot)d(CTCCCATCC) is a portion of the gene recognition sequence of the protein transcription factor IIIA. The crystal structure of this oligonucleotide was shown to be A-form The present study employs Nuclear Magnetic Resonance, optical, chemical and enzymatic techniques to investigate the solution structure of this DNA 9-mer. (157 refs., 19 figs., 10 tabs.

  4. INVESTIGATION OF THERAPY IMPROVEMENT USING REAL-TIME PHOTOACOUSTIC IMAGING GUIDED HIGH INTENSITY FOCUSED ULTRASOUND

    E-Print Network [OSTI]

    Cui, Huizhong

    2013-05-31

    . Although several groups showed that magnetic resonance imaging (MRI),[32, 91, 92] thermoacoustic tomography (TAT),[93] ultrasound imaging[25, 94] have the capabilities of monitoring the thermal lesion generated by HIFU in the targeted region, PAI has... modes (such as head and neck imaging), special RF coils are used to fit closely to the patient’s anatomy, and these coils will interfere with HIFU transducer placement. Photoacoustic imaging, also called optoacoustic imaging or thermoacoustic imaging...

  5. X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er)

    SciTech Connect (OSTI)

    Nandi, Shibabrata

    2009-12-19

    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.

  6. Medical Imaging: ECE-4BF3 Michael D. Noseworthy, Ph.D., P.Eng.

    E-Print Network [OSTI]

    Haykin, Simon

    acquisition and formation; post-processing for magnetic resonance imaging and spectroscopy; comparisons Objectives This course is designed to allow students to become familiar with medical imaging technologies applications with other imaging modalities (e.g. PET, SPECT, ultrasound, mammography, CT, EEG, MEG

  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 Emission Tomography (PET) and Diffusion Tensor Imaging (DTI) have accelerated brain research in many aspects. In order to better understand the synergy of the many processes involved in normal brain function

  8. Spectroscopic ion beam imaging for investigations into magnetic field mapping of a plasma

    E-Print Network [OSTI]

    is the inference of the magnetic field (Bp and Bt) of a magnetically confined plasma from the curvature of a singly changes in magnetic field with time in almost any magnetic confinement device. II. PRINCIPLE OF LOCAL,3 As an HIBP's charged probing ions travel through a plasma, they are deflected by the confining magnetic field

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

    SciTech Connect (OSTI)

    Cai, Min

    2011-11-30

    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.

  10. Characterization of a novel weak interaction between MUC1 and Src-SH3 using nuclear magnetic resonance spectroscopy

    SciTech Connect (OSTI)

    Gunasekara, Nirosha [Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.21 WCM Health Science Centre, 8440-112th Street, Edmonton, Alberta, Canada T6G 2R7 (Canada)] [Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.21 WCM Health Science Centre, 8440-112th Street, Edmonton, Alberta, Canada T6G 2R7 (Canada); Sykes, Brian, E-mail: brian.sykes@ualberta.ca [Department of Biochemistry, 4-19B Medical Sciences Bldg., University of Alberta Edmonton, Alberta, Canada T6G 2H7 (Canada)] [Department of Biochemistry, 4-19B Medical Sciences Bldg., University of Alberta Edmonton, Alberta, Canada T6G 2H7 (Canada); Hugh, Judith, E-mail: judithh@ualberta.ca [Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.21 WCM Health Science Centre, 8440-112th Street, Edmonton, Alberta, Canada T6G 2R7 (Canada)] [Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.21 WCM Health Science Centre, 8440-112th Street, Edmonton, Alberta, Canada T6G 2R7 (Canada)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer MUC1 binds the Src-SH3 domain potentially triggering Src dependent cell migration. Black-Right-Pointing-Pointer NMR Spectroscopy was used to monitor MUC1-CD and Src SH3 domain titrations. Black-Right-Pointing-Pointer MUC1-CD peptides bind with a low affinity (K{sub d} of 2-3 mM) to a non-canonical site. Black-Right-Pointing-Pointer Weak interactions may mediate dynamic processes like migration. Black-Right-Pointing-Pointer The MUC1-CD and Src-SH3 interaction may be a prime target to inhibit cell migration. -- Abstract: Breast cancer causes death through cancer cell migration and subsequent metastasis to distant organs. In vitro, the MUC1 mucin can mediate breast cancer cell migration by binding to intercellular adhesion molecule-1 (ICAM-1). This migration is dependent on MUC1 cytoplasmic domain (MUC1-CD) activation of the non-receptor tyrosine kinase, Src, possibly through competitive displacement of an inhibitory Src intramolecular SH3 binding. Therefore, we characterized the binding site and affinity of the MUC1-CD for Src-SH3 using multidimensional nuclear magnetic resonance (NMR) spectroscopy to monitor the titration of the {sup 15}N labeled Src-SH3 domain with synthetic native and mutant peptides of MUC1-CD. The results revealed that the dissociation constant (K{sub d}) for the interaction of the native MUC1-CD peptides and Src-SH3 domain was weak with a K{sub d} of 2-3 mM. Notably, the SH3 residues most perturbed upon peptide binding were located outside the usual hydrophobic binding cleft in a previously described alternate binding site on the Src-SH3, suggesting that MUC1-CD binds to a non-canonical site. The binding characteristics outlined here suggest that the interaction between Src-SH3 and MUC1-CD represents a novel weak electrostatic interaction of the type which is increasingly recognized as important in transient and dynamic protein complexes required for cell migration and signal transduction. As such, this study forms the foundation for the design of specific inhibitors of this interaction which may target breast cancer metastases with exquisite specificity.

