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Sample records for high field esr

  1. High-field/high-pressure ESR.

    Science.gov (United States)

    Sakurai, T; Okubo, S; Ohta, H

    2017-07-01

    We present a historical review of high-pressure ESR systems with emphasis on our recent development of a high-pressure, high-field, multi-frequency ESR system. Until 2000, the X-band system was almost established using a resonator filled with dielectric materials or a combination of the anvil cell and dielectric resonators. Recent developments have shifted from that in the low-frequency region, such as X-band, to that in multi-frequency region. High-pressure, high-field, multi-frequency ESR systems are classified into two types. First are the systems that use a vector network analyzer or a quasi-optical bridge, which have high sensitivity but a limited frequency region; the second are like our system, which has a very broad frequency region covering the THz region, but lower sensitivity. We will demonstrate the usefulness of our high-pressure ESR system, in addition to its experimental limitations. We also discuss the recent progress of our system and future plans. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. High field ESR spectroscopy on (Gd,La)OFeAs superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Alfonsov, A.; Kataev, V.; Leps, N.; Klingeler, R.; Kondrat, A.; Hess, C.; Wurmehl, S.; Werner, J.; Behr, G.; Buechner, B. [IFW Dresden, D-01171 Dresden (Germany); Muranyi, F. [Universitaet Zuerich, CH-8057 Zuerich (Switzerland)

    2010-07-01

    In the present work we have studied polycrystalline samples of the (Gd,La)O{sub 1-x}F{sub x}FeAs superconductor with different levels of fluorine and gadolinium doping by means of high field/high frequency electron spin resonance (HF-ESR) spectroscopy. The Gd ESR signal is found to be sensitive to the magnetic phase transition from the paramagnetic to the spin density wave (SDW) state occurring in the parent (Gd,La)OFeAs compounds at temperatures T{sub SDW}{proportional_to}130-150 K. In addition, in case of LaO{sub 1-x}F{sub x}FeAs with 5% Gd doping there is a clear indication of the suppression of the magnetic order in the samples with the superconducting ground state. The GdOFeAs samples reveal an antiferromagnetic coupling between Gd and Fe planes which reflects in the splitting and shift of Gd ESR line below T{sub SDW}{proportional_to}130 K. Surprisingly, the 15% and 17% fluorine doped GdOFeAs samples, with T{sub c}=20 K and T{sub c}=45 K respectively, show the low-T ESR response similar to the undoped sample which indicates that the SDW is not completely suppressed in the SC samples. We compare HF-ESR data with results of transport measurements on these samples and discuss a possible contribution of magnetic rare-earths to the interplay between magnetism of the FeAs planes and superconductivity which evolves upon the fluorine doping.

  3. Disappearance of Ising nature in Ca3ZnMnO6 studied by high-field ESR.

    Science.gov (United States)

    Ruan, M Y; Ouyang, Z W; Guo, Y M; Cheng, J J; Sun, Y C; Xia, Z C; Rao, G H; Okubo, S; Ohta, H

    2014-06-11

    High-field electron spin resonance measurements of an antiferromagnet Ca3ZnMnO6 isostructure, with the Ising-chain multiferroic Ca3CoMnO6, have been carried out. Two distinct resonance modes were observed below TN = 25 K, which is well explained by conventional antiferromagnetic resonance theory with easy-plane anisotropy. The zero-field spin gap is derived to be about 166 GHz, originating from the easy-plane anisotropy and exchange interaction. Our result suggests that the Dzyaloshinsky-Moriya interaction, which may induce spin canting, is absent. Disappearance of Ising anisotropy in Ca3ZnMnO6 suggests that the Co(4+) ion, as well as the Co-Mn superexchange, plays an important role for the Ising nature in Ca3CoMnO6.

  4. Exotic spin phases in the one-dimensional spin-1/2 quantum magnet LiCuSbO{sub 4} as seen by high-field NMR and ESR spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Iakovleva, Margarita [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); Zavoisky Physical Technical Institute, Kazan (Russian Federation); Grafe, Hans-Joachim; Kataev, Vladislav; Alfonsov, Alexey; Sturza, Mihai I.; Wurmehl, Sabine [IFW Dresden, Dresden (Germany); Vavilova, Evgeniia [Zavoisky Physical Technical Institute, Kazan (Russian Federation); Nojiri, Hiroyuki [Institute of Materials Research, Sendai (Japan); Buechner, Bernd [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany)

    2016-07-01

    We will present our recent results of high-field NMR and sub-THz ESR studies of the quantum magnet LiCuSbO{sub 4} (LCSO) that presents an excellent model system of a one-dimensional spin-1/2 quantum magnet with frustrated exchange interactions. Such networks are predicted to exhibit a plethora of novel ground states beyond classical ferro- or antiferromagnetic phases. In LCSO the absence of a long-range magnetic order down to sub-Kelvin temperatures is suggestive of the realization of a quantum spin liquid state. Our NMR and ESR measurements in strong magnetic fields up to 16 Tesla reveal clear indications for the occurrence of an exotic field-induced hidden phase which we will discuss in terms of multipolar physics.

  5. Superconductivity and magnetism in the oxypnictides: high field ESR and {mu}SR studies of (La,Gd)FeAsO{sub 1-x}F{sub x} compounds

    Energy Technology Data Exchange (ETDEWEB)

    Muranyi, Ferenc [Physics Institute, University of Zuerich (Switzerland); IFW Dresden (Germany); Alfonsov, Alexey; Kataev, Vladislav; Koehler, Anke; Werner, Jochen; Behr, Guenter; Leps, Norman; Klingeler, Ruediger; Kondrat, Agnieszka; Hess, Christian; Buechner, Bernd [IFW Dresden (Germany); Khasanov, Rustem; Luetkens, Hubertus [Paul Scherrer Institut, Villigen PSI (Switzerland); Klaus, Hans-Henning [IFP, TU Dresden (Germany)

    2009-07-01

    The discovery of a new class of superconducting materials, ReFeAsO{sub 1-x}F{sub x}, stirred up the scientific community. Here we report the Gd{sup 3+} high field ESR study of differently doped (La,Gd)FeAsO{sub 1-x}F{sub x} compounds. In lightly Gd-doped LaFeAsO samples the SDW transition yields line-broadening at the transition temperature, the SDW transition is then suppressed upon F-doping. In the dense compound, GdFeAsO, with SDW transition around 140 K, the Gd-ESR was also studied. With 15% F-doping superconductivity appears at {proportional_to} 21 K. The SDW and SC transitions are clearly seen in ESR and in {mu} SR as well. Surprisingly the reminiscence of the SDW transition of the undoped material (GdFeAsO) was identified in the doped (15% F) compound at lower temperature ({proportional_to} 80 K). This indicates the importance of the the interplay between superconductivity and magnetism in oxypnictides.

  6. Breather excitation observed by high-field ESR in one-dimensional antiferromagnet BaCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2}O{sub 7} (x=0.65)

    Energy Technology Data Exchange (ETDEWEB)

    Ohta, H. E-mail: ohta@phys.sci.kobe-u.ac.jp; Okubo, S.; Fukuoka, D.; Inagaki, Y.; Kunimoto, T.; Kimata, M.; Koyama, K.; Motokawa, M.; Hiroi, Z

    2004-05-01

    We have performed the high-field ESR of the one-dimensional BaCu{sub 2}(Si{sub 1-x}Ge{sub x}){sub 2}O{sub 7} (x=0.65) antiferromagnet at 0.5 and 1.8 K in the wider frequency and magnetic field region (40-500 GHz, up to 30 T), and found the breather excitation predicted by the Oshikawa-Affleck (OA) theory. The observed field-induced gap for B||c (chain direction) shows the B{sup 2/3} dependence suggested by the OA theory, and the dependence is weak for the other directions which is consistent with the anisotropy of the Dzyaloshinsky-Moriya interaction. The results will be also discussed in connection with the breather excitation observed in Cu-benzoate.

  7. ESR-dosimetry in thermal and epithermal neutron fields for application in boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Tobias

    2016-01-22

    Dosimetry is essential for every form of radiotherapy. In Boron Neutron Capture Therapy (BNCT) mixed neutron and gamma fields have to be considered. Dose is deposited in different neutron interactions with elements in the penetrated tissue and by gamma particles, which are always part of a neutron field. The therapeutic dose in BNCT is deposited by densely ionising particles, originating from the fragmentation of the isotope boron-10 after capture of a thermal neutron. Despite being investigated for decades, dosimetry in neutron beams or fields for BNCT remains complex, due to the variety in type and energy of the secondary particles. Today usually ionisation chambers combined with metal foils are used. The applied techniques require extensive effort and are time consuming, while the resulting uncertainties remain high. Consequently, the investigation of more effective techniques or alternative dosimeters is an important field of research. In this work the possibilities of ESR-dosimeters in those fields have been investigated. Certain materials, such as alanine, generate stable radicals upon irradiation. Using Electron Spin Resonance (ESR) spectrometry the amount of radicals, which is proportional to absorbed dose, can be quantified. Different ESR detector materials have been irradiated in the thermal neutron field of the research reactor TRIGA research reactor in Mainz, Germany, with five setups, generating different secondary particle spectra. Further irradiations have been conducted in two epithermal neutron beams. The detector response, however, strongly depends on the dose depositing particle type and energy. It is hence necessary to accompany measurements by computational modelling and simulation. In this work the Monte Carlo code FLUKA was used to calculate absorbed doses and dose components. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using amorphous track models. For the simulation, detailed models of

  8. High-field magnetization and ESR in the triangular-lattice antiferromagnets Ba{sub 3}MnSb{sub 2}O{sub 9} and Ba{sub 3}TNb{sub 2}O{sub 9} (T=Ni, Co)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.C. [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Ouyang, Z.W., E-mail: zwouyang@mail.hust.edu.cn [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Ruan, M.Y.; Guo, Y.M.; Cheng, J.J. [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Tian, Z.M. [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Xia, Z.C. [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Rao, G.H. [School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China)

    2015-11-01

    We report high-field magnetization and electronic spin resonance (ESR) study on the triangular-lattice antiferromagnets Ba{sub 3}MnSb{sub 2}O{sub 9} and Ba{sub 3}TNb{sub 2}O{sub 9} (T=Ni, Co). The antiferromagnetic (AFM) ordering at T{sub N} is clearly characterized by the temperature dependent ESR spectra. In Ba{sub 3}CoNb{sub 2}O{sub 9}, the complicated ESR peaks are observed above T{sub N}. No obvious frequency–field relationship could be deduced. In Ba{sub 3}NiNb{sub 2}O{sub 9}, the AFM resonance with easy-plane anisotropy is observed, and accordingly, the magnetic exchange interactions are estimated. For Ba{sub 3}MnSb{sub 2}O{sub 9}, the remarkable finding is that single resonance peak at paramagnetic state splits into double peaks below the ordering temperature. Possible interpretations for these unusual AFM resonance modes have been proposed. - Highlights: • In Ba{sub 3}NiNb{sub 2}O{sub 9}, anisotropy is observed, exchange interactions are estimated. • In Ba{sub 3}MnSb{sub 2}O{sub 9}, single resonance peaksplits into double peaks below T{sub N}. • Complicated ESR spectra have been observed in Ba{sub 3}CoNb{sub 2}O{sub 9} above T{sub N}.

  9. ESR studies of high-energy phosphorus-ion implanted synthetic diamond crystals

    Energy Technology Data Exchange (ETDEWEB)

    Isoya, J. [University of Library and Information Science, Tsukuba, Ibaraki (Japan); Kanda, H.; Morita, Y.; Ohshima, T.

    1997-03-01

    Phosphorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using electron spin resonance (ESR) technique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. (author)

  10. ESR detection procedure of irradiated papaya containing high water content

    Science.gov (United States)

    Kikuchi, Masahiro; Shimoyama, Yuhei; Ukai, Mitsuko; Kobayashi, Yasuhiko

    2011-05-01

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the γ-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  11. ESR detection procedure of irradiated papaya containing high water content

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Masahiro, E-mail: kikuchi.masahiro@jaea.go.j [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Shimoyama, Yuhei [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Ukai, Mitsuko [Hokkaido University of Education, 1-2 Hachiman-cho, Hakodate, Hokkaido 040-8567 (Japan); Kobayashi, Yasuhiko [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-05-15

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the {gamma}-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  12. Diagnostic applications of an optoelectronic device for high temporal resolution of erythrocyte sedimentation (ESR-graphy)

    Science.gov (United States)

    Voeikov, Vladimir L.; Buravleva, Ekaterina; Bulargina, Yulia; Gurfinkel, Youri I.

    2001-10-01

    An automatic device for high-temporal resolution of the process of erythrocytes sedimentation in blood was designed. The position of the boundary between red blood and plasma is registered each 30 sec in several pipettes simultaneously with +/- 10 mkm precision. Data are processed by a PC and presented as velocity-time curves (ESR-grams) and the curves describing time evolution of the boundary position. ESR-grams demonstrate non-monotonous character of erythrocytes sedimentation in blood. Blood of particular donor being in a stable physiological state taken on different days is characterized by similar ESR-grams. Pathological deviations from a normal physiological state are reflected in the shortening of duration of each process stage and increasing of average sedimentation rate. Intravenous infusion of some medical preparations may lead either to improving (prolonging of macrokinetic stages, decreasing of sedimentation rate), or to worsening of studied parameters depending on an individual. The low extent of blood dilution with saline in vitro lead as a rule to decreasing of sedimentation rate and improving of microkinetic parameters of the process. Adding of highly diluted hydrogen peroxide to blood samples of patients resulted in the improving of sedimentation kinetics. ESR-graphy may widen opportunities of practical medicine in diagnostics, prognostics and drug therapy.

  13. Storing quantum information in spins and high-sensitivity ESR.

    Science.gov (United States)

    Morton, John J L; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per Hz, with prospects to scale down to even fewer spins. Copyright © 2017. Published by Elsevier Inc.

  14. Investigation of the isochronous mode of the experimental storage ring (ESR) and the collector ring (CR). Decay spectroscopy of highly charged stored {sup 140}Pr ions at the FRS-ESR facility

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, Sergey A.

    2008-11-15

    The combination of the present fragment separator FRS and the cooler-storage ring ESR at GSI provides conditions for accurate mass and unique half-life measurements of exotic nuclei. A major part of this doctoral work has been devoted to investigations of the isochronous ion-optical operating mode of the present ESR facility and the planned Collector Ring (CR) facility at FAIR. A detailed ion-optical study of the isochronous storage ring with the emphasis on the main parameters has been done. For example, a simple scaling law providing a quantitative estimate for the mass resolving power as a function of the transverse acceptance has been derived. The ion-optical matching of the FRS-ESR has been calculated and experimentally verified for both the standard and the isochronous operating modes of the ESR. In addition, the dispersion function of a stored ion beam has been measured for both ion-optical modes at the straight section. The improved setting for higher transmission in the standard mode has been used in an experiment on the half-life measurements of highly-charged ions. Orbital electron capture (EC) and/or {beta}{sup +}-decay rates of {sup 140}Pr ions with zero-, one- and two- bound electrons have been measured. A complementary future study of EC-decay in highly-charged {sup 64}Cu ions is discussed. Based on the present experience, the ion-optical matching between the future in-flight fragment separator Super-FRS and the CR has been calculated. The isochronous mode of the CR has been calculated. A dedicated Monte-Carlo code (ISOCHRON) has been developed in order to investigate the influence of the transverse acceptance, the closed orbit distortions, the fringe fields of the quadrupoles, the magnetic field imperfections of the magnets on the mass resolving power. The influence of chromaticity on the isochronicity has been investigated. The correction of the chromaticity and of second-order isochronicity has been performed employing sextupole magnets in the

  15. ESR and ligand field theory studies of Nd{sub 2}O{sub 3} doped borochoromate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, M.A., E-mail: moukhtar_hassan@yahoo.com [Physics Department, Faculty of Science, Azhar University, Cairo (Egypt); Farouk, M., E-mail: mf_egypt22375@yahoo.com [Physics Department, Faculty of Science, Azhar University, Cairo (Egypt); Abdullah, A.H. [Applied Science Department, College of Technological Studies (Kuwait); Kashef, I.; ElOkr, M.M. [Physics Department, Faculty of Science, Azhar University, Cairo (Egypt)

    2012-10-25

    Highlights: Black-Right-Pointing-Pointer The xCr{sub 2}O{sub 3}-(25-x)Li{sub 2}O-yNd{sub 2}O{sub 3}-(75-y)B{sub 2}O{sub 3} glassy system was fabricated by a quenching method. Black-Right-Pointing-Pointer ESR, IR and optical properties were studied and the ligand field theory was discussed. Black-Right-Pointing-Pointer The conversion of chromium ions from Cr{sup 3+} to Cr{sup 6+} structural units occur at {approx}x = 0.3 mol% of this study. Black-Right-Pointing-Pointer The addition of Nd{sub 2}O{sub 3} reduces the number of chromium ions Cr{sup 6+} ions. - Abstract: Glassy system of compositions xCr{sub 2}O{sub 3}-(25-x)Li{sub 2}O-yNd{sub 2}O{sub 3}-(75-y)B{sub 2}O{sub 3} where x = 0, 0.1, 0.2, 0.3, 0.5 at y = 1.0 mol% and x = 1.0, at y = 0 mol% has been prepared by conventional melt quenching technique. The electron spin resonance (ESR) of the prepared glassy system was investigated; the obtained ESR parameters indicate the presence of chromium ions predominantly in Cr{sup 3+} with small traces of Cr{sup 6+}. The former is suggested to occupy modifier positions at lower Cr{sub 2}O{sub 3} content (up to x = 0.3, y = 1 mol%). For higher Cr{sub 2}O{sub 3} content (x > 0.3, y = 1 mol%) the chromium ions participate in the network as a former. The optical results have been analyzed in the light of ligand field theory. The value of the crystal field strength (Dq) and the inter-electronic repulsion Racah parameter (B) has been calculated from the optical transitions energies for all chromium doped glassy. The (Dq/B) ratio is found to be around 2.06; which indicate that the Cr{sup 3+} ions are in the weak ligand field sites. The IR absorption and density has been measured, the obtained data reveal that, both N{sub 4} ratio and density are almost composition independent.

  16. Computational Modeling of Electroslag Remelting (ESR) Process Used for the Production of High-Performance Alloys

    Science.gov (United States)

    Kelkar, Kanchan M.; Patankar, Suhas V.; Srivatsa, Shesh K.; Minisandram, Ramesh S.; Evans, David G.; deBarbadillo, John J.; Smith, Richard H.; Helmink, Randolph C.; Mitchell, Alec; Sizek, Howard A.

    This paper presents a comprehensive computational model for the prediction of the transient Electroslag Remelting (ESR) process for cylindrical ingots based on axisymmetric two-dimensional analysis. The model analyzes the behavior of the slag and growing ingot during the entire ESR process involving a hot-slag start with an initial transient, near-steady melting, hot-topping and subsequent solidification of the slag and ingot after melting ends. The results of model application for an illustrative ESR process for Alloy 718 and its validation using results from an industrial trial are presented. They demonstrate the comprehensive capabilities of the model in predicting the behavior of the ingot and slag during the entire process and properties of the final ingot produced. Such analysis can benefit the optimization of existing process schedules and design of new processes for different alloys and different ingot sizes.

  17. CW ESR studies on endohedral fullerenes

    Science.gov (United States)

    Bartl, Anton; Dunsch, Lothar; Kirbach, Uwe

    1996-12-01

    Electron spin resonance (ESR) spectroscopy is used in this study in connection with the mass spectrometry one of the most promising method to characterize the state of endohedral fullerenes. The aim of this contribution is to study scandium, yttrium, lanthanum, cerium, praseodymium, samarium, europium, holmium, thulium and lutetium containing fullerenes in dependence on the production and handling conditions with respect to their electronic structure. For the most metallofullerenes both single filled and double filled fullerenes were measured. The mass spectrometric signals of single filled fullerenes are much larger than the signals of double and higher filled metallofullerenes. ESR spectroscopic properties were followed especially in solution of isolated metallofullerenes of high purity characterized by well resolved ESR spectra but also of the solid soot extract resulting in low resolved ESR spectra. In this way new information on the electronic states and the influence of oxygen on endohedral metallofullerene were obtained. The interaction of the lanthanofullerence with oxygen is studied in detail. Different stabilities in different solvents in the presence of oxygen were found for La at C82 molecules. For scandium, yttrium and lanthanum containing fullerenes ESR spectra with hyperfine structure splittings corresponding to the nuclear spin of the metal ion were found. Experiments with lanthanoides results in fullerenes, showing mass spectra with lines equivalent to the corresponding endohedral compounds with single and double filed cages, but no ESR spectra due to the interaction of an unpaired electron with the nuclear spin of the lanthanoide ion could be detected in the magnetic field range of 0 to 800 mT.

  18. Construction of imaging system for wide-field-range ESR spectra using localized microwave field and its case study of crystal orientation in suspension of copper sulfate pentahydrate (CuSO4 . 5H2O).

    Science.gov (United States)

    Tani, Atsushi; Ueno, Takehiro; Yamanaka, Chihiro; Katsura, Makoto; Ikeya, Motoji

    2005-02-01

    A scanning electron spin resonance (ESR) microscope using a localized microwave field was redesigned to measure ESR spectra from 0 to 400 mT using electromagnets. Divalent copper ion (Cu2+) in copper sulfate pentahydrate (CuSO4 . 5H2O) was imaged, after the powdered samples were cemented in silicone rubber under a magnetic field. The ratio of the two signal intensities at g=2.27 and 2.08 clearly indicates the orientation of the particles. This method can be used for mapping the local magnetic field and its direction.

  19. Construction of imaging system for wide-field-range ESR spectra using localized microwave field and its case study of crystal orientation in suspension of copper sulfate pentahydrate (CuSO{sub 4}.5H{sub 2}O)

    Energy Technology Data Exchange (ETDEWEB)

    Tani, Atsushi [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan)]. E-mail: atani@ess.sci.osaka-u.ac.jp; Ueno, Takehiro [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Yamanaka, Chihiro [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Katsura, Makoto [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan); Ikeya, Motoji [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama Toyonaka, Osaka 560-0043 (Japan)

    2005-02-01

    A scanning electron spin resonance (ESR) microscope using a localized microwave field was redesigned to measure ESR spectra from 0 to 400mT using electromagnets. Divalent copper ion (Cu{sup 2+}) in copper sulfate pentahydrate (CuSO{sub 4}.5H{sub 2}O) was imaged, after the powdered samples were cemented in silicone rubber under a magnetic field. The ratio of the two signal intensities at g=2.27 and 2.08 clearly indicates the orientation of the particles. This method can be used for mapping the local magnetic field and its direction.

  20. Observations of diverging field-aligned ion flow with the ESR

    Directory of Open Access Journals (Sweden)

    S. C. Buchert

    2004-03-01

    Full Text Available We report on observations of a diverging ion flow along the geomagnetic field that is often seen at the EISCAT Svalbard radar. The flow is upward above the peak of the electron density in the F-region and downward below the peak. We estimate that in such events mass transport along the field line is important for the ionization balance, and that the shape of the F-layer and its ion composition should be strongly influenced by it. Diverging flow typically occurs when there are signatures of direct entry of sheath plasma to the ionosphere in the form of intense soft particle precipitation, and we suggest that it is caused by the ionization and ionospheric electron heating associated with this precipitation. On average, 30% of all events with ion upflow also show significant ion downflow below. Key words.Ionosphere (polar ionosphere; ionization mechanism; plasma temperature and density

  1. Observations of diverging field-aligned ion flow with the ESR

    Directory of Open Access Journals (Sweden)

    S. C. Buchert

    2004-03-01

    Full Text Available We report on observations of a diverging ion flow along the geomagnetic field that is often seen at the EISCAT Svalbard radar. The flow is upward above the peak of the electron density in the F-region and downward below the peak. We estimate that in such events mass transport along the field line is important for the ionization balance, and that the shape of the F-layer and its ion composition should be strongly influenced by it. Diverging flow typically occurs when there are signatures of direct entry of sheath plasma to the ionosphere in the form of intense soft particle precipitation, and we suggest that it is caused by the ionization and ionospheric electron heating associated with this precipitation. On average, 30% of all events with ion upflow also show significant ion downflow below.

    Key words.Ionosphere (polar ionosphere; ionization mechanism; plasma temperature and density

  2. Optimization of Coplanar Waveguide Resonators for ESR Studies on Metals

    Science.gov (United States)

    Clauss, Conrad; Dressel, Martin; Scheffler, Marc

    2015-03-01

    We present simulations and analytic calculations of the electromagnetic microwave fields of coplanar waveguide (CPW) resonators in the vicinity of highly conducting metallic samples. The CPW structures are designed with the aim of investigating electron spin resonance (ESR) in metallic heavy-fermion systems, in particular YbRh2Si2, close to the quantum critical point. Utilizing CPW resonators for ESR experiments allows for studies at mK temperatures and a wide range of freely selectable frequencies. It is therefore of great interest to evaluate the performance of resonant CPW structures with nearby metallic samples. Here we study the microwave fields at the sample surface as a function of sample distance from the waveguide structure and analyze the implications of the sample on the performance of the resonator. The simulation results reveal an optimum sample distance for which the microwave magnetic fields at the sample are maximized and thus best suited for ESR studies.

  3. ESR dosimetry: achievements and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Baffa, O., E-mail: baffa@usp.br [Universidade de Sao Paulo, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR) and more recently as Electron Magnetic Resonance (Emr), is a spectroscopy technique able to detect unpaired electrons such as those created by the interaction ionizing radiation with matter. When the unpaired electrons created by ionizing radiation are stable over some reasonable time, ESR can be used to measure the radiation dose deposited in the material under study. In principle, any insulating material that satisfies this requisite can be used as a dosimeter. ESR has been used in retrospective dosimetry in case of radiological accidents using natural constituents of human body such as teeth, bones and nails as well as fortuitous materials as sugar, sweeteners and plastics. When using teeth the typical detected dose is 0.5 Gy for, for X-Band spectrometers (9 GHz) and even lower doses if higher frequency spectrometers are used. Clinical dosimetry is another area of potential use of this dosimetric modality. In this application the amino acid alanine has been proposed and being used. Alanine dosimeters are very easy to prepare and require no complicated treatments for use. Alanine/ESR dosimetry satisfies many of the required properties for clinical applications such as water equivalent composition, independence of response for the energy range used in therapy and high precision. Other organic materials such as ammonium tartrate are being investigated to increase the sensitivity of ESR for clinical applications. Finally, industrial applications can also benefit from this dosimetry. The challenges to expand applications, the number of users and research groups of ESR dosimetry will be discussed. (Author)

  4. Physics book: CRYRING@ESR

    Science.gov (United States)

    Lestinsky, M.; Andrianov, V.; Aurand, B.; Bagnoud, V.; Bernhardt, D.; Beyer, H.; Bishop, S.; Blaum, K.; Bleile, A.; Borovik, At.; Bosch, F.; Bostock, C. J.; Brandau, C.; Bräuning-Demian, A.; Bray, I.; Davinson, T.; Ebinger, B.; Echler, A.; Egelhof, P.; Ehresmann, A.; Engström, M.; Enss, C.; Ferreira, N.; Fischer, D.; Fleischmann, A.; Förster, E.; Fritzsche, S.; Geithner, R.; Geyer, S.; Glorius, J.; Göbel, K.; Gorda, O.; Goullon, J.; Grabitz, P.; Grisenti, R.; Gumberidze, A.; Hagmann, S.; Heil, M.; Heinz, A.; Herfurth, F.; Heß, R.; Hillenbrand, P.-M.; Hubele, R.; Indelicato, P.; Källberg, A.; Kester, O.; Kiselev, O.; Knie, A.; Kozhuharov, C.; Kraft-Bermuth, S.; Kühl, T.; Lane, G.; Litvinov, Yu. A.; Liesen, D.; Ma, X. W.; Märtin, R.; Moshammer, R.; Müller, A.; Namba, S.; Neumeyer, P.; Nilsson, T.; Nörtershäuser, W.; Paulus, G.; Petridis, N.; Reed, M.; Reifarth, R.; Reiß, P.; Rothhardt, J.; Sanchez, R.; Sanjari, M. S.; Schippers, S.; Schmidt, H. T.; Schneider, D.; Scholz, P.; Schuch, R.; Schulz, M.; Shabaev, V.; Simonsson, A.; Sjöholm, J.; Skeppstedt, Ö.; Sonnabend, K.; Spillmann, U.; Stiebing, K.; Steck, M.; Stöhlker, T.; Surzhykov, A.; Torilov, S.; Träbert, E.; Trassinelli, M.; Trotsenko, S.; Tu, X. L.; Uschmann, I.; Walker, P. M.; Weber, G.; Winters, D. F. A.; Woods, P. J.; Zhao, H. Y.; Zhang, Y. H.

    2016-09-01

    The exploration of the unique properties of stored and cooled beams of highly-charged ions as provided by heavy-ion storage rings has opened novel and fascinating research opportunities in the realm of atomic and nuclear physics research. Since the late 1980s, pioneering work has been performed at the CRYRING at Stockholm (Abrahamsson et al. 1993) and at the Test Storage Ring (TSR) at Heidelberg (Baumann et al. 1988). For the heaviest ions in the highest charge-states, a real quantum jump was achieved in the early 1990s by the commissioning of the Experimental Storage Ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt (Franzke 1987) where challenging experiments on the electron dynamics in the strong field regime as well as nuclear physics studies on exotic nuclei and at the borderline to atomic physics were performed. Meanwhile also at Lanzhou a heavy-ion storage ring has been taken in operation, exploiting the unique research opportunities in particular for medium-heavy ions and exotic nuclei (Xia et al. 2002).

  5. Experimental Progress in Fast Cooling in the ESR

    CERN Document Server

    Steck, Markus; Beller, Peter; Franzke, Bernhard; Nolden, Fritz

    2005-01-01

    The ESR storage ring at GSI is operated with highly charged heavy ions. Due to the high electric charge the ions interact much stronger with electromagnetic fields. Therefore both cooling methods which are applied to stored ions in the ESR, stochastic cooling and electron cooling, are more powerful than for singly charged particles. The experimental results exhibit cooling times for stochastic cooling of a few seconds. For cold ion beams, electron cooling provides cooling times which are one to two orders of magnitude smaller. The beams are cooled to beam parameters which are limited by intrabeam scattering. At small ion numbers, however, intrabeam scattering is suppressed by electron cooling, clear evidence was found that the ion beam forms a one-dimensional ordered structure, a linear chain of ions. The strengths of stochastic cooling and electron cooling are complementary and can be combined favorably. Stochastic cooling is employed for pre-cooling of hot secondary beams followed by electron cooling to pro...

  6. Validation of ESR analyzer using Westergren ESR method.

    Science.gov (United States)

    Sikka, Meera; Tandon, Rajesh; Rusia, Usha; Madan, Nishi

    2007-07-01

    Erythrocyte sedimentation rate (ESR) is one of the most frequently ordered laboratory test. ESR analyzers were developed to provide a quick and efficient measure of ESR. We compared the results of ESR obtained by an ESR analyzer with those by the Westergren method in a group of 75 patients Linear regression analysis showed a good correlation between the two results (r = 0.818, p < 0.01). The intra class correlation was 0.82. The analyzer method had the advantages of safety, decreased technician time and improved patient care by providing quick results.

  7. Genetic polymorphisms in ESR1 and ESR2 genes, and risk of hypospadias in a multiethnic study population.

    Science.gov (United States)

    Choudhry, Shweta; Baskin, Laurence S; Lammer, Edward J; Witte, John S; Dasgupta, Sudeshna; Ma, Chen; Surampalli, Abhilasha; Shen, Joel; Shaw, Gary M; Carmichael, Suzan L

    2015-05-01

    Estrogenic endocrine disruptors acting via estrogen receptors α (ESR1) and β (ESR2) have been implicated in the etiology of hypospadias, a common congenital malformation of the male external genitalia. We determined the association of single nucleotide polymorphisms in ESR1 and ESR2 genes with hypospadias in a racially/ethnically diverse study population of California births. We investigated the relationship between hypospadias and 108 ESR1 and 36 ESR2 single nucleotide polymorphisms in 647 cases and 877 population based nonmalformed controls among infants born in selected California counties from 1990 to 2003. Subgroup analyses were performed by race/ethnicity (nonHispanic white and Hispanic subjects) and by hypospadias severity (mild to moderate and severe). Odds ratios for 33 of the 108 ESR1 single nucleotide polymorphisms had p values less than 0.05 (p = 0.05 to 0.007) for risk of hypospadias. However, none of the 36 ESR2 single nucleotide polymorphisms was significantly associated. In stratified analyses the association results were consistent by disease severity but different sets of single nucleotide polymorphisms were significantly associated with hypospadias in nonHispanic white and Hispanic subjects. Due to high linkage disequilibrium across the single nucleotide polymorphisms, haplotype analyses were conducted and identified 6 haplotype blocks in ESR1 gene that had haplotypes significantly associated with an increased risk of hypospadias (OR 1.3 to 1.8, p = 0.04 to 0.00001). Similar to single nucleotide polymorphism analysis, different ESR1 haplotypes were associated with risk of hypospadias in nonHispanic white and Hispanic subjects. No significant haplotype association was observed for ESR2. The data provide evidence that ESR1 single nucleotide polymorphisms and haplotypes influence the risk of hypospadias in white and Hispanic subjects, and warrant further examination in other study populations. Copyright © 2015 American Urological Association

  8. ESR identification of irradiated foodstuffs: LARQUA research

    Energy Technology Data Exchange (ETDEWEB)

    Raffi, J. [Laboratoire de Recherche sur la Qualite des Aliments, Marseille (France)

    1996-12-31

    As electron spin resonance (ESR) spectroscopy is the leading method for identification of irradiated foodstuffs, meat and fish bones, fruit and relative products (of vegetable origin), sea-food etc. were studied. In order to prepare a large co-trial on ESR identification of irradiation of irradiated foodstuffs, experiments were carried out at LARQUA, especially on fruits and vegetables. The radicals induced in the fruit pulp are not stable because the water content of fruit is generally high, but ESR can be used with dried fruit or dry components such as achenes, pips or stones. Different responses are observed, depending on the fruit. In ``sugatype`` fruits (papaya, dried grapes), an ESR multicomponent signal is radio-induced, but the non-irradiated fruit presents no ESR signal or a single-line, while in ``cellulose type`` fruits (pistachio nut, berries), a triplet is induced. But a six line signal due to Mn{sup 2+} and a central single line may also be present both in irradiated and non-irradiated samples. In the case of aromatic herbs, the proposed official CEN protocol for irradiated food containing cellulose was used. (author).

  9. Status and outlook of the CRYRING@ESR project

    Science.gov (United States)

    Geithner, W.; Andelkovic, Z.; Beck, D.; Bräuning, H.; Bräuning-Demian, A.; Danared, H.; Dimopoulou, C.; Engström, M.; Fedotova, S.; Gorda, O.; Herfurth, F.; Hess, R.; Källberg, A.; Kleffner, C.; Kotovskiy, N.; Kraus, I.; Lestinsky, M.; Litvinov, S.; Nolden, F.; Reiter, A.; Sieber, T.; Steck, M.; Vorobyev, G.

    2017-11-01

    Once operational, CRYRING@ESR will store and decelerate ions delivered by the experimental storage ring ESR at energies well below those of ESR. In addition to that, CRYRING@ESR has an electron cooler operating with an ultracold electron beam, allowing to provide cooled ion beams for precision experiments. These ions will be delivered to a broad range of experiments presently in preparation; either in-ring or extracted to a dedicated beamline for experiments. An overview and status report of the installation and commissioning of the CRYRING-@ESR storage ring for highly charged ions at the GSI Helmholtzzentrum für Schwerionenforschung is presented. The installation of this storage ring started in 2014 and was completing end of 2016, when this publication was written.

  10. Status and outlook of the CRYRING@ESR project

    Energy Technology Data Exchange (ETDEWEB)

    Geithner, W., E-mail: w.geithner@gsi.de; Andelkovic, Z.; Beck, D.; Bräuning, H.; Bräuning-Demian, A. [GSI Helmholtzzentrum für Schwerionenforschung (Germany); Danared, H. [European Spallation Source ESS (Sweden); Dimopoulou, C. [GSI Helmholtzzentrum für Schwerionenforschung (Germany); Engström, M. [Fysikum, Stockholm University (Sweden); Fedotova, S.; Gorda, O.; Herfurth, F.; Hess, R. [GSI Helmholtzzentrum für Schwerionenforschung (Germany); Källberg, A. [Fysikum, Stockholm University (Sweden); Kleffner, C.; Kotovskiy, N.; Kraus, I.; Lestinsky, M.; Litvinov, S.; Nolden, F.; Reiter, A. [GSI Helmholtzzentrum für Schwerionenforschung (Germany); and others

    2017-11-15

    Once operational, CRYRING@ESR will store and decelerate ions delivered by the experimental storage ring ESR at energies well below those of ESR. In addition to that, CRYRING@ESR has an electron cooler operating with an ultracold electron beam, allowing to provide cooled ion beams for precision experiments. These ions will be delivered to a broad range of experiments presently in preparation; either in-ring or extracted to a dedicated beamline for experiments. An overview and status report of the installation and commissioning of the CRYRING-@ESR storage ring for highly charged ions at the GSI Helmholtzzentrum für Schwerionenforschung is presented. The installation of this storage ring started in 2014 and was completing end of 2016, when this publication was written.

  11. High temperature tensile and creep properties of a cast AIM and ESR intermetallic alloy based on Fe{sub 3}Al

    Energy Technology Data Exchange (ETDEWEB)

    Baligidad, R.G. [Defence Metallurgical Research Lab., Hyderabad (India); Prakash, U. [Defence Metallurgical Research Lab., Hyderabad (India); Radhakrishna, A. [Defence Metallurgical Research Lab., Hyderabad (India)

    1997-07-15

    A high carbon intermetallic Fe-16 wt.% A1-1.1 wt.% C alloy based on Fe{sub 3}Al was melted under a flux cover by air induction melting (AIM). The AIM ingots exhibited excellent elevated temperature tensile properties in the temperature range (600-800 C) studied, in contrast to poor properties expected in ingots melted without a flux cover. Subsequent processing of the AIM ingots through electroslag remelting (ESR) resulted in improvement in ductility. However, the AIM ingots exhibited better creep properties because of their coarser gain structure. The presence of large (1.1 wt.%) amount of carbon in the alloy resulted in significant improvement in elevated temperature tensile as well as creep properties over those reported for Fe{sub 3}Al based intermetallic alloys with lower carbon contents. These improvements in mechanical properties are attributed to the extensive precipitation of Fe{sub 3}AlC phase and to the formation of a duplex Fe{sub 3}Al-Fe{sub 3}AlC structure at such high levels of carbon. It is suggested that carbon may be an important alloying addition to Fe{sub 3}Al-based intermetallic alloys. (orig.)

  12. ESR (Erythrocyte Sedimentation Rate) Test

    Science.gov (United States)

    ... products and services. Advertising & Sponsorship: Policy | Opportunities Erythrocyte Sedimentation Rate (ESR) Share this page: Was this page helpful? Also known as: Sed Rate; Sedimentation Rate; Westergren Sedimentation Rate Formal name: Erythrocyte Sedimentation ...

  13. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  14. ESR and magnetization studies of Fe2O3-Bi2O3-ZnO-PbO glass system

    Science.gov (United States)

    Pelluri, Sandhya Rani; Singh, Rajender

    2016-11-01

    The electron spin resonance (ESR) and magnetization measurements were undertaken to understand the magnetic phenomena in the glass system with composition (Fe2O3)x (70 Bi2O3 20 ZnO 10 PbO)1-x (x=15, 20 and 25 mol%). At high temperature the ESR spectra consists of narrow resonance at g~2. As the temperature decreases a second resonance peak emerges and with further decrease in temperature, the second resonance peak progressively shifts towards lower field value. The ESR data shows the formation of superparamagnetic clusters. The temperature dependent magnetization data exhibits a spin glass-like transition and a superparamagnetic blocking at a temperature which increases with increase in x value.

  15. Effect of estrogen receptor-alpha (ESR1 gene polymorphism on high density lipoprotein levels in response to hormone replacement therapy

    Directory of Open Access Journals (Sweden)

    N.C. Nogueira-de-Souza

    2009-12-01

    Full Text Available Studies have shown that estrogen replacement therapy and estrogen plus progestin replacement therapy alter serum levels of total, LDL and HDL cholesterol levels. However, HDL cholesterol levels in women vary considerably in response to hormone replacement therapy (HRT. A significant portion of the variability of these levels has been attributed to genetic factors. Therefore, we investigated the influence of estrogen receptor-alpha (ESR1 gene polymorphisms on HDL levels in response to postmenopausal HRT. We performed a prospective cohort study on 54 postmenopausal women who had not used HRT before the study and had no significant general medical illness. HRT consisted of conjugated equine estrogen and medroxyprogesterone acetate continuously for 1 year. The lipoprotein levels were measured from blood samples taken before the start of therapy and after 1 year of HRT. ESR1 polymorphism (MspI C>T, HaeIII C>T, PvuII C>T, and XbaI A>G frequencies were assayed by restriction fragment length polymorphism. A general linear model was used to describe the relationships between HDL levels and genotypes after adjusting for age. A significant increase in HDL levels was observed after HRT (P = 0.029. Women with the ESR1 PvuII TT genotype showed a statistically significant increase in HDL levels after HRT (P = 0.032. No association was found between other ESR1 polymorphisms and HDL levels. According to our results, the ESR1 PvuII TT genotype was associated with increased levels of HDL after 1 year of HRT.

  16. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2003-02-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene.

  17. ESR identification of gamma-irradiated albendazole

    Science.gov (United States)

    Çolak, Seyda

    2010-01-01

    The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

  18. Yleiskustannusten kohdistaminen ESR-hankkeelle

    OpenAIRE

    Maja, Anette

    2006-01-01

    Opinnäytetyön tarkoituksena oli luoda excel-pohjaiset laskentamallit ESR-hankkeiden yleiskustannusten kohdistamiseen ja selventää yleiskustannusten kohdistamismenetelmiä. Suurin osa hankkeen toiminnasta aiheutuneista kustannuksista on ESR-ohjeiden mukaan hyväksyttäviä kustannuksia. Kaikkia kustannuksia, eritoten yleiskustannuksia, ei kuitenkaan aina siirretä hankkeille, sillä siirron vaatimaa työmäärää pidetään suurena hyötyyn nähden. Kokonaiskustannuksiin verrattuna yleiskustannusten määrä o...

  19. CH{sub 3} and CD{sub 3} radicals isolated in argon: high resolution ESR spectra and analysis by three-dimensional quantum rotor model. A case study of low temperature quantum effects on radicals

    Energy Technology Data Exchange (ETDEWEB)

    Shiotani, Masaru; Yamada, Tomoya; Komaguchi, Kenji [Hiroshima Univ., Higashi-Hiroshima (Japan). Faculty of Engineering; Benetis, N.P.; Lund, A.; Soernes, A.R.

    1998-10-01

    The present study deals with high resolution isotropic ESR spectra of the CH{sub 3} and CD{sub 3} radicals isolated in solid argon matrix at low temperature from 4 K to 40 K. Argon gases mixed with methane (Ar/methane {approx_equal} 500 mole ratio) were condensed at the end of Suprasile ESR tube at 4.2 K. Methyl radicals were generated by X-ray irradiation at 4 K and subjected to an ESR study. The 6.0 K ESR spectrum of the CH{sub 4}/Ar system is shown in Fig. 1. For CH{sub 3} radical the {sup 1}H hyperfine (hf) quartet was observed with an equal intensity (A-lines). The E-lines were absent at 4 K, but became visible at m{sub F} = {+-}1/2 positions above 12 K increased with temperature. The CD{sub 3} gave a peculiar spectrum at 4 K with an abnormally strong central singlet superimposed on a much weaker seven line spectrum of a freely rotating CD{sub 3}. The temperature dependent spectra showed clear quantum effects due to three-dimensional spin-rotation couplings. The spectra were analyzed with the following assumptions: (a) a planar D{sub 3} geometry, (b) a free and three-dimensional quantum rotation and (c) a thermally isolated radical. Application of the Pauli principle in combination to the D{sub 3} point group resulted in interesting selections for ESR-transitions for both the CH{sub 3} and CD{sub 3} spectra. That is, the {sup 1}H hf quartet of CH{sub 3} radical (A-lines) was attributed to the rotational ground state, J=0, with totally symmetric A{sub 1} nuclear states. The central strong singlet of CD{sub 3} was attributed to one spin-rotation state with A{sub 2} antisymmetric nuclear states at the lowest rotational level of J=0. (author)

  20. ESR and EISCAT observations of the response of the cusp and cleft to IMF orientation changes

    Directory of Open Access Journals (Sweden)

    I. W. McCrea

    2000-09-01

    Full Text Available We report observations of the cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter VHF radar at Tromsø and the EISCAT Svalbard radar (ESR. We compare them with observations of the dayside auroral luminosity, as seen by meridian scanning photometers at Ny Ålesund and of HF radar backscatter, as observed by the CUTLASS radar. We study the response to an interval of about one hour when the interplanetary magnetic field (IMF, monitored by the WIND and ACE spacecraft, was southward. The cusp/cleft aurora is shown to correspond to a spatially extended region of elevated electron temperatures in the VHF radar data. Initial conditions were characterised by a northward-directed IMF and cusp/cleft aurora poleward of the ESR. A strong southward turning then occurred, causing an equatorward motion of the cusp/cleft aurora. Within the equatorward expanding, southward-IMF cusp/cleft, the ESR observed structured and elevated plasma densities and ion and electron temperatures. Cleft ion fountain upflows were seen in association with elevated ion temperatures and rapid eastward convection, consistent with the magnetic curvature force on newly opened field lines for the observed negative IMF By. Subsequently, the ESR beam remained immediately poleward of the main cusp/cleft and a sequence of poleward-moving auroral transients passed over it. After the last of these, the ESR was in the polar cap and the radar observations were characterised by extremely low ionospheric densities and downward field-aligned flows. The IMF then turned northward again and the auroral oval contracted such that the ESR moved back into the cusp/cleft region. For the poleward-retreating, northward-IMF cusp/cleft, the convection flows were slower, upflows were weaker and the electron density and temperature enhancements were less structured. Following the northward turning, the bands of high electron temperature and cusp/cleft aurora bifurcated

  1. ESR and EISCAT observations of the response of the cusp and cleft to IMF orientation changes

    Directory of Open Access Journals (Sweden)

    I. W. McCrea

    Full Text Available We report observations of the cusp/cleft ionosphere made on December 16th 1998 by the EISCAT (European incoherent scatter VHF radar at Tromsø and the EISCAT Svalbard radar (ESR. We compare them with observations of the dayside auroral luminosity, as seen by meridian scanning photometers at Ny Ålesund and of HF radar backscatter, as observed by the CUTLASS radar. We study the response to an interval of about one hour when the interplanetary magnetic field (IMF, monitored by the WIND and ACE spacecraft, was southward. The cusp/cleft aurora is shown to correspond to a spatially extended region of elevated electron temperatures in the VHF radar data. Initial conditions were characterised by a northward-directed IMF and cusp/cleft aurora poleward of the ESR. A strong southward turning then occurred, causing an equatorward motion of the cusp/cleft aurora. Within the equatorward expanding, southward-IMF cusp/cleft, the ESR observed structured and elevated plasma densities and ion and electron temperatures. Cleft ion fountain upflows were seen in association with elevated ion temperatures and rapid eastward convection, consistent with the magnetic curvature force on newly opened field lines for the observed negative IMF By. Subsequently, the ESR beam remained immediately poleward of the main cusp/cleft and a sequence of poleward-moving auroral transients passed over it. After the last of these, the ESR was in the polar cap and the radar observations were characterised by extremely low ionospheric densities and downward field-aligned flows. The IMF then turned northward again and the auroral oval contracted such that the ESR moved back into the cusp/cleft region. For the poleward-retreating, northward-IMF cusp/cleft, the convection flows were slower, upflows were weaker and the electron density and temperature enhancements were less structured. Following the northward turning, the bands of high electron temperature and cusp

  2. ESR powder line shape calculations

    Energy Technology Data Exchange (ETDEWEB)

    Vitko, J. Jr.; Huddleston, R.E.

    1976-05-01

    A program has been developed for computing the ESR spectrum of a collection of randomly oriented spins subject only to an electronic Zeeman interaction and having a Lorentzian single crystal line shape. Other single crystal line shapes, including numerical solutions of the Bloch equations, can be accommodated with minor modifications. The program differs in several features from those existing elsewhere, thus enabling one to study saturation effects, over-modulation effects, both absorptive and dispersive signals, and second and higher order derivative signals.