  11. Informatics methods to enable sharing of quantitative imaging research data,

    E-Print Network [OSTI]

    Rubin, Daniel L.

    reuse of quantitative imaging data in the community. Methods: We performed a survey of the current tools online at www.sciencedirect.com Magnetic Resonance Imaging 30 (2012) 1249­1256 Disclosures of conflict of interest: Mia Levy, none; John Freymann, none; Justin Kirby, none; Andriy Fedorov, Ph.D., none; Fiona

  12. 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)

    2014-02-10

    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.

  13. Enhanced production of electron cyclotron resonance plasma by exciting selective microwave mode on a large-bore electron cyclotron resonance ion source with permanent magnet

    SciTech Connect (OSTI)

    Kimura, Daiju, E-mail: kimura@nf.eie.eng.osaka-u.ac.jp; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Imai, Youta; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)] [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    2014-02-15

    We are constructing a tandem type ECRIS. The first stage is large-bore with cylindrically comb-shaped magnet. We optimize the ion beam current and ion saturation current by a mobile plate tuner. They change by the position of the plate tuner for 2.45 GHz, 11–13 GHz, and multi-frequencies. The peak positions of them are close to the position where the microwave mode forms standing wave between the plate tuner and the extractor. The absorbed powers are estimated for each mode. We show a new guiding principle, which the number of efficient microwave mode should be selected to fit to that of multipole of the comb-shaped magnets. We obtained the excitation of the selective modes using new mobile plate tuner to enhance ECR efficiency.

  14. IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 20, NO. 23, DECEMBER 1, 2008 1905 A Magnetically Actuated Resonant Mass Sensor With

    E-Print Network [OSTI]

    Alaca, B. Erdem

    of the resonating structure and the diffraction grating by electroplating of Ni, which also brings about motion. The typical surface roughness associated with the electroplating of Ni as the moving reflector

  15. Magnetic States in Fe Nanoparticles Imaged by Off-axis Electron Holography Luise Theil Kuhn1*

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    a procedure that is described elsewhere [1]. In FIG. 1 (d), a magnetic vortex surrounds a flux tube that runs.e. their magnetic configurations may be vortex-like. The critical size for this transition from single domain to vortex behaviour is crucial for determining the net magnetic moments carried by magnetic nanoparticles, i

  16. Video Toroid Cavity Imager

    DOE Patents [OSTI]

    Gerald, Rex E. II; Sanchez, Jairo; Rathke, Jerome W.

    2004-08-10

    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.

  17. Multifrequency spin resonance in diamond

    SciTech Connect (OSTI)

    Childress, Lilian; McIntyre, Jean

    2010-09-15

    Magnetic resonance techniques provide a powerful tool for controlling spin systems, with applications ranging from quantum information processing to medical imaging. Nevertheless, the behavior of a spin system under strong excitation remains a rich dynamical problem. In this paper, we examine spin resonance of the nitrogen-vacancy center in diamond under conditions outside the regime where the usual rotating-wave approximation applies, focusing on effects of multifrequency excitation and excitation with orientation parallel to the spin quantization axis. Strong-field phenomena such as multiphoton transitions and coherent destruction of tunneling are observed in the spectra and analyzed via numerical and analytic theory. In addition to illustrating the response of a spin system to strong multifrequency excitation, these observations may inform techniques for manipulating electron-nuclear spin quantum registers.

  18. Abstract--For the past decade, improving the performance and accuracy of medical image registration has been a driving

    E-Print Network [OSTI]

    Bhattacharyya, Shuvra S.

    technologies have enabled diagnoses and procedures simply not possible a decade ago. The increasing acquisition emission tomography (PET), magnetic resonance (MRI), ultrasound (US), etc.) and the sheer volume of data registration. Image registration is the process of fusing two images such that the features in one image

  19. Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

    SciTech Connect (OSTI)

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J., E-mail: mrichards@astro.psu.edu, E-mail: asc5097@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2014-11-10

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The H? tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  20. 2D image of local density and magnetic fluctuations from line-integrated interferometry-polarimetry measurements

    SciTech Connect (OSTI)

    Lin, L. Ding, W. X.; Brower, D. L.

    2014-11-15

    Combined polarimetry-interferometry capability permits simultaneous measurement of line-integrated density and Faraday effect with fast time response (?1 ?s) and high sensitivity. Faraday effect fluctuations with phase shift of order 0.05° associated with global tearing modes are resolved with an uncertainty ?0.01°. For physics investigations, local density fluctuations are obtained by inverting the line-integrated interferometry data. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of the polarimetry data. Reconstructed 2D images of density and magnetic field fluctuations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved.

  1. 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.

    1987-01-01

    choice for the phase of the spin wave function for the transverse satellite spin resonance. M. M. Salomaa, ROTA-86 Symposium, Helsinki University of Technology, Espoo, Finland, 1986; M. M. Salomaa and G. E. Volovik, Europhys. Lett. 2, 781 (1986). o...

  2. Atomic magnetic gradiometer for room temperature high sensitivity magnetic field detection

    DOE Patents [OSTI]

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

    2009-08-11

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

  3. Continuous-wave operation of a frequency-tunable 460-GHz second-harmonic gyrotron for enhanced nuclear magnetic resonance

    E-Print Network [OSTI]

    Torrezan de Sousa, Antonio Carlos

    The design, operation, and characterization of a continuous-wave (CW) tunable second-harmonic 460-GHz gyrotron are reported. The gyrotron is intended to be used as a submillimeter-wave source for 700-MHz nuclear magnetic ...

  4. 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.

    2006-01-10

    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.

  5. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOE Patents [OSTI]

    Campbell, A.N.; Anderson, R.E.; Cole, E.I. Jr.

    1995-11-07

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits are disclosed. 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. 17 figs.

  6. 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)

    1995-01-01

    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.

  7. 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.

    2015-05-21

    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

  8. 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.

    2015-05-01

    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.

  9. 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)

    2010-08-15

    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.

  10. 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)

    2014-02-15

    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.

  11. Proc. 26th Annual Int. Conf. of the IEEE Engineering in Medicine and Biology Society (EMBS), San Francisco, CA, 2004. Abstract--We develop an image registration system

    E-Print Network [OSTI]

    Alterovitz, Ron

    of the prostate and surrounding tissues to register cancerous tumor locations for targeted prostate brachytherapy. The probe is removed during magnetic resonance (MR) imaging for brachytherapy planning and therapy. Given 2 grid from the MRS image to the probe-out MR image for use during treatment planning. Keywords--brachytherapy

  12. Repetitive resonant railgun power supply

    DOE Patents [OSTI]

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

    1988-01-01

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

  13. 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

  14. 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

  15. VESSEL SEGMENTATION IN MEDICAL IMAGING USING A TIGHT-FRAME BASED ALGORITHM

    E-Print Network [OSTI]

    Chan, Raymond

    VESSEL SEGMENTATION IN MEDICAL IMAGING USING A TIGHT-FRAME BASED ALGORITHM XIAOHAO CAI, RAYMOND vessels in magnetic resonance angiography images. Our method iteratively refines a region that encloses the potential boundary of the vessels. At each iteration, we apply the tight-frame algorithm to denoise

  16. DICOVERY OF "BIOMARKERS" FOR ALZHEIMER'S DISEASE PREDICTION FROM STRUCTURAL MR IMAGES

    E-Print Network [OSTI]

    DICOVERY OF "BIOMARKERS" FOR ALZHEIMER'S DISEASE PREDICTION FROM STRUCTURAL MR IMAGES Y. Liu1,2,3 , L. A. Teverovskiy2 , O. L. Lopez3 , H. Aizenstein3 , C. C. Meltzer3,4 , J. T. Becker3 1 Penn State discrimination using high-resolutionMagnetic Resonance (MR) brain images. We focus on the exploration of a very

  17. Nanoscale femtosecond imaging of transient hot solid density plasmas with elemental and charge state sensitivity using resonant coherent diffraction

    E-Print Network [OSTI]

    Kluge, Thomas; Chung, H -K; Gutt, C; Huang, L G; Zacharias, M; Schramm, U; Cowan, T E

    2015-01-01

    Here we propose to exploit the low energy bandwidth, small wavelength and penetration power of ultrashort pulses from XFELs for resonant Small Angle Scattering (SAXS) on plasma structures in laser excited plasmas. Small angle scattering allows to detect nanoscale density fluctuations in forward scattering direction. Typically, the SAXS signal from laser excited plasmas is expected to be dominated by the free electron distribution. We propose that the ionic scattering signal becomes visible when the X-ray energy is in resonance with an electron transition between two bound states (Resonant coherent X-ray diffraction, RCXD). In this case the scattering cross-section dramatically increases so that the signal of X-ray scattering from ions silhouettes against the free electron scattering background which allows to measure the opacity and derived quantities with high spatial and temporal resolution, being fundamentally limited only by the X-ray wavelength and timing. Deriving quantities such as ion spatial distribu...

  18. Injection-controlled laser resonator

    DOE Patents [OSTI]

    Chang, J.J.