  3. ESR dosimetry using eggshells and tooth enamel for accidental dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Toshihide; Yamanaka, Chihiro; Ikeya, Motoji [Department of Earth and Space Science, Faculty of Science, Osaka Univ., Toyonaka, Osaka (Japan)

    1997-07-01

    The CO{sub 2}{sup -} signal of eggshells showed a good dose linearity and was appropriate in the wide dose range from 1 to 10 kGy, while ESR signal of CO{sub 2}{sup -} in sea and fresh water shells were saturated at a dose od below 10 kGy. The minimum detectable dose and G-value of CO{sub 2}{sup -} in eggshells were estimated 0.3 Gy and 0.28, respectively. The lifetime of CO{sub 2}{sup -} in eggshells could not be determined exactly because of overlapping organic signals, however it is still sufficiently long for practical use as ESR dosimeter materials. Various bird`s or reptile`s eggshells would be available as natural retrospective ESR dosimeter materials after nuclear accidents. Eggshells will be useful for the food irradiation dosimetry in the dose range of about a few kGy. Tooth enamel is one of the most useful dosimeter materials in public at a accident because of its high sensitivity. ESR dosimetry will replace TLD in near future if the cost of an ESR reader is further reduced . (author)

  4. Magnetic anisotropy of the spin-antiferromagnet GdNi{sub 2}B{sub 2}C probed by high-frequency ESR

    Energy Technology Data Exchange (ETDEWEB)

    Kataev, V; Schaufuss, U; Muranyi, F; Alfonsov, A; Buechner, B [IFW Dresden, PO Box 270116, D-01171 Dresden (Germany); Doerr, M [Institut fuer Festkoerperphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Rotter, M, E-mail: v.kataev@ifw-dresden.d [Oxford University, Physics Department, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)

    2009-03-01

    A Gd{sup 3+} electron spin resonance study in a frequency range 10 - 350 GHz on a single crystal of the spin-only antiferromagnet GdNi{sub 2}B{sub 2}C is reported. The Korringa relaxation broadening of the Gd-ESR signal is surprisingly anisotropic implying anisotropic interactions between the localized Gd{sup 3+} spins and the conduction electrons. In the antiferromagnetic state at T

  5. ESR and iron status in pregnancy.

    Science.gov (United States)

    Madan, N; Kapoor, S; Rusia, U; Sharma, S; Nayyar, V L; Sundaram, K R; Sood, S K

    1997-10-01

    ESR (Westergen) correlated significantly with the iron status (as measured by Hb concentration, haematocrit, red cell count, MCH, P/H ratio, serum iron, TIBC and percent saturation of transferrin) in a group of pregnant women (PW) at term. Serum ferritin correlated negatively with the ESR but the correlation was not statistically significant. Serum ferritin levels of or = 50 mm 1st hour and 5 (19.2%) PW with ESR or = 50 mm 1st hour in 50% and 50 micrograms/L had ESR > or = 50 mm 1st hour, suggesting the possible effect of chronic infection in raising ferritin levels in these PW.

  6. Degradation and ESR Failures in MnO2 Chip Tantalum Capacitors

    Science.gov (United States)

    Teverovsky, Alexander A.

    2017-01-01

    Equivalent series resistance (ESR) of chip tantalum capacitors determines the rate of energy delivery and power dissipation thus affecting temperature and reliability of the parts. Employment of advanced capacitors with reduced ESR decreases power losses and improves efficiency in power systems. Stability of ESR is essential for correct operations of power units and might cause malfunctioning and failures when ESR becomes too high or too low. Several cases with ESR values in CWR29 capacitors exceeding the specified limit that were observed recently raised concerns regarding environmental factors affecting ESR and the adequacy of the existing screening and qualification testing. In this work, results of stress testing of various types of military and commercial capacitors obtained over years by GSFC test lab and NEPP projects that involved ESR measurements are described. Environmental stress tests include testing in humidity and vacuum chambers, temperature cycling, long-term storage at high temperatures, and various soldering simulation tests. Note that in many cases parts failed due to excessive leakage currents or reduced breakdown voltages. However, only ESR-related degradation and failures are discussed. Mechanisms of moisture effect are discussed and recommendations to improve screening and qualification system are suggested.

  7. Current topics in ESR dating

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Anne R., E-mail: Anne.R.Skinner@williams.edu [Williams College, Williamstown, MA (United States)

    2011-09-15

    After over 25 years, the use of electron spin resonance (ESR) is well-established in dating sites of geological, paleontological and archaeological interest. Like any scientific technique, there have been changes in understanding and in methodology. Improvements have not, however, changed the observation that external dose calculations are still a significant source of uncertainty in ages. Examples from Europe, Africa and the Americans illustrate this point. For Pradayrol Cave (France), the occupation age, 330 ka, is unchallenged, making this the oldest known Neanderthal site in France. For Roc de Marsal, also in France, on the other hand, discrepancies between TL and sedimentary dose rates imply substantial differences in interpretation. In the Western Egyptian Desert, where artifacts and datable material are not well-correlated, the dating results show consistency with expectations based on global climate change, even in deflated sites. Climate change is also the question in geological studies in the Bahamas where, despite concerns about cosmic dose history, ESR dates confirm other evidence for sea level changes. We show that an uncertain age is not the same as an impossible one.

  8. Computer enhancement of ESR spectra of magnetite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Dobosz, B.; Krzyminiewski, R. [Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Koralewski, M. [Optics Laboratory, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Hałupka-Bryl, M. [Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); The PhD Program in Nanoscience and Nanotechnology, The Nanobiomedical Centre, Umultowska 85, 61-614 Poznan (Poland)

    2016-06-01

    We present ESR measurements of non-interacting magnetic nanoparticle systems. Temperature and orientational dependence of ESR spectra were measured for Fe{sub 3}O{sub 4} nanoparticle coated by dextran or oleic acid, frozen in different magnetic field. Several parameters describing magnetic properties such as g-factor, line width, the anisotropy constant were calculated and discussed. The ESR spectra of investigated nanoparticles were also subjected to Computer Resolution Enhancement Method (CREM). This procedure allows to separate a narrow line on the background of the broad line, which presence in this type of materials was recognized in the recent literature and have been further discussed in the paper. CREM is a valuable tool for monitoring of changes on the surface of magnetic core of nanoparticles. - Highlights: • CREM – a new tool for monitoring of changes on the surface of magnetic core of nanoparticles. • CREM allows to separate a narrow line on the background of the broad line. • Temperature and orientational dependence of ESR spectra of Fe{sub 3}O{sub 4} nanoparticles were measured. • Parameters describing magnetic properties were calculated and discussed.

  9. Erythrocyte Sedimentation Rate (ESR): MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/erythrocytesedimentationrateesr.html Erythrocyte Sedimentation Rate (ESR) To use the sharing features ... this page, please enable JavaScript. What is an Erythrocyte Sedimentation Rate (ESR)? An erythrocyte sedimentation rate (ESR) ...

  10. ESR1 amplification in breast cancer by optimized RNase FISH: frequent but low-level and heterogeneous.

    Directory of Open Access Journals (Sweden)

    Cathy B Moelans

    Full Text Available Prevalence of ESR1 amplification in breast cancer is highly disputed and discrepancies have been related to different technical protocols and different scoring approaches. In addition, pre-mRNA artifacts have been proposed to influence outcome of ESR1 FISH analysis. We analyzed ESR1 gene copy number status combining an improved RNase FISH protocol with multiplex ligation-dependent probe amplification (MLPA after laser microdissection. FISH showed a high prevalence of ESR1 gains and amplifications despite RNase treatment but MLPA did not confirm ESR1 copy number increases detected by FISH in more than half of cases. We suggest that the combination of the ESR1-specific intra-tumor heterogeneity and low-level copy number increase accounts for these discrepancies.

  11. High Magnetic Fields in Chemistry

    Science.gov (United States)

    Steiner, U. E.; Gilch, P.

    Recent applications of large ( 1 T - 30 T) magnetic fields in modern chemical research are reviewed. Magnetic field effects of chemical relevance appear on the levels of quantum mechanics, thermodynamics, and oscopic forces. Quantum mechanical magnetic field effects are governed by the Zeeman interaction and are borne out as static and dynamic effects in spectroscopy and in chemical kinetics. Magnetic circular dichroism (MCD) spectroscopy and magnetic fluorescence quenching in the gas phase serve to illustrate the former, while radical pair spin chemistry is representative of the latter. The principles of the radical pair mechanism are outlined and high-field applications are illustrated in some detail for photo-induced electron transfer reactions of some transition metal complexes. Thermodynamic effects concern the magnetization of chemical samples, which is the focus of magnetochemistry or — more modern — molecular magnetism, and the equilibrium of chemical reactions. Representative examples of both aspects are described. Finally, the exploitation of orientational forces caused by the magnetic anisotropy of larger particles (from omolecules to micro-crystals) is exemplified. Crystal growth in a magnetic field may hold a potential for achieving better control of the quality of protein crystals for structural analysis.

  12. High Field Atherosclerotic Plaque MRI

    OpenAIRE

    Yuan, Chun; Wang, Jinnan; Balu, Niranjan

    2012-01-01

    Manifestations of atherosclerotic plaque in different arterial beds range from perfusion deficits to overt ischemia such as stroke and myocardial infarction. Atherosclerotic plaque composition is known to be associated with its propensity to rupture and cause vascular events. MRI of atherosclerotic plaque using clinical 1.5T scanners can detect plaque composition. Plaque MRI at higher field strengths offers both opportunities and challenges to improving the high spatial-resolution and contras...

  13. [Organ specific ESR features in mouse main organs and ESR application to the model of pancreatic disorders].

    Science.gov (United States)

    Nonaka, A; Manabe, T; Tamura, K; Asano, N; Imanishi, K; Yamaki, K; Tobe, T

    1990-02-01

    Nine main organs in the mouse were studied by ESR spectroscopy at 77K. Manganese ions were readily detected in the pancreas, small intestine, stomach and kidney. In particular, the pancreas gave strong ESR signals for the transition metal, suggesting that Mn(II) plays an important role in pancreatic function. All organs reveal different ESR spectra indicating organ specificity. C-centered radical, R-OO radical and C0Q10 or ascorbate radical are stable in the tissue. In the brain, heart and pancreas, N-centered radical heme-NO adduct was detected at 6 and 24 h after excision since common process is involved in tissue degeneration and ESR is sensitive to proteolysis and necrosis of tissues. In endotoxemia and/or CDE-diet-induced pancreatic lesions, R-OO radical and Mn(II) ion were detected in the signal at 77K. By the spin-trapping method (DMPO) at 25 degrees C, DMPO-OH adduct and 3-Line and 6-Line were detected in CDE diet-induced acute pancreatitis. These results suggest that damaged pancreatic tissues are in a highly oxidative environment that probably contains oxygen radicals, and that free radicals are considered to play an important role in the development of pancreatic lesions.

  14. ESR dating of the fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2004-01-15

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs, grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Ulzin nuclear reactor. ESR signals of quartz grains separated from fault rocks collected from the E-W trend fault are saturated. This indicates that the last movement of these faults had occurred before the quaternary period. ESR dates from the NW trend faults range from 300ka to 700ka. On the other hand, ESR date of the NS trend fault is about 50ka. Results of this research suggest that long-term cyclic fault activity near the Ulzin nuclear reactor continued into the pleistocene.

  15. Mass and lifetime measurements at the storage ring ESR

    CERN Document Server

    Attallah, F; Litvinov, Y A; Radon, T; Stadlmann, J; Beckert, Karl; Bosch, F; Falch, M; Franzke, B; Geissel, H; Kerscher, T; Klepper, O; Kluge, H J; Kozhuharov, C; Löbner, K E G; Münzenberg, G; Nolden, F; Novikov, Y N; Patyk, Z; Quint, W; Schatz, H; Scheidenberger, C; Schlitt, B; Steck, Markus; Sümmerer, K; Weick, H; Wollnik, H

    2002-01-01

    We present results from two methods of direct mass measurements of relativistic exotic nuclei stored in the storage ring ESR. Schottky Mass Spectrometry (SMS) with electron-cooled ions is well suited for long-lived nuclei (T sub 1 sub / sub 2>=10 s), and the Isochronous mass measurements (IMS) for hot fragments (T sub 1 sub / sub 2>=1 mu s). In addition, SMS provides information on nuclear lifetime for bare and highly ionized atoms.

  16. Analysis of ESR1 mutation in circulating tumor DNA demonstrates evolution during therapy for metastatic breast cancer.

    Science.gov (United States)

    Schiavon, Gaia; Hrebien, Sarah; Garcia-Murillas, Isaac; Cutts, Rosalind J; Pearson, Alex; Tarazona, Noelia; Fenwick, Kerry; Kozarewa, Iwanka; Lopez-Knowles, Elena; Ribas, Ricardo; Nerurkar, Ashutosh; Osin, Peter; Chandarlapaty, Sarat; Martin, Lesley-Ann; Dowsett, Mitch; Smith, Ian E; Turner, Nicholas C

    2015-11-11

    Acquired ESR1 mutations are a major mechanism of resistance to aromatase inhibitors (AIs). We developed ultra high-sensitivity multiplex digital polymerase chain reaction assays for ESR1 mutations in circulating tumor DNA (ctDNA) and investigated the clinical relevance and origin of ESR1 mutations in 171 women with advanced breast cancer. ESR1 mutation status in ctDNA showed high concordance with contemporaneous tumor biopsies and was accurately assessed in samples shipped at room temperature in preservative tubes. ESR1 mutations were found exclusively in estrogen receptor-positive breast cancer patients previously exposed to AI. Patients with ESR1 mutations had a substantially shorter progression-free survival on subsequent AI-based therapy [hazard ratio, 3.1; 95% confidence interval (CI), 1.9 to 23.1; P = 0.0041]. ESR1 mutation prevalence differed markedly between patients who were first exposed to AI during the adjuvant and metastatic settings [5.8% (3 of 52) versus 36.4% (16 of 44), respectively; P = 0.0002]. In an independent cohort, ESR1 mutations were identified in 0% (0 of 32; 95% CI, 0 to 10.9) tumor biopsies taken after progression on adjuvant AI. In a patient with serial sampling, ESR1 mutation was selected during metastatic AI therapy to become the dominant clone in the cancer. ESR1 mutations can be robustly identified with ctDNA analysis and predict for resistance to subsequent AI therapy. ESR1 mutations are rarely acquired during adjuvant AI but are commonly selected by therapy for metastatic disease, providing evidence that mechanisms of resistance to targeted therapy may be substantially different between the treatment of micrometastatic and overt metastatic cancer. Copyright © 2015, American Association for the Advancement of Science.

  17. Towards high efficiency heliostat fields

    Science.gov (United States)

    Arbes, Florian; Wöhrbach, Markus; Gebreiter, Daniel; Weinrebe, Gerhard

    2017-06-01

    CSP power plants have great potential to substantially contribute to world energy supply. To set this free, cost reductions are required for future projects. Heliostat field layout optimization offers a great opportunity to improve field efficiency. Field efficiency primarily depends on the positions of the heliostats around the tower, commonly known as the heliostat field layout. Heliostat shape also influences efficiency. Improvements to optical efficiency results in electricity cost reduction without adding any extra technical complexity. Due to computational challenges heliostat fields are often arranged in patterns. The mathematical models of the radial staggered or spiral patterns are based on two parameters and thus lead to uniform patterns. Optical efficiencies of a heliostat field do not change uniformly with the distance to the tower, they even differ in the northern and southern field. A fixed pattern is not optimal in many parts of the heliostat field, especially when used as large scaled heliostat field. In this paper, two methods are described which allow to modify field density suitable to inconsistent field efficiencies. A new software for large scale heliostat field evaluation is presented, it allows for fast optimizations of several parameters for pattern modification routines. It was used to design a heliostat field with 23,000 heliostats, which is currently planned for a site in South Africa.

  18. ESR spectroscopic properties of irradiated gum Arabic.

    Science.gov (United States)

    Leonor, S J; Gómez, J A; Kinoshita, A; Calandreli, I; Tfouni, E; Baffa, O

    2013-12-01

    Electron spin resonance (ESR) spectra of irradiated gum Arabic with doses between 0.5 and 5 kGy were studied. A linear relationship between the absorbed dose and the intensities of the ESR spectra was observed. ESR spectra of irradiated gum Arabic showed a decay of relative concentrations of free radicals originated by radiation and the production of at least two species of free radicals with half-times: 3.3 and 125.4 h. The results of spectral simulations for these radical groups were giso=2.0046; A=1.2 mT and gx=gy=2.0062, gz=2.0025. Hydration and dehydration of irradiated gum Arabic returns the ESR spectrum to its initial state before irradiation. The results show that ESR can be used as simple and reliable method to detect irradiated gum Arabic up to 60 days after initial radiation with doses on the order of 5 kGy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. ESR melting under constant voltage conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schlienger, M.E.

    1997-02-01

    Typical industrial ESR melting practice includes operation at a constant current. This constant current operation is achieved through the use of a power supply whose output provides this constant current characteristic. Analysis of this melting mode indicates that the ESR process under conditions of constant current is inherently unstable. Analysis also indicates that ESR melting under the condition of a constant applied voltage yields a process which is inherently stable. This paper reviews the process stability arguments for both constant current and constant voltage operation. Explanations are given as to why there is a difference between the two modes of operation. Finally, constant voltage process considerations such as melt rate control, response to electrode anomalies and impact on solidification will be discussed.

  20. Diffusion studies on permeable nitroxyl spin probes through bilayer lipid membranes: A low frequency ESR study

    Energy Technology Data Exchange (ETDEWEB)

    Meenakumari, V.; Benial, A. Milton Franklin, E-mail: miltonfranklin@yahoo.com [Department of Physics, NMSSVN College, Nagamalai, Madurai-625019, Tamilnadu (India); Utsumi, Hideo; Ichikawa, Kazuhiro; Yamada, Ken-ichi [Department of Bio-functional Science, Kyushu University, Fukuoka (Japan); Hyodo, Fuminori [Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka (Japan); Jawahar, A. [Department of Chemistry, NMSSVN College, Nagamalai, Madurai-625019, Tamilnadu (India)

    2015-06-24

    Electron spin resonance (ESR) studies were carried out for permeable 2mM {sup 14}N-labeled deutrated 3 Methoxy carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) in pure water and 1mM, 2mM, 3mM, 4mM concentration of 14N-labeled deutrated MC-PROXYL in 400mM concentration of liposomal solution by using a 300 MHz ESR spectrometer. The ESR parameters such as linewidth, hyperfine coupling constant, g-factor, partition parameter and permeability were reported for these samples. The line broadening was observed for the nitroxyl spin probe in the liposomal solution. The line broadening indicates that the high viscous nature of the liposomal solution. The partition parameter and permeability values indicate the maximum diffusion of nitroxyl spin probes in the bilayer lipid membranes at 2 mM concentration of nitroxyl radical. This study illustrates that ESR can be used to differentiate between the intra and extra- membrane water by loading the liposome vesicles with a lipid-permeable nitroxyl spin probe. From the ESR results, the spin probe concentration was optimized as 2mM in liposomal solution for ESR phantom studies/imaging, invivo and invitro experiments.

  1. Analysis list: ESR1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ESR1 Breast,Others,Prostate,Uterus + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ESR...1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ESR1.5.tsv http://dbarchive....biosciencedbc.jp/kyushu-u/hg19/target/ESR1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ESR1....Breast.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ESR1.Others.tsv,h...ttp://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ESR1.Prostate.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ESR

  2. Radiation dosimetry by ESR in bone

    Energy Technology Data Exchange (ETDEWEB)

    Gallegos, R. (Universidad de San Agustin de Arequipa (Peru)); Marticorena, B. (Instituto Peruano de Energia Nuclear, Lima)

    1983-05-01

    The absorption speed in bovine bone samples irradiated with a /sup 90/Sr ..beta..-source of 45 mCi is studied with ESR. The signal changes linearly with the absorbed quantity of radiation to a maximum dose of 1.5 x 10/sup 6/ rads. This positive result allows to foresee the use of bone as a radiation dosimeter.

  3. [Biomedical application of electron spin resonance (ESR) spectroscopy--assessment of antioxidant property for development of drugs].

    Science.gov (United States)

    Lee, Masaichi-Chang-il

    2008-05-01

    Reactive oxygen species (ROS) are associated with oxidative stress-mediated alterations under pathophysiological conditions, and particularly brain ischemia, brain tumor, and neurodegenerative diseases. Electron spin resonance (ESR) is recognized as one of the most powerful techniques available for the detection of ROS in tissues and cells. We previously developed an in vitro ESR-based technique for the detection of free radical reactions in biological systems. In addition, significant advances in the field of in vivo ESR techniques over recent years have now made it possible to visualize the distribution and metabolism of oxidative stress, and the degree of tissue oxygenation in vivo. Nitroxyl radicals are very useful as exogenous spin probes for measuring free radical distribution, oxygen concentration, and redox metabolism by in vivo ESR in biological systems, using a combination of these ESR methods collectively focused on animal models of disease such as spontaneously hypertensive rat (SHR) or stroke-prone SHR (SHRSP) for the assessment of antioxidant property of drugs. Our results suggest that ESR could be applied to the assessment of antioxidant property on oxidative stress in target organs, especially brain, using animal disease models, SHR or SHRSP. After screening drugs for antioxidant property using such as in vitro or in vivo ESR assessment, we'll be able to develop and find novel antioxidant drugs for ROS-induced brain disease in the near future.

  4. Analysis list: ESR2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ESR2 Bone + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ESR2.1.tsv ...http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ESR2.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/ESR...2.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/ESR2.Bone.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Bone.gml ...

  5. Expression of estrogen receptor α 36 (ESR36 in the hamster ovary throughout the estrous cycle: effects of gonadotropins.

    Directory of Open Access Journals (Sweden)

    Prabuddha Chakraborty

    Full Text Available Estradiol-17β (E plays an important role in ovarian follicular development. Evidence indicates that some of the effect of E is mediated by the transmembrane estrogen receptor. In this study, we examined the spatio-temporal expression of recently discovered ERα36 (ESR36, a splice variant of Esr1 and a receptor for non-genomic E signaling, in the hamster ovary during the estrous cycle and the role of gonadotropins and ovarian steroid hormones in ESR36 expression. ESR36 expression was high on estrus (D1:0900 h and declined precipitously by proestrus (D4:0900 h and remained low up to D4:1600 h. Immunofluorescence findings corroborated immunoblot findings and revealed that ESR36 was expressed only in the cell membrane of both follicular and non-follicular cells, except the oocytes. Ovarian ESR36 was capable of binding to the E-affinity matrix, and have different molecular weight than that of the ESR1 or GPER. Hypophysectomy (Hx resulted in a marked decline in ESR36 protein levels. FSH and LH, alone or combined, markedly upregulated ESR36 protein in Hx hamsters to the levels observed in D1 hamsters, but neither E nor P had any effect. Inhibition of the gonadotropin surge by phenobarbital treatment on D4:1100 h attenuated ESR36 expression in D1:0900 h ovaries, but the decline was restored by either FSH or LH replacement on D4 afternoon. This is the first report to show that ESR36, which is distinct from ESR1 or GPER is expressed in the plasma membrane of ovarian follicular and non-follicular cells, binds to E and its expression is regulated directly by the gonadotropins. In light of our previous findings, the results suggest that ovarian cells contain at least two distinct membrane estrogen receptors, such as GPER and ESR36, and strongly suggest for a non-genomic action of E regulating ovarian follicular functions.

  6. ESR studies of spin-polarized atomic hydrogen using a 114-GHz heterodyne spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Statt, B.W.; Hardy, W.N.; Berlinsky, A.J.; Klein, E.

    1985-12-01

    Spin-polarized atomic hydrogen (Harrow-down) gas has been studied using electron spin resonance (ESR) techniques at low temperatures. The ESR apparatus and consequent data analysis required for accurate quantitative results are described in detail. Crucial to the data analysis is the ability to confine the sample of Harrow-down gas inside a liquid helium-coated microwave cavity where the magnetic field and temperature are constant. Results obtained so far are reported, which include the first detailed study of the one-body surface relaxation rate due to microscopic magnetic impurities in the cell walls.

  7. Idea Generation in Highly Institutionalized Fields

    DEFF Research Database (Denmark)

    Agoguè, Marine; Boxenbaum, Eva

    The early phase of innovation processes in highly institutionalized fields relies on the capabilities of actors to generate new ideas that break with the field frame. Informed by a dominant logic, a field frame shapes collective cognition and can thus prevent the generation of new ideas and block...

  8. Analysis list: Esr1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Esr1 Blood,Breast,Cardiovascular,Gonad,Liver,Uterus + mm9 http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/target/Esr1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Esr1.5.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/target/Esr1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm...9/colo/Esr1.Blood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Esr1.Br...east.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Esr1.Cardiovascular.tsv,http://dbarchive.bioscience

  9. High field MRI in the diagnosis of multiple sclerosis: high field-high yield?

    Energy Technology Data Exchange (ETDEWEB)

    Wattjes, Mike P.; Barkhof, Frederik [VU University Medical Center, MS Center Amsterdam, Department of Radiology, Amsterdam (Netherlands)

    2009-05-15

    Following the approval of the U.S. Food and Drug Administration (FDA), high field magnetic resonance imaging (MRI) has been increasingly incorporated into the clinical setting. Especially in the field of neuroimaging, the number of high field MRI applications has been increased dramatically. Taking advantage on increased signal-to-noise ratio (SNR) and chemical shift, higher magnetic field strengths offer new perspectives particularly in brain imaging and also challenges in terms of several technical and physical consequences. Over the past few years, many applications of high field MRI in patients with suspected and definite multiple sclerosis (MS) have been reported including conventional and quantitative MRI methods. Conventional pulse sequences at 3 T offers higher lesion detection rates when compared to 1.5 T, particularly in anatomic regions which are important for the diagnosis of patients with MS. MR spectroscopy at 3 T is characterized by an improved spectral resolution due to increased chemical shift allowing a better quantification of metabolites. It detects significant axonal damage already in patients presenting with clinically isolated syndromes and can quantify metabolites of special interest such as glutamate which is technically difficult to quantify at lower field strengths. Furthermore, the higher susceptibility and SNR offer advantages in the field of functional MRI and diffusion tensor imaging. The recently introduced new generation of ultra-high field systems beyond 3 T allows scanning in submillimeter resolution and gives new insights into in vivo MS pathology on MRI. The objectives of this article are to review the current knowledge and level of evidence concerning the application of high field MRI in MS and to give some ideas of research perspectives in the future. (orig.)

  10. ESR study of free radicals in mango

    Science.gov (United States)

    Kikuchi, Masahiro; Hussain, Mohammad S.; Morishita, Norio; Ukai, Mitsuko; Kobayashi, Yasuhiko; Shimoyama, Yuhei

    2010-01-01

    An electron spin resonance (ESR) spectroscopic study of radicals induced in irradiated fresh mangoes was performed. Mangoes in the fresh state were irradiated with γ-rays, lyophilized and then crushed into a powder. The ESR spectrum of the powder showed a strong main peak at g = 2.004 and a pair of peaks centered at the main peak. The main peak was detected from both flesh and skin specimens. This peak height gradually decreased during storage following irradiation. On the other hand, the side peaks showed a well-defined dose-response relationship even at 9 days post-irradiation. The side peaks therefore provide a useful means to define the irradiation of fresh mangoes.

  11. ESR dating at Mezmaiskaya Cave, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, A.R. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States)]. E-mail: anne.r.skinner@williams.edu; Blackwell, B.A.B. [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Martin, Sara [Department of Chemistry, Williams College, Williamstown, MA, 01267 (United States); Ortega, A. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Flushing, NY, 11366 (United States); Golovanova, L.V. [Laboratory of Prehistory, St. Petersburg (Russian Federation); Doronichev, V.B. [Laboratory of Prehistory, St. Petersburg (Russian Federation)

    2005-02-01

    Mezmaiskaya Cave has yielded more than 10,000 artifacts, thousands of very well preserved faunal remains, and hominin remains, found in seven Middle Paleolithic (Mousterian) and three Upper Paleolithic levels. A complete Neanderthal infant skeleton was preserved in anatomical juxtaposition lying on a large limestone block, overlain by the earliest Mousterian layer, Layer 3. Twenty-four skull fragments from a 1-2 year-old Neanderthal infant, showing post-mortem deformation, occurred in a pit originating in the Mousterian Layer 2 and penetrating into underlying layers 2A and 2B(1). Bone from Layer 2A was dated by AMS {sup 14}C at 35.8-36.3{+-}0.5 kyr BP. Direct dating of Neanderthal bone from Layer 3 gave an age of 29 kyr, but that is now considered to be due to contamination by modern carbon. Fourteen large mammal teeth from Layers 2 through 3 have been dated by standard electron spin resonance (ESR). Low U concentrations in both the enamel and dentine ensure that ESR ages do not depend significantly on the U uptake model, but do depend strongly on the sedimentary dose rates. Assuming a sedimentary water concentration equal to 20 wt%, ESR ages for the Mousterian layers range from 36.2 to 73.0{+-}5.0 ka.

  12. Phase transitions of natural corals monitored by ESR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vongsavat, V. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand); Winotai, P. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand); Meejoo, S. [Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400 (Thailand)]. E-mail: scsmj@mahidol.ac.th

    2006-01-15

    The main purpose of this work is to present a systematic study of structure of marine exoskeletons, Acropora coral and its structural transformation upon heat treatments. The coralline sample was ground and characterized as powder throughout this work. Structural identifications of all samples have been confirmed using X-ray diffraction and IR spectroscopy. It was clearly found that the fresh specimen is made of aragonite, a common phase of the mineral CaCO{sub 3}. Thermal analyses, DSC and TGA were used to monitor structural and thermal decompositions and an irreversible solid-state phase transition from aragonite to calcite of the marine carbonate. Next, the coral powder was annealed at specific temperatures over the range 350-900 deg. C, and the effects of heat treatment on the structure of coralline samples were carefully studied by Rietveld refinement method. In addition, we have examined Mn{sup 2+} paramagnetic ions and free radicals present in the coral and changes of those upon heating by using ESR spectroscopy. The local environments of Mn{sup 2+} ions were verified from the calculated ESR spectra using appropriate spin Hamiltonian parameters, i.e. gyromagnetic tensor g , zero-field splitting D and hyperfine tensor A . This work reported structures and compositions as well as physical, chemical and thermal properties of the coralline material upon heat treatments qualitatively and quantitatively.

  13. Synchrotron Applications of High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This workshop aims at discussing the scientific potential of X-ray diffraction and spectroscopy in magnetic fields above 30 T. Pulsed magnetic fields in the range of 30 to 40 T have recently become available at Spring-8 and the ESRF (European synchrotron radiation facility). This document gathers the transparencies of the 6 following presentations: 1) pulsed magnetic fields at ESRF: first results; 2) X-ray spectroscopy and diffraction experiments by using mini-coils: applications to valence state transition and frustrated magnet; 3) R{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4}: an ideal system to be studied in X-ray under high magnetic field?; 4) high field studies at the Advanced Photon Source: present status and future plans; 5) synchrotron X-ray diffraction studies under extreme conditions; and 6) projects for pulsed and steady high magnetic fields at the ESRF.

  14. Neutron Scattering and High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Winn, Barry L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stone, Matthew B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-11-01

    The workshop “Neutron Scattering and High Magnetic Fields” was held September 4-5, 2014 at the Oak Ridge National Laboratory (ORNL). The workshop was held in response to a recent report by the National Research Council of the National Academy of Sciences entitled “High Magnetic Field Science and Its Application in the United States: Current Status and Future Directions.”1 This report highlights the fact that neutron scattering measurements carried out in high magnetic fields provide important opportunities for new science. The workshop explored the range of the scientific discoveries that could be enabled with neutron scattering measurements at high fields (25 Tesla or larger), the various technologies that might be utilized to build specialized instruments and sample environment equipment to enable this research at ORNL, and possible routes to funding and constructing these facilities and portable high field sample environments.

  15. The influence of surface modification, coating agents and pH value of aqueous solutions on physical properties of magnetite nanoparticles investigated by ESR method

    Energy Technology Data Exchange (ETDEWEB)

    Dobosz, Bernadeta, E-mail: benia@amu.edu.pl [Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Krzyminiewski, Ryszard [Medical Physics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Kurczewska, Joanna; Schroeder, Grzegorz [Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89B, 61-614 Poznań (Poland)

    2017-05-01

    The article presents the results of electron spin resonance (ESR) studies for aqueous solutions of functionalized superparamagnetic iron(II,III) oxide nanoparticles. The samples studied differed in type of organic ligands at the magnetite surface, type of coating agent and pH value of aqueous solutions. The ESR spectra of the samples were obtained at room temperature and at 230 K. The field cooling (FC) experiment was performed for selected samples, and the effective anisotropy field (H{sub K2}) and the first order magnetocrystalline anisotropy constant (K{sub 1}) was calculated. The process of the nanoparticles diffusion in different environments (human blood, human serum) forced by an inhomogeneous magnetic field was monitored and their interactions with different solvents have been discussed. It has been shown that ESR method is useful to observe the impact of organic ligands at the magnetite surface, type of coating agent and pH value of aqueous solutions on the properties of iron(II,III) oxide nanoparticles. - Highlights: • The influence of different organic ligands, coatings and pH values of aqueous solutions on the physical properties of the magnetite nanoparticles studied by ESR method. • Nanoparticles diffusion forced by inhomogeneous magnetic field monitored by ESR and explained. • A narrow line separated in ESR spectra by CREM. • The influence of different coatings and pH values of aqueous solutions on ESR spectra of TEMPO attached to the magnetite core.

  16. The recent in vivo ESR imaging in Yamagata

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Hidekatsu; Ohya, Hiroaki [Inst. for Life Support Technology, Matsuei, Yamagata (Japan)

    2002-04-01

    In vivo ESR imaging systems operating at ca. 700 MHz were developed in our institute. ESR imaging of living small animals that had received some nitroxide radicals and their reduced form have been conducted. These imaging techniques can be applied to some disease models. We think that the ESR imaging of nitroxide radicals in the biological systems is useful to estimate in vivo reduction or oxidation, i.e., redox status in the target area (such as the brain). (author)

  17. Effect of boron addition and ESR process on the creep properties of type 316L(N) stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, W. K.; Kim, D. H.; Jang, J. S.; Kook, I. H.; Ryu, W. S. [KAERI, Taejon (Korea, Republic of)

    1999-10-01

    The effects of B-addition and ESR(electroslag remelting) process on the creep properties of 316L(N) stainless steel were investigated at 550 deg C in air. High temperature tensile strength for three heats was similar, but creep rupture time of B-doped and ESR-processed 316L(N) steels increased significantly in comparison with B-undoped steels. Also, the creep rupture elongation increased and minimum creep rate decreased inversely. Cross section of crept specimen showed the typical wedge cracks regardless of B-addition or ESR. The size and spacing of grain boundary cavitation in B-doped and ESR-processed steels were smaller than those of B-undoped steels. It was concluded that 0.0025% boron addition increases creep rupture time by delaying the onset of the tertiary stage due to suppression of grain boundary cavitation and wedge cracking.

  18. ESR investigations of gamma irradiated medical devices.

    Science.gov (United States)

    Turker, N Selcan; Özer, A Yekta; Çolak, Şeyda; Kutlu, Burak; Nohutçu, Rahime

    2017-12-01

    Guided tissue regeneration (GTR) and guided bone regeneration (GBR) biomaterials have been employed in recent years for periodontal procedures. In the present study, widely used dental GTR/GBR biomaterials (grafts: G1, G2, G3 and membranes: M1, M2, M3, M4) were exposed to gamma irradiation at an absorbed dose range of 0-50kGy and the radiolytic intermediates that have been created in the samples upon irradiation were characterized in detail by Electron Spin Resonance (ESR) spectroscopy. We aimed to standardize the measurement conditions for practical applications of gamma radiation sterilization of GTR/GBR biomaterials. We investigated the characteristic features of free radicals in gamma irradiated GTR/GBR biomaterials and examined the stability of the induced radicals at room temperature and accelerated stability conditions with ESR spectroscopy including dose-response curves, microwave power studies, dosimetric features of the biomaterials, variations of the peak heights with temperature, and long term stabilities of the radical species. Long-term stability studies have shown that G1 is quite stable even in accelerated storage conditions. The signal intensities of graft-type GTR/GBR biomaterials stored in normal and stability conditions have decreased very rapidly even only a few days after gamma irradiation sterilization. Thus, those samples indicating relatively low stability features can be very good candidates for the radiosterilization process. The beta-tricalcium phosphate and PLGA containing G1 and M1 respectively have found to be the most gamma stable bone substitute biomaterials and be safely sterilized by gamma radiation. ESR spectroscopy is an appropriate technique in giving important detailed spectroscopic findings in the gamma radiation sterilization studies of GTR/GBR biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. ESR of vitreous silica containing hydroxyl

    Energy Technology Data Exchange (ETDEWEB)

    Shendrik, A.V. (Latvijskij Gosudarstvennyj Univ., Riga (USSR))

    1981-09-16

    H(II) centers in vitreous silica containing Al or Ge were investigated by ESR measurements at 77 K. Vitreous silica samples were melted in an electric resistance furnace in hydrogen atmosphere or by SiCl/sub 4/ vapor oxidation in the flame of an oxyhydrogen burner and irradiated with /sup 60/Co-gamma doses of 5 x 10/sup 7/ rad at 300 K. It was found that hydrogen atoms are localized at the H(II) center near the non-bridging oxygen of the germanium-oxygen structural unit.

  20. ESR in 2D triangular chromium lattices

    Energy Technology Data Exchange (ETDEWEB)

    Hemmida, M; Nidda, H-A Krug von; Loidl, A, E-mail: mhemmida@yahoo.d [Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg (Germany)

    2010-01-01

    The spin dynamics in some two-dimensional (2D) triangular Cr-antiferromagnetic frustrated lattices, i.e. HCrO{sub 2}, LiCrO{sub 2}, and NaCrO{sub 2} with ordered rock-salt structure as well as the delafossite compounds CuCrO{sub 2} and AgCrO{sub 2}, has been investigated by Electron Spin Resonance (ESR). On approaching the Neel temperature T{sub N} from above, the divergence of the temperature dependent linewidth is well described in terms of a Berezinskii-Kosterlitz-Thouless (BKT) like scenario due to magnetic vortex-antivortex pairing.

  1. Biallelic and monoallelic ESR2 variants associated with 46,XY disorders of sex development.

    Science.gov (United States)

    Baetens, Dorien; Güran, Tülay; Mendonca, Berenice B; Gomes, Nathalia L; De Cauwer, Lode; Peelman, Frank; Verdin, Hannah; Vuylsteke, Marnik; Van der Linden, Malaïka; Stoop, Hans; Looijenga, Leendert H; De Bosscher, Karolien; Cools, Martine; De Baere, Elfride

    2017-10-26

    PurposeDisorders or differences of sex development (DSDs) are rare congenital conditions characterized by atypical sex development. Despite advances in genomic technologies, the molecular cause remains unknown in 50% of cases.MethodsHomozygosity mapping and whole-exome sequencing revealed an ESR2 variant in an individual with syndromic 46,XY DSD. Additional cases with 46,XY DSD underwent whole-exome sequencing and targeted next-generation sequencing of ESR2. Functional characterization of the identified variants included luciferase assays and protein structure analysis. Gonadal ESR2 expression was assessed in human embryonic data sets and immunostaining of estrogen receptor-β (ER-β) was performed in an 8-week-old human male embryo.ResultsWe identified a homozygous ESR2 variant, c.541_543del p.(Asn181del), located in the highly conserved DNA-binding domain of ER-β, in an individual with syndromic 46,XY DSD. Two additional heterozygous missense variants, c.251G>T p.(Gly84Val) and c.1277T>G p.(Leu426Arg), located in the N-terminus and the ligand-binding domain of ER-β, were found in unrelated, nonsyndromic 46,XY DSD cases. Significantly increased transcriptional activation and an impact on protein conformation were shown for the p.(Asn181del) and p.(Leu426Arg) variants. Testicular ESR2 expression was previously documented and ER-β immunostaining was positive in the developing intestine and eyes.ConclusionOur study supports a role for ESR2 as a novel candidate gene for 46,XY DSD.Genetics in Medicine advance online publication, 26 October 2017; doi:10.1038/gim.2017.163.

  2. High-field measurements on YBCO

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.L.; Fowler, C.M.; Freeman, B.L.; Goettee, J.D.; Hults, W.L.; King, J.C.; Rickel, D.G. [Los Alamos National Lab., NM (United States); Brooks, J.S.; Mankiewich, P.M.; De Obaldia, E.I.; Skocpol, W.J. [Boston Univ., MA (United States); O`Malley, M.L. [AT& T Bell Labs., Holmdel, NJ (United States)

    1994-04-01

    The authors have performed resistance measurements on thin films of the high-temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) in applied magnetic fields to above 200 T (2 MegaOersted) at temperatures as low as 2.5 K. The fields are produced by an explosively driven flux-compression system. The authors can see a particularly clear onset, without replotting the data, of the {open_quotes}hydrodynamic{close_quotes} flow of vortices probably because of the very fast increasing field. The low-temperature {open_quotes}critical field{close_quotes} for the field parallel to the c-axis of the sample is 135 T. The data in the other direction are still preliminary. The authors discuss possible interpretation of the results.

  3. High magnetic fields science and technology

    CERN Document Server

    Miura, Noboru

    2003-01-01

    This three-volume book provides a comprehensive review of experiments in very strong magnetic fields that can only be generated with very special magnets. The first volume is entirely devoted to the technology of laboratory magnets: permanent, superconducting, high-power water-cooled and hybrid; pulsed magnets, both nondestructive and destructive (megagauss fields). Volumes 2 and 3 contain reviews of the different areas of research where strong magnetic fields are an essential research tool. These volumes deal primarily with solid-state physics; other research areas covered are biological syst

  4. Study of a Single-Power Two-Circuit ESR Process with Current-Carrying Mold: Mathematical Simulation of the Process and Experimental Verification

    Science.gov (United States)

    Dong, Yanwu; Hou, Zhiwen; Jiang, Zhouhua; Cao, Haibo; Feng, Qianlong; Cao, Yulong

    2017-12-01

    A novel single-power two-circuit ESR process (ESR-STCCM) with current-carrying mold has been investigated via numerical simulation and experimental research in this paper. A 2D quasi-steady-state mathematical model is developed to describe ESR-STCCM. The electromagnetic field, flow field, slag pool temperature distribution, and the shape of a molten steel pool in ESR-STCCM have been investigated by FLUENT software as well as user-defined functions (UDF). The results indicate that ESR-STCCM is different from the conventional ESR process. The maximum electromagnetic force, current density, Joule heat, and slag pool flow velocity are located in the lower part of the conductor in the ESR-STCCM process. The direction of the maximum electromagnetic force inclines upward. There are two distinct vortices in the slag pool. The larger swirl rotates counterclockwise near the conductor, with a value of 0.0263 m s-1 due to the interaction of the electromagnetic force and gravity. The maximum temperature of the slag pool is 2070 K (1797 °C) and is located in the center of the swirl with a filling ratio of 0.6 and a 20 mm electrode immersion depth. The depth of a molten steel pool is shallower, which is conducive to improving solidification quality. In addition, the filling ratio of 0.6 is conducive to controlling steel solidification quality. Some experiments have been done, and the numerical model is confirmed by experimental results.

  5. Molecular dynamics in high electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Apostol, M., E-mail: apoma@theory.nipne.ro; Cune, L.C.

    2016-06-15

    Highlights: • New method for rotation molecular spectra in high electric fields. • Parametric resonances – new features in spectra. • New elementary excitations in polar solids from dipolar interaction (“dipolons”). • Discussion about a possible origin of the ferroelectricity from dipolar interactions. - Abstract: Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the classical motion of the dipoles consists of rotations and vibrations about equilibrium positions; this motion may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called “dipolons”); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.

  6. Dynamic nuclear polarization at high magnetic fields.

    Science.gov (United States)

    Maly, Thorsten; Debelouchina, Galia T; Bajaj, Vikram S; Hu, Kan-Nian; Joo, Chan-Gyu; Mak-Jurkauskas, Melody L; Sirigiri, Jagadishwar R; van der Wel, Patrick C A; Herzfeld, Judith; Temkin, Richard J; Griffin, Robert G

    2008-02-07

    Dynamic nuclear polarization (DNP) is a method that permits NMR signal intensities of solids and liquids to be enhanced significantly, and is therefore potentially an important tool in structural and mechanistic studies of biologically relevant molecules. During a DNP experiment, the large polarization of an exogeneous or endogeneous unpaired electron is transferred to the nuclei of interest (I) by microwave (microw) irradiation of the sample. The maximum theoretical enhancement achievable is given by the gyromagnetic ratios (gamma(e)gamma(l)), being approximately 660 for protons. In the early 1950s, the DNP phenomenon was demonstrated experimentally, and intensively investigated in the following four decades, primarily at low magnetic fields. This review focuses on recent developments in the field of DNP with a special emphasis on work done at high magnetic fields (> or =5 T), the regime where contemporary NMR experiments are performed. After a brief historical survey, we present a review of the classical continuous wave (cw) DNP mechanisms-the Overhauser effect, the solid effect, the cross effect, and thermal mixing. A special section is devoted to the theory of coherent polarization transfer mechanisms, since they are potentially more efficient at high fields than classical polarization schemes. The implementation of DNP at high magnetic fields has required the development and improvement of new and existing instrumentation. Therefore, we also review some recent developments in microw and probe technology, followed by an overview of DNP applications in biological solids and liquids. Finally, we outline some possible areas for future developments.

  7. Physics of semiconductors in high magnetic fields

    CERN Document Server

    Miura, Noboru

    2008-01-01

    This book summarizes most of the fundamental physical phenomena which semiconductors and their modulated structures exhibit in high magnetic fields. Readers can learn not only the basic theoretical background but also the present state of the art from the most advanced data in this rapidly growing research area.

  8. Strain sensors for high field pulse magnets

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Christian [Los Alamos National Laboratory; Zheng, Yan [Los Alamos National Laboratory; Easton, Daniel [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory

    2009-01-01

    In this paper we present an investigation into several strain sensing technologies that are being considered to monitor mechanical deformation within the steel reinforcement shells used in high field pulsed magnets. Such systems generally operate at cryogenic temperatures to mitigate heating issues that are inherent in the coils of nondestructive, high field pulsed magnets. The objective of this preliminary study is to characterize the performance of various strain sensing technologies at liquid nitrogen temperatures (-196 C). Four sensor types are considered in this investigation: fiber Bragg gratings (FBG), resistive foil strain gauges (RFSG), piezoelectric polymers (PVDF), and piezoceramics (PZT). Three operational conditions are considered for each sensor: bond integrity, sensitivity as a function of temperature, and thermal cycling effects. Several experiments were conducted as part of this study, investigating adhesion with various substrate materials (stainless steel, aluminum, and carbon fiber), sensitivity to static (FBG and RFSG) and dynamic (RFSG, PVDF and PZT) load conditions, and sensor diagnostics using PZT sensors. This work has been conducted in collaboration with the National High Magnetic Field Laboratory (NHMFL), and the results of this study will be used to identify the set of sensing technologies that would be best suited for integration within high field pulsed magnets at the NHMFL facility.

  9. High-performance phase-field modeling

    KAUST Repository

    Vignal, Philippe

    2015-04-27

    Many processes in engineering and sciences involve the evolution of interfaces. Among the mathematical frameworks developed to model these types of problems, the phase-field method has emerged as a possible solution. Phase-fields nonetheless lead to complex nonlinear, high-order partial differential equations, whose solution poses mathematical and computational challenges. Guaranteeing some of the physical properties of the equations has lead to the development of efficient algorithms and discretizations capable of recovering said properties by construction [2, 5]. This work builds-up on these ideas, and proposes novel discretization strategies that guarantee numerical energy dissipation for both conserved and non-conserved phase-field models. The temporal discretization is based on a novel method which relies on Taylor series and ensures strong energy stability. It is second-order accurate, and can also be rendered linear to speed-up the solution process [4]. The spatial discretization relies on Isogeometric Analysis, a finite element method that possesses the k-refinement technology and enables the generation of high-order, high-continuity basis functions. These basis functions are well suited to handle the high-order operators present in phase-field models. Two-dimensional and three dimensional results of the Allen-Cahn, Cahn-Hilliard, Swift-Hohenberg and phase-field crystal equation will be presented, which corroborate the theoretical findings, and illustrate the robustness of the method. Results related to more challenging examples, namely the Navier-Stokes Cahn-Hilliard and a diusion-reaction Cahn-Hilliard system, will also be presented. The implementation was done in PetIGA and PetIGA-MF, high-performance Isogeometric Analysis frameworks [1, 3], designed to handle non-linear, time-dependent problems.

  10. ESR dating of tooth enamel from yunxian homo erectus site, China

    Science.gov (United States)

    Chen, Tie-Mei; Yang, Quan; Hu, Yan-Qiu; Bao, Wen-Bo; Li, Tian-Yuan

    Two almost complete fossil hominid crania (EV9001 and EV9002) were found in 1989 and 1990 in Middle Pleistocene terrace deposit of Han River, Yunxian county, Hubei province, China. They are classified as Homo erectus. Nine fossil animal teeth stratigraphically associated with the skulls were selected for electron spin resonance (ESR) dating. The simple exponential function was used for determination of the accumulated dose De and its appropriateness was discussed on the base of the experimental study. The closed system assumption was checked and the early uranium uptake model was applied to age determination. A mean age value was yielded to be 581±93 ka. It deviates from the palaeomagnetic dating result of 830-870 ka. Micro-regional complete saturation of ESR signal in enamel of very high U-content may account for the underestimation of ESR ages. Nevertheless both ESR and palaeomagnetic dating results place Yunxian crania in between the Homo erectus of Lantian and Zhoukoudian, which means that Yunxian crania constitute an important link in the human evolutionary lineage of China.

  11. Wuhan pulsed high magnetic field center

    OpenAIRE

    Li, Liang; Peng, Tao; Ding, Honfa; Han, Xiaotao; Ding, Tonghai; Chen, Jin; Wang, Junfeng; Xie, Jianfeng; Wang, Shaoliang; Duan, Xianzhong; Wang, Cheng; Herlach, Fritz; Vanacken, Johan; Pan, Yuan

    2008-01-01

    Wuhan pulsed high magnetic field facility is under development. Magnets of bore sizes from 12 to 34 mm with the peak field in the range of 50 to 80 T have been designed. The pulsed power supplies consists of a 12 MJ, 25 kV capacitor bank and a 100 MVA/100 MJ flywheel pulse generator. A prototype 1 MJ, 25 kV capacitor bank is under construction. Five magnets wound with CuNb wire and copper wire reinforced internally with Zylon fiber composites and externally with stainless steel shells have be...

  12. ESR Fine Structure of Manganese Ions in Zeolite A Detects Strong Variations of the Coordination Environment

    OpenAIRE

    De Vos, D.E.; Weckhuysen, B.M.; Bein, T.

    1996-01-01

    The electron spin resonance spectra of Mn 2+ exchanged zeolite A have been investigated as a function of the monovalent co-cation (K + ,Na + ,Li + ,Cs + ,or NH4 + ), Mn 2+ content, recording frequency, and temperature. Three new Mn 2+ species are observed with a well-resolved fine structure; this allows for the first time a direct quantitative determination of the zero-field splitting (ZFS) parameters in zeolites. In hydrated zeolites, three ESR active Mn 2+ species are observed, characterize...

  13. ESR studies on Er sup 3 sup + -doped YBiPt compound

    CERN Document Server

    Guener, S; Aktas, B

    2003-01-01

    The semi-metallic cubic compound YBiPt doped by Er sup 3 sup + (4f sup 1 sup 1) has been studied by ESR technique between 4 and 300 K. X-band and Q-band measurements have been performed. The angular dependence of the ESR spectra on the crystal orientation with respect to the static magnetic field has been measured. Two anisotropic lines with hyperfine peaks coming from the interaction between electronic and nuclear spins of sup 1 sup 6 sup 7 Er sup 3 sup + (I=7/2) isotopes have been observed below 30 K in the spectra. Computer modeling showed that these lines are the ESR signals from the quadruplet ground state of Er sup 3 sup + ions in the cubic crystal field. The values of crystal field parameters B sub 4 =-5.68 x 10 sup - sup 4 cm sup - sup 1 and B sub 6 =-6.64 x 10 sup - sup 6 cm sup - sup 1 have been extracted. Also an isotropic line near g=2 have been observed in both frequency bands. Dysonian lineshape of the spectra components due to the skin-depth effect shows the conducting property of the sample un...

  14. High Field Pulse Magnets with New Materials

    Science.gov (United States)

    Li, L.; Lesch, B.; Cochran, V. G.; Eyssa, Y.; Tozer, S.; Mielke, C. H.; Rickel, D.; van Sciver, S. W.; Schneider-Muntau, H. J.

    2004-11-01

    High performance pulse magnets using the combination of CuNb conductor and Zylon fiber composite reinforcement with bore sizes of 24, 15 and 10 mm have been designed, manufactured and tested to destruction. The magnets successfully reached the peak fields of 64, 70 and 77.8 T respectively with no destruction. Failures occurred near the end flanges at the layer. The magnet design, manufacturing and testing, and the mode of the failure are described and analyzed.

  15. High field superconductor development and understanding

    Energy Technology Data Exchange (ETDEWEB)

    Larbalestier, David C. [Florida State Univ., Tallahassee, FL (United States); Lee, Peter J. [Florida State Univ., Tallahassee, FL (United States); Tarantini, Chiara [Florida State Univ., Tallahassee, FL (United States)

    2014-09-28

    All present circular accelerators use superconducting magnets to bend and to focus the particle beams. The most powerful of these machines is the large hadron collider (LHC) at CERN. The main ring dipole magnets of the LHC are made from Nb-Ti but, as the machine is upgraded to higher luminosity, more powerful magnets made of Nb3Sn will be required. Our work addresses how to make the Nb3Sn conductors more effective and more suitable for use in the LHC. The most important property of the superconducting conductor used for an accelerator magnet is that it must have very high critical current density, the property that allows the generation of high magnetic fields in small spaces. Nb3Sn is the original high field superconductor, the material which was discovered in 1960 to allow a high current density in the field of about 9 T. For the high luminosity upgrade of the LHC, much higher current densities in fields of about 12 Tesla will be required. The critical value of the current density is of order 2600 A/mm2 in a field of 12 Tesla. But there are very important secondary factors that complicate the attainment of this critical current density. The first is that the effective filament diameter must be no larger than about 40 µm. The second factor is that 50% of the cross-section of the Nb3Sn conductor that is pure copper must be protected from any poisoning by any Sn leakage through the diffusion barrier that protects the package of niobium and tin from which the Nb3Sn is formed by a high temperature reaction. These three, somewhat conflicting requirements, mean that optimization of the conductor is complex. The work described in this contract report addresses these conflicting requirements. They show that very sophisticated characterizations can uncover the way to satisfy all 3 requirements and they also suggest that the ultimate optimization of Nb3Sn is still not yet in sight

  16. ESR, electrochemical and reactivity studies of antitrypanosomal palladium thiosemicarbazone complexes.

    Science.gov (United States)

    Otero, Lucía; Folch, Christian; Barriga, Germán; Rigol, Carolina; Opazo, Lucia; Vieites, Marisol; Gambino, Dinorah; Cerecetto, Hugo; Norambuena, Ester; Olea-Azar, Claudio

    2008-08-01

    Cyclic voltammetry (CV) and electron spin resonance (ESR) techniques were used in the investigation of novel palladium complexes with bioactive thiosemicarbazones derived from 5-nitrofurane or 5-nitrofurylacroleine. Sixteen palladium complexes grouped in two series of the formula [PdCl(2)HL] or [PdL(2)] were studied. ESR spectra of the free radicals obtained by electrolytic reduction were characterized and analyzed. The ESR spectra showed two different hyperfine patterns. The stoichiometry of the complexes does not seem to affect significantly the hyperfine constants however we observed great differences between 5-nitrofurane and 5-nitrofurylacroleine derivatives. The scavenger properties of this family of compounds were lower than Trolox.

  17. ESR, electrochemical and reactivity studies of antitrypanosomal palladium thiosemicarbazone complexes

    Science.gov (United States)

    Otero, Lucía; Folch, Christian; Barriga, Germán; Rigol, Carolina; Opazo, Lucia; Vieites, Marisol; Gambino, Dinorah; Cerecetto, Hugo; Norambuena, Ester; Olea-Azar, Claudio

    2008-08-01

    Cyclic voltammetry (CV) and electron spin resonance (ESR) techniques were used in the investigation of novel palladium complexes with bioactive thiosemicarbazones derived from 5-nitrofurane or 5-nitrofurylacroleine. Sixteen palladium complexes grouped in two series of the formula [PdCl 2HL] or [PdL 2] were studied. ESR spectra of the free radicals obtained by electrolytic reduction were characterized and analyzed. The ESR spectra showed two different hyperfine patterns. The stoichiometry of the complexes does not seem to affect significantly the hyperfine constants however we observed great differences between 5-nitrofurane and 5-nitrofurylacroleine derivatives. The scavenger properties of this family of compounds were lower than Trolox.

  18. High-power 95 GHz pulsed electron spin resonance spectrometer

    Science.gov (United States)

    Hofbauer, W.; Earle, K. A.; Dunnam, C. R.; Moscicki, J. K.; Freed, J. H.

    2004-05-01

    High-field/high-frequency electron spin resonance (ESR) offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a major factor limiting the achievable spectral coverage and thereby the multiplex advantage of Fourier transform ESR (FTESR) experiments. High-power pulses are needed to perform two-dimensional (2D) FTESR experiments, which can unravel the dynamics of a spin system in great detail, making it an excellent tool for studying spin and molecular dynamics. We report on the design and implementation of a high-power, high-bandwidth, pulsed ESR spectrometer operating at 95 GHz. One of the principal design goals was the ability to investigate dynamic processes in aqueous samples at physiological temperatures with the intent to study biological systems. In initial experiments on aqueous samples at room temperature, we achieved 200 MHz spectral coverage at a sensitivity of 1.1×1010√s spins and a dead time of less than 50 ns. 2D-electron-electron double resonance experiments on aqueous samples are discussed to demonstrate the practical application of such a spectrometer.

  19. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) as inflammation markers in elderly patients with stable chronic obstructive pulmonary disease (COPD).

    Science.gov (United States)

    Corsonello, Andrea; Pedone, Claudio; Battaglia, Salvatore; Paglino, Giuseppe; Bellia, Vincenzo; Incalzi, Raffaele Antonelli

    2011-01-01

    Erythrocyte sedimentation rate (ESR) might represent a less expensive alternative to C-reactive protein (CRP) as a marker of systemic inflammation in stable chronic obstructive pulmonary disease (COPD). We tried to verify this hypothesis in 223 consecutive outpatients aged 65 years or more with stable COPD enrolled in a multicenter observational study. Patients were grouped according to normal/increased ESR/CRP values and groups were compared with regard to clinical and laboratory characteristics. Correlations between CRP, ESR and selected variables of interest were assessed by Spearman's ζ-test and multivariate linear regression analysis. CRP was weakly and inversely correlated with the forced expiratory volume in the first second (FEV1%) (Spearman's ζ = -0.15; p < 0.027), while ESR was not (Spearman's ζ = -0.05; p = 0.411). The highest prevalence of anemia and hypoalbuminemia and the lowest FEV1% were recorded in high ESR-high CRP group. For anemia B = 14.180 ± 3.521 (± S.E.M.); p = 0.001 and hypoalbuminemia B = 10.241 ± 3.790; p = 0.007 qualified as significant independent correlates of ESR values, while only FEV1 remained significantly associated with CRP values (B = -0.570 ± 0.258; p = 0.028). In conclusion, CRP, but not ESR, shows a weak correlation with COPD severity, while anemia and hypoalbuminemia are main correlates of high ESR. Neither ESR, nor CRP qualify as reliable markers of COPD severity and seem to reflect the effects of different determinants. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Ribavirin restores ESR1 gene expression and tamoxifen sensitivity in ESR1 negative breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Sappok Anne

    2011-12-01

    Full Text Available Abstract Tumor growth is estrogen independent in approximately one-third of all breast cancers, which makes these patients unresponsive to hormonal treatment. This unresponsiveness to hormonal treatment may be explained through the absence of the estrogen receptor alpha (ESR1. The ESR1 gene re-expression through epigenetic modulators such as DNA methyltransferase inhibitors and/or histone deacetylase inhibitors restores tamoxifen sensitivity in ESR1 negative breast cancer cell lines and opens new treatment horizons in patients who were previously associated with a poor prognosis. In the study presented herein, we tested the ability of ribavirin, which shares some structural similarities with the DNA-methyltransferase inhibitor 5-azacytidine and which is widely known as an anti-viral agent in the treatment of hepatitis C, to restore ESR1 gene re-expression in ESR1 negative breast cancer cell lines. In our study we identified ribavirin to restore ESR1 gene re-expression alone and even more in combination with suberoylanilide hydroxamic acid (SAHA - up to 276 fold induction. Ribavirin and analogs could pave the way to novel translational research projects that aim to restore ESR1 gene re-expression and thus the susceptibility to tamoxifen-based endocrine treatment strategies.

  1. High-intensity, focused ultrasonic fields

    DEFF Research Database (Denmark)

    Jensen, Leif Bjørnø

    1988-01-01

    The use of extracorporeal shock wave lithotripsy (ESWL) for disintegration of body stones has increased considerably during recent years. A worldwide activity in this field is reflected in a growing number of international publications and in the development and manufacturing of several ESWL...... machines marketed by companies in Germany and France, in particular. Two main types of ESWL systems are prevailing, the spark gap-based and the piezoelectric disk-based systems. This paper is introduced by a brief reconsideration of the features of pressure waves in water produced by an electrical...... distribution, etc. involving nonlinearity, diffraction, and absorption in the high-intensity focused ultrasonic fields produced by an ellipsoid as well as a spherical cap focusing geometry. Data from the development of an ESWL of the piezoelectric disk type are reported including demands to transducers...

  2. The association between a novel polymorphism (rs1062577) in ESR1 and breast cancer susceptibility in the Han Chinese women.

    Science.gov (United States)

    Chen, Li; Kang, Hui; Jin, Guo-Jiang; Chen, Xin; Zhang, Qing-Yang; Lao, Wen-Ting; Li, Rui

    2016-07-01

    The aim of the present study was to analyze the genetic association between the three estrogen receptor 1 (ESR1) single nucleotide polymorphisms (SNPs; rs1062577, rs2881766, and rs9479118) and breast cancer risk in Han Chinese women. To investigate the possible association of genetic polymorphisms of any of the three ESR1 SNPs in breast cancer patients (n = 198) and healthy controls (n = 218) collected from the college hospital, peripheral blood mononuclear cells samples were analyzed by high-resolution melt-polymerase chain reaction. Odds ratios and 95% confidence intervals were used to evaluate the association between the ESR1 SNPs and breast cancer. Patients genotyped AA for ESR1 rs1062577 showed increased breast cancer risk (p = 0.005). In the menarche at ≤ 13-year-old group, there were significant differences in alleles A versus T at rs1062577 and alleles G versus T at rs2881766 between the breast cancer group and the control group. In the > 13-year-old group, the AA genotype at rs1062577, the GG genotype at rs2881766, and the CC genotype at rs9479118 increased breast cancer susceptibility. These results showed that the ESR1 rs1062577 polymorphism increased breast cancer risk in Han Chinese women, which might be used as a new SNP marker.

  3. [Neurofunctional MRI at high magnetic fields].

    Science.gov (United States)

    Speck, O; Turner, R

    2013-05-01

    Functional magnetic resonance imaging (fMRI) examinations are limited in their sensitivity due to the low activation-induced signal change. Within short tolerable scan times the spatial resolution is thus limited. fMRI is a reliable tool in neuroscience as well as for clinical applications such as presurgical mapping of brain function. The fMRI sensitivity improves greatly (more than linearly) with increasing magnetic field strengths. For many years this was the main driving force in the push towards higher field strengths, such as 7 T. The sensitivity gain is greatest for high spatial resolution and fMRI with very high sub-millimeter resolution becomes feasible. Current results demonstrate that the localization of the blood oxygenation level dependent (BOLD) signal is better than previously assumed. High-field fMRI not only allows quantitative improvements but also opens the way to new information content, such as columnar and layer-dependent functional structures of the cortex. This may pave the way for further information, e.g. the directionality of cortico-cortical connections; however, these possibilities also pose new challenges. New methods for processing such high resolution data are required which do not require spatial smoothing and preserve the high information content. Common spatial resolutions of 2-3 mm are still very well suited for examinations at 3 T where they benefit from the low signal void, lower geometrical distortion and reduced acoustic noise. To achieve higher resolution at 7 T parallel imaging and geometric distortion correction are essential and permit the best congruence with structural data. The echo time at 7 T should be adjusted to about 20-25 ms. Data processing for single subjects or patients should be performed with little or no smoothing to retain resolution. Group studies could achieve good correlation with local normalization. New methods for information extraction, such as multivariate pattern analysis may allow

  4. A high performance field-reversed configuration

    Energy Technology Data Exchange (ETDEWEB)

    Binderbauer, M. W.; Tajima, T.; Steinhauer, L. C.; Garate, E.; Tuszewski, M.; Smirnov, A.; Gota, H.; Barnes, D.; Deng, B. H.; Thompson, M. C.; Trask, E.; Yang, X.; Putvinski, S.; Rostoker, N.; Andow, R.; Aefsky, S.; Bolte, N.; Bui, D. Q.; Ceccherini, F.; Clary, R. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States); and others

    2015-05-15

    Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ∼1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

  5. Millimeter and submillimeter wave ESR measurement of Ho{sub 2}Cu{sub 2}O{sub 5} aligned powder sample

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, S. [Kobe Univ., Graduate School of Science and Technology, Kobe, Hyogo (Japan); Goto, T.; Tanaka, T.; Ohta, H. [Kobe Univ. (Japan). Dept. of Physics; Mogi, I.; Watanabe, K.; Motokawa, M. [Tohoku Univ., Sendai (Japan). Inst. for Materials Research

    1999-07-01

    To gain information of anisotropy of Ho{sub 2}Cu{sub 2}O{sub 5} the aligned powder sample was prepared under the static high magnetic field of 5T. Millimeter and submillimeter wave ESR measurements of aligned Ho{sub 2}Cu{sub 2}O{sub 5} samples have been performed for the first time in the frequency region from 50 to 430 GHz using the pulsed magnetic field up to 16T at 1.8K. Antiferromagnetic resonances were observed clearly at 1.8K. AFMR modes of easy axis change at two critical fields. The temperature dependence measurements were also performed and the Neel temperature of the system is discussed. (author)

  6. High Performance Clocks and Gravity Field Determination

    Science.gov (United States)

    Müller, J.; Dirkx, D.; Kopeikin, S. M.; Lion, G.; Panet, I.; Petit, G.; Visser, P. N. A. M.

    2018-02-01

    Time measured by an ideal clock crucially depends on the gravitational potential and velocity of the clock according to general relativity. Technological advances in manufacturing high-precision atomic clocks have rapidly improved their accuracy and stability over the last decade that approached the level of 10^{-18}. This notable achievement along with the direct sensitivity of clocks to the strength of the gravitational field make them practically important for various geodetic applications that are addressed in the present paper. Based on a fully relativistic description of the background gravitational physics, we discuss the impact of those highly-precise clocks on the realization of reference frames and time scales used in geodesy. We discuss the current definitions of basic geodetic concepts and come to the conclusion that the advances in clocks and other metrological technologies will soon require the re-definition of time scales or, at least, clarification to ensure their continuity and consistent use in practice. The relative frequency shift between two clocks is directly related to the difference in the values of the gravity potential at the points of clock's localization. According to general relativity the relative accuracy of clocks in 10^{-18} is equivalent to measuring the gravitational red shift effect between two clocks with the height difference amounting to 1 cm. This makes the clocks an indispensable tool in high-precision geodesy in addition to laser ranging and space geodetic techniques. We show how clock measurements can provide geopotential numbers for the realization of gravity-field-related height systems and can resolve discrepancies in classically-determined height systems as well as between national height systems. Another application of clocks is the direct use of observed potential differences for the improved recovery of regional gravity field solutions. Finally, clock measurements for space-borne gravimetry are analyzed along with

  7. Crystal field interactions studied by high-field magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Radwanski, R.J.; Franse, J.J.M. (Van der Waals-Zeeman Lab., Univ. Amsterdam (Netherlands))

    1992-03-01

    The effect of crystalline electric field (CEF) interactions of the 4f ions on the magnetization process is reviewed for some intermetallic compounds. Special emphasis is given to metamagnetic transitions. The transitions in Ho{sub 2}Co{sub 17} are exchange-driven transitions associated with the formation of a non-collinear magnetic structure in contrast to the transition found in DyCo{sub 2}Si{sub 2} that is of a level-crossing type. The transition found in Pr{sub 2}Fe{sub 14}B results from a competition between lower and higher order crystal field terms. The formation of the rare earth moment under the action of CEF and exchange interactions as well as of external fields is analyzed. (orig.).

  8. Nonlinear relaxation field in charged systems under high electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Morawetz, K

    2000-07-01

    The influence of an external electric field on the current in charged systems is investigated. The results from the classical hierarchy of density matrices are compared with the results from the quantum kinetic theory. The kinetic theory yields a systematic treatment of the nonlinear current beyond linear response. To this end the dynamically screened and field-dependent Lenard-Balescu equation is integrated analytically and the nonlinear relaxation field is calculated. The classical linear response result known as Debye - On-Sager relaxation effect is only obtained if asymmetric screening is assumed. Considering the kinetic equation of one specie the other species have to be screened dynamically while the screening with the same specie itself has to be performed statically. Different other approximations are discussed and compared. (author)

  9. "Molecular" MR imaging at high fields.

    Science.gov (United States)

    Gore, John C; Zu, Zhongliang; Wang, Ping; Li, Hua; Xu, Junzhong; Dortch, Richard; Gochberg, Daniel F

    2017-05-01

    Magnetic resonance imaging (MRI) and spectroscopy (MRS) have contributed considerably to clinical radiology, and a variety of MR techniques have been developed to evaluate pathological processes as well as normal tissue biology at the cellular and molecular level. However, in comparison to nuclear imaging, MRI has relatively poor sensitivity for detecting true molecular changes or for detecting the presence of targeted contrast agents, though these remain under active development. In recent years very high field (7T and above) MRI systems have been developed for human studies and these provide new opportunities and technical challenges for molecular imaging. We identify 5 types of intrinsic contrast mechanisms that do not require the use of exogenous agents but which can provide molecular and cellular information. We can derive information on tissue composition by (i) imaging different nuclei, especially sodium (ii) exploiting chemical shift differences as in MRS (iii) exploiting specific relaxation mechanisms (iv) exploiting tissue differences in the exchange rates of molecular species such as amides or hydroxyls and (v) differences in susceptibility. The increased signal strength at higher fields enables higher resolution images to be acquired, along with increased sensitivity to detecting subtle effects caused by molecular changes in tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. High sensitivity field asymmetric ion mobility spectrometer.

    Science.gov (United States)

    Chavarria, Mario A; Matheoud, Alessandro V; Marmillod, Philippe; Liu, Youjiang; Kong, Deyi; Brugger, Jürgen; Boero, Giovanni

    2017-03-01

    A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 10 12 V/A with an effective equivalent input noise level down to about 1 fA/Hz 1/2 during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.

  11. High sensitivity field asymmetric ion mobility spectrometer

    Science.gov (United States)

    Chavarria, Mario A.; Matheoud, Alessandro V.; Marmillod, Philippe; Liu, Youjiang; Kong, Deyi; Brugger, Jürgen; Boero, Giovanni

    2017-03-01

    A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 1012 V/A with an effective equivalent input noise level down to about 1 fA/Hz1/2 during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.

  12. Association of ESR1 gene tagging SNPs with breast cancer risk

    DEFF Research Database (Denmark)

    Dunning, Alison M; Healey, Catherine S; Baynes, Caroline

    2009-01-01

    associations were revealed. SNP rs3020314, tagging a region of ESR1 intron 4, is associated with an increase in breast cancer susceptibility with a dominant mode of action in European populations. Carriers of the c-allele have an odds ratio (OR) of 1.05 [95% Confidence Intervals (CI) 1.02-1.09] relative to t......We have conducted a three-stage, comprehensive single nucleotide polymorphism (SNP)-tagging association study of ESR1 gene variants (SNPs) in more than 55,000 breast cancer cases and controls from studies within the Breast Cancer Association Consortium (BCAC). No large risks or highly significant......, and it may subtly alter the ratio of two mRNA splice forms....

  13. Plant Responses to High Frequency Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Alain Vian

    2016-01-01

    Full Text Available High frequency nonionizing electromagnetic fields (HF-EMF that are increasingly present in the environment constitute a genuine environmental stimulus able to evoke specific responses in plants that share many similarities with those observed after a stressful treatment. Plants constitute an outstanding model to study such interactions since their architecture (high surface area to volume ratio optimizes their interaction with the environment. In the present review, after identifying the main exposure devices (transverse and gigahertz electromagnetic cells, wave guide, and mode stirred reverberating chamber and general physics laws that govern EMF interactions with plants, we illustrate some of the observed responses after exposure to HF-EMF at the cellular, molecular, and whole plant scale. Indeed, numerous metabolic activities (reactive oxygen species metabolism, α- and β-amylase, Krebs cycle, pentose phosphate pathway, chlorophyll content, terpene emission, etc. are modified, gene expression altered (calmodulin, calcium-dependent protein kinase, and proteinase inhibitor, and growth reduced (stem elongation and dry weight after low power (i.e., nonthermal HF-EMF exposure. These changes occur not only in the tissues directly exposed but also systemically in distant tissues. While the long-term impact of these metabolic changes remains largely unknown, we propose to consider nonionizing HF-EMF radiation as a noninjurious, genuine environmental factor that readily evokes changes in plant metabolism.

  14. Plant Responses to High Frequency Electromagnetic Fields

    Science.gov (United States)

    Vian, Alain; Davies, Eric; Gendraud, Michel; Bonnet, Pierre

    2016-01-01

    High frequency nonionizing electromagnetic fields (HF-EMF) that are increasingly present in the environment constitute a genuine environmental stimulus able to evoke specific responses in plants that share many similarities with those observed after a stressful treatment. Plants constitute an outstanding model to study such interactions since their architecture (high surface area to volume ratio) optimizes their interaction with the environment. In the present review, after identifying the main exposure devices (transverse and gigahertz electromagnetic cells, wave guide, and mode stirred reverberating chamber) and general physics laws that govern EMF interactions with plants, we illustrate some of the observed responses after exposure to HF-EMF at the cellular, molecular, and whole plant scale. Indeed, numerous metabolic activities (reactive oxygen species metabolism, α- and β-amylase, Krebs cycle, pentose phosphate pathway, chlorophyll content, terpene emission, etc.) are modified, gene expression altered (calmodulin, calcium-dependent protein kinase, and proteinase inhibitor), and growth reduced (stem elongation and dry weight) after low power (i.e., nonthermal) HF-EMF exposure. These changes occur not only in the tissues directly exposed but also systemically in distant tissues. While the long-term impact of these metabolic changes remains largely unknown, we propose to consider nonionizing HF-EMF radiation as a noninjurious, genuine environmental factor that readily evokes changes in plant metabolism. PMID:26981524

  15. High-Gain High-Field Fusion Plasma

    Science.gov (United States)

    Li, Ge

    2015-01-01

    A Faraday wheel (FW)—an electric generator of constant electrical polarity that produces huge currents—could be implemented in an existing tokamak to study high-gain high-field (HGHF) fusion plasma, such as the Experimental Advanced Superconducting Tokamak (EAST). HGHF plasma can be realized in EAST by updating its pulsed-power system to compress plasma in two steps by induction fields; high gains of the Lawson trinity parameter and fusion power are both predicted by formulating the HGHF plasma. Both gain rates are faster than the decrease rate of the plasma volume. The formulation is checked by earlier ATC tests. Good agreement between theory and tests indicates that scaling to over 10 T at EAST may be possible by two-step compressions with a compression ratio of the minor radius of up to 3. These results point to a quick new path of fusion plasma study, i.e., simulating the Sun by EAST. PMID:26507314

  16. ESR rate can be a marker for coronary artery disease

    Directory of Open Access Journals (Sweden)

    Eghbal Eftekhaari T

    2012-12-01

    Full Text Available Tasnim Eghbal EftekhaariClinical Research Development Center of Shahid Mohammadi Hospital, Research Center for Cardiovascular Diseases, Department of Research and Technology, Hormozgan University of Medical Sciences, Bandar-e-Abbas, IranThe aim of Yayan’s1 study was to utilize the erythrocyte sedimentation rate (ESR as a rapid guide to identify patients with acute coronary syndrome (ACS or myocardial infarction. ESR is arguably a nonspecific biomarker which is elevated in almost every condition. Prakash et al2 have pointed to conflicting reports in the literature documenting the tendency of patients with periodontitis to develop anemia. Hence, this study was undertaken to assess whether periodontitis can cause an anemic state by evaluating and comparing the red blood cell count and levels of hemoglobin, hematocrit, ESR, serum iron, and serum ferritin between subjects with and without periodontitis, anemia, rheumatoid arthritis, and other hematologic conditions.1 However, this study shows that there is no statistically significant difference between rates of ESR in men and women. The purpose of referring to this reference is that most elderly people suffer from periodontitis and this condition is not negligible given that many older people also suffer for concomitant ischemic heart disease. Inflammation arising within the gastrointestinal tract may be of great importance in the pathogenesis of irritable bowel syndrome,2 regarding this fact that ESR is commonly used to assess the acute phase response,3 this acute phase response may be nonspecific. Elevated ESR is seen more often in elderly patients than in their younger counterparts3 (imagine an elderly patient with elevated ESR and consider whether ESR would be used as the sole basis for diagnosis of heart pain? Of course not!. ESR elevated concomitantly with C-reactive protein is used to confirm adult-onset Still’s disease.4 In an adult who is a heavy smoker with dyslipidemia, a personal

  17. Magnetic field effect in highly pure, highly fluorescent conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Graupner, W.; Sacher, M.; Graupner, M.; Zenz, C.; Grampp, G.; Hermetter, A.; Leising, G.

    1998-07-01

    The authors report on the magnetic field effect (MFE) on the photoluminescence in films of a highly fluorescent conjugated laddertype poly(paraphenylene) (LPPP). They observe no MFE for the pure material, however, the introduction of a very small content of chemical defects via photo-oxidation leads to a MFE proportional to the amount of defects. The chemically induced increase in MFE is correlated with a change in other properties of the LPPP films, such as photoluminescence emission and excitation spectra, transient photoluminescence and infrared spectra.

  18. High magnetic field ohmically decoupled non-contact technology

    Science.gov (United States)

    Wilgen, John [Oak Ridge, TN; Kisner, Roger [Knoxville, TN; Ludtka, Gerard [Oak Ridge, TN; Ludtka, Gail [Oak Ridge, TN; Jaramillo, Roger [Knoxville, TN

    2009-05-19

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  19. Ultrafast outflows disappear in high radiation fields

    Science.gov (United States)

    Pinto, C.; Alston, W.; Parker, M. L.; Fabian, A. C.; Gallo, L. C.; Buisson, D. J. K.; Walton, D. J.; Kara, E.; Jiang, J.; Lohfink, A.; Reynolds, C. S.

    2018-01-01

    Ultrafast outflows (UFOs) are the most extreme winds launched by active galactic nuclei (AGN) due to their mildly-relativistic speeds (˜0.1 - 0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their nature and launching mechanism are however not well understood. Recently, we have discovered the presence of a variable UFO in the narrow-line Seyfert 1 IRAS 13224-3809. The UFO varies in response to the brightness of the source. In this work we perform flux-resolved X-ray spectroscopy to study the variability of the UFO and found that the ionisation parameter is correlated with the luminosity. In the brightest states the gas is almost completely ionised by the powerful radiation field and the UFO is hardly detected. This agrees with our recent results obtained with principal component analysis. We might have found the tip of the iceberg: the high ionisation of the outflowing gas may explain why it is commonly difficult to detect UFOs in AGN and possibly suggest that we may underestimate their actual feedback. We have also found a tentative correlation between the outflow velocity and the luminosity, which is expected from theoretical predictions of radiation-pressure driven winds. This trend is rather marginal due to the Fe XXV-XXVI degeneracy. Further work is needed to break such degeneracy through time-resolved spectroscopy.

  20. Quantifying the impact of µCT-scanning of human fossil teeth on ESR age results.

    Science.gov (United States)

    Duval, Mathieu; Martín-Francés, Laura

    2017-05-01

    Fossil human teeth are nowadays systematically CT-scanned by palaeoanthropologists prior to any further analysis. It has been recently demonstrated that this noninvasive technique has, in most cases, virtually no influence on ancient DNA preservation. However, it may have nevertheless an impact on other techniques, like Electron Spin Resonance (ESR) dating, by artificially ageing the apparent age of the sample. To evaluate this impact, we µCT-scanned several modern enamel fragments following the standard analytical procedures employed by the Dental Anthropology Group at CENIEH, Spain, and then performed ESR dose reconstruction for each of them. The results of our experiment demonstrate that the systematic high-resolution µCT-scanning of fossil hominin remains introduces a nonnegligible X-ray dose into the tooth enamel, equivalent to 15-30 Gy depending on the parameters used. This dose may be multiplied by a factor of ∼8 if no metallic filter is used. However, this dose estimate cannot be universally extrapolated to any µCT-scan experiment but has instead to be specifically assessed for each device and set of parameters employed. The impact on the ESR age results is directly dependent on the magnitude of the geological dose measured in fossil enamel but could potentially lead to an age overestimation up to 40% in case of Late Pleistocene samples, if not taken into consideration. © 2017 Wiley Periodicals, Inc.

  1. Toward an integrated computational approach to CW-ESR spectra of free radicals.

    Science.gov (United States)

    Barone, Vincenzo; Polimeno, Antonino

    2006-10-28

    Interpretation of structural properties and dynamic behaviour of molecules in solution is of fundamental importance to understand their stability, chemical reactivity and catalytic action. Information can be gained, in principle, by a variety of spectroscopic techniques, magnetic as well as optical. In particular, continuous wave electron spin resonance (CW-ESR) measurements are highly informative. However, the wealth of structural and dynamic information which can be extracted from ESR spectroscopy is, at present, limited by the necessity of employing computationally efficient models, which are increasingly complex as they need to take into account diverse relaxation processes affecting the spectrum. In this paper, we address the basic theoretical tools needed to predict, essentially ab initio, CW-ESR spectra observables according to the stochastic Liouville equation (SLE) approach, combined with quantum mechanical and hybrid methods for the accurate and efficient computation of structural, spectroscopic and magnetic properties of molecular systems. We shall discuss, on one hand, the quantum mechanical calculation of magnetic observables, via density functional theory (DFT), time-dependent DFT (TD-DFT) and application of the polarizable continuum model (PCM) for the description of environmental effects, including anisotropic environments and systems where different regions are characterized by different dielectric constants. One the other hand, the explicit evaluation of dynamical effects will be discussed based on the numerically exact treatment of the SLE in the presence of several relaxation processes, which has been proven to be a challenging task.

  2. Application of ESR spin label oximetry in food science.

    Science.gov (United States)

    Zhou, Yu-Ting; Yin, Jun-Jie; Lo, Y Martin

    2011-12-01

    Lipid oxidation attributed to the presence of oxygen has long been a focal area for food science research due in early years mainly to its broad impact on the quality and shelf stability. The need to effectively strategize interventions to detect and eventually eliminate lipid oxidation in food remains as evidence on nutritional and health implications continue to accumulate. Electron spin resonance (ESR) spin label oximetry has been shown capable of detecting dissolved oxygen concentration in both liquid and gaseous phases based on the collision between oxygen and stable free radicals. This review aimed to summarize not just the principles and rationale of ESR spin label oximetry but also the wide spectrum of ESR spin label oximetry applications to date. The feasibility to identify in very early stage oxygen generation and consumption offers a promising tool for controlling lipid oxidation in food and biological systems. Copyright © 2012 John Wiley & Sons, Ltd.

  3. A new ESR dosimeter based on bioglass material

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, G.M. E-mail: gamalhassan65@hotmail.com; Sharaf, M.A.; Desouky, Omar S

    2004-06-01

    Bioglass (Bio-G) samples were irradiated with {sup 60}Co {gamma}-rays to study radicals for dosimetric materials with electron spin resonance (ESR). The ESR spectrum of Bio-G is characterized by two main signals. The first signal at g congruent with 4.3 corresponds to Fe{sup 3+} impurities and the second signal at g congruent with 2.0130 with line-width 10.85 G is ascribed as a hole center. The {gamma}-ray dose response and thermal stability were studied to establish the suitability of Bio-G as an ESR dosimeter. A radical formation efficiency, G-value, of 0.53{+-}0.11 was obtained. The lifetime of radicals and the activation energy were estimated from Arrhenius plots to be approximately 255{+-}46 days and 0.71 eV, respectively.

  4. ESR dating of barite in sea-floor hydrothermal sulfide deposits at Okinawa Trough

    Science.gov (United States)

    Fujiwara, T.; Toyoda, S.; Uchida, A.; Ishibashi, J.; Nakai, S.; Takamasa, A.

    2013-12-01

    The temporal change of submarine hydrothermal activities has been an important issue in the aspect of the evolution of hydrothermal systems which is related with ore formation and biological systems sustained by the chemical species arising from hydrothermal activities (Macdonald et al., 1980). With this aspect, Okumura et al. (2010) made the first practical application of ESR (electron spin resonance) dating technique to a sample of submarine hydrothermal barite to obtain preliminary ages, while Kasuya et al. (1991) first pointed out that barite can be used for ESR dating. ESR is a method to observe radicals having unpaired electrons. As natural radiation creates unpaired electrons in minerals, the age is deduced by dividing the natural radiation dose (obtained from the amount of unpaired electrons) by the dose rate which is estimated by the amount of environmental radioactive elements. The samples were taken by the research cruises, NT12-10 and NT11-20 and NT12-06 operated by JAMSTEC from Hatoma, Yoron, Izena, North Iheya, and Yonaguni IV Knolls of Okinawa Trough. The blocks of sulfide deposits were cut into pieces, and about 2.0g was crushed. The samples were soaked in 12M hydrochloric acid, left for approximately 24 hours. Then, 13M nitric acid was added. Finally, after rinsing in distilled water, the sample was filtered and dried. Impurities were removed by handpicking. A X-ray diffraction study was made to confirm that the grains are pure barite. After γ-ray irradiation at Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, they were measured at room temperature with an ESR spectrometer (JES-PX2300) with a microwave power of 1mW, and the magnetic field modulation amplitude of 0.1mT. The equivalent natural radiation doses were obtained from the increase of ESR signal intensity of SO3- by irradiation. The bulk Ra concentration was measured by the low background pure Ge gamma ray spectrometer. Assuming that Ra is populated only in barite

  5. Estimation of absorbed dose in irradiated dates ( Phoenix dactylifera L.). Test of ESR response function by a weighted linear least-squares regression analysis

    Science.gov (United States)

    Ghelawi, M. A.; Moore, J. S.; Bisby, R. H.; Dodd, N. J. F.

    2001-01-01

    Food spoilage is caused by infestation by insects, contamination by bacteria and fungi and by deterioration by enzymes. In the third world, it has been estimated that 25% of agricultural products are lost before they reach the market. One way to decrease such losses is by treatment with ionising radiation and maximum permitted doses have been established for treatment of a wide variety of foods. For dates this dose is 2.0 kGy. Detection of irradiated foods is now essential and here we have used ESR to detect and estimate the dose received by a single date. The ESR spectrum of unirradiated date stone contains a single line g=2.0045 (signal A). Irradiation up to 2.0 kGy induces radical formation with g=1.9895, g=2.0159 (signal C) and g=1.9984 (signal B) high field. The lines with g=1.9895 and 2.0159 are readily detected and stable at room temperature for at least 27 months for samples irradiated up to this dose. The yield of the radicals resulting in these lines increase linearly up to a dose of 5.0 kGy as is evidenced by the linear increase in their intensity. In blind trials of 21 unirradiated and irradiated dates we are able to identify with 100% accuracy an irradiated sample and to estimate the dose to which the sample was irradiated to within ˜0.5 kGy.

  6. Investigating High Field Gravity using Astrophysical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Elliott D.; /SLAC

    2008-02-01

    The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques. As the subject matter is vast, compromises are necessary in order to convey the central ideas to the reader. Many general references are included for those who want to learn more. The paragraphs below elaborate on the structure of these lectures. I hope this discussion will clarify my motivation and make the lectures easier to follow. The lectures begin with a brief review of more theoretical ideas. First, elements of general relativity are reviewed, concentrating on those aspects that are needed to understand compact stellar objects (white dwarf stars, neutron stars, and black holes). I then review the equations of state of these objects, concentrating on the simplest standard models from astrophysics. After these mathematical preliminaries, Sec. 2(c) discusses 'The End State of Stars'. Most of this section also uses the simplest standard models. However, as these lectures are for particle physicists, I also discuss some of the more recent approaches to the equation of state of very dense compact objects. These particle-physics-motivated equations of state can dramatically change how we view the formation of black holes. Section 3 focuses on the properties of the objects that we want to characterize and measure. X-ray binary systems and Active Galactic Nuclei (AGN) are stressed because the lectures center on understanding very dense stellar objects, black hole candidates (BHCs), and their accompanying high gravitational fields. The use of x-ray timing and gamma-ray experiments is also introduced in this section. Sections 4 and 5 review information from x-ray and gamma-ray experiments. These sections also discuss the current state of the art in x-ray and gamma-ray satellite

  7. Threats to ultra-high-field MRI

    Science.gov (United States)

    Le Bihan, Denis

    2009-08-01

    In 2004 the European Commission (EC) adopted a directive restricting occupational exposure to electromagnetic fields. This directive (2004/40/CE), which examines the possible health risks of the electromagnetic fields from mobile phones, Wi-Fi, Bluetooth and other devices, concluded that upper limits on radiation and applied electromagnetic fields are necessary to prevent workers from suffering any undue acute health effects. But although not initially intended, the biggest impact of the directive could be on magnetic resonance imaging (MRI), which is used in hospitals worldwide to produce images of unrivalled quality of the brain and other soft tissues.

  8. Scaling down the two-dimensional electron gas spin resonance (ESR) phenomena in GaAs/AlGaAs heterostructures to sub-micron samples

    Science.gov (United States)

    Bandaru, Prabhakar; Yablonovitch, Eli; Jiang, Hong-Wen

    2002-03-01

    Electron Spin Resonance (ESR) has been proposed as a technique for achieving single electron and subsequently single spin control, important for the emerging fields of spintronics and quantum computing. In this paper, we report on ESR in the quantum Hall regime, of sub-micron structures containing a few hundred electrons. These phenomena are contrasted with ESR phenomena in structures containing 10^7 - 10^9 electrons, which have been performed so far (Reference 1). There are several novel features observed in the ESR of small structures, such as a very large decrease of resistance and shift in the quantum Hall minima to lower magnetic fields after the resonance. These imply a reduction in the number of electrons and could result from the greater influence of the surface and impurity potential fluctuations intrinsic to a small sample. The ESR peak intensity is hypothesized to result from the transfer of electrons from the localized states to the extended states. References: 1.H.W.Jiang and E. Yablonovitch, Phys. Rev.B., 64, R041307, (2001) 2.M.Dobers, K.v. Klitzing and G. Weimann,Phys. Rev. B, 38, 5453, (1988).

  9. Highly educated but in the wrong field?

    DEFF Research Database (Denmark)

    Reimer, David; Steinmetz, Stephanie

    2009-01-01

      This paper investigates the impact of gender differences in tertiary education, i.e., field of study and level of tertiary degree, on two selected labour market risks: unemployment and low-status jobs. Using Labour Force Survey data from the year 2000, results of the logistic regression models...... and non-linear decomposition analyses generally confirm our expectation that the field of study explains a sizable portion of the gender gap in unemployment and low-status jobs in both countries. However, the level of tertiary degree earned explains only part of the female disadvantage behind holding...... a low-status job in Spain. The analyses also show that compared to men, women with a degree in a predominantly male field of study seem to be systematically disadvantaged in both Germany and Spain, particularly with respect to unemployment. Overall, the analyses reveal that gender differentiation...

  10. ESR dosimetry of irradiated chicken legs and chicken eggs

    Energy Technology Data Exchange (ETDEWEB)

    Onori, S.; Pantaloni, M. [Istituto Superiore di Sanita, Rome (Italy). Lab. di Fisica

    1996-12-31

    Ionising radiation induces stable free radicals in chicken bones and in the shell of chicken eggs which can be detected, by the electrons spin resonance (ESR) technique, well beyond the shelf-life of the food and can be used for dosimetry. The method usually adopted to evaluate ``a posteriori`` the dose given during the ionising radiation treatment of food, is the dose additive method. To assess the dose, the ESR signal amplitude of the irradiated food (bone or egg shell in the present case) is measured and then the dose-effect relationship is obtained by re-irradiating the sample with some additive doses (usually of 1 kGy). The dose-effect curve is back-extrapolated and the initial given dose determined. At the Istituto Superiore di Sanita (ISS), Rome, Italy, a research programme was approved two years ago aimed to, (1) study new methodological approaches for ESR dose assessment, and (2) analyse the factors which may influence the ESR readout of irradiated chicken bones and chicken egg shells. (author).

  11. Plasma instabilities in high electric fields

    DEFF Research Database (Denmark)

    Morawetz, K.; Jauho, Antti-Pekka

    1994-01-01

    expression is derived for the nonequilibrium dielectric function epsilon(K, omega). For certain values of momenta K and frequency omega, Imepsilon(K, omega) becomes negative, implying a plasma instability. This new instability exists only for strong electric fields, underlining its nonequilibrium origin....

  12. High Field Magnetization of Tb Single Crystals

    DEFF Research Database (Denmark)

    Roeland, L. W.; Cock, G. J.; Lindgård, Per-Anker

    1975-01-01

    The magnetization of Tb single crystals was measured in magnetic fields to 34T along the hard direction at temperature of 1.8, 4.2, 65.5 and 77K, and along with easy direction at 4.2 and 77K. The data are compared with the results of a self-consistent spin wave calculation using a phenomenologica...... data on Tb. The conduction-electron polarization at zero field and temperature is (0.33+or-0.05) mu B/ion, and the susceptibility is greater than the Pauli susceptibility calculated from the band-structure.......The magnetization of Tb single crystals was measured in magnetic fields to 34T along the hard direction at temperature of 1.8, 4.2, 65.5 and 77K, and along with easy direction at 4.2 and 77K. The data are compared with the results of a self-consistent spin wave calculation using a phenomenological...... Hamiltonian including isotropic exchange interactions, effective single-ion anisotropy and magnetoelastic contributions. The parameters of this Hamiltonian were determined by fitting the theoretical results for the spin wave dispersion and energy gap as a function of temperature and magnetic field to existing...

  13. File list: Oth.ALL.05.ESR1.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.ESR1.AllCell hg19 TFs and others ESR1 All cell types SRX016326,SRX026903...,SRX1012689,SRX490434,SRX490433,SRX469398,SRX1272813,SRX036563 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.ALL.05.ESR1.AllCell.bed ...

  14. File list: Oth.Prs.20.ESR1.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Prs.20.ESR1.AllCell hg19 TFs and others ESR1 Prostate SRX222275,SRX222273,SRX22...2272,SRX222274 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Prs.20.ESR1.AllCell.bed ...

  15. File list: Oth.Prs.50.ESR1.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Prs.50.ESR1.AllCell hg19 TFs and others ESR1 Prostate SRX222275,SRX222273,SRX22...2272,SRX222274 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Prs.50.ESR1.AllCell.bed ...

  16. Dielectric shimming : exploiting dielectric interactions in High Field MRI

    NARCIS (Netherlands)

    Brink, Wyger Maurits

    2016-01-01

    This thesis reports on the utility of high permittivity dielectric materials for adjusting the radiofrequency (RF) field in high field MR. The performance-driven trend towards higher static magnetic field strengths drives MR operation into the regime where the dimensions of the body section being

  17. ESR, thermoelectrical and positron annihilation Doppler broadening studies of CuZnFe{sub 2}O{sub 4}-BaTiO{sub 3} composite

    Energy Technology Data Exchange (ETDEWEB)

    Hemeda, O.M. [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Mahmoud, K.R. [Physics Department, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh (Egypt); Sharshar, T. [Physics Department, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh (Egypt); Physics Department, Faculty of Science, Taif University, Al-Hawiah, Taif, P.O. Box 888 Zip Code 21974 (Saudi Arabia); Elsheshtawy, M. [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); Hamad, Mahmoud A., E-mail: m_hamad76@yahoo.com [Physics Department, Faculty of Science, Tanta University, Tanta (Egypt); King Marriott Academy for Engineering & Technology, Alexandria (Egypt)

    2017-05-01

    Composite materials of Cu{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} (CZF) and barium titanate (BT) with different concentrations were prepared by high energy ball milling method. The composite samples of CZF and BT were studied using Infrared, ESR and positron annihilation Doppler broadening (PADB) spectroscopy techniques as well as thermo-electric power measurements. The results confirm formation of the composite, and presence of two ferrimagnetic and ferroelectric phases, simultaneously. In addition, Fe–O bond for both tetrahedral and octahedral sites, population and distribution of cations at A and B sites are varied with BT content. The values of resonance field, line width of ESR spectrum and charge carrier concentration increase by increasing BT content. The value of the g factor for our samples with low BT content is greater than g-factor value of the isolated free electron. On the contrary, the g-factor values for samples with high BT content are smaller than the free isolated electron. PADB line-shape S-parameter suggests that there are increases of the density of the delocalized electrons, defect size and concentration caused by highly adding BT phase. In addition, PADB results confirm the homogeneity of composite phases and same structure of defects in BT-CZF composite samples. - Highlights: • Composite materials of Cu{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4} (CZF) and barium titanate (BT) were prepared. • The resonance field and charge carrier concentration increase by increasing BT. • there is increase of the density of delocalized electrons by highly adding BT. • In addition, PADB results confirm the homogeneity of composite phases.

  18. Flatland Electrons in High Magnetic Fields

    Science.gov (United States)

    Shayegan, M.

    This paper provides a review of recent developments in the physics of two-dimensional carrier systems in perpendicular magnetic fields. The emphasis is on many-body phenomena in very clean GaAs/AlGaAs heterostructures, probed via magnetotransport measurements. Topics that are discussed include the integer and fractional quantum Hall effects, Wigner crystallization, composite Fermions, Skyrmions, stripe and bubble phases in single layer systems, and electron-hole pairing and Bose-Einstein condensation in interacting bilayer systems.