    1995-07-18

    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.

  19. Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

    DOE Patents [OSTI]

    Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)

    2000-12-19

    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.

  20. 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.; Dal Savio, C.; Karrai, K.; Dantelle, G.; Thiaville, A.; Rohart, S.

    2012-04-09

    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.

  1. 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.

    2004-01-01

    been offerred to ex- plain this disagreement.5,6 Namely, finite LDOS are pre- dicted at the Zn or Cu sites only, with no continuous LDOS between these lattice sites. This is of course not what has been observed, which is quasi... two STM images. One is a topographic image (an energy- integrated spatial image), which gives the top BiO layer, showing only the Bi atoms. They are observed to be dis- placed from their ideal orthorhombic lattice sites, forming a supermodulation...

  2. 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

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

    E-Print Network [OSTI]

    Eyüboðlu, Murat

    of electrodes can be used to determine lead-sensitivity maps of biopotential recording set-ups [4]. Finally

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

    E-Print Network [OSTI]

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

    2012-10-24

    /Tcardiac=0.4, but read 0.2 for the apex and - 0.08 for the base level. The difference indicated that the apex twisted more than the base. Conclusion It is feasible to empirically model the spatial and temporal evolution of the LV wall motion using a two...

  5. Safety Guidelines for Conducting Magnetic Resonance Imaging (MRI) Experiments Involving Human Subjects UCSD Center for Functional MRI, April 4, 2008

    E-Print Network [OSTI]

    California at San Diego, University of

    Subjects UCSD Center for Functional MRI, April 4, 2008 NOTE: These safety guidelines supplement and update the main safety guidelines from July 2007. Guidelines 1 through 6 apply to all subjects and studies. 1) For all subjects and studies, a safety-certified adult should continuously monitor the subject's status

  6. 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

  7. COBIOT-591; NO OF PAGES 8 Please cite this article in press as: Xia Z, Rao J. Biosensing and imaging based on bioluminescence resonance energy transfer, Curr Opin Biotechnol (2009), doi:10.1016/j.copbio.2009.01.001

    E-Print Network [OSTI]

    Rao, Jianghong

    2009-01-01

    and imaging based on bioluminescence resonance energy transfer, Curr Opin Biotechnol (2009), doi:10.1016/j resonance energy transfer Zuyong Xia and Jianghong Rao Bioluminescence resonance energy transfer (BRET) operates with biochemical energy generated by bioluminescent proteins to excite fluorophores and offers

  8. A New Approach to Lung Image Segmentation using Fuzzy Possibilistic C-Means Algorithm

    E-Print Network [OSTI]

    Gomathi, M

    2010-01-01

    Image segmentation is a vital part of image processing. Segmentation has its application widespread in the field of medical images in order to diagnose curious diseases. The same medical images can be segmented manually. But the accuracy of image segmentation using the segmentation algorithms is more when compared with the manual segmentation. In the field of medical diagnosis an extensive diversity of imaging techniques is presently available, such as radiography, computed tomography (CT) and magnetic resonance imaging (MRI). Medical image segmentation is an essential step for most consequent image analysis tasks. Although the original FCM algorithm yields good results for segmenting noise free images, it fails to segment images corrupted by noise, outliers and other imaging artifact. This paper presents an image segmentation approach using Modified Fuzzy C-Means (FCM) algorithm and Fuzzy Possibilistic c-means algorithm (FPCM). This approach is a generalized version of standard Fuzzy CMeans Clustering (FCM) ...

  9. Ab Initio Calculation of Nuclear Magnetic Resonance Chemical Shift Anisotropy Tensors 1. Influence of Basis Set on the Calculation of 31P Chemical Shifts

    SciTech Connect (OSTI)

    Alam, T.M.

    1998-09-01

    The influence of changes in the contracted Gaussian basis set used for ab initio calculations of nuclear magnetic resonance (NMR) phosphorous chemical shift anisotropy (CSA) tensors was investigated. The isotropic chemical shitl and chemical shift anisotropy were found to converge with increasing complexity of the basis set at the Hartree-Fock @IF) level. The addition of d polarization function on the phosphorous nucIei was found to have a major impact of the calculated chemical shi~ but diminished with increasing number of polarization fimctions. At least 2 d polarization fimctions are required for accurate calculations of the isotropic phosphorous chemical shift. The introduction of density fictional theory (DFT) techniques through tie use of hybrid B3LYP methods for the calculation of the phosphorous chemical shift tensor resulted in a poorer estimation of the NMR values, even though DFT techniques result in improved energy and force constant calculations. The convergence of the W parametem with increasing basis set complexity was also observed for the DFT calculations, but produced results with consistent large deviations from experiment. The use of a HF 6-31 l++G(242p) basis set represents a good compromise between accuracy of the simulation and the complexity of the calculation for future ab initio calculations of 31P NMR parameters in larger complexes.

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

    E-Print Network [OSTI]

    Jackson, Jennifer M.

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

  11. Real time image integrator for magnetic surface mapping experiments in TJ-I U torsatron

    SciTech Connect (OSTI)

    Marin, J.; Carballo, I.; Olmos, P.; Ascasibar, E.; Pastor, I.; Qin, J.; Herranz, J.; Fraguas, A.L. [CIEMAT, Madrid (Spain)] [CIEMAT, Madrid (Spain)

    1996-02-01

    The authors describe in this paper a video integrator system developed for mapping the magnetic surfaces inside the TJ-I U torsatron built at CIEMAT and devoted to fusion plasma studies. A description of the video integrator hardware as well as some of the results carried out with the system are also presented and discussed.

  12. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two0PhotosPresentationsWorld's largestX-Ray ImagingImaging

  13. Film vs. magnetic tape recording for IRLS AN/AAD-5 for open skies imaging

    SciTech Connect (OSTI)

    Kumar, V.; Saatzer, P.; Goede, W.

    1996-11-01

    The United States Government (USG) Full Operational Capability (FOC) Open Skies aircraft (OC-135) will be equipped with an Infrared Line Scanner AN/AAD-5, fully compliant with the treaty requirements. An extensive trade study is conducted to explore the possibility of switching from film recording to either analog or digital magnetic tape recording when the AAD-5 IRLS is flown in the Open Skies Aircraft. This paper presents preliminary trade study results and the overall conclusions and recommendations based on the analysis. A flight measurement program is now being carried out under the Follow On Sensor Evaluation Program (FOSEP) to evaluate the digital magnetic recording as compared to the film recording and the results of these fight measurement will be presented at a later date. 6 figs., 4 tabs.

  14. Mon. Not. R. Astron. Soc. 000, 131 (2012) Printed 27 June 2012 (MN LATEX style file v2.2) Stokes IQUV Magnetic Doppler Imaging of Ap stars

    E-Print Network [OSTI]

    2012-01-01

    IQUV Magnetic Doppler Imaging of Ap stars I. ESPaDOnS and NARVAL Observations J. Silvester1,2 , G, corresponding to 297 individual polarised spectra, have been obtained for 7 bright Ap stars using the ESPa generation of surface maps of Ap stars, this study estab- lishes the performance and stability of the ESPa

  15. 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

  16. Rigid overlay of volume sonography and MR image data of the female pelvic floor using a fiducial based alignment--feasibility

    E-Print Network [OSTI]

    of the authors [1], advances in 3D sonographical imaging as well as in data acquisition techniques allowRigid overlay of volume sonography and MR image data of the female pelvic floor using a fiducial with enhanced informative content. In this paper, we present an overlay technique of magnetic resonance (MR

  17. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two0PhotosPresentationsWorld's largestX-Ray Imaging

  18. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two0PhotosPresentationsWorld's largestX-RayX-Ray Imaging of

  19. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos Alamos verifies largest single goldWind PowerX-Ray Imaging

  20. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos Alamos verifies largest single goldWind PowerX-Ray ImagingX-Ray

  1. X-Ray Imaging Current-Driven Magnetic Domain-Wall Motion in Nanowires

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos Alamos verifies largest single goldWind PowerX-RayX-Ray Imaging

  2. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLos Alamos verifies largest single goldWindX-Ray Imaging of the Dynamic

  3. 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.; Malta, M.; Torresi, R. M.

    2011-05-01

    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.

  4. Multimodality Image Fusion-Guided Procedures: Technique, Accuracy, and Applications

    SciTech Connect (OSTI)

    Abi-Jaoudeh, Nadine, E-mail: naj@mail.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States); Kruecker, Jochen, E-mail: jochen.kruecker@philips.com [Philips Research North America (United States); Kadoury, Samuel, E-mail: samuel.kadoury@polymtl.ca [Ecole Polytechnique de Montreal, Department of Computer and Software Engineering, Institute of Biomedical Engineering (Canada); Kobeiter, Hicham, E-mail: hicham.kobeiter@gmail.com [CHU Henri Mondor, UPEC, Departments of Radiology and d'imagrie medicale (France); Venkatesan, Aradhana M., E-mail: VenkatesanA@cc.nih.gov; Levy, Elliot, E-mail: levyeb@cc.nih.gov; Wood, Bradford J., E-mail: bwood@cc.nih.gov [National Institutes of Health, Radiology and Imaging Sciences (United States)

    2012-10-15

    Personalized therapies play an increasingly critical role in cancer care: Image guidance with multimodality image fusion facilitates the targeting of specific tissue for tissue characterization and plays a role in drug discovery and optimization of tailored therapies. Positron-emission tomography (PET), magnetic resonance imaging (MRI), and contrast-enhanced computed tomography (CT) may offer additional information not otherwise available to the operator during minimally invasive image-guided procedures, such as biopsy and ablation. With use of multimodality image fusion for image-guided interventions, navigation with advanced modalities does not require the physical presence of the PET, MRI, or CT imaging system. Several commercially available methods of image-fusion and device navigation are reviewed along with an explanation of common tracking hardware and software. An overview of current clinical applications for multimodality navigation is provided.