  19. Matrix isolation ESR spectroscopy and magnetic anisotropy of D{sub 3h} symmetric septet trinitrenes

    Energy Technology Data Exchange (ETDEWEB)

    Misochko, Eugenii Ya.; Akimov, Alexander V.; Masitov, Artem A.; Korchagin, Denis V.; Aldoshin, Sergei M.; Chapyshev, Sergei V. [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region 142432 (Russian Federation)

    2013-05-28

    The fine-structure (FS) parameters D of a series of D{sub 3h} symmetric septet trinitrenes were analyzed theoretically using density functional theory (DFT) calculations and compared with the experimental D values derived from ESR spectra. ESR studies show that D{sub 3h} symmetric septet 1,3,5-trichloro-2,4,6-trinitrenobenzene with D=-0.0957 cm{sup -1} and E= 0 cm{sup -1} is the major paramagnetic product of the photolysis of 1,3,5-triazido-2,4,6-trichlorobenzene in solid argon matrices at 15 K. Trinitrenes of this type display in the powder X-band ESR spectra intense Z{sub 1}-transition at very low magnetic fields, the position of which allows one to precisely calculate the parameter D of such molecules. Thus, our revision of the FS parameters of well-known 1,3,5-tricyano-2,4,6-trinitrenobenzene [E. Wasserman, K. Schueller, and W. A. Yager, Chem. Phys. Lett. 2, 259 (1968)] shows that this trinitrene has Double-Vertical-Line D Double-Vertical-Line = 0.092 cm{sup -1} and E= 0 cm{sup -1}. DFT calculations reveal that, unlike C{sub 2v} symmetric septet trinitrenes, D{sub 3h} symmetric trinitrenes have the same orientations of the spin-spin coupling tensor D-caret{sub SS} and the spin-orbit coupling tensor D-caret{sub SOC} and, as a result, have negative signs for both the D{sub SS} and D{sub SOC} values. The negative magnetic anisotropy of septet 2,4,6-trinitrenobenzenes is considerably strengthened on introduction of heavy atoms in the molecules, owing to an increase in contributions of various excitation states to the D{sub SOC} term.

  20. Investigations of the MCP Detector of a Time-Of-Flight Detector for IMS at the FRS-ESR

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, Christine; Diwisch, Marcel; Kuzminchuk-Feuerstein, Natalia [Justus Liebig Universitaet Giessen (Germany); Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [Justus Liebig Universitaet Giessen (Germany); GSI, Darmstadt (Germany)

    2013-07-01

    The Isochronous Mass Spectrometry at the FRS-ESR facility at GSI can be used to perform high-precision mass measurements of exotic nuclei. The mass values are obtained from measuring the revolution time of the ions in the storage ring with a time-of-flight detector. The ions pass a thin carbon foil in the detector and release secondary electrons. These electrons are guided by electric and magnetic fields to two MCP detectors. Their number is amplified by micro channel plates and the resulting current is detected by an anode. In order to achieve an accurate time signal, the timing performance of the MCP detector is very important. The timing performance and the signal shape of the detector setup has been improved by including a new anode design. At the same time, the detector performance dependence on the magnetic field and the electron velocity inside of the MCP-detector was tested. The new detector design and the test results are presented.

  1. Copper (II) complexes of N4, N4-disubstituted thio- and selenosemicarbazones of 2-acetylpyridine: ESR studies

    Science.gov (United States)

    K. Bhoon, Yudhvir; Scovill, John P.; Klayman, Daniel L.

    Copper(II) complexes of 3-azabicyclo[3.2.2]nonane-3-thiocarboxylic acid 2-[1-(pyridinyl)ethylidene]hydrazide, and its selenium analog, 3-azabicyclo[3.2.2]nonane-3-selenocarboxylic acid 2-[1-(2-pyridinyl)ethylidene]hydrazide, were studied by ESR spectrometry in chloroform solution at room temperature and at liquid nitrogen temperature. ESR spectra were also observed for the complexes as magnetically doped samples in the corresponding Ni(II) lattices at room temperature. Nitrogen superhyperfine splitting is observed at room temperature in all the spectra. Splitting patterns indicate the non-equivalent nature of the two coordinating nitrogen atoms. The covalency parameter for the metal—ligand bond was determined for selected complexes. An order of ligand field strength has been proposed based on the magnitude of the g| component of g observed in the polycrystalline state.

  2. ESR spectroscopic investigations of the radiation-grafting of fluoropolymers

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, G.; Roduner, E. [University of Stuttgart (Germany); Brack, H.P.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    ESR spectroscopic investigations have clarified the influence of several preparative parameters on the reaction rates and yields obtained in the radiation-grafting method used at PSI to prepare proton-conducting polymer membranes. At a given irradiation dose, a higher concentration of reactive radical sites was detected in ETFE films than in FEP films. This higher concentration explains the higher grafting levels and rates of the ETFE films found in our previous grafting experiments. Taken together, the in-situ ESR experiments and grafting experiments show that the rates of disappearance of radical species and grafting rates and final grafting levels depend strongly on the reaction temperature and the oxygen content of the system. Average grafted chain lengths were calculated to contain about 1,000 monomer units. (author) 2 figs., 4 refs.

  3. An ESR study of manganese binding in plant tissue.

    Science.gov (United States)

    Bacić, G; Schara, M; Ratković, S

    1993-02-01

    Two different fractions of manganese were found in the maize plant root apoplasm (intercellular space containing cell walls) after soaking the roots in MnCl2 solutions (concentration range 0.01-10 mmol.l-1): (a) an Mn2+ fraction in the water free space (WFS) which gave a characteristic six-line spectrum, and (b) an immobilized fraction that gave no detectable ESR spectrum. Both fractions affect proton NMR relaxation (T1) of the tissue water through water exchange across cell membranes. ESR spectra of free and total manganese of the root tissue treated with MnCl2 also revealed different time courses for saturation of WFS and DFS with Mn2+. Binding of manganese in the extracellular space of the tissue seems to be the rate limiting step in permeation of Mn2+ across the root cell membranes.

  4. Esr1+ cells in the ventromedial hypothalamus control female aggression.

    Science.gov (United States)

    Hashikawa, Koichi; Hashikawa, Yoshiko; Tremblay, Robin; Zhang, Jiaxing; Feng, James E; Sabol, Alexander; Piper, Walter T; Lee, Hyosang; Rudy, Bernardo; Lin, Dayu

    2017-11-01

    As an essential means of resolving conflicts, aggression is expressed by both sexes but often at a higher level in males than in females. Recent studies suggest that cells in the ventrolateral part of the ventromedial hypothalamus (VMHvl) that express estrogen receptor-α (Esr1) and progesterone receptor are essential for male but not female mouse aggression. In contrast, here we show that VMHvlEsr1+ cells are indispensable for female aggression. This population was active when females attacked naturally. Inactivation of these cells reduced female aggression whereas their activation elicited attack. Additionally, we found that female VMHvl contains two anatomically distinguishable subdivisions that showed differential gene expression, projection and activation patterns after mating and fighting. These results support an essential role of the VMHvl in both male and female aggression and reveal the existence of two previously unappreciated subdivisions in the female VMHvl that are involved in distinct social behaviors.

  5. Radiofrequency solutions in clinical high field magnetic resonance

    NARCIS (Netherlands)

    Andreychenko, A.|info:eu-repo/dai/nl/341697672

    2013-01-01

    Magnetic resonance imaging (MRI) and spectroscopy (MRS) benefit from the sensitivity gain at high field (≥7T). However, high field brings also certain challenges associated with growing frequency and spectral dispersion. Frequency growth results in degraded performance of large volume radiofrequency

  6. High field electrical behaviour in lithium–phospho–vanadate glass ...

    Indian Academy of Sciences (India)

    High field electrical behaviour; lithium–phospho–vanadate glass system. 1. Introduction. High field electrical switching behaviour is one of the fascinating properties in oxide glasses, since it exhibits reversible threshold and irreversible memory states. Several investigations have been initiated to study switching in glasses ...

  7. High-order-harmonic generation from field-distorted orbitals

    DEFF Research Database (Denmark)

    Spiewanowski, Maciek; Etches, Adam; Madsen, Lars Bojer

    2013-01-01

    We investigate the effect on high-order-harmonic generation of the distortion of molecular orbitals by the driving laser field. Calculations for high-order-harmonic generation including orbital distortion are performed for N2. Our results allow us to suggest that field distortion is the reason why...

  8. High School Students' Representations and Understandings of Electric Fields

    Science.gov (United States)

    Cao, Ying; Brizuela, Bárbara M.

    2016-01-01

    This study investigates the representations and understandings of electric fields expressed by Chinese high school students 15 to 16 years old who have not received high school level physics instruction. The physics education research literature has reported students' conceptions of electric fields post-instruction as indicated by students'…

  9. Persistent free radicals in woodsmoke: an ESR spin trapping study.

    Science.gov (United States)

    Lachocki, T M; Church, D F; Pryor, W A

    1989-01-01

    Free radicals are detected in the gas-phase smoke resulting from the combustion of wood using the electron spin resonance (ESR) spin trapping method. The materials were pyrolyzed by rapid heating in a quartz tube in a flowing air stream. The filtered smoke was bubbled into a dodecane solution of alpha-phenyl-N-tert-butyl nitrone, and the resulting nitroxide radicals were detected by ESR. The radicals spin trapped from woodsmoke are compared to those we have spin trapped from tobacco smoke; the smoke from both yellow pine and oak produce more intense ESR spectra than does tobacco smoke per unit mass burned under the conditions of these experiments. When woodsmoke is bubbled through pure dodecane and the resulting woodsmoke/dodecane solution is held for a delay time before the PBN is added, radicals are detected even after the woodsmoke/dodecane solution is aged for more than 20 min. Similar experiments with tobacco smoke show that radicals no longer are trapped even after much shorter delay times from tobacco smoke/dodecane solutions.

  10. Rapid screening for anthocyanins in cane sugars using ESR spectroscopy.

    Science.gov (United States)

    Thamaphat, Kheamrutai; Goodman, Bernard A; Limsuwan, Pichet; Smith, Siwaporn Meejoo

    2015-03-15

    Anthocyanin, which is soluble in water and released into sugar steam during extraction, was investigated in this study. The anthocyanin content in refined sugar, plantation white sugar, soft brown sugar and raw sugar was determined using electron spin resonance (ESR) spectroscopy, which was operated at room temperature, and compared with spectra from standard anthocyanin. The ESR spectra of red and violet anthocyanins was predominantly g ≈ 2.0055, which corresponded to an unpaired electron located in the pyrylium ring. Signals for Fe(III) and Mn(II), which naturally occur in plants, were found in raw sugar, soft brown sugar and standard anthocyanin but were absent from refined sugar and plantation white sugar due to the refining process. In addition, the ESR results were correlated with the apparent colour of the sugar, which was determined using the method of the International Commission for Uniform Methods of Sugar Analysis and inductively coupled plasma optical emission spectroscopy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. ESR dosimeter material properties of phenols compound exposed to radiotherapeutic electron beams

    Science.gov (United States)

    Gallo, Salvatore; Iacoviello, Giuseppina; Bartolotta, Antonio; Dondi, Daniele; Panzeca, Salvatore; Marrale, Maurizio

    2017-09-01

    There is a need for a sensitive dosimeter using Electron Spin Resonance spectroscopy for use in medical applications, since non-destructive read-out and dose archival could be achieved with this method. This work reports a systematic ESR investigation of IRGANOX ® 1076 exposed to clinical electron beams produced by a LINAC used for radiation therapy treatments. Recently, dosimetric features of this material were investigated for irradiation with 60Co γ -photons and neutrons in both pellet and film shape and have been found promising thanks to their high efficiency of radiation-matter energy transfer and radical stability at room temperature. Here the analysis of the dosimetric features of these ESR dosimeters exposed to clinical electron beams at energies of 7, 10 and 14 MeV, is described in terms of dependence on microwave power and modulation amplitude, response on dose, dependence on beam type, detection limits, and signal stability after irradiation. The analysis of the ESR signal as function of absorbed dose highlights that the response of this material is linear in the dose range investigated (1-13 Gy) and is independent of the beam energy. The minimum detectable dose is found to be smaller than 1 Gy. Comparison of electron stopping power values of these dosimeters with those of water and soft tissue highlights equivalence of the response to electron beams in the energy range considered. The signal intensity was monitored for 40 days after irradiation and for all energies considered and it shows negligible variations in the first 500 h after irradiation whereas after 1100 h the signal decay is only of about 4%. In conclusion, it is found that phenolic compounds possess good dosimetric features which make it useful as a sensitive dosimeter for medical applications.

  12. Magnetic probe array with high sensitivity for fluctuating field.

    Science.gov (United States)

    Kanamaru, Yuki; Gota, Hiroshi; Fujimoto, Kayoko; Ikeyama, Taeko; Asai, Tomohiko; Takahashi, Tsutomu; Nogi, Yasuyuki

    2007-03-01

    A magnetic probe array is constructed to measure precisely the spatial structure of a small fluctuating field included in a strong confinement field that varies with time. To exclude the effect of the confinement field, the magnetic probes consisting of figure-eight-wound coils are prepared. The spatial structure of the fluctuating field is obtained from a Fourier analysis of the probe signal. It is found that the probe array is more sensitive to the fluctuating field with a high mode number than that with a low mode number. An experimental demonstration of the present method is attempted using a field-reversed configuration plasma, where the fluctuating field with 0.1% of the confinement field is successfully detected.

  13. Liquid Droplet Dynamics in Gravity Compensating High Magnetic Field

    Science.gov (United States)

    Bojarevics, V.; Easter, S.; Pericleous, K.

    2012-01-01

    Numerical models are used to investigate behavior of liquid droplets suspended in high DC magnetic fields of various configurations providing microgravity-like conditions. Using a DC field it is possible to create conditions with laminar viscosity and heat transfer to measure viscosity, surface tension, electrical and thermal conductivities, and heat capacity of a liquid sample. The oscillations in a high DC magnetic field are quite different for an electrically conducting droplet, like liquid silicon or metal. The droplet behavior in a high magnetic field is the subject of investigation in this paper. At the high values of magnetic field some oscillation modes are damped quickly, while others are modified with a considerable shift of the oscillating droplet frequencies and the damping constants from the non-magnetic case.

  14. Estrogen receptor 1 (ESR1; ERα), not ESR2 (ERβ), modulates estrogen-induced sex reversal in the American alligator, a species with temperature-dependent sex determination.

    Science.gov (United States)

    Kohno, Satomi; Bernhard, Melissa C; Katsu, Yoshinao; Zhu, Jianguo; Bryan, Teresa A; Doheny, Brenna M; Iguchi, Taisen; Guillette, Louis J

    2015-05-01

    All crocodilians and many turtles exhibit temperature-dependent sex determination where the temperature of the incubated egg, during a thermo-sensitive period (TSP), determines the sex of the offspring. Estrogens play a critical role in sex determination in crocodilians and turtles, as it likely does in most nonmammalian vertebrates. Indeed, administration of estrogens during the TSP induces male to female sex reversal at a male-producing temperature (MPT). However, it is not clear how estrogens override the influence of temperature during sex determination in these species. Most vertebrates have 2 forms of nuclear estrogen receptor (ESR): ESR1 (ERα) and ESR2 (ERβ). However, there is no direct evidence concerning which ESR is involved in sex determination, because a specific agonist or antagonist for each ESR has not been tested in nonmammalian species. We identified specific pharmaceutical agonists for each ESR using an in vitro transactivation assay employing American alligator ESR1 and ESR2; these were 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT) and 7-bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY 200070), respectively. Alligator eggs were exposed to PPT or WAY 200070 at a MPT just before the TSP, and their sex was examined at the last stage of embryonic development. Estradiol-17β and PPT, but not WAY 200070, induced sex reversal at a MPT. PPT-exposed embryos exposed to the highest dose (5.0 μg/g egg weight) exhibited enlargement and advanced differentiation of the Müllerian duct. These results indicate that ESR1 is likely the principal ESR involved in sex reversal as well as embryonic Müllerian duct survival and growth in American alligators.

  15. Electron transport in reduced graphene oxides in high electric field

    Science.gov (United States)

    Jian, Wen-Bin; Lai, Jian-Jhong; Wang, Sheng-Tsung; Tsao, Rui-Wen; Su, Min-Chia; Tsai, Wei-Yu; Rosenstein, Baruch; Zhou, Xufeng; Liu, Zhaoping

    Due to a honeycomb structure, charge carriers in graphene exhibit quasiparticles of linear energy-momentum dispersion and phenomena of Schwinger pair creation may be explored. Because graphene is easily broken in high electric fields, single-layer reduced graphene oxides (rGO) are used instead. The rGO shows a small band gap while it reveals a graphene like behavior in high electric fields. Electron transport in rGO exhibits two-dimensional Mott's variable range hopping. The temperature behavior of resistance in low electric fields and the electric field behavior of resistance at low temperatures are all well explained by the Mott model. At temperatures higher than 200 K, the electric field behavior does not agree with the model while it shows a power law behavior with an exponent of 3/2, being in agreement with the Schwinger model. Comparing with graphene, the rGO is more sustainable to high electric field thus presenting a complete high-electric field behavior. When the rGO is gated away from the charge neutral point, the turn-on electric field of Schwinger phenomena is increased. A summary figure is given to present electric field behaviors and power law variations of resistances of single-layer rGO, graphene, and MoS2.

  16. ESR and X-ray diffraction studies on thin films of poly-3-hexylthiophene: Molecular orientation and magnetic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Keisuke [Material Science and Engeneering, Muroran Institute of Technology, 27-1 Mizomoto, Muroran, 050-8585 (Japan); Kojima, Takashi; Fukuda, Hisashi [Electrical and Electronic Engineering, Muroran Institute of Technology, 27-1 Mizomoto, Muroran, 050-8585 (Japan); Yashiro, Hisashi [Application Laboratory, Rigaku Corporation, 3-9-12 Akishima, Tokyo 196-8666 (Japan); Matsuura, Toshihiko [Laboratory of Biotechnology, Hokkaido University of Education, 1-2 Hachiman, Hakodate 040-8567 (Japan); Shimoyama, Yuhei [Material Science and Engeneering, Muroran Institute of Technology, 27-1 Mizomoto, Muroran, 050-8585 (Japan)], E-mail: simoyama@mmm.muroran-it.ac.jp

    2008-03-03

    Poly-3-hexylthiophene (P3HT) thin films were investigated by X-ray diffraction (XRD) and electron spin resonance (ESR) to reveal the film structure and molecular organization. The XRD data showed a diffraction pattern with a plane separation between the planes containing thiophene rings of 16.0 A. Comparison between the XRD patterns of powder and thin films of P3HT suggests that the main chains are folded on the substrate. Angular variation of the line position (g-value) of ESR spectra revealed that thiophene ring of P3HT orients along the substrate normal axis. The ESR linewidth varied by the angular rotation, indicating the one-dimensional spin-chain interactions in the P3HT thin films with a linear network of spin-chains. An organic thin-film transistor (OTFT) with P3HT film as a channel layer was then demonstrated. The P3HT films showed conducting characteristics with holes as carriers. The OTFTs indicated a field-effect mobility of 4.93 x 10{sup -3} cm{sup 2}/Vs and an on/off ratio of 73 in the accumulation mode.

  17. High magnetic field {mu}SR instrument scientific case

    Energy Technology Data Exchange (ETDEWEB)

    Amato, A

    2005-10-15

    In order to gain more insight into the specific behavior of materials, it is often necessary to perform measurements as a function of different external parameters. Despite its high sensitivity to internal fields, this simple observation also applies for the {mu}SR technique. The most common parameter which can be tuned during an experiment is the sample temperature. By using a range of cryostats, temperatures between 0.02 and 900 K can be covered at the PSI {mu}SR Facility. On the other hand, and by using high-energy muons, pressures as high as 10'000 bars can nowadays be reached during {mu}SR experiments. As will be demonstrated in the following Sections, the magnetic field is an additional external parameter playing a fundamental role when studying the ground state properties of materials in condensed matter physics and chemistry. However, the availability of high magnetic fields for {mu}SR experiments is still rather limited. Hence, if on one hand the high value of the gyromagnetic ratio of the muon provides the high magnetic sensitivity of the method, on the other hand it can lead to very high muon-spin precession frequencies when performing measurements in applied fields (the muon-spin precession frequency in a field of 1 Tesla s 135.5 MHz). Consequently, the use of ultra-fast detectors and electronics is mandatory when measuring in magnetic fields exceeding 1 Tesla. If such fields are very intense when compared to the Earth magnetic field < 10{sup -4} Tesla), the energy associated with them is still modest in view of the thermal energy. Hence, the Zeeman energy splitting of a free electron in a magnetic field of 1 Tesla corresponds to a thermal energy as low as 0.67 Kelvin. It is worth mentioning that nowadays magnetic fields of the order of 10 to 15 Tesla are quite common in condensed matter laboratories and have opened up vast new exciting experimental possibilities. (author)

  18. Advanced measurements and techniques in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, L.J.; Rickel, D.G. [Los Alamos National Lab., NM (United States); Lacerda, A.H. [Florida State Univ., Tallahassee, FL (United States); Kim, Y. [Northeastern Univ., Boston, MA (United States)

    1997-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). High magnetic fields present a unique environment for studying the electronic structure of materials. Two classes of materials were chosen for experiments at the national high Magnetic Field Laboratory at Los Alamos: highly correlated electron systems and semiconductors. Magnetotransport and thermodynamic experiments were performed on the renormalized ground states of highly correlated electron systems (such as heavy fermion materials and Kondo insulators) in the presence of magnetic fields that are large enough to disrupt the many-body correlations. A variety of optical measurements in high magnetic fields were performed on semiconductor heterostructures including GaAs/AlGaAs single heterojunctions (HEMT structure), coupled double quantum wells (CDQW), asymmetric coupled double quantum wells (ACDQW), multiple quantum wells and a CdTe single crystal thin film.

  19. Improving Magnet Designs With High and Low Field Regions

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

    2011-01-01

    A general scheme for increasing the difference in magnetic flux density between a high and a low magnetic field region by removing unnecessary magnet material is presented. This is important in, e.g., magnetic refrigeration where magnet arrays have to deliver high field regions in close proximity...... to low field regions. Also, a general way to replace magnet material with a high permeability soft magnetic material where appropriate is discussed. As an example, these schemes are applied to a two dimensional concentric Halbach cylinder design resulting in a reduction of the amount of magnet material...

  20. Magnetostructural transitions in a frustrated magnet at high fields.

    Science.gov (United States)

    Tsurkan, V; Zherlitsyn, S; Felea, V; Yasin, S; Skourski, Yu; Deisenhofer, J; von Nidda, H-A Krug; Lemmens, P; Wosnitza, J; Loidl, A

    2011-06-17

    Ultrasound and magnetization studies of bond-frustrated ZnCr(2)S(4) spinel are performed in static magnetic fields up to 18 T and in pulsed fields up to 62 T. At temperatures below the antiferromagnetic transition at T(N1)≈14  K, the sound velocity as a function of the magnetic field reveals a sequence of steps followed by plateaus indicating a succession of crystallographic structures with constant stiffness. At the same time, the magnetization evolves continuously with a field up to full magnetic polarization without any plateaus in contrast to geometrically frustrated chromium oxide spinels. The observed high-field magnetostructural states are discussed within a H-T phase diagram taking into account the field and temperature evolution of three coexisting spin structures and subsequent lattice transformations induced by the magnetic field.

  1. Beneficial use of off-specification fly ashes to increase the shear strength and stiffness of expansive soil-rubber (ESR) mixtures.

    Science.gov (United States)

    2011-07-01

    The use of off-specification fly ashes to increase the shear strength and stiffness of an expansive soil-rubber (ESR) mixture is investigated systematically in this study. The off-specification fly ashes used include a high-sulfur content and a high-...

  2. Strong magnetic fields in normal galaxies at high redshift

    Science.gov (United States)

    Bernet, Martin L.; Miniati, Francesco; Lilly, Simon J.; Kronberg, Philipp P.; Dessauges-Zavadsky, Miroslava

    2008-07-01

    The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It was recently demonstrated that field strengths as traced by rotation measures of distant (and hence ancient) quasars are comparable to those seen today, but it was unclear whether the high fields were in the unusual environments of the quasars themselves or distributed along the lines of sight. Here we report high-resolution spectra that demonstrate that the quasars with strong MgII absorption lines are unambiguously associated with larger rotation measures. Because MgII absorption occurs in the haloes of normal galaxies along the sightlines to the quasars, this association requires that organized fields of surprisingly high strengths are associated with normal galaxies when the Universe was only about one-third of its present age.

  3. Probing High Temperature Superconductors with Magnetometry in Ultrahigh Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lu [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-07-26

    The objective of this research is to investigate the high-field magnetic properties of high temperature superconductors, materials that conduct electricity without loss. A technique known as high-resolution torque magnetometry that was developed to directly measure the magnetization of high temperature superconductors. This technique was implemented using the 65 Tesla pulsed magnetic field facility that is part of the National High Magnetic Field Laboratory at Los Alamos National Laboratory. This research addressed unanswered questions about the interplay between magnetism and superconductivity, determine the electronic structure of high temperature superconductors, and shed light on the mechanism of high temperature superconductivity and on potential applications of these materials in areas such as energy generation and power transmission. Further applications of the technology resolve the novel physical phenomena such as correlated topological insulators, and spin liquid state in quantum magnets.

  4. High-field EPR spectroscopy of thermal donors in silicon

    DEFF Research Database (Denmark)

    Dirksen, R.; Rasmussen, F.B.; Gregorkiewicz, T.

    1997-01-01

    Thermal donors generated in p-type boron-doped Czochralski-grown silicon by a 450 degrees C heat treatment have been studied by high-field magnetic resonance spectroscopy. In the experiments conducted at a microwave frequency of 140 GHz and in a magnetic field of approximately 5 T four individual...

  5. High magnetic fields in couplers of x-band acceleratingstructures

    CERN Document Server

    Dolgashev, V A

    2003-01-01

    Recent high power tests of x-band accelerating structures at SLAC have shown that Coupler models were matched with an automated procedure that uses the commercial To reduce the high magnetic fields new couplers were designed. These couplers and typical results for couplers with sharp and rounded irises are discussed in code HFSS. This matching procedure is based on calculation of reflection from have 3 mm radius waveguide-to-coupler-cell iris and maximum magnetic field below is consistent with a model of pulsed heating due to high magnetic fields. The magnetic fields, 3D electrodynamics models of the couplers were built and matched. matching, the magnetic and electric fields in the couplers were calculated for typical observed damage is located in the region of high magnetic fields. To calculate these on sharp (approx 80 micron radius) edges of the waveguide-to-coupler-cell irises. For operation parameters. Highest magnetic fields on the order of 1 MA/m were found some input couplers, electric fields on these...

  6. Alignment of molecular materials in high magnetic fields

    NARCIS (Netherlands)

    Christianen, P.C.M.; Shklyarevskiy, O.I.; Boamfa, M.I.; Maan, J.C.

    2004-01-01

    The potential of using high magnetic fields to align functional molecular materials is discussed, illustrated by magnetic orientation of two different types of materials. Alignment of side chain polymer liquid crystals leads to macroscopically ordered, transparant and strongly birefringent material.

  7. File list: Oth.Oth.05.ESR1.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Oth.05.ESR1.AllCell hg19 TFs and others ESR1 Others SRX371435,SRX371448,SRX3714...1434,SRX371427,SRX371443,SRX371442,SRX371444,SRX371439,SRX371436,SRX371428,SRX371449,SRX371445 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Oth.05.ESR1.AllCell.bed ...

  8. Comparison of the DAS28-CRP and DAS28-ESR in patients with rheumatoid arthritis.

    Science.gov (United States)

    Sengul, Ilker; Akcay-Yalbuzdag, Seniz; Ince, Bugra; Goksel-Karatepe, Altinay; Kaya, Taciser

    2015-07-01

    To compare the Disease Activity Score with 28 joint (DAS28) using erythrocyte sedimentation rate (ESR) (DAS28-ESR) and DAS28 using C-reactive protein (CRP) (DAS28-CRP) with thresholds validated for DAS28-ESR in Turkish patients with rheumatoid arthritis. The DAS28 data of 112 patients with rheumatoid arthritis followed in a local outpatient clinic were used. First, the correlation between DAS28-CRP and DAS28-ESR and the correlation between their unique components ([0.36 × In (CRP + 1) + 0.96] and [0.70 × In (ESR)]) were analyzed. Second, a Bland-Altman plot was constructed for the evaluation of the level of agreement between DAS28-CRP and DAS28-ESR. Lastly, the agreement between these two methods was analyzed by κ coefficient. Although there was a strong correlation between DAS28-CRP and DAS28-ESR, the correlation between their unique components was fair. Although more than 95% of the point data fall between the upper and lower bounds of the limit of agreement, the percentage error (46%) was higher than the acceptable proportion of 30%. The κ coefficient of agreement between DAS28- ESR and DAS28-CRP with validated thresholds for DAS28-ESR was 0.42, which was close to the lower boundary for moderate agreement. The results of this study demonstrated that there is discordance between DAS28-ESR and DAS28-CRP with the validated thresholds for DAS28-ESR. Using the DAS28-CRP with threshold values validated for DAS28-ESR may lead to errors in the determination of disease activity and therefore may lead to errors in the management of patients with rheumatoid arthritis. © 2015 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  9. ESR study of MMA polymerization by a peroxide/amine system: bone cement formation.

    Science.gov (United States)

    Oldfield, F F; Yasuda, H K

    1999-03-15

    Electron spin resonance (ESR) spectroscopy was used to gain insight at the molecular level into the curing of bone cement. Methyl methacrylate was polymerized using a N,N-dimethyl-p-toluidine (TD)/benzoyl peroxide (BPO) redox system in the presence of polymethyl methacrylate (PMMA) powder. The conventional nine-line ESR spectrum for the growing polymer radical was detected at the gel stage of polymerization. While the optimum free radical concentration was observed near the equimolar amine/BPO concentration, excess amine led to a change in the chemical structure of the trapped radical and inhibited the polymerization process. At a high amine/BPO ratio the nine-line signal disappeared and a three-line nitroxide-based radical appeared. The appearance of this nitroxide signal seems to depend on the amine/BPO molar ratio and on the presence of PMMA. An excess amount of amine with respect to BPO was found to inhibit the polymerization process. When BPO was removed, the system still polymerized but with a longer gelation time and a lower radical concentration. These results demonstrate that trapped free radicals in the bulk polymerization of MMA convert to polymeric peroxides that act as initiators in bone cement. When the accelerator 4-dimethylamino phenethyl alcohol (TDOH) was used, a higher radical concentration was observed in the polymerizing system. TDOH shows potential for being a more effective accelerator than TD for bone cement curing. Copyright 1999 John Wiley & Sons, Inc.

  10. Electroslag Remelting (ESR) Slags for Removal of Radioactive Oxide Contaminants from Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Chernicoff, W.P.; Chou, K.C.; Gao, H.; MacDonald, C.J.; Molecke, M.A.; Pal, U.B.; Van Den, J.; Woolley, D.

    1999-06-30

    Downsizing and decommissioning of nuclear operations is increasing the stockpile of Radioactive Scrap Metal (RSM). It is estimated that the annual generation of RSM for the entire DOE complex will be approximately 120,000 metric tons beginning in the year 2000. Out of which contaminated stainless steel with high chromium and nickel contents constitutes 25-30 wt. % [1]. Disposal of this material not only represents resource and value lost, but also necessitates long term monitoring for environmental compliance. The latter results in additional recurring expense. Therefore, it is desirable to be able to decontaminate the radioactive stainless steel to a satisfactory level that can be recycled or at least used for fabrication of containers for RSM disposal instead of using virgin stainless steel. Decontamination of radioactive stainless steel using the ESR process is investigated. In this paper the relevant slag properties, capacity to incorporate the radioactive contaminant, slag-metal partition coefficient, volatilization rate, volatile species, viscosity, electrical conductivity and surface tension are presented as a function of temperature. The impact of these properties on the ESR decontamination process is discussed.

  11. Optical measurement of the longitudinal ion distribution of bunched ion beams in the ESR

    Energy Technology Data Exchange (ETDEWEB)

    Wen, W.Q. [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); University of Chinese Academy of Sciences, 100049 Beijing (China); Lochmann, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Ma, X., E-mail: x.ma@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); Bussmann, M. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Winters, D.F.A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Nörtershäuser, W. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Botermann, B. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Geppert, C.; Frömmgen, N.; Hammen, M. [Institut für Kernchemie, Universität Mainz, 55128 Mainz (Germany); Hannen, V.; Jöhren, R. [Institut für Kernphysik, Universität Münster, 48149 Münster (Germany); and others

    2013-05-21

    An optical technique to study the longitudinal distribution of ions in a bunched ion beam circulating in a storage ring is presented. It is based on the arrival-time analysis of photons emitted after collisional excitation of residual gas molecules. The beam-induced fluorescence was investigated in the ultraviolet regime with a channeltron and in the visible region using a photomultiplier tube. Both were applied to investigate the longitudinal shape of bunched and electron-cooled {sup 209}Bi{sup 80+} ion beams at about 400 MeV/u in the experimental storage ring (ESR) at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Bunch lengths were determined with an uncertainty of about 0.5 m using the UV-sensitive channeltron and with slightly lower accuracy from the photomultiplier data due to the slower transitions in the red region of the spectrum. The Gaussian shape of the longitudinal distribution of ions inside the bunch was confirmed. With the information of the transverse beam size that can be measured simultaneously by a newly installed ionization profile monitor (IPM) at the ESR, an accurate determination of the ion density in the bunched beam will be allowed. -- Highlights: ► Optical methods to measure the bunch shape of ion beam at storage ring. ► High resolution of bunch length was obtained from the UV-sensitive channeltron. ► The Gaussian shape of longitudinal distribution of the ions in the bunch was confirmed.

  12. Overlay control methodology comparison: field-by-field and high-order methods

    Science.gov (United States)

    Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

    2012-03-01

    Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

  13. Mitigated-force carriage for high magnetic field environments

    Science.gov (United States)

    Ludtka, Gerard M.; Ludtka, Gail M.; Wilgen, John B.; Murphy, Bart L.

    2015-05-19

    A carriage for high magnetic field environments includes a plurality of work-piece separators disposed in an operable relationship with a work-piece processing magnet having a magnetic field strength of at least 1 Tesla for supporting and separating a plurality of work-pieces by a preselected, essentially equal spacing, so that, as a first work-piece is inserted into the magnetic field, a second work-piece is simultaneously withdrawn from the magnetic field, so that an attractive magnetic force imparted on the first work-piece offsets a resistive magnetic force imparted on the second work-piece.

  14. Magnetic field management of substations in high rise buildings

    Energy Technology Data Exchange (ETDEWEB)

    Farag, A.S.; Al-Shehri, A.M. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia); Cheng, T.C.; Du, Y.; Hu, L.; Penn, D. [Univ. of Southern California, LADWP, Los Angeles, CA (United States)

    1995-12-01

    The electric and magnetic field issue has become an area of increasing public concern. Utilities have been carrying out extensive projects to characterize and manage the magnetic fields around their substations in an effort to answer public concerns over the possible health hazard caused by these fields. This paper describes various techniques available for managing magnetic field strength levels in substations. The design guideline aids in the planning, design, construction of substation facilities. Low-frequency magnetic field is directly associated with current-carrying sources and its magnitude is proportional to the distance from the sources. Distribution substations in high-rise buildings are very close to public areas and the magnetic fields imposed by these substations might be relatively higher than that imposed by outdoor substations. Options to manage these substations fields are considered in this paper. Techniques to manage magnetic fields in substations such as: source relocation, compaction, rephasing, return-current control, passive and active shielding are discussed. Several techniques were applied to reduce the magnetic fields in the conference room located in the main floor above a substation located in the basement of the main office high-rise building of LADWP. 10 refs, 14 figs, 3 tabs

  15. High-field spin dynamics of antiferromagnetic quantum spin chains

    DEFF Research Database (Denmark)

    Enderle, M.; Regnault, L.P.; Broholm, C.

    2000-01-01

    The characteristic internal order of macroscopic quantum ground states in one-dimensional spin systems is usually not directly accessible, but reflected in the spin dynamics and the field dependence of the magnetic excitations. In high magnetic fields quantum phase transitions are expected. We...... present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights...

  16. Design of High Field Solenoids made of High Temperature Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bartalesi, Antonio; /Pisa U.

    2010-12-01

    This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed and verified with the analytical results. To study the anisotropic behavior of a coil made by layers of superconductor and insulation, a finite element meso-mechanic model is proposed and designed. The resulting material properties are then used in the main solenoid analysis. In parallel, design work is performed as well: an existing Insert Test Facility (ITF) is adapted and structurally verified to support a coil made of YBa{sub 2}Cu{sub 3}O{sub 7}, a High Temperature Superconductor (HTS). Finally, a technological winding process was proposed and the required tooling is designed.

  17. ESR1 gene promoter region methylation in free circulating DNA and its correlation with estrogen receptor protein expression in tumor tissue in breast cancer patients.

    Science.gov (United States)

    Martínez-Galán, Joaquina; Torres-Torres, Blanca; Núñez, María Isabel; López-Peñalver, Jesús; Del Moral, Rosario; Ruiz De Almodóvar, José Mariano; Menjón, Salomón; Concha, Angel; Chamorro, Clara; Ríos, Sandra; Delgado, Juan Ramón

    2014-02-04

    Tumor expression of estrogen receptor (ER) is an important marker of prognosis, and is predictive of response to endocrine therapy in breast cancer. Several studies have observed that epigenetic events, such methylation of cytosines and deacetylation of histones, are involved in the complex mechanisms that regulate promoter transcription. However, the exact interplay of these factors in transcription activity is not well understood. In this study, we explored the relationship between ER expression status in tumor tissue samples and the methylation of the 5' CpG promoter region of the estrogen receptor gene (ESR1) isolated from free circulating DNA (fcDNA) in plasma samples from breast cancer patients. Patients (n = 110) with non-metastatic breast cancer had analyses performed of ER expression (luminal phenotype in tumor tissue, by immunohistochemistry method), and the ESR1-DNA methylation status (fcDNA in plasma, by quantitative methylation specific PCR technique). Our results showed a significant association between presence of methylated ESR1 in patients with breast cancer and ER negative status in the tumor tissue (p = 0.0179). There was a trend towards a higher probability of ESR1-methylation in those phenotypes with poor prognosis i.e. 80% of triple negative patients, 60% of HER2 patients, compared to 28% and 5.9% of patients with better prognosis such as luminal A and luminal B, respectively. Silencing, by methylation, of the promoter region of the ESR1 affects the expression of the estrogen receptor protein in tumors of breast cancer patients; high methylation of ESR1-DNA is associated with estrogen receptor negative status which, in turn, may be implicated in the patient's resistance to hormonal treatment in breast cancer. As such, epigenetic markers in plasma may be of interest as new targets for anticancer therapy, especially with respect to endocrine treatment.

  18. Large field-of-view transmission line resonator for high field MRI

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Johannesson, Kristjan Sundgaard; Boer, Vincent

    2016-01-01

    Transmission line resonators is often a preferable choice for coils in high field magnetic resonance imaging (MRI), because they provide a number of advantages over traditional loop coils. The size of such resonators, however, is limited to shorter than half a wavelength due to high standing wave...... ratio, which leads to inhomogeneous field distribution along the resonator. In this work, it is demonstrated that the resonator length can be extended to over half a wavelength with the help of series capacitors. The approach allows for reduced standing wave ratio and improved field homogeneity....... Achieved magnetic field distribution is compared to the conventional transmission line resonator. Imaging experiments are performed using 7 Tesla MRI system. The developed resonator is useful for building coils with large field-of-view....

  19. Magnetoresistance peculiarities of bismuth wires in high magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Condrea, E., E-mail: condrea@nano.asm.md [Institute of Electronic Engineering and Nanotechnologies, Academy of Science of Moldova, 2028 Chisinau, Republic of Moldova (Moldova, Republic of); International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, 51-421 Wroclaw (Poland); Gilewski, A. [International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, 51-421 Wroclaw (Poland); MagNet, 50-421 Wroclaw (Poland); Nicorici, A. [Institute of Electronic Engineering and Nanotechnologies, Academy of Science of Moldova, 2028 Chisinau, Republic of Moldova (Moldova, Republic of)

    2016-03-11

    Magnetoresistance measurements of Bi wires performed in the magnetic field oriented along the bisector axis revealed unexpected anomalous peaks in a high magnetic field far above the quantum limit of the electrons. By combining a magnetic field and an uniaxial strain, we obtained a modification of the electronic structure; as a result, the quantum limit for light and heavy electrons is changed in a different way. For the case where heavy electrons are in the quantum limit, a correlation between the exit of the lowest Landau level of light electrons and the Lifshitz transition was found. - Highlights: • Glass-coated single-crystalline Bi wires attain high limit of elastic strain of up to 3.0%. • Selective modification of the electronic structure of Bi wires is obtained by combining a high magnetic field and uniaxial strain. • The correlation between the exit of the lowest Landau level of electrons and Lifshitz transition was found.

  20. ESR studies on the thermal decomposition of trimethylamine oxide to formaldehyde and dimethylamine in jumbo squid (Dosidicus gigas) extract.

    Science.gov (United States)

    Zhu, Junli; Jia, Jia; Li, Xuepeng; Dong, Liangliang; Li, Jianrong

    2013-12-15

    The effects of ferrous iron, heating temperature and different additives on the decomposition of trimethylamine oxide (TMAO) to formaldehyde (FA) and dimethylamine (DMA) and generation of free radicals in jumbo squid (Dosidicus gigas) extract during heating were evaluated by electron spin resonance (ESR). The thermal decomposition of TMAO to TMA, DMA and FA and free radical signals was observed in squid extract, whereas no DMA, FA and free radical signals were detected in cod extract or in aqueous TMAO solution in vitro at high temperatures. Significant increase in levels of DMA, FA and radicals intensity were observed in squid extract and TMAO solution in the presence of ferrous iron with increasing temperature. Hydrogen peroxide stimulated the production of DMA, FA and ESR signals in squid extract, while citric acid, trisodium citrate, calcium chloride, tea polyphenols and resveratrol had the opposite effect. Similar ESR spectra of six peaks regarded as amminium radical were detected in the squid extract and TMAO-iron(II) solution, suggesting that the amminium radical was involved in the decomposition of TMAO. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. [Survey of risks related to static magnetic fields in ultra high field MRI].

    Science.gov (United States)

    Möller, H E; von Cramon, D Y

    2008-04-01

    In magnetic resonance imaging (MRI), substantial improvements with respect to sensitivity are expected due to the development of so-called ultra high field scanners, i. e., whole-body scanners with a magnetic field strength of 7 T or above. Users of this technology need to evaluate this benefit for potential risks since commercially available systems are not certified as a medical device for human use. This review provides a detailed survey of static field bioeffects related to the exposure of subjects being scanned, to occupational exposure, and to exposure of the general public under consideration of current standards and directives. According to present knowledge, it is not expected that exposure of human subjects to static magnetic fields of 7 T implies a specific risk of damage or disease provided that known contraindications are observed. The available database does not permit definition of exact thresholds for harmful effects. However, experience from previous application of ultra high field MRI indicates that transient phenomena, such as vertigo, nausea, metallic taste, or magneto-phosphenes, are more frequently observed. In particular, movements in the field or the gradient of the fringe field seem to lead to detectable effects. Besides such observations, there is a strong demand for systematic investigation of potential interaction mechanisms related to static field exposure during MRI examinations.

  2. High-field formation and field ion microscopy of monatomic carbon chains

    Energy Technology Data Exchange (ETDEWEB)

    Ksenofontov, V A; Mazilova, T I; Mikhailovskij, I M; Sadanov, E V; Velicodnaja, O A; Mazilov, A A [National Scientific Center, Kharkov Institute of Physics and Technology, Academicheskaja, 1, 61108 Kharkov (Ukraine)

    2007-11-21

    By methods of field ion microscopy and mass spectrometry, the presence of linear carbon chains at the surface of carbon fibers after high-voltage treatment using a pulse generator with pulse duration of 10 ns was revealed. The carbon chains attached to the specimen tips can be produced in situ in a field ion microscope using low-temperature pulsed evaporation by electric fields of the order of 80 V nm{sup -1}. These nanowires are perfectly resolved in the field ion microscope. An analysis of the cluster images and determination of the field-enhancement factors strongly indicate that the field produced clusters are linear chains of one carbon atom in diameter. The process of field evaporation at the pulse voltage loading is sporadic with an anomalously large instant rate of evaporation corresponding to explosive removal of about 10{sup 11} atomic layers s{sup -1}. Atomic C chains are produced during the high-field unraveling of nanofibers at 4.2 and 77 K.

  3. Influence of sample treatment on ESR signal of irradiated citrus

    Energy Technology Data Exchange (ETDEWEB)

    De Jesus, E.F.O.; Lopes, R.T. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Rossi, A.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-11-01

    EST spectra of the hard seed cover and kernel coating of irradiated orange and tangerine fruits were obtained under different sample drying conditions to analyze the effect of treatment on ESR line at g = 2.0033 (line A). The spectra shows almost the same lines that appear in stalks, achenes, seeds and skins of fresh fruit. The peak-to-peak intensity of the line A of the spectra shows a linear variation with dose in the range studied (up to 5 kGy) under controlled sample preparation. Q-band ESR spectra shows that this line is composed for three different lines from different species, A{sub 1}, A{sub 2} and A{sub 3}. The A{sub 2} and A{sub 3} lines are associated with dose but grow also during drying of the sample and are probably due to `cellulosic` components of the seed cover. The A{sub 1} line appears only when sample is dried and is probably associated with the quinones of the internal kernel coat. (author).

  4. Radiation-induced defects in magnesium lactate as ESR dosimeter

    CERN Document Server

    Hassan, G M; Takaki, S

    1999-01-01

    Magnesium lactate (Mg-lactate: (CH sub 3 CH(OH)COO) sub 2 Mg), magnesium lactate doped with lithium lactate (Mg(Li)-lactate) and nominal pure lithium lactate (CH sub 3 CH(OH)COOLi) doped with Mg-lactate (Li(Mg)-lactate) were irradiated by gamma-rays to study radicals for materials of radiation dosimeter with electron spin resonance (ESR). Quartet spectra were ascribed to lactate radicals in Mg-lactate and Li(Mg)-lactate with the spectroscopic splitting factors (g-factor) of 2.0032+-0.004 and 2.0029+-0.004 and the intensity ratio of 1:3:3:1 due to the hyperfine coupling constants of (A/g beta) of 1.92+-0.06 and 1.82+-0.06 mT, respectively. The response to gamma-ray dose and the thermal stability as well as the effect of UV-illumination have been studied to establish this material as an ESR dosimeter. The number of free radicals per 100 eV (G-value) was obtained to be 1.15+-0.32, 1.35+-0.35, 0.46+-0.14 and 0.78+-0.24 for Mg-lactate, Mg(Li)-lactate, Li-lactate and Lie(Mg)-lactate, respectively. Thermoluminescenc...

  5. Homogenous BSCCO-2212 Round Wires for Very High Field Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Scott Campbell

    2012-06-30

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for {approx}18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb{sub 3}Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T{sub c} (HTS) counterparts, the HTS materials have

  6. Calculation of electric fields induced by body and head motion in high-field MRI

    Science.gov (United States)

    Liu, Feng; Zhao, Huawei; Crozier, Stuart

    2003-03-01

    In modern magnetic resonance imaging (MRI), patients are exposed to strong, nonuniform static magnetic fields outside the central imaging region, in which the movement of the body may be able to induce electric currents in tissues which could be possibly harmful. This paper presents theoretical investigations into the spatial distribution of induced electric fields and currents in the patient when moving into the MRI scanner and also for head motion at various positions in the magnet. The numerical calculations are based on an efficient, quasi-static, finite-difference scheme and an anatomically realistic, full-body, male model. 3D field profiles from an actively shielded 4 T magnet system are used and the body model projected through the field profile with a range of velocities. The simulation shows that it possible to induce electric fields/currents near the level of physiological significance under some circumstances and provides insight into the spatial characteristics of the induced fields. The results are extrapolated to very high field strengths and tabulated data shows the expected induced currents and fields with both movement velocity and field strength.

  7. Effect of magnetic field inhomogeneity on ion cyclotron motion coherence at high magnetic field.

    Science.gov (United States)

    Vladimirov, Gleb; Kostyukevich, Yury; Hendrickson, Christopher L; Blakney, Greg T; Nikolaev, Eugene

    2015-01-01

    A three-dimensional code based on the particle-in-cell algorithm modified to account for the inhomogeneity of the magnetic field was applied to determine the effect of Z(1), Z(2), Z(3), Z(4), X, Y, ZX, ZY, XZ(2) YZ(2), XY and X(2)-Y(2) components of an orthogonal magnetic field expansion on ion motion during detection in an FT-ICR cell. Simulations were performed for magnetic field strengths of 4.7, 7, 14.5 and 21 Tesla, including experimentally determined magnetic field spatial distributions for existing 4.7 T and 14.5 T magnets. The effect of magnetic field inhomogeneity on ion cloud stabilization ("ion condensation") at high numbers of ions was investigated by direct simulations of individual ion trajectories. Z(1), Z(2), Z(3) and Z(4) components have the largest effect (especially Z(1)) on ion cloud stability. Higher magnetic field strength and lower m/z demand higher relative magnetic field homogeneity to maintain cloud coherence for a fixed time period. The dependence of mass resolving power upper limit on Z(1) inhomogeneity is evaluated for different magnetic fields and m/z. The results serve to set the homogeneity requirements for various orthogonal magnetic field components (shims) for future FT-ICR magnet design.

  8. Exposure to high-frequency transient electromagnetic fields.

    Science.gov (United States)

    Skotte, J H

    1996-02-01

    The purpose of this study was to assess exposure to high-frequency transient (HFT) electromagnetic fields in occupational and residential environments. Exposure to HFT electromagnetic fields was measured with personal dosimeters for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. The measure of exposure to HFT fields was specified as the proportion of time (parts per million) in which the electric field exceeds a nominal threshold level of 200 V.m-1 at 5-20 MHz. Recently the specification of the HFT channel of the dosimeter has been found to be incomplete; therefore a testing of the threshold level and the sensitivity to electromagnetic fields from radio-telephones was carried out. The percentage of measurements with a mean workday exposure above 0.1 ppm was 6.5-9.4% for the utility groups and 0.9% for all the nonwork measurements. It is likely that the use of radio-telephones has contributed significantly to the number of HFT events in some of the measurements, especially for the generation workers. The nominal threshold level of the dosimeter was found to vary considerably depending on the polarization of the field (20-400 V.m-1 at 13.56 MHz for one instrument). Generally speaking, HFT fields appeared infrequently. The workday exposure to HFT fields and 50 Hz magnetic fields ranked the groups differently. There is a need for developing instrumentation for HFT field measurements further.

  9. Magnetoresistance peculiarities of bismuth wires in high magnetic field

    Science.gov (United States)

    Condrea, E.; Gilewski, A.; Nicorici, A.

    2016-03-01

    Magnetoresistance measurements of Bi wires performed in the magnetic field oriented along the bisector axis revealed unexpected anomalous peaks in a high magnetic field far above the quantum limit of the electrons. By combining a magnetic field and an uniaxial strain, we obtained a modification of the electronic structure; as a result, the quantum limit for light and heavy electrons is changed in a different way. For the case where heavy electrons are in the quantum limit, a correlation between the exit of the lowest Landau level of light electrons and the Lifshitz transition was found.

  10. Disintegration and field evaporation of thiolate polymers in high electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Nickerson, B.S., E-mail: brenden.nickerson@dal.ca; Karahka, M.; Kreuzer, H.J.

    2015-12-15

    High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the “band gap” with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. - Highlights: • Simple model of thiolate polymers is used to understand trends leading to field evaporation. • Potential energy curves followed by dipole moment, electric polarizability and dielectric constant are examined. • Features including coil, tilt and electrostriction are featured alongside evaporated species and HOMO/LUMO gap.

  11. High-field thermal transport properties of REBCO coated conductors

    Science.gov (United States)

    Bonura, Marco; Senatore, Carmine

    2015-02-01

    The use of REBCO coated conductors (CCs) is envisaged for many applications, extending from power cables to high-field magnets. Whatever the case, thermal properties of REBCO tapes play a key role for the stability of superconducting devices. In this work, we present the first study on the longitudinal thermal conductivity (κ) of REBCO CCs in magnetic fields up to 19 T applied both parallel and perpendicularly to the thermal-current direction. Copper-stabilized tapes from six industrial manufacturers have been investigated. We show that zero-field κ of CCs can be calculated with an accuracy of +/- 15% from the residual resistivity ratio of the stabilizer and the Cu/non-Cu ratio. Measurements performed at high fields have allowed us to evaluate the consistency of the procedures generally used for estimating in-field κ in the framework of the Wiedemann-Franz law from an electrical characterization of the materials. In-field data are intended to provide primary ingredients for the thermal stability analysis of high-temperature superconductor-based magnets.

  12. Improving NASICON Sinterability through Crystallization under High Frequency Electrical Fields

    Directory of Open Access Journals (Sweden)

    Ilya eLisenker

    2016-03-01

    Full Text Available The effect of high frequency (HF electric fields on the crystallization and sintering rates of a lithium aluminum germanium phosphate (LAGP ion conducting ceramic was investigated. LAGP with the nominal composition Li1.5Al0.5Ge1.5(PO43 was crystallized and sintered, both conventionally and under effect of electrical field. Electrical field application, of 300V/cm at 1MHz, produced up to a 40% improvement in sintering rate of LAGP that was crystallized and sintered under the HF field. Heat sink effect of the electrodes appears to arrest thermal runaway and subsequent flash behavior. Sintered pellets were characterized using XRD, SEM, TEM and EIS to compare conventionally and field sintered processes. The as-sintered structure appears largely unaffected by the field as the sintering curves tend to converge beyond initial stages of sintering. Differences in densities and microstructure after 1 hour of sintering were minor with measured sintering strains of 31% vs. 26% with and without field, respectively . Ionic conductivity of the sintered pellets was evaluated and no deterioration due to the use of HF field was noted, though capacitance of grain boundaries due to secondary phases was significantly increased.

  13. Low-temperature carrier dynamics in high-mobility organic transistors of alkylated dinaphtho-thienothiophene as investigated by electron spin resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Yutaro; Tanaka, Hisaaki, E-mail: htanaka@nuap.nagoya-u.ac.jp; Kuroda, Shin-ichi [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Shimoi, Yukihiro [Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takimiya, Kazuo [Emergent Molecular Function Research Group, RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198 (Japan)

    2014-07-21

    Charge carriers in high-mobility organic thin-film transistors of alkylated dinaphtho-thienothiophene (C{sub 10}-DNTT) have been directly observed by field-induced electron spin resonance (FI-ESR) down to 4 K. FI-ESR spectra of π-electron hole carriers of C{sub 10}-DNTT exhibited clear anisotropy, indicating a highly organized end-on molecular orientation at the device interface. The intra-grain and inter-grain carrier motion were probed by the motional narrowing effect of the ESR spectra. The intra-grain motion was clearly observed even at 4 K, showing intrinsically high mobility of C{sub 10}-DNTT crystallites. On the other hand, significantly low activation energy of ∼10 meV for inter-grain carrier hopping, compared with pristine DNTT, was observed, which shows that the alkyl substitution drastically enhances the carrier mobility of DNTT system.

  14. Diffusion of minority carriers against electric field (high injection level)

    Science.gov (United States)

    Gert, A. V.; Dmitriev, A. P.; Levinshtein, M. E.; Yuferev, V. S.; Palmour, J. W.

    2017-11-01

    A one-dimensional analytic model describing the motion of minority carriers against the electric field direction under the conditions of high injection level is developed. The results of the model can also be used to estimate the motion of carriers against the field in the case of an arbitrary injection level. The model makes it possible to describe, in good agreement with the results of computer simulation, the modulation of the collector layer resistance in a high voltage SiC bipolar transistor.

  15. Low-field MRI can be more sensitive than high-field MRI

    Science.gov (United States)

    Coffey, Aaron M.; Truong, Milton L.; Chekmenev, Eduard Y.

    2013-12-01

    MRI signal-to-noise ratio (SNR) is the key factor for image quality. Conventionally, SNR is proportional to nuclear spin polarization, which scales linearly with magnetic field strength. Yet ever-stronger magnets present numerous technical and financial limitations. Low-field MRI can mitigate these constraints with equivalent SNR from non-equilibrium ‘hyperpolarization' schemes, which increase polarization by orders of magnitude independently of the magnetic field. Here, theory and experimental validation demonstrate that combination of field independent polarization (e.g. hyperpolarization) with frequency optimized MRI detection coils (i.e. multi-turn coils using the maximum allowed conductor length) results in low-field MRI sensitivity approaching and even rivaling that of high-field MRI. Four read-out frequencies were tested using samples with identical numbers of 1H and 13C spins. Experimental SNRs at 0.0475 T were ∼40% of those obtained at 4.7 T. Conservatively, theoretical SNRs at 0.0475 T 1.13-fold higher than those at 4.7 T were possible despite an ∼100-fold lower detection frequency, indicating feasibility of high-sensitivity MRI without technically challenging, expensive high-field magnets. The data at 4.7 T and 0.0475 T was obtained from different spectrometers with different RF probes. The SNR comparison between the two field strengths accounted for many differences in parameters such as system noise figures and variations in the probe detection coils including Q factors and coil diameters.

  16. ESR detection of irradiated carob pods (Ceratoniasiliqua L) and its dosimetric feature

    Science.gov (United States)

    Tuner, Hasan; Polat, Mustafa

    2017-12-01

    Un-irradiated carob powder exhibited a weak ESR singlet at g = 2.0041 ± 0.0006 with peak-to-peak linewidth (ΔHpp) of 0.33 ± 0.01 mT. Irradiated carob powder exhibited an ESR spectrum consisting many resonance lines and similar to ESR spectrum of sugar in all aspects. A linear function of the absorbed radiation dose was found to describe best the dose-response curves of the ESR signal intensity Ipp. It is concluded that due to the similarity of carob powder ESR spectrum to the irradiated sugar and the fact that it is widely consumed, carob powder has the potential to be used as a retrospective and/or accidental dosimetric material.

  17. Electric and magnetic field measurements in a high voltage center.

    Science.gov (United States)

    Safigianni, Anastasia S; Spyridopoulos, Anastasios I; Kanas, Vasilis L

    2012-01-01

    This paper investigates the electric and magnetic fields inside a large high voltage center constituted both of 400/150 and 150/20 kV substation areas. Results of previous field measurements and calculations in substations, made by the authors of this paper or other researchers, are presented first. The basic data distinguishing the examined center from previously examined substations follow. The main results of the field measurements in the areas of the above-mentioned center are presented in relevant diagrams. General conclusions arising from the comparison of the measured field values with relevant reference levels in force for safe public and occupational exposure as well as with the results of previous research are finally given.

  18. Field high-throughput phenotyping: the new crop breeding frontier.

    Science.gov (United States)

    Araus, José Luis; Cairns, Jill E

    2014-01-01

    Constraints in field phenotyping capability limit our ability to dissect the genetics of quantitative traits, particularly those related to yield and stress tolerance (e.g., yield potential as well as increased drought, heat tolerance, and nutrient efficiency, etc.). The development of effective field-based high-throughput phenotyping platforms (HTPPs) remains a bottleneck for future breeding advances. However, progress in sensors, aeronautics, and high-performance computing are paving the way. Here, we review recent advances in field HTPPs, which should combine at an affordable cost, high capacity for data recording, scoring and processing, and non-invasive remote sensing methods, together with automated environmental data collection. Laboratory analyses of key plant parts may complement direct phenotyping under field conditions. Improvements in user-friendly data management together with a more powerful interpretation of results should increase the use of field HTPPs, therefore increasing the efficiency of crop genetic improvement to meet the needs of future generations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Field-effect transistor having a superlattice channel and high carrier velocities at high applied fields

    Science.gov (United States)

    Chaffin, deceased, Roger J.; Dawson, Ralph; Fritz, Ian J.; Osbourn, Gordon C.; Zipperian, Thomas E.

    1989-01-01

    A field effect transistor comprises a semiconductor having a source, a drain, a channel and a gate in operational relationship. The semiconductor is a strained layer superlattice comprising alternating quantum well and barrier layers, the quantum well layers and barrier layers being selected from the group of layer pairs consisting of InGaAs/AlGaAs, InAs/InAlGaAs, and InAs/InAlAsP. The layer thicknesses of the quantum well and barrier layers are sufficiently thin that the alternating layers constitute a superlattice which has a superlattice conduction band energy level structure in k-vector space which includes a lowest energy .GAMMA.-valley and a next lowest energy L-valley, each k-vector corresponding to one of the orthogonal directions defined by the planes of said layers and the directions perpendicular thereto. The layer thicknesses of the quantum well layers are selected to provide a superlattice L.sub.2D -valley which has a shape which is substantially more two-dimensional than that of said bulk L-valley.

  20. High School Students' Understandings and Representations of the Electric Field

    CERN Document Server

    Cao, Ying

    2014-01-01

    This study investigates the understandings and representations of the electric field expressed by Chinese high school students ages 15 to 16 who have not yet received high school-level physics instruction. The literature has reported students' ideas of the electric field post-instruction as indicated by their performance on textbook-style questionnaires. However, by relying on measures such as questionnaires, previous research has inadequately captured the thinking process that led students to answer questions in the ways that they did. The present study portrays the beginning of this process by closely examining students' understandings pre-instruction. The participants in this study were asked to engage in a lesson that included informal group tasks that involved playing a Web-based hockey game that replicated an electric field and drawing comic strips that used charges as characters. The lesson was videotaped, students' work was collected, and three students were interviewed afterward to ascertain more det...

  1. Nb3Sn High Field Magnets for the High Luminosity LHC Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, Giorgio

    2015-06-01

    The High Luminosity upgrade of the Large Hadron Collider at CERN requires a new generation of high field superconducting magnets. High field large aperture quadrupoles (MQXF) are needed for the low-beta triplets close to the ATLAS and CMS detectors, and high field two-in-one dipoles (11 T dipoles) are needed to make room for additional collimation. The MQXF quadrupoles, with a field gradient of 140 T/m in 150 mm aperture, have a peak coil field of 12.1 T at nominal current. The 11 T dipoles, with an aperture of 60 mm, have a peak coil field of 11.6 T at nominal current. Both magnets require Nb3Sn conductor and are the first applications of this superconductor to actual accelerator magnets.

  2. Disintegration and field evaporation of thiolate polymers in high electric fields.

    Science.gov (United States)

    Nickerson, B S; Karahka, M; Kreuzer, H J

    2015-12-01

    High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the "band gap" with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. FIELD EVALUATION OF A HIGH-VOLUME DICHOTOMOUS SAMPLER

    Science.gov (United States)

    This study presents the field evaluation of a high-volume dichotomous sampler that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. The key feature of this device is the utilization of a round-nozzle virtual impactor with a 50% cutpoint at 2.5 5m to split PM10 into...

  4. Survey of high field superconducting material for accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Scahlan, R.; Greene, A.F.; Suenaga, M.

    1986-05-01

    The high field superconductors which could be used in accelerator dipole magnets are surveyed, ranking these candidates with respect to ease of fabrication and cost as well as superconducting properties. Emphasis is on Nb/sub 3/Sn and NbTi. 27 refs., 2 figs. (LEW)

  5. National Program on High Field Accelerator Magnet R&D

    Energy Technology Data Exchange (ETDEWEB)

    Apollinari, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Cooley, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Zlobin, A. V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Caspi, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gourlay, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prestemon, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Larbalestier, D. [National High Magnetic Field Laboratory, Tallahassee, FL (United States); Gupta, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wanderer, P. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-09-26

    A National High-Field Magnet (HFM) Program is proposed as a thrust of the updated DOE-HEP General Accelerator R&D Program. The program responds to Recommendation 24 of the 2014 Particle Physics Project Prioritization Panel (P5) Report.

  6. Multibeam synthesis of high-power subcycle field waveforms

    Science.gov (United States)

    Serebryannikov, E. E.; Panchenko, V. Ya.; Zheltikov, A. M.

    2017-09-01

    We identify physical scenarios whereby high-peak-power subcycle attosecond field waveforms can be synthesized by coherently combining a multibeam high-order harmonic output generated by a laser driver consisting of a pair of few-cycle pulses with different carrier frequencies. With the relative amplitudes, phases, and group delays of these driver pulses carefully adjusted in each of the driver beams toward confining the recollisions of highest-ponderomotive-energy electrons to an extremely short time gate within a fraction of the driver field cycle, the phase-matched multibeam high-harmonic output can be tailored to yield an intense isolated subgigawatt sub-10-attosecond field waveform. As a general tendency, propagation effects are shown to limit the minimum pulse width of the multibeam high-harmonic output. Still, with appropriate optimization of the gas pressure and the beam geometry, ≈10 -as field waveforms can be synthesized at the expense of one to two orders of magnitude of the output radiation energy.

  7. High mobility polymer gated organic field effect transistor using zinc ...

    Indian Academy of Sciences (India)

    Mater. Sci., Vol. 37, No. 1, February 2014, pp. 95–99. c Indian Academy of Sciences. High mobility polymer gated organic field effect transistor using zinc phthalocyanine. K R RAJESH. ∗. , V KANNAN, M R KIM, Y S CHAE and J K RHEE. Millimeter- Wave Innovation Technology Research Centre (MINT), Dongguk University,.

  8. High mobility polymer gated organic field effect transistor using zinc ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 37; Issue 1. High mobility polymer gated organic field effect transistor using zinc ... fabricated using evaporated zinc phthalocyanine as the active layer. Parylene film prepared by chemical vapour deposition was used as the organic gate insulator. The annealing of the ...

  9. ESR identification of the nitrogen acceptor in 2H-polytype synthetic MoS2: Dopant level and activation

    Science.gov (United States)

    Schoenaers, B.; Stesmans, A.; Afanas'ev, V. V.

    2017-10-01

    Multi-frequency electron spin resonance (ESR) study of p-type synthetic 2H MoS2 reveals a previously unreported signal of axial-symmetry [g// = 2.032(2); g⊥ = 2.270(2)] characteristic for a hole-type center in MoS2. It is identified as originating from N acceptor dopants, the N atoms substituting for S sites, with a density of ˜2.3 x 1017 cm-3, thus predominantly accounting for the p-type sample doping. For the applied magnetic field along the c-axis, the signal is mainly comprised of a 14N hyperfine 1:1:1 triplet of splitting A// = 14.7 ± 0.2 G with, on top, a center line accounting for ˜26% of the total signal intensity. The additional observation of a weak half-field signal (g = 3.92) correlating with the main full-field Zeeman response points to the presence of spin S ≥ 1 N agglomerates. The overall signal properties indicate that only ˜74% of the N acceptors occur as isolated decoupled dopants. Monitoring of the ESR signal intensity over a broad temperature range unveils the N dopant as a shallow acceptor of activation energy Ea = 45 ± 7 meV, thus well fit for stable substitutional p-type doping in MoS2-based novel nanoelectronic devices.

  10. ESR identification of the nitrogen acceptor in 2H-polytype synthetic MoS2: Dopant level and activation

    Directory of Open Access Journals (Sweden)

    B. Schoenaers

    2017-10-01

    Full Text Available Multi-frequency electron spin resonance (ESR study of p-type synthetic 2H MoS2 reveals a previously unreported signal of axial-symmetry [g// = 2.032(2; g⊥ = 2.270(2] characteristic for a hole-type center in MoS2. It is identified as originating from N acceptor dopants, the N atoms substituting for S sites, with a density of ∼2.3 x 1017 cm-3, thus predominantly accounting for the p-type sample doping. For the applied magnetic field along the c-axis, the signal is mainly comprised of a 14N hyperfine 1:1:1 triplet of splitting A// = 14.7 ± 0.2 G with, on top, a center line accounting for ∼26% of the total signal intensity. The additional observation of a weak half-field signal (g = 3.92 correlating with the main full-field Zeeman response points to the presence of spin S ≥ 1 N agglomerates. The overall signal properties indicate that only ∼74% of the N acceptors occur as isolated decoupled dopants. Monitoring of the ESR signal intensity over a broad temperature range unveils the N dopant as a shallow acceptor of activation energy Ea = 45 ± 7 meV, thus well fit for stable substitutional p-type doping in MoS2-based novel nanoelectronic devices.

  11. An ESR Saturation Treatment for Solvated-Electron Systems

    Science.gov (United States)

    Hiromitsu, Ichiro; Hase, Hirotomo; Higashimura, Takenobu

    1985-06-01

    ESR saturation measurements of solvated electrons (esol-) in alkaline ices were carried out at 73 K and 4 K. When there was no cross-relaxation for esol-, the observed line widths of esol- did not agree with those calculated by Zhidkov’s treatment. The larger spin-packet width found at 73 K than that at 4 K was interpreted in terms of spectral diffusion. When cross-relaxation occurred between esol- and neighbouring radicals, the line widths of esol- were interpreted as being due to both the spectral diffusion and the cross-relaxation. A more comprehensive treatment including a cross-relaxation time is presented; this treatment succeeds in fitting the observed line widths to the theoretical ones.

  12. High school students' representations and understandings of electric fields

    Science.gov (United States)

    Cao, Ying; Brizuela, Bárbara M.

    2016-12-01

    This study investigates the representations and understandings of electric fields expressed by Chinese high school students 15 to 16 years old who have not received high school level physics instruction. The physics education research literature has reported students' conceptions of electric fields postinstruction as indicated by students' performance on textbook-style questions. It has, however, inadequately captured student ideas expressed in other situations yet informative to educational research. In this study, we explore students' ideas of electric fields preinstruction as shown by students' representations produced in open-ended activities. 92 participant students completed a worksheet that involved drawing comic strips about electric charges as characters of a cartoon series. Three students who had spontaneously produced arrow diagrams were interviewed individually after class. We identified nine ideas related to electric fields that these three students spontaneously leveraged in the comic strip activity. In this paper, we describe in detail each idea and its situated context. As most research in the literature has understood students as having relatively fixed conceptions and mostly identified divergences in those conceptions from canonical targets, this study shows students' reasoning to be more variable in particular moments, and that variability includes common sense resources that can be productive for learning about electric fields.

  13. Self propagating high temperature synthesis of ferrites in magnetic fields

    CERN Document Server

    Affleck, L

    2002-01-01

    Self propagating high temperature synthesis (SHS) reactions have been performed on mixtures of BaO sub 2 , Fe and Fe sub 2 O sub 3 to form barium ferrite, BaFe sub 1 sub 2 O sub 1 sub 9. Reactions were conducted in zero field and in an applied magnetic field of 1.1 T with the aim of exploring the influence of the field. The temperature and velocity of the reactions were measured and the products, both post-SHS and post-annealing, were characterised by techniques including X-ray diffraction, Moessbauer spectroscopy, vibrating sample magnetometry and electron microprobe analysis. The applied magnetic field was found to lead to hotter and faster reactions, a greater degree of conversion of the reactants, a needle-like microstructure in the post-SHS product, and a reduced coercive field (approx 20-30 %) in the annealed product, compared to zero field. Sodium perchlorate was used as an internal oxidising agent, and found to produce similar effects. Correlations were observed between the temperature reached in the ...

  14. Effect of niobium and carbon on microstructure and compressive yield strength of as cast ESR Fe-8.5Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Baligidad, R.G.; Dutta, A.; Rao, A.S.

    2005-03-15

    The effect of niobium (1.5 and 3.5 wt-%) addition on the microstructure and mechanical properties of as cast ESR Fe-8.5Al-0.1C alloy has been studied. Alloys were prepared by a combination of air induction melting with flux cover (AIMFC) and electroslag remelting (ESR). As cast ESR alloys were characterised using an optical microscope, a scanning electron microscope (SEM) and an electron probe microanalyser (EPMA). Compression tests were carried out on as cast ESR alloy samples at temperatures up to 800{sup o}C. Addition of 1.5 wt-% Nb to Fe-8.5Al-0.1C alloy resulted in a marginal improvement in the compressive yield strength at test temperatures up to 1073 K, whereas addition of 3.5 wt-% Nb significantly improved the strength. This significant improvement in the room and high temperature compressive strength may be attributed to solid solution strengthening as well as precipitation hardening by the presence of fine and higher volume fractions of niobium and niobium carbide precipitates, in contrast to the relatively soft Fe{sub 3}AlC{sub 0.5} precipitates present in the Fe-8.5Al-0.1C alloy. (author)

  15. Electron-electron interactions in graphene field-induced quantum dots in a high magnetic field

    DEFF Research Database (Denmark)

    Orlof, A.; Shylau, Artsem; Zozoulenko, I. V.

    2015-01-01

    We study the effect of electron-electron interaction in graphene quantum dots defined by an external electrostatic potential and a high magnetic field. To account for the electron-electron interaction, we use the Thomas-Fermi approximation and find that electron screening causes the formation...

  16. High-field phase-diagram of Fe arsenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Y.J.; Jaroszynski, J.; Yamamoto, A.; Gurevich, A.; Riggs, S.C.; Boebinger, G.S.; Larbalestier, D. [National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310 (United States); Wen, H.H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhigadlo, N.D.; Katrych, S.; Bukowski, Z.; Karpinski, J. [Laboratory for Solid State Physics, ETH Zuerich, CH-8093 Zuerich (Switzerland); Liu, R.H.; Chen, H.; Chen, X.H. [Hefei National Laboratory for Physical Science a Microscale and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Balicas, L., E-mail: balicas@magnet.fsu.ed [National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310 (United States)

    2009-05-01

    Here, we report an overview of the phase-diagram of single-layered and double-layered Fe arsenide superconductors at high magnetic fields. Our systematic magneto-transport measurements of polycrystalline SmFeAsO{sub 1-x}F{sub x} at different doping levels confirm the upward curvature of the upper critical magnetic field H{sub c2}(T) as a function of temperature T defining the phase boundary between the superconducting and metallic states for crystallites with the ab planes oriented nearly perpendicular to the magnetic field. We further show from measurements on single-crystals that this feature, which was interpreted in terms of the existence of two superconducting gaps, is ubiquitous among both series of single- and double-layered compounds. In all compounds explored by us the zero temperature upper critical field H{sub c2}(0), estimated either through the Ginzburg-Landau or the Werthamer-Helfand-Hohenberg single gap theories, strongly surpasses the weak-coupling Pauli paramagnetic limiting field. This clearly indicates the strong-coupling nature of the superconducting state and the importance of magnetic correlations for these materials. Our measurements indicate that the superconducting anisotropy, as estimated through the ratio of the effective masses gamma = (m{sub c}/m{sub ab}){sup 1/2} for carriers moving along the c-axis and the ab-planes, respectively, is relatively modest as compared to the high-T{sub c} cuprates, but it is temperature, field and even doping dependent. Finally, our preliminary estimations of the irreversibility field H{sub m}(T), separating the vortex-solid from the vortex-liquid phase in the single-layered compounds, indicates that it is well described by the melting of a vortex lattice in a moderately anisotropic uniaxial superconductor.

  17. Magnetic resonance imaging and spectroscopy at ultra high fields

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, Thomas

    2009-06-23

    The goal of the work presented in this thesis was to explore the possibilities and limitations of MRI / MRS using an ultra high field of 17.6 tesla. A broad range of specific applications and MR methods, from MRI to MRSI and MRS were investigated. The main foci were on sodium magnetic resonance spectroscopic imaging of rodents, magnetic resonance spectroscopy of the mouse brain, and the detection of small amounts of iron labeled stem cells in the rat brain using MRI Sodium spectroscopic imaging was explored since it benefits tremendously from the high magnetic field. Due to the intrinsically low signal in vivo, originating from the low concentrations and short transverse relaxation times, only limited results have been achieved by other researchers until now. Results in the literature include studies conducted on large animals such as dogs to animals as small as rats. No studies performed on mice have been reported, despite the fact that the mouse is the most important laboratory animal due to the ready availability of transgenic strains. Hence, this study concentrated on sodium MRSI of small rodents, mostly mice (brain, heart, and kidney), and in the case of the brain on young rats. The second part of this work concentrated on proton magnetic resonance spectroscopy of the rodent brain. Due to the high magnetic field strength not only the increasing signal but also the extended spectral resolution was advantageous for such kind of studies. The difficulties/limitations of ultra high field MRS were also investigated. In the last part of the presented work detection limits of iron labeled stem cells in vivo using magnetic resonance imaging were explored. The studies provided very useful benchmarks for future researchers in terms of the number of labeled stem cells that are required for high-field MRI studies. Overall this work has shown many of the benefits and the areas that need special attention of ultra high fields in MR. Three topics in MRI, MRS and MRSI were

  18. Mechanical design of a high field common coil magnet

    CERN Document Server

    Caspi, S; Dietderich, D R; Gourlay, S A; Gupta, R; McInturff, A; Millos, G; Scanlan, R M

    1999-01-01

    A common coil design for high field 2-in-1 accelerator magnets has been previously presented as a "conductor-friendly" option for high field magnets applicable for a Very Large Hadron Collider. This paper presents the mechanical design for a 14 tesla 2-in-1 dipole based on the common coil design approach. The magnet will use a high current density Nb/sub 3/Sn conductor. The design addresses mechanical issues particular to the common coil geometry: horizontal support against coil edges, vertical preload on coil faces, end loading and support, and coil stresses and strains. The magnet is the second in a series of racetrack coil magnets that will provide experimental verification of the common coil design approach. (9 refs).

  19. Mechanical design of a high field common coil magnet

    Energy Technology Data Exchange (ETDEWEB)

    Caspi, S.; Chow, K.; Dietderich, D.; Gourlay, S.; Gupta, R.; McInturff, A.; Millos, G.; Scanlan, R.

    1999-03-18

    A common coil design for high field 2-in-1 accelerator magnets has been previously presented as a 'conductor-friendly' option for high field magnets applicable for a Very Large Hadron Collider. This paper presents the mechanical design for a 14 tesla 2-in-1 dipole based on the common coil design approach. The magnet will use a high current density Nb{sub 3}Sn conductor. The design addresses mechanical issues particular to the common coil geometry: horizontal support against coil edges, vertical preload on coil faces, end loading and support, and coil stresses and strains. The magnet is the second in a series of racetrack coil magnets that will provide experimental verification of the common coil design approach.

  20. FIELD CALIBRATION OF A TLD ALBEDO DOSEMETER IN THE HIGH-ENERGY NEUTRON FIELD OF CERF.

    Science.gov (United States)

    Haninger, T; Kleinau, P; Haninger, S

    2017-04-28

    The new albedo dosemeter-type AWST-TL-GD 04 has been calibrated in the CERF neutron field (Cern-EU high-energy Reference Field). This type of albedo dosemeter is based on thermoluminescent detectors (TLDs) and used by the individual monitoring service of the Helmholtz Zentrum München (AWST) since 2015 for monitoring persons, who are exposed occupationally against photon and neutron radiation. The motivation for this experiment was to gain a field specific neutron correction factor Nn for workplaces at high-energy particle accelerators. Nn is a dimensionless factor relative to a basic detector calibration with 137Cs and is used to calculate the personal neutron dose in terms of Hp(10) from the neutron albedo signal. The results show that the sensitivity of the albedo dosemeter for this specific neutron field is not significantly lower as for fast neutrons of a radionuclide source like 252Cf. The neutron correction factor varies between 0.73 and 1.16 with a midrange value of 0.94. The albedo dosemeter is therefore appropriate to monitor persons, which are exposed at high-energy particle accelerators. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Contribution of polymorphisms in ESR1, ESR2, FSHR, CYP19A1 ...

    Indian Academy of Sciences (India)

    Migraine, a highly prevalent headache disorder, is regarded as a polygenic multifactorial disease. Single-nucleotide polymorphisms (SNPs) in the genes that involved in sex hormone metabolism may comprise risk for migraine, but the results of previous genetic association studies are conflicting. The aim of this study was to ...

  2. Control and data acquisition systems for high field superconducting wigglers

    CERN Document Server

    Batrakov, A; Karpov, G; Kozak, V; Kuzin, M; Kuper, E; Mamkin, V; Mezentsev, N A; Repkov, V V; Selivanov, A; Shkaruba, V A

    2001-01-01

    This paper describes the control and DAQ system of superconducting wigglers with magnetic field range up to 10.3 T. The first version of the system controls a 7 T superconducting wiggler prepared for installation at Bessy-II (Germany). The second one controls a 10 T wiggler which is under testing now at the SPring-8 site (Japan). Both systems are based on VME apparatus. The set of specialized VME modules is elaborated to arrange wiggler power supply control, full time wiggler monitoring, and magnetic field high accuracy measurement and field stabilization. The software for the control of the wigglers is written in C language for VxWorks operation system for a Motorola-162 VME controller. The task initialization, stops and acquisition of the data can be done from the nearest personal computer (FTP host for VME), or from the remote system as well.

  3. Rf Gun with High-Current Density Field Emission Cathode

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2005-12-19

    High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes

  4. Behavior of InP:Fe under high electric field

    Science.gov (United States)

    Turki, K.; Picoli, G.; Viallet, J. E.

    1993-06-01

    The behavior of semi-insulating InP:Fe under high electric field is investigated. The current-voltage (I-V) characteristics are studied on both long liquid-encapsulated Czochralski-grown samples and short epitaxial-grown layers. These characteristics show a linear regime at low voltages followed, for higher voltages, by a nonlinear behavior and a current breakdown. The critical electric field at which the nonlinearity begins is found to be independent of the sample thickness, the material compensation, and the nature of the contacts, and is equal to 10 kV/cm. This fact rules out the usual explanation in terms of Lampert's injection theory. In the nonlinear regime, a slow transient response (≊1 s at room temperature) is observed only for long samples. The time constant of this effect exhibits a thermal activation energy (≊0.64 eV) close to that of the iron-related deep level. Field-dependent effects on the thermal emission rate and the capture cross section are discussed. Considering a field enhancement of the capture cross section, we propose a model to explain both the nonlinear characteristics and the slow dynamic behavior of long samples. The current breakdown observed at higher fields is attributed to an impact ionization of the deep levels and not to a trap-filled-limit voltage as previously reported.

  5. ESR1 is co-expressed with closely adjacent uncharacterised genes spanning a breast cancer susceptibility locus at 6q25.1.

    Directory of Open Access Journals (Sweden)

    Anita K Dunbier

    2011-04-01

    Full Text Available Approximately 80% of human breast carcinomas present as oestrogen receptor α-positive (ER+ve disease, and ER status is a critical factor in treatment decision-making. Recently, single nucleotide polymorphisms (SNPs in the region immediately upstream of the ER gene (ESR1 on 6q25.1 have been associated with breast cancer risk. Our investigation of factors associated with the level of expression of ESR1 in ER+ve tumours has revealed unexpected associations between genes in this region and ESR1 expression that are important to consider in studies of the genetic causes of breast cancer risk. RNA from tumour biopsies taken from 104 postmenopausal women before and after 2 weeks treatment with an aromatase (oestrogen synthase inhibitor was analyzed on Illumina 48K microarrays. Multiple-testing corrected Spearman correlation revealed that three previously uncharacterized open reading frames (ORFs located immediately upstream of ESR1, C6ORF96, C6ORF97, and C6ORF211 were highly correlated with ESR1 (Rs =  0.67, 0.64, and 0.55 respectively, FDR<1 × 10(-7. Publicly available datasets confirmed this relationship in other groups of ER+ve tumours. DNA copy number changes did not account for the correlations. The correlations were maintained in cultured cells. An ERα antagonist did not affect the ORFs' expression or their correlation with ESR1, suggesting their transcriptional co-activation is not directly mediated by ERα. siRNA inhibition of C6ORF211 suppressed proliferation in MCF7 cells, and C6ORF211 positively correlated with a proliferation metagene in tumours. In contrast, C6ORF97 expression correlated negatively with the metagene and predicted for improved disease-free survival in a tamoxifen-treated published dataset, independently of ESR1. Our observations suggest that some of the biological effects previously attributed to ER could be mediated and/or modified by these co-expressed genes. The co-expression and function of these genes may be

  6. Dosimetry in radiation fields around high-energy proton accelerators

    CERN Document Server

    Agosteo, S; Silari, M; Theis, C

    2008-01-01

    Radiation dosimetry at high-energy proton accelerators is a difficult task because of the complexity of the stray radiation field. A good knowledge of this mixed radiation field is very important to be able to select the type of detectors (active and/or passive) to be employed for routine area monitoring and to choose the personal dosimeter legally required for estimating the effective dose received by individuals. At the same time, the response function of the detectors to the mixed field must be thoroughly understood. A proper calibration of a device, which may involve a complex series of measurements in various reference fields, is needed. Monte Carlo simulations provide a complementary – and sometimes the principal – mean of determining the response function. The ambient dose equivalent rates during operation range from a few hundreds of μSv per year to a few mSv per year. To measure such rates one needs detectors of high sensitivity and/or capable of integrating over long periods. The main challenge...

  7. Ligand effects on ESR and optical properties of gold atoms in gamma irradiated organic solid solutions at 77 K.

    Science.gov (United States)

    Hase, Yoko Miyatake; Ito, Yoshitaka; Tajima, Yusuke

    2005-10-13

    Ligand effects on ESR and optical properties of Au0 atoms produced at 77 K in gamma irradiated solid solutions of AuCl/MTHF and AuCl/EtOH with and without HCl were investigated. Four groups of ESR lines were observed at 73 K more clearly around the magnetic fields at about 250, 280, 340, and 400 mT for both gamma irradiated MTHF and EtOH solid solutions with HCl than those without HCl. The values of a and g(J) calculated by Breit-Rabi analysis showed a remarkable dependence on the solvent polarity. It was confirmed that the signals were the hyperfine quartet corresponding to the transitions between the Zeeman levels of Au0 atoms with nuclear spin of 3/2 in the ground state, 2S(1/2). It was also confirmed that Au0 atoms produced after gamma irradiation were located in the nuclear environment of isotropic interaction with surrounding ligand molecules. Delocalization of the unpaired spin density of Au0 onto ligands is found to be as large as one in the case of Cu0 atoms. Our previous hypothesis of the occurrence of configuration mixing of d valence orbital into the wave function of the atom in its 2S(1/2) was strongly supported. The dependence of the ESR, optical absorption, and the steady-state emission and excitation characteristics on solvent polarity was cleared in this study. We observed two kinds of emissions i.e., a band at 385 nm and a set of emission bands at 456, 482, 484, and 520 nm. These correspond to two bands out of the six kinds of emissions observed previously. The bands were attributed to exciplex (Au0 x Ln...Au+)* and the excited Au0 atoms trapped in a large cavity, respectively. The negative counterion of Au+ of the gold compound plays an important role for the formation of the exciplexes.

  8. Raman spectroscopy of graphite in high magnetic fields

    Science.gov (United States)

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

    2011-03-01

    Recently, much attention has been paid to electron-phonon coupling in graphene. In particular, significant re-normalization and broadening of long-wavelength optical phonons are predicted to occur through resonant interaction with Landau-quantized Dirac fermions. We report here on a high-field magneto-Raman spectroscopy study of highly-oriented pyrolytic graphite (HOPG) and natural graphite at temperatures down to 5 K and in magnetic fields up to 45 T. The E2 g graphite phonon line exhibits anticrossing-like behavior at approximately 30 T, which we attribute to the magneto-phonon resonance (MPR) of graphite's massless holes at the H-point. Additionally, we observed features related to inter-Landau-level transitions at the K-point of graphite. We also observed weak graphene-like signatures of MPR, indicating the existence of graphene flakes on the graphite surface.

  9. ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer.

    Science.gov (United States)

    Leyland-Jones, Brian; Gray, Kathryn P; Abramovitz, Mark; Bouzyk, Mark; Young, Brandon; Long, Bradley; Kammler, Roswitha; Dell'Orto, Patrizia; Biasi, Maria Olivia; Thürlimann, Beat; Harvey, Vernon; Neven, Patrick; Arnould, Laurent; Maibach, Rudolf; Price, Karen N; Coates, Alan S; Goldhirsch, Aron; Gelber, Richard D; Pagani, Olivia; Viale, Giuseppe; Rae, James M; Regan, Meredith M

    2015-12-01

    Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.

  10. Development of high magnetic fields for energy research

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.D.; Campbell, L.J.; Modler, R.; Movshovich, R. [Los Alamos National Lab., NM (United States); Lawrence, J.M. [Univ. of California, Irvine, CA (United States); Awschalom, D.D. [Univ. of California, Santa Barbara, CA (United States)

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The primary purpose of work has been to develop the scientific basis for DOE support of a program that would build a novel, nondestructive 100-tesla magnet that would be available as a user facility for cutting-edge, energy-related research and technology at very high magnetic fields.

  11. Key techniques of the high precision gravity field system

    Science.gov (United States)

    Xu, Weimin; Chen, Shi; Lu, Hongyan; Shi, Lei

    2017-04-01

    Ground-based gravity time series provide a direct method to monitor all sources of mass changes from local to global scale. But the effectively infinite spatial sensitivity of gravity measurements make it difficult to isolate the signal of interest. The high precision gravity field system is an alternative approach of modeling mass changes under-ground. The field system, consists of absolute gravity, gravity and gravity gradient, GNSS, leveling and climate hydrology measurements, can improve the signal-to-noise ratio for many applications by removing contributions of unwanted signal from elevation changes, air pressure changes, local hydrology, and others. The networks of field system combination, such as field-profile in more than 100 kilometers, can be used in critical zone with high seismic risk for monitoring earth dynamics, volcanic and seismic phenomena. The system is constituted by 9 typical observation stations in 3*3 array (or 4 in 2*2 array) in 60 square meters field, each station is designed for integrated measurements, including absolute gravity, gravity gradient, elevation changes, air pressure and hydrology. Time-lapse gravity changes resulting from absolute gravimeter (FG5 or A10) with standard deviation less than 2 μGal, without the contributions of Earth tides, loading and polar motion. Additional measurements such as air pressure change, local hydrology and soil moisture are indispensable. The elevation changes resulting from GNSS (on the base station) and leveling (between stations) with precision less than 10 mm. The gravity gradient is the significant measurement for delimiting the location of the related mass changes underground the station, which is measured by Scintrex CG-5 gravimeters in different height (80cm in the test field), with precision less than 10 E. It is necessary to improve the precision of gravity gradient measurements by certain method in field experiment for the high precision measurement system. Acknowledgment: This

  12. Estrogen Receptor Alpha (ESR1-Dependent Regulation of the Mouse Oviductal Transcriptome.

    Directory of Open Access Journals (Sweden)

    Katheryn L Cerny

    Full Text Available Estrogen receptor-α (ESR1 is an important transcriptional regulator in the mammalian oviduct, however ESR1-dependent regulation of the transcriptome of this organ is not well defined, especially at the genomic level. The objective of this study was therefore to investigate estradiol- and ESR1-dependent regulation of the transcriptome of the oviduct using transgenic mice, both with (ESR1KO and without (wild-type, WT a global deletion of ESR1. Oviducts were collected from ESR1KO and WT littermates at 23 days of age, or ESR1KO and WT mice were treated with 5 IU PMSG to stimulate follicular development and the production of ovarian estradiol, and the oviducts collected 48 h later. RNA extracted from whole oviducts was hybridized to Affymetrix Genechip Mouse Genome 430-2.0 arrays (n = 3 arrays per genotype and treatment or reverse transcribed to cDNA for analysis of the expression of selected mRNAs by real-time PCR. Following microarray analysis, a statistical two-way ANOVA and pairwise comparison (LSD test revealed 2428 differentially expressed transcripts (DEG's, P < 0.01. Genotype affected the expression of 2215 genes, treatment (PMSG affected the expression of 465 genes, and genotype x treatment affected the expression of 438 genes. With the goal of determining estradiol/ESR1-regulated function, gene ontology (GO and bioinformatic pathway analyses were performed on DEG's in the oviducts of PMSG-treated ESR1KO versus PMSG-treated WT mice. Significantly enriched GO molecular function categories included binding and catalytic activity. Significantly enriched GO cellular component categories indicated the extracellular region. Significantly enriched GO biological process categories involved a single organism, modulation of a measurable attribute and developmental processes. Bioinformatic analysis revealed ESR1-regulation of the immune response within the oviduct as the primary canonical pathway. In summary, a transcriptomal profile of estradiol- and

  13. Strong-field relativistic processes in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Postavaru, Octavian

    2010-12-08

    In this thesis we investigate strong-field relativistic processes in highly charged ions. In the first part, we study resonance fluorescence of laser-driven highly charged ions in the relativistic regime by solving the time-dependent master equation in a multi-level model. Our ab initio approach based on the Dirac equation allows for investigating highly relativistic ions, and, consequently, provides a sensitive means to test correlated relativistic dynamics, bound-state quantum electrodynamic phenomena and nuclear effects by applying coherent light with x-ray frequencies. Atomic dipole or multipole moments may be determined to unprecedented accuracy by measuring the interference-narrowed fluorescence spectrum. Furthermore, we investigate the level structure of heavy hydrogenlike ions in laser beams. Interaction with the light field leads to dynamic shifts of the electronic energy levels, which is relevant for spectroscopic experiments. We apply a fully relativistic description of the electronic states by means of the Dirac equation. Our formalism goes beyond the dipole approximation and takes into account non-dipole effects of retardation and interaction with the magnetic field components of the laser beam. We predicted cross sections for the inter-shell trielectronic recombination (TR) and quadruelectronic recombination processes which have been experimentally confirmed in electron beam ion trap measurements, mainly for C-like ions, of Ar, Fe and Kr. For Kr{sup 30}+, inter-shell TR contributions of nearly 6% to the total resonant photorecombination rate were found. (orig.)

  14. The Mechanical Design Optimization of a High Field HTS Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, SL; Gupta, RC

    2015-06-01

    This paper describes the conceptual design optimization of a large aperture, high field (24 T at 4 K) solenoid for a 1.7 MJ superconducting magnetic energy storage device. The magnet is designed to be built entirely of second generation (2G) high temperature superconductor tape with excellent electrical and mechanical properties at the cryogenic temperatures. The critical parameters that govern the magnet performance are examined in detail through a multiphysics approach using ANSYS software. The analysis results formed the basis for the performance specification as well as the construction of the magnet.

  15. Electric Field Simulations and Analysis for High Voltage High Power Medium Frequency Transformer

    Directory of Open Access Journals (Sweden)

    Pei Huang

    2017-03-01

    Full Text Available The electronic power transformer (EPT raises concerns for its notable size and volume reduction compared with traditional line frequency transformers. Medium frequency transformers (MFTs are important components in high voltage and high power energy conversion systems such as EPTs. High voltage and high power make the reliable insulation design of MFT more difficult. In this paper, the influence of wire type and interleaved winding structure on the electric field distribution of MFT is discussed in detail. The electric field distributions for six kinds of typical non-interleaved windings with different wire types are researched using a 2-D finite element method (FEM. The electric field distributions for one non-interleaved winding and two interleaved windings are also studied using 2-D FEM. Furthermore, the maximum electric field intensities are obtained and compared. The results show that, in this case study, compared with foil conductor, smaller maximum electric field intensity can be achieved using litz wire in secondary winding. Besides, interleaving can increase the maximum electric field intensity when insulation distance is constant. The proposed method of studying the electric field distribution and analysis results are expected to make a contribution to the improvement of electric field distribution in transformers.

  16. The High Field Path to Practical Fusion Energy

    Science.gov (United States)

    Mumgaard, Robert; Whyte, D.; Greenwald, M.; Hartwig, Z.; Brunner, D.; Sorbom, B.; Marmar, E.; Minervini, J.; Bonoli, P.; Irby, J.; Labombard, B.; Terry, J.; Vieira, R.; Wukitch, S.

    2017-10-01

    We propose a faster, lower cost development path for fusion energy enabled by high temperature superconductors, devices at high magnetic field, innovative technologies and modern approaches to technology development. Timeliness, scale, and economic-viability are the drivers for fusion energy to combat climate change and aid economic development. The opportunities provided by high-temperature superconductors, innovative engineering and physics, and new organizational structures identified over the last few years open new possibilities for realizing practical fusion energy that could meet mid-century de-carbonization needs. We discuss re-factoring the fusion energy development path with an emphasis on concrete risk retirement strategies utilizing a modular approach based on the high-field tokamak that leverages the broader tokamak physics understanding of confinement, stability, and operational limits. Elements of this plan include development of high-temperature superconductor magnets, simplified immersion blankets, advanced long-leg divertors, a compact divertor test tokamak, efficient current drive, modular construction, and demountable magnet joints. An R&D plan culminating in the construction of an integrated pilot plant and test facility modeled on the ARC concept is presented.

  17. Excitation thresholds of field-aligned irregularities and associated ionospheric hysteresis at very high latitudes observed using SPEAR-induced HF radar backscatter

    Directory of Open Access Journals (Sweden)

    D. M. Wright

    2009-07-01

    Full Text Available On 10 October 2006 the SPEAR high power radar facility was operated in a power-stepping mode where both CUTLASS radars were detecting backscatter from the SPEAR-induced field-aligned irregularities (FAIs. The effective radiated power of SPEAR was varied from 1–10 MW. The aim of the experiment was to investigate the power thresholds for excitation (Pt and collapse (Pc of artificially-induced FAIs in the ionosphere over Svalbard. It was demonstrated that FAI could be excited by a SPEAR ERP of only 1 MW, representing only 1/30th of SPEAR's total capability, and that once created the irregularities could be maintained for even lower powers. The experiment also demonstrated that the very high latitude ionosphere exhibits hysteresis, where the down-going part of the power cycle provided a higher density of irregularities than for the equivalent part of the up-going cycle. Although this second result is similar to that observed previously by CUTLASS in conjunction with the Tromsø heater, the same is not true for the equivalent incoherent scatter measurements. The EISCAT Svalbard Radar (ESR failed to detect any hysteresis in the plasma parameters over Svalbard in stark contract with the measurements made using the Tromsø UHF.

  18. Excitation thresholds of field-aligned irregularities and associated ionospheric hysteresis at very high latitudes observed using SPEAR-induced HF radar backscatter

    Directory of Open Access Journals (Sweden)

    D. M. Wright

    2009-07-01

    Full Text Available On 10 October 2006 the SPEAR high power radar facility was operated in a power-stepping mode where both CUTLASS radars were detecting backscatter from the SPEAR-induced field-aligned irregularities (FAIs. The effective radiated power of SPEAR was varied from 1–10 MW. The aim of the experiment was to investigate the power thresholds for excitation (Pt and collapse (Pc of artificially-induced FAIs in the ionosphere over Svalbard. It was demonstrated that FAI could be excited by a SPEAR ERP of only 1 MW, representing only 1/30th of SPEAR's total capability, and that once created the irregularities could be maintained for even lower powers. The experiment also demonstrated that the very high latitude ionosphere exhibits hysteresis, where the down-going part of the power cycle provided a higher density of irregularities than for the equivalent part of the up-going cycle. Although this second result is similar to that observed previously by CUTLASS in conjunction with the Tromsø heater, the same is not true for the equivalent incoherent scatter measurements. The EISCAT Svalbard Radar (ESR failed to detect any hysteresis in the plasma parameters over Svalbard in stark contract with the measurements made using the Tromsø UHF.