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

    SciTech Connect (OSTI)

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

    2012-03-15

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

  6. Novel image processing techniques to better understand white matter disruption in multiple sclerosis

    E-Print Network [OSTI]

    In Multiple Sclerosis (MS) patients, conventional magnetic resonance imaging (MRI) shows a pattern of white rights reserved. Keywords: Multiple Sclerosis; Diffusion Tensor MRI; Atlas; Visualization; Tractography Institutes of Health, USA, RG 3478A2/2 from the National Multiple Sclerosis Society, USA, and NSF ITR 0426558

  7. 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

  8. MR imaging in the non-human primate: studies of function and of dynamic connectivity

    E-Print Network [OSTI]

    of Physiology of Cognitive Processes, Spemannstr 38, 72076 Tu¨ bingen, Germany e-mail: nikos.logothetis@tuebingen.mpg.de Current Opinion in Neurobiology 2003, 13:1­13 This review comes from a themed issue on New technologies extracellular field potential MRI magnetic resonance imaging MUA multiple-unit spiking activity PET positron

  9. Electromagnetic imaging of dynamic brain activity

    SciTech Connect (OSTI)

    Mosher, J.; Leahy, R.; Lewis, P.; Lewine, J.; George, J.; Singh, M.

    1991-12-31

    Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

  10. A MAgnEt for InvEstMEnt Fermilab's specialized operations attract funding from the federal government

    E-Print Network [OSTI]

    Quigg, Chris

    and lower manufacturing costs. These advances hastened the development of magnetic resonance imaging (MRI to the universe's greatest mysteries, training the next generation of scientists, and pioneering innovative experiment. #12;A CAtAlyst for Industry InnovAtIon Fermilab's scientific breakthroughs--and its

  11. Dynamic control of spin states in interacting magnetic elements

    DOE Patents [OSTI]

    Jain, Shikha; Novosad, Valentyn

    2014-10-07

    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.

  12. Magnetostrictive resonance excitation

    DOE Patents [OSTI]

    Schwarz, Ricardo B. (Los Alamos, NM); Kuokkala, Veli-Tapani (Tampere, FI)

    1992-01-01

    The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection coil varies with the strain in the material whereby resonance responses of the sample can be readily detected. A suitable sample may be a magnetostrictive material or some other material having at least one side coated with a magnetostrictive material. When the sample is a suitable shape, i.e., a cube, rectangular parallelepiped, solid sphere or spherical shell, the elastic moduli or the material can be analytically determined from the measured resonance frequency spectrum. No mechanical transducers are required and the sample excitation is obtained without contact with the sample, leading to highly reproducible results and a measurement capability over a wide temperature range, e.g. from liquid nitrogen temperature to the Curie temperature of the magnetostrictive material.

  13. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeat Pumps Heat Pumpsfacility doe logo CH2M-WG logoImaging

  14. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower,PrincipalIdahoImaging Print The

  15. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation CurrentHenry Bellamy, Ph.D.FoodHydropower,PrincipalIdahoImaging Print

  16. IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 20, NO. 8, AUGUST 2001 677 Automated Segmentation of Multiple Sclerosis

    E-Print Network [OSTI]

    of Multiple Sclerosis Lesions by Model Outlier Detection Koen Van Leemput*, Frederik Maes, Dirk Vandermeulen for segmentation of multiple sclerosis (MS) lesions from multispec- tral magnetic resonance (MR) images. The method measurements. Index Terms--Digital brain atlas, MRI, multiple sclerosis, tissue classification. I. INTRODUCTION

  17. 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

  18. 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)

    2014-07-21

    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.

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

    E-Print Network [OSTI]

    Heras, Jonathan Jaime

    2.1.9 NMR SPECTROMETER (HARDWARE) 2.2. MAGNETIC RESONANCE IMAGING 2.2.1 MAGNETIC FIELD GRADIENTS 2.2.2 SLICE SELECTION 2.2.3 K-SPACE VECTOR FORMALISM... , kB is the Boltzmann constant, T is the absolute temperature, ? is the Planck constant divided by 2pi, and ? is the gyromagnetic ratio. The gyromagnetic ratio is nucleus specific, and has a value of 42.58 MHz/Tesla for 1H. The spin...

  20. 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

    2015-01-20

    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

  1. 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)

    2015-02-03

    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.

  2. Multiple resonant railgun power supply

    DOE Patents [OSTI]

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

    1988-01-01

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

  3. Composite arrays of superconducting microstrip line resonators

    SciTech Connect (OSTI)

    Mohebbi, H. R. Miao, G. X.; Benningshof, O. W. B.; Taminiau, I. A. J.; Cory, D. G.

    2014-03-07

    A novel design of an array of half-wave superconductive microstrip resonators is described. The resonator is intended to be useful for electron spin resonance studies of thin film samples at cryogenic temperatures. It achieves a high quality factor, has a small mode-volume, and creates a uniform magnetic field in a plane above the resonator. The device is made of thin film Niobium on sapphire wafer and is tested with a static magnetic field. Variation of Q-factor versus the magnetic field's strength at different temperatures is reported and is in a good agreement with simulation when the loss due to the vortices is included. Also, the power-dependence response of the resonator is shown in experiments and is verified by capturing the nonlinearity associated with the surface impedance of the superconducting film into the circuit model of the device.

  4. Resonant-cavity antenna for plasma heating

    DOE Patents [OSTI]

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

    1984-01-10

    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.

  5. Resonance-inclined optical nuclear spin polarization of liquids in diamond structures

    E-Print Network [OSTI]

    Chen, Qiong; Jelezko, Fedor; Retzker, Alex; Plenio, Martin B

    2015-01-01

    Dynamic nuclear polarization (DNP) of molecules in a solution at room temperature has potential to revolutionize nuclear magnetic resonance spectroscopy and imaging. The prevalent methods for achieving DNP in solutions are typically most effective in the regime of small interaction correlation times between the electron and nuclear spins, limiting the size of accessible molecules. To solve this limitation, we design a mechanism for DNP in the liquid phase that is applicable for large interaction correlation times. Importantly, while this mechanism makes use of a resonance condition similar to solid-state DNP, the polarization transfer is robust to a relatively large detuning from the resonance due to molecular motion. We combine this scheme with optically polarized nitrogen vacancy (NV) center spins in nanodiamonds to design a setup that employs optical pumping and is therefore not limited by room temperature electron thermal polarisation. We illustrate numerically the effectiveness of the model in a flow cel...

  6. Nuclear magnetic resonance evidence for a strong modulation of the Bose-Einstein condensate in BaCuSi2O6

    E-Print Network [OSTI]

    Fisher, Ian

    Mexico 87545, USA 4Geballe Laboratory for Advanced Materials and Department of Applied Physics, Stanford-Einstein condensation BEC has been considerably renewed since it was shown to occur in cold atomic gases.1 In condensed by an energy gap from a band of triplet excita- tions. Applying an external magnetic field H lowers the energy

  7. PUBLICATIONS IN REFEREED JOURNALS Aubin M., Faddegon, B. and Pouliot J., Clinical Electron Beam Verification with an a-Si Electronic Portal Imaging Device, Submitted

    E-Print Network [OSTI]

    Pouliot, Jean

    in inverse planned HDR prostate brachytherapy for dose escalation of DIL defined by combined MRI., and Hsu I.C., Inverse Planning for the Magnetic Resonance Imaging (MRI)- Based Intracavitary Brachytherapy III M., Hsu I-C., High Dose Rate (HDR) Brachytherapy Salvage for Local Prostate Recurrence After

  8. Magnetic Stereoscopy

    E-Print Network [OSTI]

    Thomas Wiegelmann; Bernd Inhester

    2006-12-21

    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.

  9. 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

  10. Nanoscale constrictions in superconducting coplanar waveguide resonators

    SciTech Connect (OSTI)

    Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando; Sesé, Javier; Atkinson, James; Barco, Enrique del; Sánchez-Azqueta, Carlos; Majer, Johannes

    2014-10-20

    We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50?nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

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

    SciTech Connect (OSTI)

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

    2008-07-15

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

  12. Stability of the electron cyclotron resonance

    E-Print Network [OSTI]

    Joachim Asch; Olivier Bourget; Cédric Meresse

    2015-10-15

    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.

  13. Revealing the Degree of Magnetic Frustration by Non-Magnetic Impurities

    SciTech Connect (OSTI)

    Not Available

    2011-08-12

    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.

  14. Scanning tunneling spectroscopy of unoccupied surface resonances

    E-Print Network [OSTI]

    Persson, Mats

    - induced series, produced when an electron is trapped in a potential well define* *d by the image Scanning tunneling spectroscopy of unoccupied surface resonances at free-electron-like metal surfaces. T. Fond'eny, S

  15. Magnetic nanoparticles for medical applications: Progress and challenges

    SciTech Connect (OSTI)

    Doaga, A.; Cojocariu, A. M.; Constantin, C. P.; Caltun, O. F. [Faculty of Physics, Alexandru Ioan Cuza University, Bd. Carol I. Nr. 11, Iasi, 700506 (Romania); Hempelmann, R. [Physical Chemistry Department, Saarland University, 66123 Saarbrücken (Germany)