  19. Spin Labeling ESR Investigation of Covalently Bound Residues in Soil

    Science.gov (United States)

    Aleksandrova, Olga; Steinhoff, Heinz-Juergen; Klasmeier, Joerg; Schulz, Marcus; Matthies, Michael

    2013-04-01

    Organic xenobiotic chemicals, such as pesticides, biocides and veterinary pharmaceuticals, interact with soil, which results in the simultaneous formations of metabolites, mineralization products, and bound or non-extractable residues (NER). Substances or metabolites with reactive functional groups, such as aniline or phenol, have a tendency to give a larger proportion of NER. Despite numerous studies on NER, the majority of their chemical structures is still unknown. Reversible sequestration and irreversible formation of NER were also observed for veterinary antibiotic pharmaceuticals, after their application to soil with and without manure. For this purpose, we hypothesized a key role of specific functional groups of soil contaminants, via which contaminants are covalently bound to soil constituents, and advance a method of spin labeling ESR investigation of reaction products using a membrane method. Spin labels (SL) represent chemically stable paramagnetic molecules used as molecular labels and molecular probes for testing the covalent binding, structural properties, and molecular mobility of different physical, chemical, and biological systems. In the case of covalent binding of SL, their ESR spectra become broadened. We used stable nitroxide radicals (NR) as SL. These radicals modeled organic chemical contaminants and differed only in one functional group. The paramagnetic SL 4-Amino Tempo (4-amino-2,2,6,6-tetramethyl-1-piperidinylox) differed from Tempo (2,2,6,6-Tetramethylpiperidinooxy) in a substituent at the para-position of the piperidine ring, whereas Aniline Tempo (1-Piperidinyloxy, 2,2,6,-tetramethyl, 6-Aniline) differed from Tempo in an Aniline substituting one CH3 functional group. Before experimental analysis, we tested temporal changes in the concentration of both NR incubated with soil and found that the life-times of them in soil exceeded 3 days. We contaminated and labeled soil samples with NR, adding to soil the aqueous solution, which already

  20. Compliance with High-Intensity Radiated Fields Regulations - Emitter's Perspective

    Science.gov (United States)

    Statman, Joseph; Jamnejad, Vahraz; Nguyen, Lee

    2012-01-01

    NASA's Deep Space Network (DSN) uses high-power transmitters on its large antennas to communicate with spacecraft of NASA and its partner agencies. The prime reflectors of the DSN antennas are parabolic, at 34m and 70m in diameter. The DSN transmitters radiate Continuous Wave (CW) signals at 20 kW - 500 kW at X-band and S-band frequencies. The combination of antenna reflector size and high frequency results in a very narrow beam with extensive oscillating near-field pattern. Another unique feature of the DSN antennas is that they (and the radiated beam) move mostly at very slow sidereal rate, essentially identical in magnitude and at the opposite direction of Earth rotation.The DSN is in the process of revamping its documentation to provide analysis of the High Intensity Radiation Fields (HIRF) environment resulting from radio frequency radiation from DSN antennas for comparison to FAA regulations regarding certification of HIRF protection as outlined in the FAA regulations on HIRF protection for aircraft electrical and electronic systems (Title 14, Code of Federal Regulations (14 CFR) [section sign][section sign] 23.1308, 25.1317, 27.1317, and 29.1317).This paper presents work done at JPL, in consultation with the FAA. The work includes analysis of the radiated field structure created by the unique DSN emitters (combination of transmitters and antennas) and comparing it to the fields defined in the environments in the FAA regulations. The paper identifies areas that required special attention, including the implications of the very narrow beam of the DSN emitters and the sidereal rate motion. The paper derives the maximum emitter power allowed without mitigation and the mitigation zones, where required.Finally, the paper presents summary of the results of the analyses of the DSN emitters and the resulting DSN process documentation.

  1. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2002-09-18

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To

  2. Field experimental observations of highly graded sediment plumes.

    Science.gov (United States)

    Jensen, Jacob Hjelmager; Saremi, Sina; Jimenez, Carlos; Hadjioannou, Louis

    2015-06-15

    A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes, gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in the water column, and facing the plume at different angles. The processes were captured using GoPro-Hero-series cameras. The high-quality underwater footage from near-surface, mid-depth and near-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Advances in High-Field BOLD fMRI

    Directory of Open Access Journals (Sweden)

    Markus Barth

    2011-11-01

    Full Text Available This review article examines the current state of BOLD fMRI at a high magnetic field strength of 7 Tesla. The following aspects are covered: a short description of the BOLD contrast, spatial and temporal resolution, BOLD sensitivity, localization and spatial specificity, technical challenges as well as an outlook on future developments are given. It is shown that the main technical challenges of performing BOLD fMRI at high magnetic field strengths—namely development of array coils, imaging sequences and parallel imaging reconstruction—have been solved successfully. The combination of these developments has lead to the availability of high-resolution BOLD fMRI protocols that are able to cover the whole brain with a repetition time (TR shorter than 3 s. The structural information available from these high-resolution fMRI images itself is already very detailed, which helps to co-localize structure and function. Potential future applications include whole-brain connectivity analysis on a laminar resolution and single subject examinations.

  4. High-field electrical and thermal transport in suspended graphene.

    Science.gov (United States)

    Dorgan, Vincent E; Behnam, Ashkan; Conley, Hiram J; Bolotin, Kirill I; Pop, Eric

    2013-10-09

    We study the intrinsic transport properties of suspended graphene devices at high fields (≥1 V/μm) and high temperatures (≥1000 K). Across 15 samples, we find peak (average) saturation velocity of 3.6 × 10(7) cm/s (1.7 × 10(7) cm/s) and peak (average) thermal conductivity of 530 W m(-1) K(-1) (310 W m(-1) K(-1)) at 1000 K. The saturation velocity is 2-4 times and the thermal conductivity 10-17 times greater than in silicon at such elevated temperatures. However, the thermal conductivity shows a steeper decrease at high temperature than in graphite, consistent with stronger effects of second-order three-phonon scattering. Our analysis of sample-to-sample variation suggests the behavior of "cleaner" devices most closely approaches the intrinsic high-field properties of graphene. This study reveals key features of charge and heat flow in graphene up to device breakdown at ~2230 K in vacuum, highlighting remaining unknowns under extreme operating conditions.

  5. Dissipation in high-temperature superconductors in a magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.H.; Gray, K.E.; Kampwirth, R.T.; McDonald, D.B.; McKay, D.M.

    1990-01-01

    The absence of a Lorentz force dependence on dissipation in the highly anisotropic highly high-temperature superconductor, Tl{sub 2}Ba{sub 2}CaCu{sub 2}O{sub x}, has been measured over a wide range of current densities in broadened resistive transitions, current-voltage characteristics, magnetoresistances, and critical current densities, J{sub c}. The magnetoresistances are very useful to find out the correct temperature and field dependences of the activation energy. As an alternative to flux motion, we consider a Josephson-coupling model which is consistent with the broadened resistive transitions and the lack of Lorentz-force dependence. We found that the Josephson-coupling model agrees with the temperature dependences of the activation energy and J{sub c} and is better matched to the weak field dependence of J{sub c} than the flux creep model. Possible origins of Josephson junctions in high-quality films and single crystals are discussed. 12 refs., 6 figs.

  6. Effect of vibrating electrode on temperature profiles, fluid flow, and pool shape in ESR system based on a comprehensive coupled model

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2015-07-01

    Full Text Available The vibrating electrode method was proposed in the electro-slag remelting (ESR process in this paper, and the effect of vibrating electrode on the solidification structure of ingot was studied. A transient three-dimensional (3D coupled mathematical model was established to simulate the electromagnetic phenomenon, fluid flow as well as pool shape in the ESR process with the vibrating electrode. The finite element volume method is developed to solve the electromagnetic field using ANSYS mechanical APDL software. Moreover, the electromagnetic force and Joule heating are interpolated as the source term of the momentum and energy equations. The multi-physical fields have been investigated and compared between the traditional electrode and the vibrating electrode in the ESR process. The results show that the drop process of metal droplets with the traditional electrode is scattered randomly. However, the drop process of metal droplets with the vibrating electrode is periodic. The highest temperature of slag layer with the vibrating electrode is higher than that with the traditional electrode, which can increase the melting rate due to the enhanced heat transfer in the vicinity of the electrode tip. The results also show that when the amplitude and frequency of the vibrating electrode increase, the cycle of drop process of metal droplets decreases significantly.

  7. REVIEW OF HIGH FIELD Q SLOPE, CAVITY MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Gianluigi Ciovati

    2008-01-23

    One of the most interesting phenomenon occurring in superconducting radio-frequency (SRF) cavities made of bulk niobium is represented by a sharp decrease of the quality factor above peak surface magnetic field of about 90 mT and is referred to as "high field Q-slope" or "Q-drop". This phenomenon was observed first in 1997 and since then some effort was devoted to the understanding of the causes behind it. Still, no clear physical interpretation of the Q-drop has emerged, despite several attempts. In this contribution, I will review the experimental results for various cavities measured in many laboratories and I will try to identify common features and differences related to the Q-drop.

  8. High electric field dielectric studies of aqueous myoglobin solutions.

    Science.gov (United States)

    Jones, G P; Davies, A E; van der Sluijs, M J

    1979-01-01

    High field dielectric measurements of the Piekara factor deltaepsilon/E2 have been carried out for a range of concentrations of horse heart myoglobin in water at 293K. Using the literature value for the dipole moment of myoglobin and the established theory for the classical orientational dipolar non-linear effect predicts a value of deltaepsilon/E2 one order of magnitude greater than that for water. The measured effect, however, was found to be one order of magnitude less than for water. This difference is explained as being most probably due to the existence of antiparallel molecular dipole pairs in the myoglobin solution. The possibility of a positive deltaepsilon due to a field induced conformational change of the myoglobin cannot, however, be ruled out.

  9. Identification of irradiated sage tea ( Salvia officinalis L.) by ESR spectroscopy

    Science.gov (United States)

    Tepe Çam, Semra; Engin, Birol

    2010-04-01

    The use of electron spin resonance (ESR) spectroscopy to accurately distinguish irradiated from unirradiated sage tea was examined. Before irradiation, sage tea samples exhibit one asymmetric singlet ESR signal centered at g=2.0037. Besides this central signal, two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. Irradiation with increasing doses caused a significant increase in radiation-induced ESR signal intensity at g=2.0265 (the left satellite signal) and this increase was found to be explained by a polynomial varying function. The stability of that radiation-induced ESR signal at room temperature was studied over a storage period of 9 months. Also, the kinetic of signal at g=2.0265 was studied in detail over a temperature range 313-353 K by annealing samples at different temperatures for various times.

  10. High-resolution field shaping utilizing a masked multileaf collimator.

    Science.gov (United States)

    Williams, P C; Cooper, P

    2000-08-01

    Multileaf collimators (MLCs) have become an important tool in the modern radiotherapy department. However, the current limit of resolution (1 cm at isocentre) can be too coarse for acceptable shielding of all fields. A number of mini- and micro-MLCs have been developed, with thinner leaves to achieve approved resolution. Currently however, such devices are limited to modest field sizes and stereotactic applications. This paper proposes a new method of high-resolution beam collimation by use of a tertiary grid collimator situated below the conventional MLC. The width of each slit in the grid is a submultiple of the MLC width. A composite shaped field is thus built up from a series of subfields, with the main MLC defining the length of each strip within each subfield. Presented here are initial findings using a prototype device. The beam uniformity achievable with such a device was examined by measuring transmission profiles through the grid using a diode. Profiles thus measured were then copied and superposed to generate composite beams, from which the uniformity achievable could be assessed. With the average dose across the profile normalized to 100%, hot spots up to 5.0% and troughs of 3% were identified for a composite beam of 2 x 5.0 mm grids, as measured at Dmax for a 6 MV beam. For a beam composed from 4 x 2.5 mm grids, the maximum across the profile was 3.0% above the average, and the minimum 2.5% below. Actual composite profiles were also formed using the integrating properties of film, with the subfield indexing performed using an engineering positioning stage. The beam uniformity for these fields compared well with that achieved in theory using the diode measurements. Finally sine wave patterns were generated to demonstrate the potential improvements in field shaping and conformity using this device as opposed to the conventional MLC alone. The scalloping effect on the field edge commonly seen on MLC fields was appreciably reduced by use of 2 x 5.0 mm

  11. Efficiency and rate capability studies of the time-of-flight detector for isochronous mass measurements of stored short-lived nuclei with the FRS-ESR facility

    Science.gov (United States)

    Kuzminchuk-Feuerstein, Natalia; Fabian, Benjamin; Diwisch, Marcel; Plaß, Wolfgang R.; Geissel, Hans; Ayet San Andrés, Samuel; Dickel, Timo; Knöbel, Ronja; Scheidenberger, Christoph; Sun, Baohua; Weick, Helmut

    2016-06-01

    A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm2 the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector.

  12. Efficiency and rate capability studies of the time-of-flight detector for isochronous mass measurements of stored short-lived nuclei with the FRS-ESR facility

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminchuk-Feuerstein, Natalia; Fabian, Benjamin [II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Diwisch, Marcel [II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen (Germany); Plaß, Wolfgang R., E-mail: Wolfgang.R.Plass@exp2.physik.uni-giessen.de [II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Geissel, Hans; Ayet San Andrés, Samuel; Dickel, Timo; Knöbel, Ronja; Scheidenberger, Christoph [II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Sun, Baohua [II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen (Germany); Weick, Helmut [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany)

    2016-06-11

    A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm{sup 2} the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector.

  13. IR and ESR studies on novel Cu(II) theophyllinato complexes containing mono- or bidentate ligands

    Science.gov (United States)

    Forizs, Edit; David, L.; Cozar, O.; Chiş, V.; Damian, G.; Csibi, Jolán

    1999-05-01

    Three mixed-ligand copper(II) complexes containing theophylline and mono- or bidentate N-donor ligands (2,2'-bipyridine, 4-fluoraniline and 1,10-phenanthroline) were synthesized and characterized by elemental analysis, IR and ESR spectra. According to IR and ESR data the Cu(II) complexes exhibit a distorted tetrahedral coordination of copper by two nitrogen atoms of the monodentate or bidentate ligands and the two monodentate theophyllinate anion bonded through N(7) atom.

  14. ESR1 and PGR polymorphisms are associated with estrogen and progesterone receptor expression in breast tumors

    OpenAIRE

    Hertz, Daniel L.; Henry, N. Lynn; Kidwell, Kelley M.; Thomas, Dafydd; Goddard, Audrey; Azzouz, Faouzi; Speth, Kelly; Li, Lang; Banerjee, Mousumi; Thibert, Jacklyn N; Kleer, Celina G.; Stearns, Vered; Hayes, Daniel F.; Skaar, Todd C.; Rae, James M.

    2016-01-01

    Hormone receptor-positive (HR+) breast cancers express the estrogen (ERα) and/or progesterone (PgR) receptors. Inherited single nucleotide polymorphisms (SNPs) in ESR1, the gene encoding ERα, have been reported to predict tamoxifen effectiveness. We hypothesized that these associations could be attributed to altered tumor gene/protein expression of ESR1/ERα and that SNPs in the PGR gene predict tumor PGR/PgR expression. Formalin-fixed paraffin-embedded breast cancer tumor specimens were analy...

  15. High Field Side MHD Activity During Local Helicity Injection

    Science.gov (United States)

    Pachicano, J. L.; Bongard, M. W.; Fonck, R. J.; Perry, J. M.; Reusch, J. A.; Richner, N. J.

    2017-10-01

    MHD is an essential part of understanding the mechanism for local helicity injection (LHI) current drive. The new high field side (HFS) LHI system on the Pegasus ST permits new tests of recent NIMROD simulations. In that model, LHI current streams in the plasma edge undergo large-scale reconnection events, leading to current drive. This produces bursty n = 1 activity around 30 kHz on low field side (LFS) Mirnov coils, consistent with experiment. The simulations also feature coherent injector streams winding down the center column. Improvements to the core high-resolution poloidal Mirnov array with Cat7A Ethernet cabling and differentially driven signal processing eliminated EMI-driven switching noise, enabling detailed spectral analysis. Preliminary results from the recovered HFS poloidal Mirnov coils suggest n = 1 activity is present at the top of the vessel core, but does not persist down the centerstack. HFS LHI experiments can exhibit an operating regime where the high amplitude MHD is abruptly reduced by more than an order of magnitude on LFS Mirnov coils, leading to higher plasma current and improved particle confinement. This reduction is not observed on the HFS midplane magnetics. Instead, they show broadband turbulence-like magnetic features with near consistent amplitude in a frequency range of 90-200 kHz. Work supported by US DOE Grant DE-FG02-96ER54375.

  16. Tunable-frequency high-field electron paramagnetic resonance

    Science.gov (United States)

    Krzystek, J.; Zvyagin, S. A.; Ozarowski, Andrew; Trofimenko, S.; Telser, Joshua

    2006-02-01

    A tunable-frequency methodology based on backward wave oscillator sources in high-frequency and -field EPR (HFEPR) is described. This methodology is illustrated by an application to three non-Kramers transition metal ion complexes and one Kramers ion complex. The complexes are of: Ni(II) ( S = 1) as found in dichlorobistriphenylphosphanenickel(II), Mn(III) ( S = 2) as found in mesotetrasulfonatoporphyrinatomanganese(III) chloride, Fe(II) ( S = 2) as found in ferrous sulfate tetrahydrate, and Co(II) ( S = 3/2) as found in azido(tris(3- tert-butylpyrazol-1-yl)hydroborate)cobalt(II). The above Ni(II) and Mn(III) complexes have been studied before by HFEPR using the multifrequency methodology based on Gunn oscillator sources, but not by the present method, while the Fe(II) and Co(II) complexes presented here have not been studied by any form of HFEPR. Highly accurate spin Hamiltonian parameters can be obtained by the experimental methodology described here, in combination with automated fitting procedures. This method is particularly successful in determining g-matrix parameters, which are very difficult to extract for high-spin systems from single frequency (or a very limited set of multi-frequency) HFEPR spectra, but is also able to deliver equally accurate values of the zero-field splitting tensor. The experimental methods involve either conventional magnetic field modulation or an optical modulation of the sub-THz wave beam. The relative merits of these and other experimental methods are discussed.

  17. ESR study of p-type natural 2H-polytype MoS2 crystals: The As acceptor activity

    Science.gov (United States)

    Stesmans, A.; Iacovo, S.; Afanas'ev, V. V.

    2016-10-01

    Low-temperature (T = 1.7-77 K) multi frequency electron spin resonance (ESR) study on p-type 2H-polytype geological MoS2 crystals reveals p-type doping predominantly originating from As atoms substituting for S sites in densities of (2.4 ± 0.2) × 1017 cm-3. Observation of a "half field"(g ˜ 3.88) signal firmly correlating with the central Zeeman As accepter signal indicates the presence of spin S > ½ As agglomerates, which together with the distinct multicomponent makeup of the Zeeman signal points to manifest non-uniform As doping; only ˜13% of the total As response originates from individual decoupled As dopants. From ESR monitoring the latter vs. T, an activation energy Ea = (0.7 ± 0.2) meV is obtained. This unveils As as a noticeable shallow acceptor dopant, appropriate for realization of effective p-type doping in targeted 2D MoS2-based switching devices.

  18. Characterization of phenolic pellets for ESR dosimetry in photon beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Salvatore; Veronese, Ivan [Universita degli Studi di Milano, Department of Physics, Milan (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano (Italy); Iacoviello, Giuseppina [Hospital ARNAS-Civico, Medical Physics Department, Palermo (Italy); Panzeca, Salvatore [Universita degli Studi di Palermo, Department of Physics and Chemistry, Palermo (Italy); Istituto Nazionale di Fisica Nucleare-Sezione di Catania, Catania (Italy); Bartolotta, Antonio; Longo, Anna [Universita degli Studi di Palermo, Department of Physics and Chemistry, Palermo (Italy); Dondi, Daniele [Universita degli Studi di Pavia, Department of Chemistry, Pavia (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pavia (Italy); Gueli, Anna Maria [Istituto Nazionale di Fisica Nucleare-Sezione di Catania, Catania (Italy); Universita degli Studi di Catania, Department of Physics and Astronomy, PH3DRA Laboratories, Catania (Italy); Loi, Gianfranco; Mones, Eleonora [Azienda Ospedaliero Universitaria Maggiore della Carita, Medical Physics Department, Novara (Italy); Marrale, Maurizio [Universita degli Studi di Palermo, Department of Physics and Chemistry, Palermo (Italy); Istituto Nazionale di Fisica Nucleare-Sezione di Catania, Catania (Italy); Universita degli Studi di Palermo, Advanced Technologies Network Center (ATeN Center), Palermo (Italy)

    2017-11-15

    This work deals with the dosimetric features of a particular phenolic compound (IRGANOX 1076 {sup registered}) for dosimetry of clinical photon beams by using electron spin resonance (ESR) spectroscopy. After the optimization of the ESR readout parameters (namely modulation amplitude and microwave power) to maximise the signal without excessive spectrum distortions, basic dosimetric properties of laboratory-made phenolic dosimeters in pellet form, such as reproducibility, dose-response, sensitivity, linearity and dose rate dependence were investigated. The dosimeters were tested by measuring the depth dose profile of a 6 MV photon beam. A satisfactory intra-batch reproducibility of the ESR signal of the manufactured dosimeters was obtained. The ESR signal proved to increase linearly with increasing dose in the investigated dose range 1-13 Gy. The presence of an intrinsic background signal limits the minimum detectable dose to a value of approximately 0.6 Gy. Reliable and accurate assessment of the dose was achieved, independently of the dose rate. Such characteristics, together with the fact that IRGANOX 1076 {sup registered} is almost tissue-equivalent, and the stability of the ESR signal, make these dosimeters promising materials for ESR dosimetric applications in radiotherapy. (orig.)

  19. Constraints from high redshift supernovae upon scalar field cosmologies

    Energy Technology Data Exchange (ETDEWEB)

    Frieman, J.A. [NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois60510 (United States)]|[Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois60637 (United States); Waga, I. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Rio de Janeiro, RJ, 21945-970 (Brazil)

    1998-04-01

    Recent observations of high-redshift type Ia supernovae have placed stringent constraints on the cosmological constant {Lambda}. We explore the implications of these SNe observations for cosmological models in which a classically evolving scalar field currently dominates the energy density of the Universe. Such models have been shown to share the advantages of {Lambda} models: compatibility with the spatial flatness predicted by inflation; a Universe older than the standard Einstein{endash}de Sitter model; and, combined with cold dark matter, predictions for large-scale structure formation in good agreement with data from galaxy surveys. Compared to the cosmological constant, these scalar field models are consistent with the SNe observations for a lower matter density, {Omega}{sub m0}{approximately}0.2, and a higher age, H{sub 0}t{sub 0}{approx_gt}1. Combined with the fact that scalar field models imprint a distinctive signature on the cosmic microwave background anisotropy, they remain currently viable and should be testable in the near future. {copyright} {ital 1998} {ital The American Physical Society}

  20. High magnetic field magnetization of a new triangular lattice antiferromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, H. D. [Univ. of Tennessee, Knoxville, TN (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States). National High Magnetic Field Lab. (MagLab); Stritzinger, Laurel Elaine Winter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harrison, Neil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-23

    In CsV(MoO4)2, the magnetic V3+ ions with octahedral oxygen-coordination form a geometrically frustrated triangular lattice. So fare, there is no magnetic properties reported on it. Recently, we successfully grew single crystals of CsV(MoO4)2 by using flux method. The susceptibility shows a sharp drop around 24 K, representing a long range magnetic ordering. To understand the physical properties of this new triangular lattice antiferromagnet (TLAF), we pursued high field magnetization measurements to answer two questions: (i) what is the saturation field, which will be very useful to calculate the exchange interaction of the system? (ii) Will it exhibit spin state transition, such as the up up down phase with 1/3-saturation moment as other TLAFs? Recently, we performed VSM measurements in Cell 8, Tallahassee, NHMFL, the results show that the magnetization reaches 0.38 MuB at 34 T, which is just 19% of the full moment of 2 MuB for V3+ (3d2) ions. Apparently we need higher field to reach 1/3 value or full moment.

  1. High temperature superconducting axial field magnetic coupler: realization and test

    Science.gov (United States)

    Belguerras, L.; Mezani, S.; Lubin, T.; Lévêque, J.; Rezzoug, A.

    2015-09-01

    Contactless torque transmission through a large airgap is required in some industrial applications in which hermetic isolation is necessary. This torque transmission usually uses magnetic couplers, whose dimension strongly depends on the airgap flux density. The use of high temperature superconducting (HTS) coils to create a strong magnetic field may constitute a solution to reduce the size of the coupler. It is also possible to use this coupler to replace a torque tube in transmitting the torque produced by a HTS motor to its load. This paper presents the detailed construction and tests of an axial field HTS magnetic coupler. Pancake coils have been manufactured from BSCCO tape and used in one rotor of the coupler. The second rotor is mainly composed of NdFeB permanent magnets. Several tests have been carried out showing that the constructed coupler is working properly. A 3D finite element (FE) model of the studied coupler has been developed. Airgap magnetic field and torque measurements have been carried out and compared to the FE results. It has been shown that the measured and the computed quantities are in satisfactory agreement.

  2. High magnetic field properties of Fe-pnictide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kurth, Fritz

    2015-11-20

    The recent discovery of high-temperature superconductivity in Fe-based materials triggered worldwide efforts to investigate their fundamental properties. Despite a lot of similarities to cuprates and MgB{sub 2}, important differences like near isotropic behaviour in contrast to cuprates and the peculiar pairing symmetry of the order parameter (OP) have been reported. The OP symmetry of Fe-based superconductors (FBS) was theoretically predicted to be of so-called s± state prior to various experimental works. Still, most of the experimental results favour the s± scenario; however, definitive evidence has not yet been reported. Although no clear understanding of the superconducting mechanisms yet exists, potential applications such as high-field magnets and Josephson devices have been explored. Indeed, a lot of reports about FBS tapes, wires, and even SQUIDs have been published to this date. In this thesis, the feasibility of high-field magnet applications of FBS is addressed by studying their transport properties, involving doped BaFe{sub 2}As{sub 2} (Ba-122) and LnFeAs(O,F) [Ln=Sm and Nd]. Particularly, it is important to study physical properties in a sample form (i.e. thin films) that is close to the conditions found in applications. However, the realisation of epitaxial FBS thin films is not an easy undertaking. Recent success in growing epitaxial FBS thin films opens a new avenue to delve into transport critical current measurements. The information obtained through this research will be useful for exploring high-field magnet applications. This thesis consists of 7 chapters: Chapter 1 describes the motivation of this study, the basic background of superconductivity, and a brief summary of the thin film growth of FBS. Chapter 2 describes experimental methods employed in this study. Chapter 3 reports on the fabrication of Co-doped Ba-122 thin films on various substrates. Particular emphasis lies on the discovery of fluoride substrates to be beneficial for

  3. High-Magnetic-Field and High-Pressure Effects in Monocrystalline URu2Si2

    NARCIS (Netherlands)

    Boer, F.R. de; Franse, J.J.M.; Louis, E.; Menovsky, A.A.; Mydosh, J.A.; Palstra, T.T.M.; Rauchschwalbe, U.; Schlabitz, W.; Steglich, F.; Visser, A. de

    1986-01-01

    High-field magnetisation and high-pressure resistivity measurements have been performed on monocrystalline samples of the superconducting compound URu2Si2 just above Tc. At 1.4 K, well below the magnetic ordering temperature of about 17.5K, two sharp transitions at 36 and 40 T have been observed in

  4. Progress with High-Field Superconducting Magnets for High-Energy Colliders

    Science.gov (United States)

    Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

    2015-10-01

    One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ˜10 T at 1.9 K. Fields above 10 T became possible with the use of Nb3Sn superconductors. Nb3Sn accelerator magnets can provide operating fields up to ˜15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. This review discusses the status and main results of Nb3Sn accelerator magnet research and development and work toward 20-T magnets.

  5. Whole-globe biomechanics using high-field MRI.

    Science.gov (United States)

    Voorhees, Andrew P; Ho, Leon C; Jan, Ning-Jiun; Tran, Huong; van der Merwe, Yolandi; Chan, Kevin; Sigal, Ian A

    2017-07-01

    The eye is a complex structure composed of several interconnected tissues acting together, across the whole globe, to resist deformation due to intraocular pressure (IOP). However, most work in the ocular biomechanics field only examines the response to IOP over smaller regions of the eye. We used high-field MRI to measure IOP induced ocular displacements and deformations over the whole globe. Seven sheep eyes were obtained from a local abattoir and imaged within 48 h using MRI at multiple levels of IOP. IOP was controlled with a gravity perfusion system and a cannula inserted into the anterior chamber. T2-weighted imaging was performed to the eyes serially at 0 mmHg, 10 mmHg, 20 mmHg and 40 mmHg of IOP using a 9.4 T MRI scanner. Manual morphometry was conducted using 3D visualization software to quantify IOP-induced effects at the globe scale (e.g. axial length and equatorial diameters) or optic nerve head scale (e.g. canal diameter, peripapillary sclera bowing). Measurement sensitivity analysis was conducted to determine measurement precision. High-field MRI revealed an outward bowing of the posterior sclera and anterior bulging of the cornea due to IOP elevation. Increments in IOP from 10 to 40 mmHg caused measurable increases in axial length in 6 of 7 eyes of 7.9 ± 5.7% (mean ± SD). Changes in equatorial diameter were minimal, 0.4 ± 1.2% between 10 and 40 mmHg, and in all cases less than the measurement sensitivity. The effects were nonlinear, with larger deformations at normal IOPs (10-20 mmHg) than at elevated IOPs (20-40 mmHg). IOP also caused measurable increases in the nasal-temporal scleral canal diameter of 13.4 ± 9.7% between 0 and 20 mmHg, but not in the superior-inferior diameter. This study demonstrates that high-field MRI can be used to visualize and measure simultaneously the effects of IOP over the whole globe, including the effects on axial length and equatorial diameter, posterior sclera displacement and bowing, and even

  6. Evaluation of the new ESR network software for the retrieval of direct sun products from CIMEL CE318 and PREDE POM01 sun-sky radiometers

    Directory of Open Access Journals (Sweden)

    V. Estellés

    2012-12-01

    Full Text Available The European Skynet Radiometers network (EuroSkyRad or ESR has been recently established as a research network of European PREDE sun-sky radiometers. Moreover, ESR is federated with SKYNET, an international network of PREDE sun-sky radiometers mostly present in East Asia. In contrast to SKYNET, the European network also integrates users of the CIMEL CE318 sky–sun photometer. Keeping instrumental duality in mind, a set of open source algorithms has been developed consisting of two modules for (1 the retrieval of direct sun products (aerosol optical depth, wavelength exponent and water vapor from the sun extinction measurements; and (2 the inversion of the sky radiance to derive other aerosol optical properties such as size distribution, single scattering albedo or refractive index. In this study we evaluate the ESR direct sun products in comparison with the AERosol RObotic NETwork (AERONET products. Specifically, we have applied the ESR algorithm to a CIMEL CE318 and PREDE POM simultaneously for a 4-yr database measured at the Burjassot site (Valencia, Spain, and compared the resultant products with the AERONET direct sun measurements obtained with the same CIMEL CE318 sky–sun photometer. The comparison shows that aerosol optical depth differences are mostly within the nominal uncertainty of 0.003 for a standard calibration instrument, and fall within the nominal AERONET uncertainty of 0.01–0.02 for a field instrument in the spectral range 340 to 1020 nm. In the cases of the Ångström exponent and the columnar water vapor, the differences are lower than 0.02 and 0.15 cm, respectively. Therefore, we present an open source code program that can be used with both CIMEL and PREDE sky radiometers and whose results are equivalent to AERONET and SKYNET retrievals.

  7. Anisotropic high field superconductinng behavior in MgB_2

    Science.gov (United States)

    Gurevich, Alexander

    2004-03-01

    I will discuss new effects resulting from the two-gap superconductivity in MgB_2, focusing on: 1. Current-induced interband breakdown and dynamic interband phase textures caused by nonequilibrium charge imbalance [1], 2. Anomalous enhancement of the upper critical field H_c2(T) by nonmagnetic impurities in dirty two-gap superconductors. A theory of H_c2 based on generalized two-gap Usadel equations, which include both intra and interband scattering channels and paramagnetic pairbreaking is presented. Solutions of these equations show that H_c2(T) can exhibit a strong upward curvature and an unusual temperature dependence of the anisotropy parameter H_c2^||/H_c2^⊥, which can both increase and decrease with T depending on the ratio of the intraband electron diffusivities D_π/D_σ [2]. The theory explains recent high-field transport experiments on resistive MgB2 films in which the upper critical field was increased by 3-10 times as compared to single crystals [3], H_c2 exceeding 50 Tesla for H||ab and 35T for H⊥ ab. The results suggest that nonmagnetic impurities due to selective atomic substitution on Mg and B sites can increase H_c2 of MgB2 to a much greater extend than in one-gap superconductors. [1]. A. Gurevich and V.M. Vinokur, PRL 90, 047004 (2003). [2]. A. Gurevich, PRB 67, 1845151 (2003) and unpublished. [3]. A. Gurevich et al. Supercond. Sci. Technol. (2003, to appear). *In collaboration with V.M. Vinokur, V. Braccini, S. Patnaik, X. Song, D.C. Larbalestier, C.B. Eom, X. Pan, X. Xi, V. Ferrando, C. Ferdighini, A. Siri, K.H. Kim and C. Mielke. Work supported by NSF Nanostructured Materials and Interfaces MRSEC at the University of Wisconsin.

  8. Dynamics of Coulomb correlations in semiconductors in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Fromer, Neil Alan [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    Current theories have been successful in explaining many nonlinear optical experiments in undoped semiconductors. However, these theories require a ground state which is assumed to be uncorrelated. Strongly correlated systems of current interest, such as a two dimensional electron gas in a high magnetic field, cannot be explained in this manner because the correlations in the ground state and the low energy collective excitations cause a breakdown of the conventional techniques. We perform ultrafast time-resolved four-wave mixing on $n$-modulation doped quantum wells, which contain a quasi-two dimensional electron gas, in a large magnetic field, when only a single Landau level is excited and also when two levels are excited together. We find evidence for memory effects and as strong coupling between the Landau levels induced by the electron gas. We compare our results with simulations based on a new microscopic approach capable of treating the collective effects and correlations of the doped electrons, and find a good qualitative agreement. By looking at the individual contributions to the model, we determine that the unusual correlation effects seen in the experiments are caused by the scattering of photo-excited electron-hole pairs with the electron gas, leading to new excited states which are not present in undoped semiconductors, and also by exciton-exciton interactions mediated by the long-lived collective excitations of the electron gas, inter-Landau level magnetoplasmons.

  9. Birkeland current effects on high-latitude groundmagnetic field perturbations

    CERN Document Server

    Laundal, K M; Lehtinen, N; Gjerloev, J W; Østgaard, N; Tenfjord, P; Reistad, J P; Snekvik, K; Milan, S E; Ohtani, S; Anderson, B J

    2016-01-01

    Magnetic perturbations on ground at high latitudes are directly associated only with the divergence-free component of the height-integrated horizontal ionospheric current, $\\textbf{J}_{\\perp,df}$. Here we show how $\\textbf{J}_{\\perp,df}$ can be expressed as the total horizontal current $\\textbf{J}_\\perp$ minus its curl-free component, the latter being completely determined by the global Birkeland current pattern. Thus in regions where $\\textbf{J}_\\perp = 0$, the global Birkeland current distribution alone determines the local magnetic perturbation. We show with observations from ground and space that in the polar cap, the ground magnetic field perturbations tend to align with the Birkeland current contribution in darkness but not in sunlight. We also show that in sunlight, the magnetic perturbations are typically such that the equivalent overhead current is anti-parallel to the convection, indicating that the Hall current system dominates. Thus the ground magnetic field in the polar cap relates to different c...

  10. Gene Expression Analyses of HER-2/neu and ESR1 in Patients with Breast Cancer

    Directory of Open Access Journals (Sweden)

    Omid Kheyri Nadergoli

    2017-10-01

    Full Text Available ABSTRACT Background: Her-2 and ESR1 genes, that interact in the cell signaling pathway, are the most important molecular markers of breast cancer, which have been amplified or overexpressed in 30% and 70%, respectively. This study was performed to evaluate the gene expression levels of Her-2 and ESR1 genes in tumor cells and its adjacent normal tissue of breast cancer patients and compared them whit clinical-pathological features. Methods: In total, 80 tissue specimens from 40 patients, with an average age of 48.47 years, were examined by Real-time PCR technique, and ultimately evaluated the expression level of Her-2 and ESR1genes. The data were analyzed by REST 2009 V2.0.13 statistical software. Results: HER2 and ESR1 overexpression was identified in 19 (48% and 12 (30% of 40 patients respectively, which was higher and lower than that recorded in international statistics, respectively. ESR1 overexpression was associated with Stage 3A and lymph node involvement 2 (N2 (P = 0.04 and P = 0.047, respectively. No significant correlation was observed between the expression of HER2 and ESR1 and other clinical-pathological features, however, the relative differences were identified in the expression levels of genes between main group and groups that were classified according to the clinical-pathological features and age. Conclusions: Overexpression of Her-2 and ESR1 genes in the patients of our study are higher and lower than international statistics, respectively, indicating the differences in genetic, environmental and ethnic factors that involved in the developing of breast cancer.

  11. High-Speed and Wide-Field Photometry with TORTORA

    Directory of Open Access Journals (Sweden)

    G. Greco

    2010-01-01

    Full Text Available We present the photometric analysis of the extended sky fields observed by the TORTORA optical monitoring system. The technology involved in the TORTORA camera is based on the use of a fast TV-CCD matrix with an image intensifier. This approach can both significantly reduce the readout noise and shorten the focal length following to monitor relatively large sky regions with high temporal resolution and adequate detection limit. The performance of the system has been tested using the relative magnitudes of standard stars by means of long image sequences collected at different airmasses and at various intensities of the moon illumination. As expected from the previous laboratory measurements, artifact sources are negligible and do not affect the photometric results. The following analysis is based on a large sample of images acquired by the TORTORA instrument since July 2006.

  12. Diffuse axonal injury at ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Christoph Moenninghoff

    Full Text Available Diffuse axonal injury (DAI is a specific type of traumatic brain injury caused by shearing forces leading to widespread tearing of axons and small vessels. Traumatic microbleeds (TMBs are regarded as a radiological marker for DAI. This study aims to compare DAI-associated TMBs at 3 Tesla (T and 7 T susceptibility weighted imaging (SWI to evaluate possible diagnostic benefits of ultra-high field (UHF MRI.10 study participants (4 male, 6 female, age range 20-74 years with known DAI were included. All MR exams were performed with a 3 T MR system (Magnetom Skyra and a 7 T MR research system (Magnetom 7 T, Siemens AG, Healthcare Sector, Erlangen, Germany each in combination with a 32-channel-receive coil. The average time interval between trauma and imaging was 22 months. Location and count of TMBs were independently evaluated by two neuroradiologists on 3 T and 7 T SWI images with similar and additionally increased spatial resolution at 7 T. Inter- and intraobserver reliability was assessed using the interclass correlation coefficient (ICC. Count and diameter of TMB were evaluated with Wilcoxon signed rank test.Susceptibility weighted imaging revealed a total of 485 TMBs (range 1-190, median 25 at 3 T, 584 TMBs (plus 20%, range 1-262, median 30.5 at 7 T with similar spatial resolution, and 684 TMBs (plus 41%, range 1-288, median 39.5 at 7 T with 10-times higher spatial resolution. Hemorrhagic DAI appeared significantly larger at 7 T compared to 3 T (p = 0.005. Inter- and intraobserver correlation regarding the counted TMB was high and almost equal 3 T and 7 T.7 T SWI improves the depiction of small hemorrhagic DAI compared to 3 T and may be supplementary to lower field strengths for diagnostic in inconclusive or medicolegal cases.

  13. High resolution, high speed, long working distance, large field of view confocal fluorescence microscope.

    Science.gov (United States)

    Pacheco, Shaun; Wang, Chengliang; Chawla, Monica K; Nguyen, Minhkhoi; Baggett, Brend K; Utzinger, Urs; Barnes, Carol A; Liang, Rongguang

    2017-10-17

    Confocal fluorescence microscopy is often used in brain imaging experiments, however conventional confocal microscopes are limited in their field of view, working distance, and speed for high resolution imaging. We report here the development of a novel high resolution, high speed, long working distance, and large field of view confocal fluorescence microscope (H2L2-CFM) with the capability of multi-region and multifocal imaging. To demonstrate the concept, a 0.5 numerical aperture (NA) confocal fluorescence microscope is prototyped with a 3 mm × 3 mm field of view and 12 mm working distance, an array of 9 beams is scanned over the field of view in 9 different regions to speed up the acquisition time by a factor of 9. We test this custom designed confocal fluorescence microscope for future use with brain clarification methods to image large volumes of the brain at subcellular resolution. This multi-region and multi-spot imaging method can be used in other imaging modalities, such as multiphoton microscopes, and the field of view can be extended well beyond 12 mm × 12 mm.

  14. Comparison of ESR1 Mutations in Tumor Tissue and Matched Plasma Samples from Metastatic Breast Cancer Patients

    Directory of Open Access Journals (Sweden)

    Takashi Takeshita

    2017-10-01

    Full Text Available BACKGROUND: ESR1 mutation in circulating cell-free DNA (cfDNA is emerging as a noninvasive biomarker of acquired resistance to endocrine therapy, but there is a paucity of data comparing the status of ESR1 gene in cfDNA with that in its corresponding tumor tissue. The objective of this study is to validate the degree of concordance of ESR1 mutations between plasma and tumor tissue. METHODS: ESR1 ligand-binding domain mutations Y537S, Y537N, Y537C, and D538G were analyzed using droplet digital PCR in 35 patients with metastatic breast cancer (MBC (35 tumor tissue samples and 67 plasma samples. RESULTS: Of the 35 paired samples, 26 (74.3% were concordant: one patient had detectable ESR1 mutations both plasma (ESR1 Y537S/Y537N and tumor tissue (ESR1 Y537S/Y537C, and 25 had WT ESR1 alleles in both. Nine (25.7% had discordance between the plasma and tissue results: five had mutations detected only in their tumor tissue (two Y537S, one Y537C, one D538G, and one Y537S/Y537N/D538G, and four had mutations detected only in their plasma (one Y537S, one Y537N, and two Y537S/Y537N/D538G. Furthermore, longitudinal plasma samples from 19 patients were used to assess changes in the presence of ESR1 mutations during treatment. Eleven patients had cfDNA ESR1 mutations over the course of treatment. A total of eight of 11 patients with MBC with cfDNA ESR1 mutations (72.7% had the polyclonal mutations. CONCLUSION: We have shown the independent distribution of ESR1 mutations between plasma and tumor tissue in 35 patients with MBC.

  15. Determination of antioxidant capacity of diverse fruits by electron spin resonance (ESR) and UV-vis spectrometries.

    Science.gov (United States)

    Zang, Shuang; Tian, Sizhu; Jiang, Jia; Han, Dandan; Yu, Xinyu; Wang, Kun; Li, Dan; Lu, Dayong; Yu, Aimin; Zhang, Ziwei

    2017-04-15

    Twenty-one kinds of fruits including strawberry, mulberry, lemon, banana, etc. were measured for antioxidant capacity based on their ability to scavenge 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Vitamin C equivalent antioxidant capacity (VCEAC) was used to quantify antioxidant capacity of the studied fruits. The results were expressed as mg of ascorbic acid equivalent per 100g fruit. Each fruit was divided into two parts: harvest part (fresh fruit analyzed immediately), and liquid nitrogen frozen part (fruit frozen and pulverized in liquid nitrogen). Antioxidant capacities of both fresh and frozen fruits were determined, and VCEAC values were proved to have no significant difference. For the frozen fruits, the antioxidant capacities were measured by electron spin resonance spectroscopy (ESR) and UV-vis spectrometry. VCEAC values obtained with UV-vis and ESR range from 11.48 to 345.75mg/100g and 7.01 to 366.26mg/100g. Experimental results indicated that VCEAC values obtained by two methods were highly correlated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Endocrine-Therapy-Resistant ESR1 Variants Revealed by Genomic Characterization of Breast-Cancer-Derived Xenografts

    Directory of Open Access Journals (Sweden)

    Shunqiang Li

    2013-09-01

    Full Text Available To characterize patient-derived xenografts (PDXs for functional studies, we made whole-genome comparisons with originating breast cancers representative of the major intrinsic subtypes. Structural and copy number aberrations were found to be retained with high fidelity. However, at the single-nucleotide level, variable numbers of PDX-specific somatic events were documented, although they were only rarely functionally significant. Variant allele frequencies were often preserved in the PDXs, demonstrating that clonal representation can be transplantable. Estrogen-receptor-positive PDXs were associated with ESR1 ligand-binding-domain mutations, gene amplification, or an ESR1/YAP1 translocation. These events produced different endocrine-therapy-response phenotypes in human, cell line, and PDX endocrine-response studies. Hence, deeply sequenced PDX models are an important resource for the search for genome-forward treatment options and capture endocrine-drug-resistance etiologies that are not observed in standard cell lines. The originating tumor genome provides a benchmark for assessing genetic drift and clonal representation after transplantation.

  17. Study of fracture properties of 0.3C-CrMoV (ESR) ultrahigh strength steel

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, M.R.; Suresh, K.R.; Sreekumar, K.; Sinha, P.P.; Ballal, N.B.; Rao, P.K.

    2005-03-15

    The fracture properties of a new ultrahigh strength low alloy steel 0.3C-CrMoV(ESR), developed primarily as a cost effective material for space launch vehicle applications, have been evaluated through two different methods. The steel was processed through electroslag remelting (ESR) with inoculation using niobium to produce 4 tonne ingots, which were forged and rolled into plates. The fracture toughness of this steel has been evaluated by testing compact tension specimens and surface cracked tension specimens following the procedures in ASTM E-399 and ASTM E-740 respectively. The steel, after quenching and tempering, has a 0.2% proof strength of 1470 MPa, ultimate tensile strength of 1725 MPa and fracture toughness of 96 MPa m. It has high residual strength also in the presence of surface cracks of 5 x 2 mm size. The microstructure consists of fine grains in the annealed condition and lath martensite in the hardened condition. After tempering, fine carbide precipitates distributed along the lath boundaries and within the laths were observed. (author)

  18. Frequency dependent power fluctuations: a feature of the ESR system or physical?

    Directory of Open Access Journals (Sweden)

    Y. Ogawa

    Full Text Available The k-dependence of the received power in high signal-to-noise ratio (SNR conditions, occurring for naturally enhanced ion-acoustic lines (NEIALs and for real satellites, is investigated by using the EISCAT Svalbard Radar (ESR, where the data are recorded in eight separate channels using different frequencies. For the real satellites we find large variations of the relative powers from event to event, which is probably due to a different number of pulses catching the satellite over the integration period. However, the large power difference remains unexpected in one case. Over short time scale (< 10 s the relative power difference seems to be highly stable. For most NEIAL events the differences between channels are within noise level. In a few cases variations of the relative power well above both the estimated and expected 1-sigma level occur over a signal preintegrated profile. We thus suggest that the frequency dependence of the power in NEIAL events has its origin in the scattering medium itself as the most plausible explanation.

    Key words: Ionosphere (auroral ionosphere; plasma waves and instabilities; instruments and techniques

  19. High Electron Confinement under High Electric Field in RF GaN-on-Silicon HEMTs

    Directory of Open Access Journals (Sweden)

    Farid Medjdoub

    2016-03-01

    Full Text Available We report on AlN/GaN high electron mobility transistors grown on silicon substrate with highly optimized electron confinement under a high electric field. The fabricated short devices (sub-10-nm barrier thickness with a gate length of 120 nm using gate-to-drain distances below 2 µm deliver a unique breakdown field close to 100 V/µm while offering high frequency performance. The low leakage current well below 1 µA/mm is achieved without using any gate dielectrics which typically degrade both the frequency performance and the device reliability. This achievement is mainly attributed to the optimization of material design and processing quality and paves the way for millimeter-wave devices operating at drain biases above 40 V, which would be only limited by the thermal dissipation.

  20. High-precision high field strength partitioning between garnet, amphibole, and alkaline melt, Kakanui, New Zealand

    NARCIS (Netherlands)

    Fulmer, E.J.; Nebel, O.; van Westrenen, W.

    2010-01-01

    The high field strength elements (HFSE: Zr, Hf, Nb, Ta, and W) are an important group of chemical tracers that are increasingly used to investigate magmatic differentiation processes. Successful modeling of these processes requires the availability of accurate mineral-melt partition coefficients

  1. Self-interacting scalar fields at high-temperature

    Energy Technology Data Exchange (ETDEWEB)

    Deur, Alexandre [University of Virginia, Charlottesville, VA (United States)

    2017-06-15

    We study two self-interacting scalar field theories in their high-temperature limit using path integrals on a lattice. We first discuss the formalism and recover known potentials to validate the method. We then discuss how these theories can model, in the high-temperature limit, the strong interaction and General Relativity. For the strong interaction, the model recovers the known phenomenology of the nearly static regime of heavy quarkonia. The model also exposes a possible origin for the emergence of the confinement scale from the approximately conformal Lagrangian. Aside from such possible insights, the main purpose of addressing the strong interaction here - given that more sophisticated approaches already exist - is mostly to further verify the pertinence of the model in the more complex case of General Relativity for which non-perturbative methods are not as developed. The results have important implications on the nature of Dark Matter. In particular, non-perturbative effects naturally provide flat rotation curves for disk galaxies, without need for non-baryonic matter, and explain as well other observations involving Dark Matter such as cluster dynamics or the dark mass of elliptical galaxies. (orig.)

  2. High-field magnetization of dilute rare earths in yttrium

    DEFF Research Database (Denmark)

    Touborg, P.; Høg, J.; Cock, G. J.

    1974-01-01

    Magnetization measurements have been performed on single crystals of Y containing small amounts of Tb, Dy, or Er at 4.2 K in fields up to 295 × 105 A/m (370 kOe). Crystal-field and molecular-field parameters obtained from measurements of the initial susceptibility versus temperature give a satisf...

  3. Identification and characterization of gamma-irradiated dried Lentinus edodes using ESR, SEM, and FTIR analyses.

    Science.gov (United States)

    Akram, Kashif; Ahn, Jae-Jun; Kwon, Joong-Ho

    2012-06-01

    A detailed electron spin resonance (ESR) analysis for different parts of gamma-irradiated (0 to 50 kGy) dried mushroom (Lentinus edodes) was conducted to identify radiation-induced signals. All studied mushroom parts except gills produced strong dose-dependent radiation-induced ESR signals particularly at about g = 2.0076, 20005, and 1.9911 demonstrating the generation of crystalline sugar radicals following irradiation. The intensity of these signals was highest in cap skin samples, followed by the cap core, stem skin, whole mushroom powder, and stem core samples, respectively. ESR-based identification was easily possible at 2 kGy or more using mushroom cap skin or cap core as samples. The radiation-induced ESR signals were found sensitive to thermal treatment showing the limitation of ESR-based detection in case of heat-processed samples. Scanning electron microscopy (SEM) showed micro-structural damage upon irradiation resulting decreased percentage of rehydration; however, no major alteration was observed through the Fourier transform infrared (FTIR) spectra. Irradiation changed the structural morphology; however, the main functional groups were stable against radiation treatment. Food irradiation can confirm hygienic quality and prolong the product shelf life. However, due to lack of international consensus, effective identification methods and detailed quality characterization are required for the general use of this technology. © 2012 Institute of Food Technologists®

  4. Activating ESR1 mutations in hormone-resistant metastatic breast cancer.

    Science.gov (United States)

    Robinson, Dan R; Wu, Yi-Mi; Vats, Pankaj; Su, Fengyun; Lonigro, Robert J; Cao, Xuhong; Kalyana-Sundaram, Shanker; Wang, Rui; Ning, Yu; Hodges, Lynda; Gursky, Amy; Siddiqui, Javed; Tomlins, Scott A; Roychowdhury, Sameek; Pienta, Kenneth J; Kim, Scott Y; Roberts, J Scott; Rae, James M; Van Poznak, Catherine H; Hayes, Daniel F; Chugh, Rashmi; Kunju, Lakshmi P; Talpaz, Moshe; Schott, Anne F; Chinnaiyan, Arul M

    2013-12-01

    Breast cancer is the most prevalent cancer in women, and over two-thirds of cases express estrogen receptor-α (ER-α, encoded by ESR1). Through a prospective clinical sequencing program for advanced cancers, we enrolled 11 patients with ER-positive metastatic breast cancer. Whole-exome and transcriptome analysis showed that six cases harbored mutations of ESR1 affecting its ligand-binding domain (LBD), all of whom had been treated with anti-estrogens and estrogen deprivation therapies. A survey of The Cancer Genome Atlas (TCGA) identified four endometrial cancers with similar mutations of ESR1. The five new LBD-localized ESR1 mutations identified here (encoding p.Leu536Gln, p.Tyr537Ser, p.Tyr537Cys, p.Tyr537Asn and p.Asp538Gly) were shown to result in constitutive activity and continued responsiveness to anti-estrogen therapies in vitro. Taken together, these studies suggest that activating mutations in ESR1 are a key mechanism in acquired endocrine resistance in breast cancer therapy.

  5. ESR imaging for estimation oxidative stress in the brain of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Hidekatsu; Itoh, Osam; Aoyama, Masaaki; Obara, Heitaro; Ohya, Hiroaki; Kamada, Hitoshi [Inst. for Life Support Technology, Matsuei, Yamagata (Japan)

    2002-04-01

    ESR imaging for estimating intracerebral oxidative stress of rats was performed. An acyl-protected hydroxylamine, 1-acetoxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine (ACP), is a very stable non-radical compound outside cells, however, within cells, it is easily deprotected with esterase to yield 1-hydroxy-3-carbamoyl-2,2,5,5-tetramethylpyrrolidine, which is oxidized by oxidative stress to yield an ESR-detectable stable nitroxide radical, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl. Thus signal intensity in the ESR image reflects the strength of intracellular oxidative stress. From in vivo ESR image data of the brain of rats that received ACP, the average values of ESR signal intensity from the hippocampus, striatum, and cerebral cortex were computed. This imaging technique was applied to an epileptic seizure model. As a result, it was found that following a kainic acid-induced seizure, the oxidative stress in the hippocampus and striatum is enhanced, but not so in the cerebral cortex. (author)

  6. Comprehensive genetic assessment of the ESR1 locus identifies a risk region for endometrial cancer

    Science.gov (United States)

    O’Mara, Tracy A; Glubb, Dylan M; Painter, Jodie N; Cheng, Timothy; Dennis, Joe; Attia, John; Holliday, Elizabeth G; McEvoy, Mark; Scott, Rodney J; Ashton, Katie; Proietto, Tony; Otton, Geoffrey; Shah, Mitul; Ahmed, Shahana; Healey, Catherine S; Gorman, Maggie; Martin, Lynn; Hodgson, Shirley; Fasching, Peter A; Hein, Alexander; Beckmann, Matthias W; Ekici, Arif B; Hall, Per; Czene, Kamila; Darabi, Hatef; Li, Jingmei; Dürst, Matthias; Runnebaum, Ingo; Hillemanns, Peter; Dörk, Thilo; Lambrechts, Diether; Depreeuw, Jeroen; Annibali, Daniela; Amant, Frederic; Zhao, Hui; Goode, Ellen L; Dowdy, Sean C; Fridley, Brooke L; Winham, Stacey J; Salvesen, Helga B; Njølstad, Tormund S; Trovik, Jone; Werner, Henrica MJ; Tham, Emma; Liu, Tao; Mints, Miriam; Bolla, Manjeet K; Michailidou, Kyriaki; Tyrer, Jonathan P; Wang, Qin; Hopper, John L; Peto, Julian; Swerdlow, Anthony J; Burwinkel, Barbara; Brenner, Hermann; Meindl, Alfons; Brauch, Hiltrud; Lindblom, Annika; Chang-Claude, Jenny; Couch, Fergus J; Giles, Graham G; Kristensen, Vessela N; Cox, Angela; Pharoah, Paul D P; Dunning, Alison M; Tomlinson, Ian; Easton, Douglas F; Thompson, Deborah J; Spurdle, Amanda B

    2015-01-01

    Excessive exposure to estrogen is a well-established risk factor for endometrial cancer (EC), particularly for cancers of endometrioid histology. The physiological function of estrogen is primarily mediated by estrogen receptor alpha, encoded by ESR1. Consequently, several studies have investigated whether variation at the ESR1 locus is associated with risk of EC, with conflicting results. We performed comprehensive fine-mapping analyses of 3,633 genotyped and imputed single nucleotide polymorphisms (SNPs) in 6,607 EC cases and 37,925 controls. There was evidence of an EC risk signal located at a potential alternative promoter of the ESR1 gene (lead SNP rs79575945, P = 1.86 × 10−5), which was stronger for cancers of endometrioid subtype (P = 3.76 × 10−6). Bioinformatic analysis suggests that this risk signal is in a functionally important region targeting ESR1, and eQTL analysis found that rs79575945 was associated with expression of SYNE1, a neighbouring gene. In summary, we have identified a single EC risk signal located at ESR1, at study-wide significance. Given SNPs located at this locus have been associated with risk for breast cancer, also a hormonally driven cancer, this study adds weight to the rationale for performing informed candidate fine-scale genetic studies across cancer types. PMID:26330482

  7. A Feasibility Study of High-Strength Bi-2223 Conductor for High-Field Solenoids.

    Science.gov (United States)

    Godeke, A; Abraimov, D V; Arroyo, E; Barret, N; Bird, M D; Francis, A; Jaroszynski, J; Kurteva, D V; Markiewicz, W D; Marks, E L; Marshall, W S; McRae, D M; Noyes, P D; Pereira, R C P; Viouchkov, Y L; Walsh, R P; White, J M

    2017-03-01

    We performed a feasibility study on a high-strength Bi2-x Pb x Sr2Ca2Cu3O10-x (Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries (SEI). It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress-strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥ 0.92% (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions.

  8. [Detection of the lethal process in plankton noctiluca by means of a forbidden transition of ESR of Mn2+ ion].

    Science.gov (United States)

    Kamenev, S E; Kopvillem, U Kh; Pasynkov, A S; Sharipov, R Z

    1981-01-01

    A forbidden ESR line of Mn2+ that is connected with the penetration of Mn into the plancton organism and binding it to a marcomolecule is selected from the experiment. A method for saturating the plancton organism with paramagnetic ions is proposed. It is shown that the constant of the axial electric field in the spin hamiltonian of Mn2+ ion described the dynamics of a selforganizing system. It is tested that the lethal process in the plancton with paramagnetic ion enrichment originated from boson avalanche. Experiments are performed with plancton noctiluca which illustrate the occurrence of avalancheline lethal process in the case of paramagnetic ion enrichment with limiting concentration. The meaning of these results for the problems of oceanology and pollution-ocean inhabitants interaction in the case of paramagnetic ions is discussed.

  9. RAPID COMMUNICATION: High performance superconducting wire in high applied magnetic fields via nanoscale defect engineering

    Science.gov (United States)

    Wee, Sung Hun; Goyal, Amit; Zuev, Yuri L.; Cantoni, Claudia

    2008-09-01

    High temperature superconducting (HTS) wires capable of carrying large critical currents with low dissipation levels in high applied magnetic fields are needed for a wide range of applications. In particular, for electric power applications involving rotating machinery, such as large-scale motors and generators, a high critical current, Ic, and a high engineering critical current density, JE, in applied magnetic fields in the range of 3-5 Tesla (T) at 65 K are required. In addition, exceeding the minimum performance requirements needed for these applications results in a lower fabrication cost, which is regarded as crucial to realize or enable many large-scale bulk applications of HTS materials. Here we report the fabrication of short segments of a potential superconducting wire comprised of a 4 µm thick YBa2Cu3O7-δ (YBCO) layer on a biaxially textured substrate with a 50% higher Ic and JE than the highest values reported previously. The YBCO film contained columns of self-assembled nanodots of BaZrO3 (BZO) roughly oriented along the c-axis of YBCO. Although the YBCO film was grown at a high deposition rate, three-dimensional self-assembly of the insulating BZO nanodots still occurred. For all magnetic field orientations, minimum Ic and JE at 65 K, 3 T for the wire were 353 A cm-1 and 65.4 kA cm-2, respectively.

  10. Testing cosmic dose rate models for ESR: Dating corals and molluscs on San Salvador, Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Deely, A.E. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Blackwell, B.A.B., E-mail: bonnie.a.b.blackwell@williams.edu [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States); Mylroie, J.E. [Dept. of Geosciences, Mississippi State University, MS, 39762-5448 (United States); Carew, J.L. [Dept. of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 29424 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Skinner, A.R. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States)

    2011-09-15

    Sealevel curves are best developed on tectonically stable coastlines, like San Salvador, where eolianites preserve transgressive and regressive phases associated with Quaternary high seastands, while reef facies mark the highstands. At 11 locations around San Salvador, terrestrial molluscs (Cerion) from the eolianites, lagoonal bivalves (Codakia), and corals from the highstand deposits were dated by ESR. Volumetrically averaged sedimentary dose rates were calculated from sedimentary geochemistry and time-averaged cosmic dose rates from each sample's current and past geologic contexts. Rice Bay Formation corals dated at 3.9 {+-} 0.3 to 7.1 {+-} 0.4 ka (OIS 1). Minimum ages for the Cockburn Town Member's regressive phase ranged from 49 {+-} 6 to 75 {+-} 8 ka, correlating with OIS 3-4. Codakia dates showed that an OIS 5a sealevel approached modern levels at 91-78 ka. In situ corals from the Cockburn Town Reef averaged from 127 {+-} 6 to 138 {+-} 10 ka, correlating well with OIS 5e. Ages from the Reef's rubble zones hint that some coral reefs grew as early as OIS 7, but were likely reworked during OIS 5. San Salvador preserves deposits from three mid to late Quaternary highstands above, and as many as three that closely approach, modern sealevel.

  11. ESR, electrochemical, molecular modeling and biological evaluation of 4-substituted and 1,4-disubstituted 7-nitroquinoxalin-2-ones as potential anti- Trypanosoma cruzi agents

    Science.gov (United States)

    Aguilera-Venegas, Benjamín; Olea-Azar, Claudio; Norambuena, Ester; Arán, Vicente J.; Mendizábal, Fernando; Lapier, Michel; Maya, Juan Diego; Kemmerling, Ulrike; López-Muñoz, Rodrigo

    2011-03-01

    Electrochemical and ESR studies were carried out in this work with the aim of characterizing the reduction mechanisms of 4-substituted and 1,4-disubstituted 7-nitroquinoxalin-2-ones by means of cyclic voltammetry in DMSO as aprotic solvent. Two reduction mechanisms were found for these compounds: the first, for compounds bearing a labile hydrogen by following a self-protonation mechanism (ECE steps), and the second, for compounds without labile hydrogen, based on a purely electrochemical reduction mechanism (typical of nitroheterocycles). The electrochemical results were corroborated using ESR spectroscopy allowing us to propose the hyperfine splitting pattern of the nitro-radical, which was later corroborated by the ESR simulation spectra. All these compounds were assayed as growth inhibitors against Trypanosoma cruzi: first, on the non-proliferative (and infective) form of the parasite (trypomastigote stage), and then, the ones that displayed activity, were assayed on the non-infective form (epimastigote stage). Thus, we found four new compounds highly active against T. cruzi. Finally, molecular modeling studies suggest the inhibition of the trypanothione reductase like one of the possible mechanisms involved in the trypanocidal action.

  12. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    Energy Technology Data Exchange (ETDEWEB)

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  13. Low and High-Frequency Field Potentials of Cortical Networks ...

    Science.gov (United States)

    Neural networks grown on microelectrode arrays (MEAs) have become an important, high content in vitro assay for assessing neuronal function. MEA experiments typically examine high- frequency (HF) (>200 Hz) spikes, and bursts which can be used to discriminate between different pharmacological agents/chemicals. However, normal brain activity is additionally composed of integrated low-frequency (0.5-100 Hz) field potentials (LFPs) which are filtered out of MEA recordings. The objective of this study was to characterize the relationship between HF and LFP neural network signals, and to assess the relative sensitivity of LFPs to selected neurotoxicants. Rat primary cortical cultures were grown on glass, single-well MEA chips. Spontaneous activity was sampled at 25 kHz and recorded (5 min) (Multi-Channel Systems) from mature networks (14 days in vitro). HF (spike, mean firing rate, MFR) and LF (power spectrum, amplitude) components were extracted from each network and served as its baseline (BL). Next, each chip was treated with either 1) a positive control, bicuculline (BIC, 25μM) or domoic acid (DA, 0.3μM), 2) or a negative control, acetaminophen (ACE, 100μM) or glyphosate (GLY, 100μM), 3) a solvent control (H2O or DMSO:EtOH), or 4) a neurotoxicant, (carbaryl, CAR 5, 30μM ; lindane, LIN 1, 10μM; permethrin, PERM 25, 50μM; triadimefon, TRI 5, 65μM). Post treatment, 5 mins of spontaneous activity was recorded and analyzed. As expected posit

  14. Transport studies in high-performance field reversed configuration plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S., E-mail: sgupta@trialphaenergy.com; Barnes, D. C.; Dettrick, S. A.; Trask, E.; Tuszewski, M.; Deng, B. H.; Gota, H.; Gupta, D.; Hubbard, K.; Korepanov, S.; Thompson, M. C.; Zhai, K.; Tajima, T. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2016-05-15

    A significant improvement of field reversed configuration (FRC) lifetime and plasma confinement times in the C-2 plasma, called High Performance FRC regime, has been observed with neutral beam injection (NBI), improved edge stability, and better wall conditioning [Binderbauer et al., Phys. Plasmas 22, 056110 (2015)]. A Quasi-1D (Q1D) fluid transport code has been developed and employed to carry out transport analysis of such C-2 plasma conditions. The Q1D code is coupled to a Monte-Carlo code to incorporate the effect of fast ions, due to NBI, on the background FRC plasma. Numerically, the Q1D transport behavior with enhanced transport coefficients (but with otherwise classical parametric dependencies) such as 5 times classical resistive diffusion, classical thermal ion conductivity, 20 times classical electron thermal conductivity, and classical fast ion behavior fit with the experimentally measured time evolution of the excluded flux radius, line-integrated density, and electron/ion temperature. The numerical study shows near sustainment of poloidal flux for nearly 1 ms in the presence of NBI.

  15. High-field magnetic transition in Er sub 2 Fe sub 14 B

    Energy Technology Data Exchange (ETDEWEB)

    Radwanski, R.J.; Boer, F.R. de (Natuurkundig Lab., Univ. van Amsterdam (Netherlands)); Zhong, X.P.; Yang, F.M.; Li, J.Y. (Magnetism Lab., Inst. of Physics, Academia Sinica, Beijing (China)); Kohashi, T.; Ono, M.; Date, M. (Dept. of Physics, Osaka Univ. (Japan)); Yamagishi, A. (Research Center for Extreme Materials, Osaka Univ. (Japan))

    1991-10-01

    Field-induced transitions in quasi-ternary Er{sub 2}Fe{sub 14}B compounds have been revealed by means of magnetization measurements at high magnetic fields. The high-field studies for Er{sub 2}Fe{sub 14}B, in particular the modest differential high-field susceptibility and the formation of a non-collinear magnetic structure at 42 T, do not confirm the substantial canted magnetic structure at low fields. (orig.).

  16. The Theory of ESR Hyperfine-Structure Narrowing as Applied to Wide-Gap Semimagnetic Semiconductors

    Science.gov (United States)

    Aliev; Tagirov; Tagiev

    1996-11-01

    The theory of ESR hyperfine-structure exchange narrowing is developed. The kinetic equations describing the nonequilibrium magnetization dynamics of hyperfine components of ESR spectra are derived by using the nonequilibrium statistical-operator method. Numerical solution of these general equations is applied to the simulation of the experimental spectra of (Cd, Mn)Te crystals with a Mn2+ ion content of between 0.05 and 0.5%. The hyperfine-splitting constant, homogeneous ESR linewidth, and mean-square value of the exchange fluctuation frequency are obtained from the fitting of the spectra for different concentrations of manganese ions. The concentration dependence of the latter quantity is discussed in relation to the spatial dependence of magnetic-ion exchange interaction and the gap value in the band structure of semimagnetic semiconductors.

  17. Preparation, mass spectrometry and solid state ESR spectroscopy of endohedral fullerenes

    Science.gov (United States)

    Bartl, A.; Dunsch, L.; Kirbach, U.

    1995-06-01

    Mass spectrometry and electron spin resonance spectroscopy are used to characterize the state of endohedral systems. Fullerenes were produced by arc vaporization in presence of holmium, lanthanum, praseodymium, thulium and yttrium and their oxides The present paper reports on solid state ESR studies for identification of the soot extract. Low resolved but split ESR spectra were found already in the solid soot extract powder, and well resolved ESR spectra in solution. The line splitting is interpreted as isotropic hyperfine coupling of an unpaired electron to the nuclear magnetic moment of a metal ion inside a fullerene molecule. It is concluded that Y, La, Pr, Ho and Tm exist in ionic form in endohedral fullerenes in both the solid and liquid state of the fullerene. Furthermore it is shown that there is more than one stable position of the metal ion inside the fullerene molecule. Mass spectrometric measurements demonstrate that M@C 82 structures are the most stable endohedral fullerene structures.

  18. Ives-Stilwell Time Dilation Li+ ESR Darmstadt Experiment and Neo-Lorentz Relativity

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2015-01-01

    Full Text Available Botermann et al in Test of Time Dilation Using Stored Li + Ions as Clocks at Relativis- tic Speed , Physical Review Letters , 2014, 113, 120405, reported results from an Ives- Stilwell-type time dilation experiment using Li + ions at speed 0.338c in the ESR storage ring at Darmstadt, and concluded that the data verifies the Special Relativity time dila- tion e ect. However numerous other experiments have shown that it is only neo-Lorentz Relativity that accounts for all data, and all detect a 3-space speed V 470 km / s essen- tially from the south. Here we show that the ESR data confirms both Special Relativity and neo-Lorentz Relativity, but that a proposed di erent re-analysis of the ESR data should enable a test that could distinguish between these two theories.

  19. ADX: a high field, high power density, advanced divertor and RF tokamak

    Science.gov (United States)

    LaBombard, B.; Marmar, E.; Irby, J.; Terry, J. L.; Vieira, R.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.; Baek, S.; Beck, W.; Bonoli, P.; Brunner, D.; Doody, J.; Ellis, R.; Ernst, D.; Fiore, C.; Freidberg, J. P.; Golfinopoulos, T.; Granetz, R.; Greenwald, M.; Hartwig, Z. S.; Hubbard, A.; Hughes, J. W.; Hutchinson, I. H.; Kessel, C.; Kotschenreuther, M.; Leccacorvi, R.; Lin, Y.; Lipschultz, B.; Mahajan, S.; Minervini, J.; Mumgaard, R.; Nygren, R.; Parker, R.; Poli, F.; Porkolab, M.; Reinke, M. L.; Rice, J.; Rognlien, T.; Rowan, W.; Shiraiwa, S.; Terry, D.; Theiler, C.; Titus, P.; Umansky, M.; Valanju, P.; Walk, J.; White, A.; Wilson, J. R.; Wright, G.; Zweben, S. J.

    2015-05-01

    The MIT Plasma Science and Fusion Center and collaborators are proposing a high-performance Advanced Divertor and RF tokamak eXperiment (ADX)—a tokamak specifically designed to address critical gaps in the world fusion research programme on the pathway to next-step devices: fusion nuclear science facility (FNSF), fusion pilot plant (FPP) and/or demonstration power plant (DEMO). This high-field (⩾6.5 T, 1.5 MA), high power density facility (P/S ˜ 1.5 MW m-2) will test innovative divertor ideas, including an ‘X-point target divertor’ concept, at the required performance parameters—reactor-level boundary plasma pressures, magnetic field strengths and parallel heat flux densities entering into the divertor region—while simultaneously producing high-performance core plasma conditions that are prototypical of a reactor: equilibrated and strongly coupled electrons and ions, regimes with low or no torque, and no fuelling from external heating and current drive systems. Equally important, the experimental platform will test innovative concepts for lower hybrid current drive and ion cyclotron range of frequency actuators with the unprecedented ability to deploy launch structures both on the low-magnetic-field side and the high-magnetic-field side—the latter being a location where energetic plasma-material interactions can be controlled and favourable RF wave physics leads to efficient current drive, current profile control, heating and flow drive. This triple combination—advanced divertors, advanced RF actuators, reactor-prototypical core plasma conditions—will enable ADX to explore enhanced core confinement physics, such as made possible by reversed central shear, using only the types of external drive systems that are considered viable for a fusion power plant. Such an integrated demonstration of high-performance core-divertor operation with steady-state sustainment would pave the way towards an attractive pilot plant, as envisioned in the ARC concept

  20. Magnetism of a novel tetranuclear nickel(II) cluster in strong magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Kataev, V [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Golze, C [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Alfonsov, A [Kazan Physical Technical Institute, Russian Academy of Sciences, 420029 Kazan (Russian Federation); Klingeler, R [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Buechner, B [Leibniz-Institute for Solid State and Materials Research IFW Dresden, PO Box 270116, 01171 Dresden (Germany); Goiran, M [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Broto, J-M [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Rakoto, H [Laboratoire National des Champs Magnetiques Pulses, 31432 Toulouse Cedex 04 (France); Mennerich, C [Institut fuer Physik der Kondens. Materie, TU Braunschweig, 38106 Braunschweig (Germany); Klauss, H-H [Institut fuer Physik der Kondens. Materie, TU Braunschweig, 38106 Braunschweig (Germany); Demeshko, S [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany); Leibeling, G [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany); Meyer, F [Georg-August-University Goettingen, Institute of Inorg. Chem., 37077 Goettingen (Germany)

    2006-11-15

    High frequency Electron Spin Resonance (ESR) up to {nu} = 1 THz and magnetization M(B) of a tetranuclear-Ni(II) single molecular complex of type [L{sub 2}Ni{sub 4}(N{sub 3})(O{sub 2}CAda){sub 4}](ClO{sub 4}) featuring an unprecedented central {mu}{sub 4} - 1,1,3,3 azide have been studied in magnetic fields up to B = 55T. Bridging ligands provide intramolecular exchange paths of different strength between the four Ni ions each having a spin S{sub Ni} = 1. T- and {nu}-dependent ESR measurements enable to accurately determine the energy spectrum of the spin states of the cluster as a function of B. A predominantly antiferromagnetic character of exchange renders the ground state nonmagnetic, S = 0, with a number of excited magnetic multiplet states, S = 1,. . . ,4. Remarkably, ESR gives evidence for the spin-level crossing in a field of {approx} 25T which turns the ground state of the cluster to a strongly magnetic one. This observation is confirmed by the static M(B) data.

  1. The spectroscopic analysis of {gamma}-irradiated glass by colorimetry, ESR and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.I. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of); Lee, Y.N. [R and D Institute Biscuit Team, 131-1, Namyoung-dong, Youngsan-Gu, Seoul 140-708 (Korea, Republic of); Cho, S.Y. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of); Whiteside, W.S. [Department of Packaging Science, 226 Poole Agricultural Center, Clemson University, Clemson, SC 29634-0320 (United States); Park, H.J. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of)], E-mail: hjpark@korea.ac.kr

    2008-09-15

    The darkening of {gamma}-irradiated glass was related to the binding of Si-O and Sn-O, and the binding of Na-O. The dosimetric range of glass color change was evaluated by colorimetry, UV-Vis spectrophotometry and ESR. Colorimetry and UV-Vis spectrophotometry, revealed linear changes up to 9 kGy. For the calibration curve of {gamma}-irradiation, the signal of g=2.01 observed by ESR responded most sensitively with a linear increase with up to 12 kGy.

  2. Responsabilidad social empresarial en empresas chihuahuenses que obtuvieron el distintivo ESR 2013

    OpenAIRE

    Alma Lilia, Sapién Aguilar; Piñón Howlet, Laura Cristina; Gutiérrez Díez, Maria del Carmen

    2016-01-01

    La responsabilidad social empresarial (RSE) se ha vuelto una tendencia mundial. El objetivo fue evaluar la implementación de la práctica de responsabilidad social en las empresas chihuahuenses que obtuvieron el distintivo de Empresa Socialmente Responsable (ESR). La naturaleza de la investigación fue mixta, de tipo aplicada y no experimental. La población de interés fueron empresas Chihuahuenses con el distintivo ESR 2013. La mayoría especificó que la principal ventaja de la implementación...

  3. Molecular structure refinement by direct fitting of atomic coordinates to experimental ESR spectra

    CERN Document Server

    Charnock, G T P; Kuprov, Ilya

    2011-01-01

    An attempt is made to bypass spectral analysis and fit internal coordinates of radicals directly to experimental liquid- and solid-state electron spin resonance (ESR) spectra. We take advantage of the recently introduced large-scale spin dynamics simulation algorithms and of the fact that the accuracy of quantum mechanical calculations of ESR parameters has improved to the point of quantitative correctness. Partial solutions are offered to the local minimum problem in spectral fitting and to the problem of spin interaction parameters (hyperfine couplings, chemical shifts, etc.) being very sensitive to distortions in molecular geometry.

  4. Microscopy with microlens arrays: high throughput, high resolution and light-field imaging.

    Science.gov (United States)

    Orth, Antony; Crozier, Kenneth

    2012-06-04

    We demonstrate highly parallelized fluorescence scanning microscopy using a refractive microlens array. Fluorescent beads and rat femur tissue are imaged over a 5.5 mm x 5.5 mm field of view at a pixel throughput of up to 4 megapixels/s and a resolution of 706 nm. We also demonstrate the ability to extract different perspective views of a pile of microspheres.

  5. Mutation and association analyses of the candidate genes ESR1, ESR2, MAX, PCNA, and KAT2A in patients with unexplained MSH2-deficient tumors.

    Science.gov (United States)

    Rahner, Nils; Brockschmidt, Felix F; Steinke, Verena; Kahl, Philip; Becker, Tim; Vasen, Hans F A; Wijnen, Juul T; Tops, Carli J M; Holinski-Feder, Elke; Ligtenberg, Marjolijn J L; Spruijt, Liesbeth; Görgens, Heike; Stemmler, Susanne; Kloor, Matthias; Dietmaier, Wolfgang; Schumacher, Johannes; Nöthen, Markus M; Propping, Peter

    2012-03-01

    Lynch syndrome (Hereditary non-polyposis colorectal cancer/HNPCC) is a cancer susceptibility syndrome which is caused by germline mutations in DNA mismatch repair (MMR) genes, in particular MLH1 and MSH2. A pathogenic germline mutation in the respective MMR gene is suggested by the finding of a loss of a mismatch repair protein in tumor tissue on immunohistochemical staining combined with an early age of onset and/or the familial occurrence of colorectal cancer. Pathogenic germline mutations are identifiable in around 60% of patients suspected of Lynch syndrome, depending on the familial occurrence. The aim of the present study was to identify novel susceptibility genes for Lynch syndrome. 64 Healthy controls and 64 Lynch syndrome patients with no pathogenic MSH2 mutation but a loss of MSH2 expression in their tumor tissue were screened for rare and disease causing germline mutations in the functional candidate genes ESR1, ESR2, MAX, PCNA, and KAT2A. Thirty variants were identified, and these were then genotyped in an independent sample of 36 mutation negative Lynch syndrome patients and 234 controls. Since a trend towards association was observed for KAT2A, an additional set of 21 tagging SNPs was analyzed at this locus in a final case-control sample of 142 mutation negative Lynch syndrome patients and 298 controls. The mutation analysis failed to reveal any rare disease-causing mutations. No association was found at the single-marker or haplotypic level for any common disease-modifying variant. The present results suggest that neither rare nor common genetic variants in ESR1, ESR2, MAX, PCNA, or KAT2A contribute to the development of Lynch syndrome.

  6. Impact of high electromagnetic field levels on childhood leukemia incidence.

    Science.gov (United States)

    Teepen, Jop C; van Dijck, Jos A A M

    2012-08-15

    The increasing exposure to electromagnetic fields (EMFs) has raised concern, as increased exposure may result in an increased risk of childhood leukemia (CL). Besides a short introduction of CL and EMF, our article gives an evaluation of the evidence of a causal relation between EMF and CL by critically appraising the epidemiological and biological evidence. The potential impact is also estimated by the population attributable risk. The etiology of CL is largely unknown, but is probably multifactorial. EMF may be one of the environmental exposures involved. Three pooled analyses of case-control studies showed a 1.4- to 1.7-fold increased CL risk for extremely low-frequency EMF (ELF-EMF) exposure levels above 0.3 μT. Several biases may have played a role in these studies, but are unlikely to fully explain the increased risk. For effects of radiofrequency ELF evidence is lacking. None of the proposed biological mechanisms by which ELF-EMF might cause CL have been confirmed. The estimated overall population attributable risk was 1.9%, with the highest estimates in Northern America and Brazil (4.2% and 4.1%, respectively). The potential impact of EMF exposure on public health is probably limited, although in some countries exposure might be relatively high and thus might have a more substantial impact. We recommend nationwide surveys to gain more insight into the contemporary exposure levels among children. Reducing exposure from power lines near densely populated areas and schools is advised. Future epidemiological studies should focus on limiting bias. Copyright © 2012 UICC.

  7. Analytical possibilities of highly focused ion beams in biomedical field

    Science.gov (United States)

    Ren, M. Q.; Ji, X.; Vajandar, S. K.; Mi, Z. H.; Hoi, A.; Walczyk, T.; van Kan, J. A.; Bettiol, A. A.; Watt, F.; Osipowicz, T.

    2017-09-01

    At the Centre for Ion Beam Applications (CIBA), a 3.5 MV HVEE Singletron™ accelerator serves to provide MeV ion beams (mostly protons or He+) to six state-of-the-art beam lines, four of which are equipped with Oxford triplet magnetic quadrupole lens systems. This facility is used for a wide range of research projects, many of which are in the field of biomedicine. Here we presented a discussion of currently ongoing biomedical work carried out using two beamlines: The Nuclear Microscopy (NM) beamline is mainly used for trace elemental quantitative mapping using a combination of Particle Induced X-ray Emission (PIXE), to measure the trace elemental concentration of inorganic elements, Rutherford Backscattering Spectrometry (RBS), to characterise the organic matrix, and Scanning Transmission Ion Microscopy (STIM) to provide information on the lateral areal density variations of the specimen. Typically, a 2.1 MeV proton beam, focused to 1-2 μm spot size with a current of 100 pA is used. The high resolution single cell imaging beamline is equipped with direct STIM to image the interior structure of single cells with proton and alpha particles of sub-50 nm beam spot sizes. Simultaneously, forward scattering transmission ion microscopy (FSTIM) is utilized to generate images with improved contrast of nanoparticles with higher atomic numbers, such as gold nanoparticles, and fluorescent nanoparticles can be imaged using Proton Induced Fluorescence (PIF). Lastly, in this facility, RBS has been included as an option if required to determine the depth distribution of nanoparticles in cells, albeit with reduced spatial resolution.

  8. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  9. High-Throughput Phase-Field Design of High-Energy-Density Polymer Nanocomposites.

    Science.gov (United States)

    Shen, Zhong-Hui; Wang, Jian-Jun; Lin, Yuanhua; Nan, Ce-Wen; Chen, Long-Qing; Shen, Yang

    2017-11-22

    Understanding the dielectric breakdown behavior of polymer nanocomposites is crucial to the design of high-energy-density dielectric materials with reliable performances. It is however challenging to predict the breakdown behavior due to the complicated factors involved in this highly nonequilibrium process. In this work, a comprehensive phase-field model is developed to investigate the breakdown behavior of polymer nanocomposites under electrostatic stimuli. It is found that the breakdown strength and path significantly depend on the microstructure of the nanocomposite. The predicted breakdown strengths for polymer nanocomposites with specific microstructures agree with existing experimental measurements. Using this phase-field model, a high throughput calculation is performed to seek the optimal microstructure. Based on the high-throughput calculation, a sandwich microstructure for PVDF-BaTiO3 nanocomposite is designed, where the upper and lower layers are filled with parallel nanosheets and the middle layer is filled with vertical nanofibers. It has an enhanced energy density of 2.44 times that of the pure PVDF polymer. The present work provides a computational approach for understanding the electrostatic breakdown, and it is expected to stimulate future experimental efforts on synthesizing polymer nanocomposites with novel microstructures to achieve high performances. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Brushless exciters using a high temperature superconducting field winding

    Science.gov (United States)

    Garces, Luis Jose [Schenectady, NY; Delmerico, Robert William [Clifton Park, NY; Jansen, Patrick Lee [Scotia, NY; Parslow, John Harold [Scotia, NY; Sanderson, Harold Copeland [Tribes Hill, NY; Sinha, Gautam [Chesterfield, MO

    2008-03-18

    A brushless exciter for a synchronous generator or motor generally includes a stator and a rotor rotatably disposed within the stator. The rotor has a field winding and a voltage rectifying bridge circuit connected in parallel to the field winding. A plurality of firing circuits are connected the voltage rectifying bridge circuit. The firing circuit is configured to fire a signal at an angle of less than 90.degree. or at an angle greater than 90.degree.. The voltage rectifying bridge circuit rectifies the AC voltage to excite or de-excite the field winding.

  11. Field Independence, Impulsiveness, High School Training, and Academic Achievement

    Science.gov (United States)

    Feij, Jan A.

    1976-01-01

    Investigates the relationship between performance on field-independence tests and two variables which may be thought of as important determinants of performance on a variety of cognitive tasks: impulsiveness and previous education. (Author/RC)

  12. High dynamic range electric field sensor for electromagnetic pulse detection

    National Research Council Canada - National Science Library

    Lin, Che-Yun; Wang, Alan X; Lee, Beom Suk; Zhang, Xingyu; Chen, Ray T

    2011-01-01

    ...) polymer Y-fed directional coupler for electromagnetic wave detection. This electrode-less, all optical, wideband electrical field sensor is fabricated using standard processing for E-O polymer photonic devices...

  13. Ultrafast carrier dynamics in graphene under a high electric field.

    Science.gov (United States)

    Tani, Shuntaro; Blanchard, François; Tanaka, Koichiro

    2012-10-19

    We investigated ultrafast carrier dynamics in graphene with near-infrared transient absorption measurement after intense half-cycle terahertz pulse excitation. The terahertz electric field efficiently drives the carriers, inducing large transparency in the near-infrared region. Theoretical calculations using the Boltzmann transport equation quantitatively reproduce the experimental findings. This good agreement suggests that the intense terahertz field should promote a remarkable impact ionization process and increase the carrier density.

  14. Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; /Fermilab; Norem, J.; /Argonne; Li, D.; Zisman, M.; /LBL, Berkeley; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Errede,; /Illinois U., Urbana

    2005-10-01

    There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

  15. Biological and Agricultural Studies on Application of Discharge Plasma and Electromagnetic Fields 5. Effects of High Electric Fields on Animals

    Science.gov (United States)

    Isaka, Katsuo

    The biological effects of extremely low frequency electric fields on animals are reviewed with emphasis on studies of the nervous system, behavior, endocrinology, and blood chemistry. First, this paper provides a histrical overview of studies on the electric field effects initiated in Russia and the United States mainly regarding electric utility workers in high voltage substations and transmission lines. Then, the possible mechanisms of electric field effects are explained using the functions of surface electric fields and induced currents in biological objects. The real mechanisms have not yet been identified. The thresholds of electric field perception levels for rats, baboons, and humans are introduced and compared. The experimental results concerning the depression of melatonin secretion in rats exposed to electric fields are described.

  16. Validity and predictive ability of the juvenile arthritis disease activity score based on CRP versus ESR in a Nordic population-based setting

    DEFF Research Database (Denmark)

    Nordal, E B; Zak, M; Aalto, K

    2012-01-01

    To compare the juvenile arthritis disease activity score (JADAS) based on C reactive protein (CRP) (JADAS-CRP) with JADAS based on erythrocyte sedimentation rate (ESR) (JADAS-ESR) and to validate JADAS in a population-based setting.......To compare the juvenile arthritis disease activity score (JADAS) based on C reactive protein (CRP) (JADAS-CRP) with JADAS based on erythrocyte sedimentation rate (ESR) (JADAS-ESR) and to validate JADAS in a population-based setting....

  17. High-speed non-intrusive measurements of fuel velocity fields at high-pressure injectors

    Science.gov (United States)

    Gürtler, Johannes; Schlüßler, Raimund; Fischer, Andreas; Czarske, Jürgen

    2017-03-01

    Using a single high-speed camera and a frequency modulated laser, a novel approach is presented for fast velocity field measurements in unsteady spray flows. The velocity range is from zero up to several 100 m/s, which requires a high measurement rate and a large dynamic. Typically, flow measurements require to seed tracer particles to the fluid. A paradigm shift to seeding-free measurements is presented. The light scattered at the phase boundaries of the fluid droplets is evaluated. In order to validate the high-speed measurement system, a detailed uncertainty analysis is performed by means of measurements as well as simulations. Thereby, variations of the scattered light intensity, which are based on the high temporal velocity gradients, are found to be the main contribution to the uncertainty. The eventually measurement results, obtained at a measurement rate of 500 kHz, exhibit spray velocities ranging from 0 m/s up to 400 m/s in less than 1 ms, and the detection of unsteady and irregular flow phenomena with a characteristic time of several μs is achieved. This demonstrates the high measurement rate, the high temporal resolution and the large measurement range of the proposed high-speed measurement system.

  18. Adsorption and desorption of dibenzothiophene on Ag-titania studied by the complementary temperature-programmed XPS and ESR

    Science.gov (United States)

    Samokhvalov, Alexander; Duin, Evert C.; Nair, Sachin; Tatarchuk, Bruce J.

    2011-02-01

    Adsorption, desorption and structure of the surface chemical compounds formed upon interaction of dibenzothiophene (DBT) in solution of n-octane with the sulfur-selective Ag/Titania sorbent for the ultradeep desulfurization of liquid fuels was characterized by the temperature-programmed X-ray photoemission spectroscopy (XPS) and Electron Spin Resonance. Adsorption of DBT proceeds via chemisorption via the oxygen-containing surface groups. Desorption of DBT and thermal regeneration of the “spent” Ag/Titania were studied by the complementary temperature-programmed XPS and ESR from 25 °C to 525 °C, in the high vacuum vs. air. The XPS spectrum of the pure DBT is reported for the first time.

  19. Adsorption and desorption of dibenzothiophene on Ag-titania studied by the complementary temperature-programmed XPS and ESR

    Energy Technology Data Exchange (ETDEWEB)

    Samokhvalov, Alexander, E-mail: alexsam@camden.rutgers.edu [Department of Chemical Engineering, Auburn University, Auburn, AL 36849 (United States); Department of Chemistry, Rutgers University, Camden, NJ 08102 (United States); Duin, Evert C. [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States); Nair, Sachin; Tatarchuk, Bruce J. [Department of Chemical Engineering, Auburn University, Auburn, AL 36849 (United States)

    2011-02-01

    Adsorption, desorption and structure of the surface chemical compounds formed upon interaction of dibenzothiophene (DBT) in solution of n-octane with the sulfur-selective Ag/Titania sorbent for the ultradeep desulfurization of liquid fuels was characterized by the temperature-programmed X-ray photoemission spectroscopy (XPS) and Electron Spin Resonance. Adsorption of DBT proceeds via chemisorption via the oxygen-containing surface groups. Desorption of DBT and thermal regeneration of the 'spent' Ag/Titania were studied by the complementary temperature-programmed XPS and ESR from 25 deg. C to 525 deg. C, in the high vacuum vs. air. The XPS spectrum of the pure DBT is reported for the first time.

  20. Generation and measurement of pulsed high magnetic field

    CERN Document Server

    Jana, S

    2000-01-01

    Pulsed magnetic field has been generated by discharging a capacitor bank through a 5-layer air-core solenoid. The strength of the magnetic field at its peak has been measured using the voltage induced in various pick-up coils, and also from the Zeeman splitting of an ion having a known g value. Synchronizing a xenon flash at the peak of the magnetic field, this lab-made instrument has been made well suited to study the Zeeman effect, etc. at a temperature of 25 K. As an application of this setup, we have investigated the Zeeman splitting of the sup 4 I sub 9 sub / sub 2-> sup 4 G sub 5 sub / sub 2 transition of the Nd sup 3 sup + -doped CsCdCl sub 3 crystal at 7.8 T, and determined the splitting factors.

  1. Solid-state NMR and ESR studies of activated carbons produced from pecan shells

    Science.gov (United States)

    Activated carbon from pecan shells has shown promise as an adsorbent in water treatment and sugar refining. However, the chemistry of the material is complex and not fully understood. We report here the application of solid state NMR and ESR to study the chemical structure, mobility, and pore volu...

  2. NMR and ESR characterization of activated carbons produced from pecan shells

    Science.gov (United States)

    A large number of solid-state NMR and ESR experiments were explored as potential tools to study chemical structure, mobility, and pore volume of activated carbon. We used a model system where pecan shells were activated with phosphoric acid, and carbonized at 450ºC for 4 h with varying amounts of ai...

  3. The use of ESR technique for assessment of heating temperatures of archaeological lentil samples

    Science.gov (United States)

    Aydaş, Canan; Engin, Birol; Dönmez, Emel Oybak; Belli, Oktay

    2010-01-01

    Heat-induced paramagnetic centers in modern and archaeological lentils ( Lens culinaris, Medik.) were studied by X-band (9.3 GHz) electron spin resonance (ESR) technique. The modern red lentil samples were heated in an electrical furnace at increasing temperatures in the range 70-500 °C. The ESR spectral parameters (the intensity, g-value and peak-to-peak line width) of the heat-induced organic radicals were investigated for modern red lentil ( Lens culinaris, Medik.) samples. The obtained ESR spectra indicate that the relative number of heat-induced paramagnetic species and peak-to-peak line widths depends on the temperature and heating time of the modern lentil. The g-values also depend on the heating temperature but not heating time. Heated modern red lentils produced a range of organic radicals with g-values from g = 2.0062 to 2.0035. ESR signals of carbonised archaeological lentil samples from two archaeological deposits of the Van province in Turkey were studied and g-values, peak-to-peak line widths, intensities and elemental compositions were compared with those obtained for modern samples in order to assess at which temperature these archaeological lentils were heated in prehistoric sites. The maximum temperatures of the previous heating of carbonised UA5 and Y11 lentil seeds are as follows about 500 °C and above 500 °C, respectively.

  4. Epistasis Between Polymorphisms in COMT, ESR1, and GCH1 Influences COMT Enzyme Activity and Pain

    Science.gov (United States)

    Smith, Shad B.; Reenilä, Ilkka; Männistö, Pekka T.; Slade, Gary D.; Maixner, William; Diatchenko, Luda; Nackley, Andrea G.

    2014-01-01

    Abnormalities in the enzymatic activity of catechol-O-methyltransferase (COMT) contribute to chronic pain conditions, such as temporomandibular disorders (TMD). Thus, we sought to determine the effects of polymorphisms in COMT and functionally-related pain genes in the COMT pathway (estrogen receptor 1: ESR1, guanosine-5-triphosphate cyclohydrolase 1: GCH1, methylenetetrahydrofolate reductase: MTHFR) on COMT enzymatic activity, musculoskeletal pain, and pain-related intermediate phenotypes among TMD cases and healthy controls. Results demonstrate that the COMT rs4680 (val158met) polymorphism is most strongly associated with outcome measures, such that individuals with the minor A allele (met) exhibit reduced COMT activity, increased TMD risk, and increased musculoskeletal pain. Epistatic interactions were observed between the COMT rs4680 polymorphism and polymorphisms in GCH1 and ESR1. Among individuals with the COMT met allele, those with two copies of the GCH1 rs10483639 minor G allele exhibit normalized COMT activity and increased mechanical pain thresholds. Among individuals with the COMT val allele, those with two copies of the ESR1 rs3020377 minor A allele exhibit reduced COMT activity, increased bodily pain, and poorer self-reported health. These data reveal that the GCH1 minor G allele confers a protective advantage among met carriers, while the ESR1 minor A allele is disadvantageous among val carriers. Furthermore, these data suggest that the ability to predict the downstream effects of genetic variation on COMT activity is critically important to understanding the molecular basis of chronic pain conditions. PMID:25218601

  5. Association analysis of polymorphisms in EGFR, HER2, ESR1 and ...

    African Journals Online (AJOL)

    Maha RebaÑ—

    2016-08-31

    Aug 31, 2016 ... polymorphisms (SNP) in the ESR1 gene have been associated with an increased risk of vascular diseases, such as arterial hypertension, cardiovascular diseases, alterations in serum lipid levels, and cerebrovascular disease [22–24]. More recently, it has been shown that genetic and epigenetic changes.

  6. Variability of electron spin resonance (ESR) signal of γ -irradiated starches

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Gilberto D.; Rodrigues Junior, Orlando; Mastro, Nelida L. del, E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    Food preservation is one of the practical applications of radiation processing of materials. Starch is an abundant and cheap nutritious biopolymer and also is the material for appropriate food systems and for technical industries. Starch granules are partially crystalline structures composed mainly of two types of starch: amylose, an essentially linear polymer, and amylopectin, with 3-44% of branch points. Electron spin resonance (ESR) spectroscopy is a very powerful and sensitive method for the characterization of the electronic structures of materials with unpaired electrons. The aim of the present work was to monitor the disappearance of the short life and long-life free radicals formed during γ-irradiation of 3 different starches. Corn, potato and fermented cassava starches were irradiated in a {sup 60}Co source Gammacell 220 with 20 kGy, dose rate around 1 kGy h{sup -1}. EPR spectra were obtained at room temperature using a Bruker EMX plus model, X band equipment. The main type of ESR signal from irradiated starch is a singlet with a g-value of about 2.0. The fading of ESR signals was followed for 350 hours, and presents differences among the different starch type reflecting differences in molecular arrangements of starch crystalline and amorphous fractions, although ESR spectra seemed to be common for all starches. (author)

  7. ESR statement on radiation protection: globalisation, personalised medicine and safety (the GPS approach).

    Science.gov (United States)

    2013-12-01

    In keeping with its responsibility for the radiation protection of patients undergoing radiological examinations and procedures, as well as of staff who are getting exposed, and with due regard to requirements under European Directives, the European Society of Radiology (ESR) issues this statement. It provides a holistic approach, termed as Globalisation (indicating all the steps and involving all stakeholders), Personalisation (referring to patient-centric) and Safety-thus called GPS. While being conscious that there is need to increase access of radiological imaging, ESR is aware about the increasing inappropriate medical exposures to ionising radiation and wide variation in patient doses for the same examination. The ESR is convinced that the different components of radiation protection are often interrelated and cannot be considered in isolation The ESR's GPS approach stands for: Globalisation (indicating all the steps and involving all stakeholders), Personalisation (referring to patient-centric) and Safety-thus called GPS It can be anticipated that enhanced protection of patients in Europe will result through the GPS approach. Although the focus is on patient safety, staff safety issues will find a place wherever pertinent.