    2013-11-13

    Magnetic nanoparticles present unique properties that make them suitable for applications in biomedical field such as magnetic resonance imaging (MRI), hyperthermia and drug delivery systems. Magnetic hyperthermia involves heating the cancer cells by using magnetic particles exposed to an alternating magnetic field. The cell temperature increases due to the thermal propagation of the heat induced by the nanoparticles into the affected region. In order to increase the effectiveness of the treatment hyperthermia can be combined with drug delivery techniques. As a spectroscopic technique MRI is used in medicine for the imaging of tissues especially the soft ones and diagnosing malignant or benign tumors. For this purpose Zn{sub x}Co{sub 1?x}Fe{sub 2}O{sub 4} ferrite nanoparticles with x between 0 and 1 have been prepared by co-precipitation method. The cristallite size was determined by X-ray diffraction, while the transmission electron microscopy illustrates the spherical shape of the nanoparticles. Magnetic characterizations of the nanoparticles were carried out at room temperature by using a vibrating sample magnetometer. The specific absorption rate (SAR) was measured by calorimetric method at different frequencies and it has been observed that this value depends on the chemical formula, the applied magnetic fields and the frequency. The study consists of evaluating the images, obtained from an MRI facility, when the nanoparticles are dispersed in agar phantoms compared with the enhanced ones when Omniscan was used as contrast agent. Layer-by-layer technique was used to achieve the necessary requirement of biocompatibility. The surface of the magnetic nanoparticles was modified by coating it with oppositely charged polyelectrolites, making it possible for the binding of a specific drug.

  16. Effects of strain and quantum confinement in optically pumped nuclear magnetic resonance in GaAs: Interpretation guided by spin-dependent band structure calculations

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

    Wood, R. M.; Saha, D.; McCarthy, L. A.; Tokarski, III, J. T.; Sanders, G. D.; Kuhns, P. L.; McGill, S. A.; Reyes, A. P.; Reno, J. L.; Stanton, C. J.; et al

    2014-10-29

    A combined experimental-theoretical study of optically pumped NMR (OPNMR) has been performed in a GaAs/Al0.1Ga0.9As quantum well film with thermally induced biaxial strain. The photon energy dependence of the Ga-71 OPNMR signal was recorded at magnetic fields of 4.9 and 9.4 T at a temperature of 4.8-5.4 K. The data were compared to the nuclear spin polarization calculated from differential absorption to spin-up and spin-down states of the conduction band using a modified Pidgeon Brown model. Reasonable agreement between theory and experiment is obtained, facilitating assignment of features in the OPNMR energy dependence to specific interband transitions. Despite the approximationsmore »made in the quantum-mechanical model and the inexact correspondence between the experimental and calculated observables, the results provide insight into how effects of strain and quantum confinement are manifested in OPNMR signals« less

  17. Grants (Dr. Anke Henning) Main Applicant; project grant; Imaging synaptic plasticity by ultra-high field magnetic

    E-Print Network [OSTI]

    Grants (Dr. Anke Henning) Submitted · Main Applicant; project grant; Imaging synaptic plasticity for our project part; Zentrum für integrative Humanphysiologie (ZIHP); November 2007 ­ December 2009 1999 of living and tuition fee; Deutscher Akademischer Austauschdienst (DAAD); August 1999 ­ May 2000 #12;

  18. MRI of the lung using hyperpolarized He-3 at very low magnetic field (3 mT)

    E-Print Network [OSTI]

    Bidinosti, C P; Tastevin, G; Vignaud, A; Nacher, P J

    2004-01-01

    Optical pumping of He-3 produces large (hyper) nuclear-spin polarizations independent of the magnetic resonance imaging (MRI) field strength. This allows lung MRI to be performed at reduced fields with many associated benefits, such as lower tissue susceptibility gradients and decreased power absorption rates. Here we present results of 2D imaging as well as accurate 1D gas diffusion mapping of the human lung using He-3 at very low field (3 mT). Furthermore, measurements of transverse relaxation in zero applied gradient are shown to accurately track pulmonary oxygen partial pressure, opening the way for novel imaging sequences.

  19. Spin-resolved two-photon photoemission study of the surface resonance state on Co/Cu,,001... O. Andreyev,1 Yu. M. Koroteev,2,3 M. Snchez Albaneda,1 M. Cinchetti,1 G. Bihlmayer,4 E. V. Chulkov,2,5 J. Lange,1

    E-Print Network [OSTI]

    Bauer, Michael

    photoemission spectra from clean Co films are found to be dominated by a peak located at a binding energy-doping of a Co 001 surface shifts an image potential state in resonance with the sp-states of the conduction band and magnetization dynamics by probing the state of crystal-induced or image-potential sur- face states.3­6 In a two

  20. Measuring and shimming the magnetic field of a 4 Tesla MRI magnet 

    E-Print Network [OSTI]

    Kyriazis, Georgios

    1993-01-01

    The Biomedical Magnetic Resonance Laboratory (BMRL) of the University of Illinois at Urbana-Champaign (UIUC) has ordered from the Texas Accelerator Center (TAC) a superconducting, self-shielded, solenoidal magnet with a maximum field of 4 Tesla...