  8. Spin dynamics in the strongly magnetically frustrated compounds YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} probed by NMR and ESR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Iakovleva, Margarita [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); E. K. Zavoisky Physical-Technical Institute, Kazan (Russian Federation); Zeisner, Julian; Zimmermann, Stephan; Buechner, Bernd [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); Valldor, Martin [Max-Planck-Institut fuer Chemische Physik fester Stoffe, Dresden (Germany); Vavilova, Evgeniia [E. K. Zavoisky Physical-Technical Institute, Kazan (Russian Federation); Grafe, Hans-Joachim; Alfonsov, Alexey; Kataev, Vladislav [IFW Dresden, Dresden (Germany)

    2016-07-01

    In the Swedenborgite type compounds YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} the magnetic lattice can be described as a stacking of kagome layers, where unconventional ground states such as a spin liquid state can be expected due to the strong geometrical frustration. We performed a combined experimental study of magnetic properties of single crystals of YBaCo{sub 3}AlO{sub 7} and YBaCo{sub 3}FeO{sub 7} with high field ESR and high field NMR spectroscopy. The experimental results show the occurrence of short-range quasi static electron spin correlations at T{sup *} ∼ 22 K for YBaCo{sub 3}AlO{sub 7} and T{sup *} ∼ 60K for YBaCo{sub 3}FeO{sub 7} but not a long-range antiferromagnetic order. We compare our results with AC and DC susceptibility measurements and discuss a possible competition between a spin glass-like state due to intrinsic structural disorder and a spin liquid state arising from strong magnetic frustration in this materials.

  9. Novel Josephson circuit elements for high magnetic field parity detection

    Science.gov (United States)

    Cassidy, Maja

    Evidence for Majorana modes in semiconductor nanowires to date has relied on DC transport measurements that probe their zero-energy characteristics. However, in order to unambiguously demonstrate the non-Abelian nature of Majoranas, it is necessary to braid them and measure their parity. Superconducting transmon qubits have been shown to be sensitive parity detectors, however traditional designs are incompatible with the strong magnetic fields required for the creation of Majoranas in nanowires. In this talk I will discuss our development of novel superconducting circuit elements such as CPW resonators, tunnel junctions, transmon qubits and on chjp microwave sources that survive magnetic fields in excess of 1T.

  10. ESR dating of submarine hydrothermal activities using barite in sulfide deposition

    Science.gov (United States)

    Toyoda, S.; Fujiwara, T.; Ishibashi, J.; Isono, Y.; Uchida, A.; Takamasa, A.; Nakai, S.

    2012-12-01

    The temporal change of submarine hydrothermal activities has been an important issue in the aspect of the evolution of hydrothermal systems which is related with ore formation (Urabe, 1995) and biological systems sustained by the chemical species arising from hydrothermal activities (Macdonald et al., 1980). Determining the ages of the hydrothermal deposit will provide essential information on such studies. Dating methods using disequilibrium between radioisotopes such as U-Th method (e.g. You and Bickle, 1998), 226}Ra-{210Pb and 228}Ra-{228Th method (e.g. Noguchi et al., 2011) have been applied to date submarine hydrothermal deposits. ESR (electron spin resonance) dating method is commonly applied to fossil teeth, shells, and quartz of Quaternay period where the natural accumulated dose is obtained from the intensities of the ESR signals which are created by natural radiation. The natural dose is divided by the dose rate to the mineral/sample to deduce the age. Okumura et al., (2010) made the first practical application of ESR (electron spin resonance) dating technique to a sample of submarine hydrothermal barite (BaSO4) to obtain preliminary ages, where Kasuya et al. (1991) first pointed out that barite can be used for ESR dating. Knowing that ESR dating of barite is promising, in this paper, we will present how we have investigated each factor that contributes ESR dating of barite in submarine hydrothermal sulfide deposition. (1) The best ESR condition for measuring the SO3- signal in barite is with the microwave power of 1mW and modulation amplitude of 0.1mT. (2) As results of heating experiments, the signal was found to be stable for the dating age range of several thousands. (3) 226Ra replacing Ba in barite is the source of the radiation. The amount of radioactive elements in sulfide mineral surrounding barite is negligible. (4) The external radiation from the sea water is negligible even in the submarine hydrothermal area where the radiation level is much

  11. Prospects of development of highly mineralized high-temperature resources of the Tarumovskoye geothermal field

    Science.gov (United States)

    Alkhasov, A. B.; Alkhasova, D. A.; Ramazanov, A. Sh.; Kasparova, M. A.

    2016-06-01

    The promising nature of integrated processing of high-temperature geothermal brines of the Tarumovskoye geothermal field is shown. Thermal energy of a geothermal brine can be converted to the electric power at a binary geothermal power plant (GPP) based on low-boiling working substance. The thermodynamic Rankine cycles are considered which are implemented in the GPP secondary loop at different evaporation temperatures of the working substance―isobutane. Among them, the most efficient cycle from the standpoint of attaining a maximum power is the supercritical one which is close to the so-called triangular cycle with an evaporation pressure of p e = 5.0 MPa. The used low-temperature brine is supplied from the GPP to a chemical plant, where main chemical components (lithium carbonate, burnt magnesia, calcium carbonate, and sodium chloride) are extracted from it according to the developed technology of comprehensive utilization of geothermal brines of chloride-sodium type. The waste water is delivered to the geotechnological complex and other consumers. For producing valuable inorganic materials, the electric power generated at the GPP is used. Owing to this, the total self-sufficiency of production and independence from external conditions is achieved. The advantages of the proposed geotechnological complex are the full utilization of the heat potential and the extraction of main chemical components of multiparameter geothermal resources. In this case, there is no need for reverse pumping, which eliminates the significant capital costs for building injection wells and a pumping station and the operating costs for their service. A characteristic of the modern state of the field and estimated figures of the integrated processing of high-temperature brines of well no. 6 are given, from which it follows that the proposed technology has a high efficiency. The comprehensive development of the field resources will make it possible to improve the economic structure of the

  12. Robustness of various metals against high THz field induced damage

    DEFF Research Database (Denmark)

    Zhu, Jianfei; Iwaszczuk, Krzysztof; Tarekegne, Abebe Tilahun

    2016-01-01

    We investigate various metals for their robustness against damage caused by strong THz field. Even though the damage process is not of a thermal nature we observe a correlation between robustness and the melting temperature. Influence of the substrate material on the damage pattern is also studied....

  13. High Fidelity Modeling of Field Reversed Configuration (FRC) Thrusters

    Science.gov (United States)

    2016-06-01

    expedited through the hiring of two new employees, Dr. Eder Sousa (recent graduate of U. of Washington) and Dr. Artan Qerushi (formerly at Tri- Alpha ...Effect on Field-Reversed Configuration Thruster Efficiency, Journal of Propulsion and Power, Vol 30, No. 6, Nov- Dec 2014. - Qerushi, A, “Overview of

  14. Multilayers for high Tc superconducting electric field effect devices

    NARCIS (Netherlands)

    Joosse, K.; Joosse, K.; Gerritsma, G.J.; Rogalla, Horst; Boguslavskij, Y.M.; Boguslavskij, Y.M.; de Vaal, J.W.

    1993-01-01

    Epitaxial multilayers, consisting of a PrBa2Cu3O7-x buffer layer, ultrathin YBa2Cu3O7-x and SrTiO3, have been grown for application in electric field effect devices. Different analytical techniques indicate a sharp interface between the layers and good dielectric properties of the SrTiO3-layer.

  15. Ultra High Field MRI-Guided Deep Brain Stimulation

    NARCIS (Netherlands)

    Forstmann, Birte U; Isaacs, Bethany R; Temel, Yasin

    2017-01-01

    Deep brain stimulation (DBS) is a neurosurgical treatment for neurological disorders often planned with 1.5-T or 3-T MRI. The clinical efficacy of DBS can be improved using ultrahigh-field (UHF) MRI for planning by increasing the level of precision required for an individualized approach.

  16. High-Field Magnetization of Light Rare-Earth Metals

    DEFF Research Database (Denmark)

    McEwen, K.A.; Cock, G.J.; Roeland, L.W.

    1973-01-01

    The magnetization of single crystals of Eu, Sm, Nd, Pr, and Pr-Nd alloys has been measured in fields up to 37 T (370 kG). The results give new information on the magnetic properties of these metals. Of particular interest is a first-order transition from a nonmagnetic to a metamagnetic phase...

  17. Impact of high electromagnetic field levels on childhood leukemia incidence

    NARCIS (Netherlands)

    Teepen, J.C.; Dijck, J.A. van

    2012-01-01

    The increasing exposure to electromagnetic fields (EMFs) has raised concern, as increased exposure may result in an increased risk of childhood leukemia (CL). Besides a short introduction of CL and EMF, our article gives an evaluation of the evidence of a causal relation between EMF and CL by

  18. The new installation at the Nijmegen High Field Magnet Laboratory

    NARCIS (Netherlands)

    Perenboom, J.A.A.J.; Wiegers, S.A.J.; Christianen, P.C.M.; Zeitler, U.; Maan, J.C.

    2004-01-01

    For research in the highest continuous and pulsed magnetic fields large, complex and powerful installations are needed. A new 20 MW installation has been built at the University of Nijmegen. The ultra-low ripple power converter, delivering 40 kA at up to 500 V, provides the capability to perform

  19. The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network

  20. High impact ionization rate in silicon by sub-picosecond THz electric field pulses (Conference Presentation)

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Hirori, Hideki

    2017-01-01

    Summary form only given. Metallic antenna arrays fabricated on high resistivity silicon are used to localize and enhance the incident THz field resulting in high electric field pulses with peak electric field strength reaching several MV/cm on the silicon surface near the antenna tips. In such hi...... carrier dynamics in other semiconductors....

  1. Nitrogen detected TROSY at high field yields high resolution and sensitivity for protein NMR.

    Science.gov (United States)

    Takeuchi, Koh; Arthanari, Haribabu; Shimada, Ichio; Wagner, Gerhard

    2015-12-01

    Detection of (15)N in multidimensional NMR experiments of proteins has sparsely been utilized because of the low gyromagnetic ratio (γ) of nitrogen and the presumed low sensitivity of such experiments. Here we show that selecting the TROSY components of proton-attached (15)N nuclei (TROSY (15)NH) yields high quality spectra in high field magnets (>600 MHz) by taking advantage of the slow (15)N transverse relaxation and compensating for the inherently low (15)N sensitivity. The (15)N TROSY transverse relaxation rates increase modestly with molecular weight but the TROSY gain in peak heights depends strongly on the magnetic field strength. Theoretical simulations predict that the narrowest line width for the TROSY (15)NH component can be obtained at 900 MHz, but sensitivity reaches its maximum around 1.2 GHz. Based on these considerations, a (15)N-detected 2D (1)H-(15)N TROSY-HSQC ((15)N-detected TROSY-HSQC) experiment was developed and high-quality 2D spectra were recorded at 800 MHz in 2 h for 1 mM maltose-binding protein at 278 K (τc ~ 40 ns). Unlike for (1)H detected TROSY, deuteration is not mandatory to benefit (15)N detected TROSY due to reduced dipolar broadening, which facilitates studies of proteins that cannot be deuterated, especially in cases where production requires eukaryotic expression systems. The option of recording (15)N TROSY of proteins expressed in H2O media also alleviates the problem of incomplete amide proton back exchange, which often hampers the detection of amide groups in the core of large molecular weight proteins that are expressed in D2O culture media and cannot be refolded for amide back exchange. These results illustrate the potential of (15)NH-detected TROSY experiments as a means to exploit the high resolution offered by high field magnets near and above 1 GHz.

  2. Measurements of Nuclear Masses and HALF-LIVES in the Storage Ring Esr

    Science.gov (United States)

    Klepper, O.; Beckert, K.; Bosch, F.; Eickhoff, H.; Franzke, B.; Fujita, Y.; Geissel, H.; Irnich, H.; Kozhuharov, C.; Kraus, G.; Menzel, G.; Münzenberg, G.; Nickel, F.; Nolden, F.; Reich, H.; Scheidenberger, C.; Schlitt, B.; Schwab, W.; Steck, M.; Sümmerer, K.; Suzuki, K.; Winkler, Th.; Jung, H. C.; Hausmann, M.; Magel, A.; Przewloka, A.; Radon, T.; Wollnik, H.; Beha, T.; Kerscher, Th.; Löbner, K. E. G.; Novikov, Yu.

    Secondary beams of 58Ni, 197Au, and 209Bi fragments have been produced at energies of 200-370 A-MeV by projectile fragmentation, separated with the fragment separator FRS and injected into the storage-cooler ring ESR for mass and half-life measurements. Radioactive beams have also been generated by completely stripping all electrons from 163Dy and 187Re ions to investigate the resulting bound-state β decay. For these studies the revolution frequencies and beam intensities of the stored and cooled unstable nuclei were measured via Schottky spectroscopy. In the 58Ni case the achieved relative momentum spread of 9-10-7 (FWHM) allowed us to resolve the ground and isomeric states of cooled 52Mn and 53Fe. The circulating beams were fully ionized which rendered possible, for the first time, to measure pure β+ branches of ground states (52Fe9, 53Fe9) and the sum of pure β+ and γ branches of isomers (52Mnm, 53Fem). In the experiment with the heavier fragments the main goal was to study nuclei which are members of α-decay chains with unknown masses. We systematically mapped the "mass surface" in the holmium to polonium region from nuclei close to stability up to nuclei with unknown masses as far as their half-lives are ≳ 0.5 min. Relative accuracies for the measured mass values in the order of 1.10-6 and below can be achieved. Via a-decay energies from the literature the "mass surface" up to the proton drip-line can be accessed. Due to the high sensitivity of the Schottky diagnosis also small number of daughter nuclei of stored ions with half-lives up to years can be detected. In this way 187Re was identified as a second case of bound-state β-decay. The status of the on-going analysis of these experiments is presented.

  3. Ultrasound versus high field magnetic resonance imaging in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Tan, York Kiat; Østergaard, Mikkel; Bird, Paul

    2014-01-01

    Over the past decade there have been significant advances in the field of musculoskeletal imaging, especially in the application of ultrasound (US) and magnetic resonance imaging (MRI) to the management of rheumatoid arthritis (RA). Both modalities offer significant advantages over the previous...... standards of clinical examination and radiography, and allow direct visualisation of both joint inflammation and structural damage. Although measuring similar pathology, each of these imaging tools has its own benefits and limitations; understanding these will help researchers and clinicians to determine...

  4. Numerical simulation of screening current distribution in HTS tape of high field magnet

    OpenAIRE

    Itoh, Ryusei; Oga, Yuki; Noguchi, So; Igarashi, Hajime; Ueda, Hiroshi

    2013-01-01

    In recent years, properties of high temperature superconducting (HTS) tapes, especially in-field performance and mechanical strength, have been continuously improved. The HTS tapes have been widely used for high field (>20 T) magnet researches and there are several technical challenges including field attenuation of an HTS magnet by screening currents induced within the HTS tapes. Several publications reported that the screening currents, induced by penetration of self magnetic fields into HT...

  5. Suitability of thermoluminescence, chemiluminescence, ESR and viscosity measurements as detection method for the irradiation of medicinal herbs; Eignung von Thermolumineszenz-, Chemilumineszenz-, ESR- und Viskositaetsmessungen zur Identifizierung strahlenbehandelter Arzneidrogen

    Energy Technology Data Exchange (ETDEWEB)

    Schuettler, C.; Gebhardt, G.; Stock, A.; Helle, N.; Boegl, K.W.

    1993-12-31

    Chemiluminescence, electron spin resonance, thermoluminescence and viscosity measurements have been investigated for their suitability as detection method for the irradiation of the medicinal herbs anise seeds (anisi fructus), valerian roots (valerianae radix), redberry leaves (uvae ursi folium), birch leaves (betulae folium), greek hay seeds (foenugraeci semen), cayenne pepper (capsici fructus acer), black-aldertee bark (frangulae cortex), fennel fruits (feoniculi fructus), rose hip shells (cynosbati fructus), coltsfoot (farfarae folium), acorus roots (calami rhizoma), chamomile flowers (matricariae flos), caraway (carvi fructus), lavender flowers (lavandulae flos), linseed (lini semen), lime tree flowers (tiliae flos), St. Mary`s thistle fruit (cardui mariae herba), lemon balm (melissae folium), java tea (orthosiphonis folium), peppermint (menthae piperitae folium), sage leaves (salviae folium), scouring rush (equiseti herba), senna leaves (sennae folium), plantain herbs (plantaginis lanceolata herba), thyme herbs (thymi herba), juniper berries (juniperi fructus), hawthorne herbs (crataegi folium), wheat starch (amylum tritici) and wormwood (absinthii herba). Depending on the herbs, the methods used were more or less suitable. Chemiluminescence measurements showed the smallest differences between untreated and irradiated samples whereas thermoluminescence measurements on isolated minerals from the vegetable drugs gave better results. In some herbs radiation-specific radicals could be identified by ESR spectroscopy. Viscosity measurement is suitable for some herbs as fast and inexpensive method for screening. (orig.) [Deutsch] Die Eignung von Chemilumineszenz-, ESR-, Thermolumineszenz- und Viskositaetsmessungen als Nachweismethode fuer die Behandlung von Arzneidrogen mit ionisierenden Strahlen wurde an Anis, Baldrianwurzel, Baerentraubenblaettern, Birkenblaettern, Bockshornsamen, Cayennepfeffer, Faulbaumrinde, Fenchel, Hagebuttenschalen, Huflattichblaettern

  6. High-field conductor testing at the FENIX facility

    Science.gov (United States)

    Shen, S. S.; Chaplin, M. R.; Felker, B.; Hassenzahl, W. V.; Kishiyama, K. I.; Parker, J. M.

    1993-04-01

    The Fusion Engineering International experiments (FENIX) Test Facility, which was commissioned at the end of 1991, is the first facility in the world capable of testing prototype conductors for the International Thermonuclear Experimental Reactor (ITER) superconducting magnets. The FENIX facility provides test conditions that simulate the ITER magnet operating environment; more importantly, it also accommodates specific experiments to determine the operational margins for the prototype conductors. The FENIX facility generates magnetic fields close to 14 T, and transport currents over 40 kA for testing the prototype conductors. This paper describes an experimental program that measures critical currents, current-sharing temperatures, forced-flow properties, and cyclic effects.

  7. High-field (high-frequency) EPR spectroscopy and structural characterization of a novel manganese(III) corrole

    OpenAIRE

    Bendix, Jesper; Gray, Harry B.; Golubkov, Galina; Gross, Zeev

    2000-01-01

    The X-ray structure, magnetic susceptibility, and high-field (high-frequency) EPR spectrum of manganese 5,10,15-tris(pentafluorophenyl) corrole unambiguously establish that the complex contains an isolated, slightly rhombic, manganese(III) center.

  8. High Field Studies for CLIC Accelerating Structures Development

    CERN Document Server

    Profatilova, I

    2017-01-01

    Compact Linear Collider RF structures need to be able to achieve the very high average accelerating gradient of 100 MV/m. One of the main challenges in reaching such high accelerating gradients is to avoid vacuum electrical breakdown within CLIC accelerating structures. Accelerating structure tests are carried out in the klystron-based test stands known as the XBoxes. In order to investigate vacuum breakdown phenomena and its statistical characteristics in a simpler system and get results in a faster way, pulsed dc systems have been developed at CERN. To acquire sufficient breakdown data in a reasonable period of time, high repetition rate pulse generators are used in the systems for breakdown studies, so-called pulsed dc system. This paper describes the pulsed dc systems and the two high repetition rate circuits, which produce high-voltage pulses for it, available at CERN.

  9. Modelling high arctic percent vegetation cover using field digital images and high resolution satellite data

    Science.gov (United States)

    Liu, Nanfeng; Treitz, Paul

    2016-10-01

    In this study, digital images collected at a study site in the Canadian High Arctic were processed and classified to examine the spatial-temporal patterns of percent vegetation cover (PVC). To obtain the PVC of different plant functional groups (i.e., forbs, graminoids/sedges and mosses), field near infrared-green-blue (NGB) digital images were classified using an object-based image analysis (OBIA) approach. The PVC analyses comparing different vegetation types confirmed: (i) the polar semi-desert exhibited the lowest PVC with a large proportion of bare soil/rock cover; (ii) the mesic tundra cover consisted of approximately 60% mosses; and (iii) the wet sedge consisted almost exclusively of graminoids and sedges. As expected, the PVC and green normalized difference vegetation index (GNDVI; (RNIR - RGreen)/(RNIR + RGreen)), derived from field NGB digital images, increased during the summer growing season for each vegetation type: i.e., ∼5% (0.01) for polar semi-desert; ∼10% (0.04) for mesic tundra; and ∼12% (0.03) for wet sedge respectively. PVC derived from field images was found to be strongly correlated with WorldView-2 derived normalized difference spectral indices (NDSI; (Rx - Ry)/(Rx + Ry)), where Rx is the reflectance of the red edge (724.1 nm) or near infrared (832.9 nm and 949.3 nm) bands; Ry is the reflectance of the yellow (607.7 nm) or red (658.8 nm) bands with R2's ranging from 0.74 to 0.81. NDSIs that incorporated the yellow band (607.7 nm) performed slightly better than the NDSIs without, indicating that this band may be more useful for investigating Arctic vegetation that often includes large proportions of senescent vegetation throughout the growing season.

  10. Flow field design for high-pressure PEM electrolysis cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian; Kær, Søren Knudsen

    micro-channels and porous media, our research group has developed an Euler-Euler model in the computational fluid dynamics modelling framework of ANSYS CFX. In addition to two-phase flow, the model accounts for turbulence, species transport in the gas phase, heat transport in all three phases (i......With the increasing interest in producing hydrogen through water electrolysis, the importance of understanding the transport phenomena governing its operation increases. To ensure optimal operating conditions for PEM electrolysis, it is particularly important to understand how the liquid feed.......e. solid, gas and liquid), as well as charge transport of electrons and ions. Our recent improvements have focused on the models ability to account for phase change and electrochemistry as well as the modelling of two-phase flow regimes. For comparison, an interdigitated and parallel channel flow field...

  11. High field magnet program at Brookhaven National Laboratory

    CERN Document Server

    Ghosh, A; Muratore, J; Parker, B; Sampson, W; Wanderer, P J; Willen, E

    2000-01-01

    The magnet program at Brookhaven National Laboratory (BNL) is focussed on superconducting magnets for particle accelerators. The effort includes magnet production at the laboratory and in industry, magnet R&D, and test facilities for magnets and superconductors. Nearly 2000 magnets-dipoles, quadrupoles, sextupoles and correctors for the arc and insertion regions-were produced for the Relativistic Heavy Ion Collider (RHIC), which is being commissioned. Currently, production of helical dipoles for the polarized proton program at RHIC, insertion region dipoles for the Large Hadron Collider (LHC) at CERN, and an insertion magnet system for the Hadron-Elektron-Ring- Analage (HERA) collider at Deutsches Elektronen-Synchrotron (DESY) is underway. The R&D effort is exploring dipoles with fields above 10 T for use in post-LHC colliders. Brittle superconductors-Nb/sub 3/Sn or HTS-are being used for these magnets. The superconductor test facility measures short-sample currents and other characteristics of sample...

  12. New high dielectric constant materials for tailoring the B1+ distribution at high magnetic fields.

    Science.gov (United States)

    Haines, K; Smith, N B; Webb, A G

    2010-04-01

    The spatial distribution of electromagnetic fields within the human body can be tailored using external dielectric materials. Here, we introduce a new material with high dielectric constant, and also low background MRI signal. The material is based upon metal titanates, which can be made into a geometrically-formable suspension in de-ionized water. The material properties of the suspension are characterized from 100 to 400 MHz. Results obtained at 7 T show a significant increase in image intensity in areas such as the temporal lobe and base of the brain with the new material placed around the head, and improved performance compared to purely water-based gels. 2010 Elsevier Inc. All rights reserved.

  13. High Frequency Electromagnetic Field Induces Lipocalin 2 Expression in

    Directory of Open Access Journals (Sweden)

    Amaneh Mohammadi Roushandeh

    2010-06-01

    Full Text Available Objective(sNeutrophil gelatinase-associated lipocalin (NGAL/Lcn2, comprise a group of small extracellular proteins with a common β-sheet-dominated 3-dimensional structure. In the past, it was assumed that the predominant role of lipocalin was acting as transport proteins. Recently it has been found that oxidative stress induces Lcn2 expression. It has been also proved that electromagnetic field (EMF produces reactive oxygen species (ROS in different tissues. Expression of Lcn2 following exposure to electromagnetic field has been investigated in this study. Materials and MethodsBalb/c mice (8 weeks old were exposed to 3 mT, 50 HZ EMF for 2 months, 4 hr/day. Afterwards, the mice were sacrificed by cervical dislocation and livers were removed. The liver specimens were stained with Haematoxylin- Eosin (H&E and analyzed under an optical microscope. Total RNA was extracted from liver and reverse transcription was performed by SuperScript III reverse transcriptase with 1 µg of total RNA. Assessment of Lcn2 expression was performed by semiquantitative and real time- PCR.ResultsThe light microscopic studies revealed that the number of lymphocyte cells was increased compared to control and dilation of sinosoids was observed in the liver. Lcn2 was up-regulated in the mice exposed to EMF both in mRNA and protein levels.ConclusionTo the extent of our knowledge, this is the first report dealing with up-regulation of Lcn2 in liver after exposure to EMF. The up-regulation might be a compensatory response that involves cell defense pathways and protective effects against ROS. However, further and complementary studies are required in this regards.

  14. Continuous online field deployable high precision and high resolution water isotope analysis from ice cores

    Science.gov (United States)

    Gkinis, Vasileios; Popp, Trevor; Johnsen, Sigfus; Blunier, Thomas; Stowasser, Christopher; Kettner, Ernesto

    2010-05-01

    One of the most important features of ice cores as climate and atmospheric paleoarchives is their potential for high temporal resolution. The measurement of chemical impurities in ice cores that fully exploits this high resolution has become standard with the advent of Continuous Flow Analysis (CFA) from continuously melted ice core segments, often performed in the field. Meanwhile, the measurement of water stable isotopic composition (deuterium and oxygen-18) continues, for the most part, to be performed offline via discrete sampling with traditional mass spectroscopy. These offline procedures are time consuming, expensive, and do not fully exploit the temporal resolution available in the ice core. Here we describe a new method and the first results for the determination of water isotopic content measured from a continuous melted rod with a commercially available near-infrared cavity ring down spectrometer (CRDS; http://www.picarro.com/) coupled to a CFA system both in the field on the Greenland ice sheet and in the laboratory. For the measurement of water isotopes a carefully controlled fraction of the CFA melt stream is evaporated directly into the laser cavity for simultaneous analysis of both deuterium and oxygen-18 content. The details of the system have been tested with a deployment to the North Greenland Eemian Ice Drilling (NEEM) coupled to the University of Bern CFA system and in the laboratory with NGRIP ice coupled to the University of Copenhagen CFA system. The results show that the system already produces the highest interpretable resolution records that are comparable or somewhat less precise than traditional mass spectroscopy discrete sample methods. The enormous potential of the system is being realized in the density and resolution of the produced records in connection with other highly resolved series (e.g. chemical impurities), and also in the efficiency by which the records can be produced. Among other things, time series from this type of

  15. Field Evidence for a Low Permeability, High Storage Fault Core at the Santa Susana Field Laboratory

    Science.gov (United States)

    Allègre, V.; Brodsky, E. E.; Parker, B. L.; Cherry, J. A.

    2015-12-01

    In situ measurements of hydrogeologic properties within fault zones are few, in part because of the challenges of measuring the scale-dependent quantities in fractured rock reservoirs. This work aims to fill the gap by utilizing a combination of tidal, barometric and seismic response analyses on pressure head time-series from the Santa Susana Field Laboratory in Southern California. The techniques sample different effective volumes and so allow us to investigate the scale-dependent structure near fault zones. Permeability and specific storage were inverted from tidal response at 14 locations, and specific storage was also computed from barometric efficiencies at 10 locations. In addition, we computed hydro-seismic transfer functions after nine local earthquakes and teleseismic events. We found that permeability computed from tidal response are quite homogeneous within about one and a half orders of magnitude over the site regardless of the presence of moderate to large faults. This result is consistent with the earlier aquifer tests using standard methods. The tidal responses also showed higher variability of specific storage inside the fault zones suggesting that fault damage zone generates a storage architecture. The storage from the tidal responses can be consistently interpreted for the tidal, barometric and seismic responses. However, the observations require that the permeability inside the fault zones at the spatial scale of the seismic response (~meters) is much lower than at the spatial scale of the tidal response (~10's of meters). The result suggests possible sensitivity to the low permeability fault core, which has been historically difficult to measure at the field scale.

  16. Nature of the Background Ultraviolet Radiation Field at High Redshifts

    Indian Academy of Sciences (India)

    tribpo

    thus necessary for the understanding of the early universe. AGNs are believed to be the major ... This ratio is insensitive to the particle density and the abundance of carbon, but is very sensitive to the ..... assuming the rest of the required flux to be of local, galactic origin, very high galactic flux is required. For most of the ...

  17. Bottom mounted seabed mooring frame for high current field

    Digital Repository Service at National Institute of Oceanography (India)

    AshokKumar, K.; Chandramohan, P.; Pednekar, P.S.; Diwan, S.G.

    and direction on the sea surface and at a fixed five layers. The company supplied frame was not suitable to use at the proposed measurement location, owing to random oscillation in the seabed, strong currents and high concentration of sediments in the water...

  18. Physical processes in high field insulating liquid conduction

    Science.gov (United States)

    Mazarakis, Michael; Kiefer, Mark; Leckbee, Joshua; Anderson, Delmar; Wilkins, Frank; Obregon, Robert

    2017-10-01

    In the power grid transmission where a large amount of energy is transmitted to long distances, High Voltage DC (HVDC) transmission of up to 1MV becomes more attractive since is more efficient than the counterpart AC. However, two of the most difficult problems to solve are the cable connections to the high voltage power sources and their insulation from the ground. The insulating systems are usually composed of transformer oil and solid insulators. The oil behavior under HVDC is similar to that of a weak electrolyte. Its behavior under HVDC is dominated more by conductivity than dielectric constant. Space charge effects in the oil bulk near high voltage electrodes and impeded plastic insulators affect the voltage oil hold-off. We have constructed an experimental facility where we study the oil and plastic insulator behavior in an actual HVDC System. Experimental results will be presented and compared with the present understanding of the physics governing the oil behavior under very high electrical stresses. Sandia National Laboratories managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. D.O.E., NNSA under contract DE-NA-0003525.

  19. Cold induced peripheral vasodilation at high altitudes- a field study

    NARCIS (Netherlands)

    Daanen, H.A.M.; Ruiten, H.J.A. van

    2000-01-01

    A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects

  20. Field experimental observations of highly graded sediment plumes

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina; Jimenez, Carlos

    2015-01-01

    , gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in the water column, and facing the plume at different angles. The processes were captured using GoPro-Hero-series cameras. The high-quality underwater footage from near-surface, mid-depth and near...

  1. Generation of Unprecedented high Electric Fields with Pyroelectric Crystals

    Science.gov (United States)

    Crimi, Sarah; Tornow, Werner; Corse, Zach

    2009-10-01

    Since a few years pyroelectric crystals in a deuterium gas environment have been used to produce neutrons via the ^2H(d,n)^3He reaction. The figure-of-merit for neutron production in the energy region of interest is about IE^3/2, where I is the deuterium ion current and E is the associated ion energy. Therefore, it is important to maximize E. Using single and double crystal arrangements with electric field enhancing nano-tips, the highest positive potentials reported in the literature were 115 keV [1] and 250 keV [2], respectively. Using longer LiTaO3 crystals than commonly employed (2.5 cm versus 1.0 cm) and without attaching a nano-tip, we have produced positive deuterium ion beams of energies up to 325 keV with a single crystal during the cooling phase from 130 ^oC to 0 ^oC. In a double crystal arrangement we have obtained positive ion energies of up to 390 keV. Details of our experimental approach will be presented.[4pt] [1] B. Naranjo et al., Nature 434, 1115 (2005).[0pt] [2] D. Gillich et al., Nucl. Instr. Meth. in Phys. Res. A 602, 306 (2009).

  2. Pelvic endometriosis: a comparison between low-field (0.2 T) and high-field (1.5 T) magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Minaif, Karine; Ajzen, Sergio [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis]. E-mail: kminaif@uol.com.br; Shigueoka, David Carlos; Minami, Cintia Cristina Satie; Sales, Danilo Moulin; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis. Unit of Abdomen; Ruano, Jose Maria Cordeiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of General Gynecology. Sector of Videlaparoscopy; Noguti, Alberto Sinhiti [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of General Gynecology

    2008-11-15

    Objective: to compare low-field (0.2 T) with high-field (1.5 T) magnetic resonance imaging in the assessment of pelvic endometriosis and adenomyosis. Materials and methods: twenty-seven female patients with clinically suspected endometriosis were prospectively evaluated by means of high-field and low-field magnetic resonance imaging. The reading of the images was performed by a single radiologist, initiating by the low-field, followed by the high-field images. High-field magnetic resonance imaging was utilized as the golden-standard. Results: among the 27 patients included in the present study, 18 (66.7%) had some type of lesion suggesting the presence of endometriosis demonstrated at high-field images. In 14 of these patients the diagnosis was correctly established by low-field magnetic resonance imaging. Endometriomas, tubal lesions, and endometriotic foci > 7 mm identified at the high-field images were also identified at low-field images with 100% accuracy, sensitivity and specificity. Among the nine patients diagnosed with adenomyosis by high-field images, eight were correctly diagnosed by low-field images with 88.9% accuracy, specificity and sensitivity. Conclusion: low-field magnetic resonance imaging demonstrated a low sensitivity in the detection of small endometriotic foci, high sensitivity in the detection of endometriomas and large endometriotic foci, and high accuracy in the detection of adenomyosis when compared with high-field magnetic resonance imaging. (author)

  3. Behavior of Rubber Materials under Exposure to High Electric Fields

    DEFF Research Database (Denmark)

    Candela Garolera, Anna; Holbøll, Joachim; Henriksen, M,

    2013-01-01

    The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence of the inte......The effect of high electrical stress on rubber materials is investigated by performing breakdown tests and tracking resistance tests on selected samples. The study is focused on the relationship between the dielectric strength and the thickness of the samples, as well as the influence...... of the interfaces between different layers of material. Tracking resistance tests are also performed on the rubber material. The purpose is to provide a complete study of the applicability of the rubber material in thunderstorm environments....

  4. Ultra-High Intensity Magnetic Field Generation in Dense Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, Nathaniel J. [Princeton Univ., NJ (United States)

    2014-01-08

    The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereas the efficient generation of electric current in low-­energy-­density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­energy-­density plasma the ideas for steady-­state current drive developed for low-­energy-­density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­energy-­density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new forms of current drive in regimes appropriate for new fusion concepts.

  5. Superconductor Requirements and Characterization for High Field Accelerator Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Barzi, E.; Zlobin, A. V.

    2015-05-01

    The 2014 Particle Physics Project Prioritization Panel (P5) strategic plan for U.S. High Energy Physics (HEP) endorses a continued world leadership role in superconducting magnet technology for future Energy Frontier Programs. This includes 10 to 15 T Nb3Sn accelerator magnets for LHC upgrades and a future 100 TeV scale pp collider, and as ultimate goal that of developing magnet technologies above 20 T based on both High Temperature Superconductors (HTS) and Low Temperature Superconductors (LTS) for accelerator magnets. To achieve these objectives, a sound conductor development and characterization program is needed and is herein described. This program is intended to be conducted in close collaboration with U.S. and International labs, Universities and Industry.

  6. Electrochemical and ESR study of 5-nitrofuryl-containing thiosemicarbazones antiprotozoal drugs.

    Science.gov (United States)

    Rigol, Carolina; Olea-Azar, C; Mendizábal, Fernando; Otero, Lucía; Gambino, Dinorah; González, Mercedes; Cerecetto, Hugo

    2005-10-01

    Cyclic voltammetry and electron spin resonance (ESR) techniques were used in the investigation of several potential antiprotozoal thiosemicarbazones nitrofurane derivatives. A self-protonation process involving the protonation of the nitro group due to the presence of an acidic proton in the thiosemicarbazone moiety was observed in the first step of a CEE(rev) reduction mechanism of these derivatives. ESR spectra of the free radicals obtained by electrolytic reduction were characterized and analyzed. AM1 methodology was used to obtain the optimized geometries and UB3LYP calculations were performed to obtain the theoretical hyperfine coupling constants. The theoretical study exhibited an unusual assignment of the spin densities showing a free radical centered in the thiosemicarbazone moiety rather than the nitro which are in agreement with the experimental hyperfine pattern.

  7. ESR study of advanced materials with new parameters frequency and pressure

    CERN Document Server

    Mizoguchi, K

    2000-01-01

    It is well known that electron spin resonance (ESR) is a useful technique to investigate the magnetic properties of electrons in condensed matter. The frequency, as an additional parameter to the temperature, gives us the possibility to study the anisotropic dynamics of charge carriers with spin, even in polycrystalline materials. Furthermore, the pressure provides us a way to discuss how interactions between the electrons and their environments are responsible for the novel physical properties in these advanced materials, such as ferromagnetisms, charge-density waves, superconductivity, and so on. Results obtained by using ESR with these parameters are overviewed. Studies as a function of the frequency are demonstrated, especially for the conductive polymers, polyacetylene, polyaniline, and polypyrrole with various dopants for which single crystals are not available yet. Alkali-electro-sodalite (AES), a kind of zeolite with a regular electron lattice known as an s-electron Mott insulator, and fullerene compo...

  8. ESR and spectral studies of Er{sup 3+} ions in soda-lime silicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Kaewwiset, W., E-mail: opticslaser@yahoo.com [Department of Physics, Faculty of Science, King Mongkut' s University of Technology, Thonburi, Bangkok 10140 (Thailand); Thamaphat, K. [Department of Physics, Faculty of Science, King Mongkut' s University of Technology, Thonburi, Bangkok 10140 (Thailand); Kaewkhao, J. [Center of Excellence in Glass Technology and Materials Science (CEGM), Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000 (Thailand); Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400 (Thailand); Limsuwan, P. [Department of Physics, Faculty of Science, King Mongkut' s University of Technology, Thonburi, Bangkok 10140 (Thailand); Thailand Center of Excellence in Physics, CHE, Ministry of Education, Bangkok 10400 (Thailand)

    2013-01-15

    Electron spin resonance (ESR), optical absorption spectra and photoluminescence spectra of Er{sup 3+} ions in soda-lime silicate glasses doped with different concentrations of Er{sub 2}O{sub 3} have been studied. The glasses of the composition (in mol%) (65-x)SiO{sub 2}:25Na{sub 2}O:10CaO:xEr{sub 2}O{sub 3} (where x=0.02, 0.05, 0.1, 0.3, 0.5, 1, 2, 3, 4 and 5) were prepared by the melt quenching method. ESR measurements were carried out at room temperature down to 1.62 K. Absorption spectra were investigated in the UV-VIS-NIR region from 300 to 1800 nm. Photoluminescence spectra were observed in the spectral range 500-800 nm under 514.5 nm argon-ion laser line excitation.

  9. [Analysis of ESR spectra in Mn2+-plant adenylate kinase complex].

    Science.gov (United States)

    Kharatian, S A; Kaiushin, L P

    1981-01-01

    Interaction of plant adenylate kinase with Mn2+-adenine nucleotide binary complex was studied by ESR technique at room temperature. The ligand environment of Mn2+ in the ternary Mn2+-adenine nucleotide-enzyme complex was shown to change, as a result of enzyme binding as compared with that of binary complex. These changes seem to be due to substitution of protein molecules for water and adenine nucleotide ones, coordinated to Mn2+ ion on ternary complex formation. The same results were obtained in ESR studies on rabbit muscle myokinase. This fact may be considered as an evidence, that plant adenylate kinase is identical to animal one in its interaction with adenine nucleotides and manganese ions.

  10. ESR (electron spin resonance)-determined osmotic behavior of bull spermatozoa

    Energy Technology Data Exchange (ETDEWEB)

    Du, J.; Kleinhans, F.W.; Spitzer, V.J.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA). Dept. of Medical Research); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine); Mazur, P. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    Our laboratories are pursuing a fundamental approach to the problems of semen cryopreservation. For many cell types (human red cells, yeast, HeLa) it has been demonstrated that there is an optimum cooling rate for cryopreservation. Faster rates allow insufficient time for cell dehydration and result in intracellular ice formation and cell death. It is possible to predict this optimal rate provided that the cell acts as an ideal osmometer and several other cell parameters are known such as the membrane hydraulic conductivity. It is the purpose of this work to examine the osmotic response of bull sperm to sucrose and NaCl utilizing electron spin resonance (ESR) to measure cell volume. For calibration purposes we also measured the ESR response of human red cells (RBC), the osmotic response of which is well documented with other methods. 15 refs., 1 fig.

  11. Insights on copper coordination and reactivity of endonuclease EcoRI by ESR spectroscopy and modeling

    Science.gov (United States)

    Ji, Ming

    2009-03-01

    The cleavage of DNA by restriction endonuclease EcoRI is catalyzed by metal ions such as Mg^2+. However, Cu^2+ does not catalyze the cleavage of DNA by EcoRI. In order to understand the functional difference between Cu^2+ and Mg^2+, coordination of Cu^2+ in the EcoRI--DNA complex was clarified by ESR and MD simulation. There are two Cu^2+ components in the specific EcoRI-DNA complex. Each component has one N atom from histidine imidazole and one oxygen atom from the phosphate backbone of DNA coordinate to Cu^2+ based on the ESR experimental results. MD simulation further confirmed that the Nδ atom of His114 imidazole and one oxygen atom from the phosphate backbone of DNA coordinate to Cu^2+. Difference in the coordination of Cu^2+ and Mg^2+ explains their different functional behaviors.

  12. Investigation of Estrogen Receptor (ESR1 for Breast Cancer from Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Tzu-Chieh Hung

    2014-01-01

    Full Text Available Recently, an important topic of breast cancer had been published in 2013. In this report, estrogen receptor (ESR1 had defined the relation of hormone-cause breast cancer. The screening of traditional Chinese medicine (TCM database has found the molecular compounds by simulating molecular docking and molecular dynamics to regulate ESR1. S-Allylmercaptocysteine and 5-hydroxy-L-tryptophan are selected according to the highest docking score than that of other TCM compounds and Raloxifene (control. The simulation from molecular dynamics is helpful in analyzing and detecting the protein-ligand interactions. After a comparing the control and the Apo form, then based on the docking poses, hydrophobic interactions, hydrogen bond and structure variations, this research postulates that S-allylmercaptocysteine may be more appropriate than other compounds for protein-ligand interaction.

  13. Gendered Fields: Sports and Advanced Course Taking in High School

    OpenAIRE

    Pearson, Jennifer; Crissey, Sarah R.; Riegle-Crumb, Catherine

    2009-01-01

    This study explores the association between sports participation and course taking in high school, specifically comparing subjects with varied gendered legacies—science and foreign language. Analyses of a nationally representative longitudinal sample (N=5,447) of U.S. adolescents from the National Longitudinal Study of Adolescent Health and the linked Adolescent Health and Academic Achievement transcript study show that male and female athletes are more likely than non-athletes to take both a...

  14. Field manual for identifying and preserving high-water mark data

    Science.gov (United States)

    Feaster, Toby D.; Koenig, Todd A.

    2017-09-26

    This field manual provides general guidance for identifying and collecting high-water marks and is meant to be used by field personnel as a quick reference. The field manual describes purposes for collecting and documenting high-water marks along with the most common types of high-water marks. The manual provides a list of suggested field equipment, describes rules of thumb and best practices for finding high-water marks, and describes the importance of evaluating each high-water mark and assigning a numeric uncertainty value as part of the flagging process. The manual also includes an appendix of photographs of a variety of high-water marks obtained from various U.S. Geological Survey field investigations along with general comments about the logic for the assigned uncertainty values.

  15. ESR (Electroslag Refining) Steel Deoxidation and Slag Practice - Influence on Inclusion Morphology,

    Science.gov (United States)

    1984-01-01

    instances the globular type D inclusions were < 6-9 pm in diamete -& similar to the modified inclusion types observed after conventional calcium ladle ...inclusion types observed after conventional calcium ladle modification. The exceptional desulphurizing ability of slags containing rare earth oxides...solidification. The absence of refractory materials ensures that only inclusions of the latter type are found in electroslag refined (ESR) steels

  16. Study of one-dimensional electron hopping and its effects on ESR line shape

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jau [Argonne National Lab., IL (United States); Dikshit, S.N. [Univ. of Chicago, IL (United States). Dept. of Chemistry; Norris, J.R. [Argonne National Lab., IL (United States)]|[Univ. of Chicago, IL (United States). Dept. of Chemistry

    1997-08-01

    Random hopping processes between discrete sites along a finite open chain or around a closed finite loop are examined. Closed form formulae are prescribed for the dependence of the ESR (electron spin resonance) line shape on the chain length and hopping rate. Significant differences between the closed loop and open chain are demonstrated. Deviation at short time from the results of diffusion in a continuum is presented.

  17. ESR2 Genetic Variants and Combined Oral Contraceptive Use Associated with the Risk of Stroke.

    Science.gov (United States)

    Xu, Zhenlin; Li, Ying; Huang, Xiaoping; Shen, Wei; Bai, Jianling; Shen, Chong; Zhao, Yang

    2017-02-01

    There is accumulating evidence suggesting an important role of estrogen receptor-β in the development of cardiovascular disease. The present study aims to investigate the relationship of estrogen receptor β gene (ESR2) polymorphisms with stroke risk in Chinese women, and further evaluate the gene-environment interaction of ESR2 and combined oral contraceptive (COC) use on stroke risk. A case-control study was conducted with 446 first-ever stroke patients and 864 control subjects recruited from our prospective female cohort. Four polymorphisms of ESR2 gene were genotyped, and the information of contraceptive use was obtained by a face-to-face interview. Women with rs1256065 CC genotype were at a 1.59 fold increased risk of stroke. Subtype analyses showed that the risk genotype of rs1256065 was associated with ischemic stroke, but not with hemorrhagic stroke. AA genotype of rs4986938 showed a significant correlation with an elevated risk of hemorrhagic stroke. COC users with rs1256065 CC genotype had a 2.36 fold increased risk of stroke, compared with the non-users with the wild-type genotype. Moreover, a significant multiplicative interaction on hemorrhagic stroke was detected between COC use and rs4986938 (pinteraction = 0.023). The risk of hemorrhagic stroke was significantly elevated among carriers of rs4986938 GA or AA genotype combined with COC use. No associations were observed for rs1256049 and rs1271572. ESR2 genetic polymorphisms were associated with the risk of first-ever stroke in Chinese women, and the AA genotype of rs4986938 combined with COC use could significantly increase the risk of hemorrhagic stroke. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  18. Evaluation of the Relative Hydrogen Embrittlement Susceptibility of ESR 4340 and Its Heat Treat Distortion Properties

    Science.gov (United States)

    1982-09-01

    of a tensile load. This was accomplished by modifying a special loading fixture developed at METTEK Laboratories for Charpy -sized specimens. Two...with regard to ballistic impact resistance, it becomes advisable to direct a program at improving the resistance of ESR steels to hydrogen...30332 1 ATTN: Dr. J. T. Berry Lukens Steel Company, Coatesville, PA 19320 1 ATTN: Dr. R. S. Swift Republic Steel Corporation, 410 Oberlin Avenue

  19. The use of ESR spectroscopy for the investigation of dosimetric properties of egg shells

    Energy Technology Data Exchange (ETDEWEB)

    Engin, Birol E-mail: bengin@taek.gov.tr; Demirtas, Hayruennisa

    2004-12-01

    Electron spin resonance (ESR) spectroscopy was used to investigate the dosimetric properties of chicken egg shells. The ESR spectra of the irradiated egg shell were found to have an asymmetric absorption characterized by a major resonance at g{sub perpendicular}=2.0019 and a minor resonance at g{sub ||}=1.9980. The study was carried out on g{sub perpendicular}=2.0019 signal because of the accuracy of measurements and the possibility of using it as ESR dosimeter. The activation energy (E), frequency factor (k{sub 0}) and mean-life ({tau}) were calculated to be 1.50{+-}0.10 eV, 2x10{sup 13} s{sup -1} and (4.4{+-}0.4)x10{sup 4} year respectively. Dose-response was investigated between dose ranges of 1 Gy and 10 kGy for {sup 60}Co {gamma}-rays. Dose-response was found to be appropriate for dosimetry in the range 3 Gy to 10 kGy. The lower limit of observable doses for egg shell sample was about 3 Gy. The other ESR dosimetric parameters of egg shell samples, fading characteristic, light effect, dose-rate dependence and energy dependence, have also been studied in detail. Apart from its non-tissue equivalence, egg shell has very good dosimetric properties with insignificant fading, light independence, linearity in dose-response (3 Gy-10 kGy), dose-rate independence and independence from energy above 500 keV. It suggests that egg shell may be used as a retrospective {gamma} radiation dosimetry after nuclear accidents or other short accidental radiation events.

  20. Electrogenic steps of light-driven proton transport in ESR, a retinal protein from Exiguobacterium sibiricum.

    Science.gov (United States)

    Siletsky, Sergey A; Mamedov, Mahir D; Lukashev, Evgeniy P; Balashov, Sergei P; Dolgikh, Dmitriy A; Rubin, Andrei B; Kirpichnikov, Mikhail P; Petrovskaya, Lada E

    2016-11-01

    A retinal protein from Exiguobacterium sibiricum (ESR) functions as a light-driven proton pump. Unlike other proton pumps, it contains Lys96 instead of a usual carboxylic residue in the internal proton donor site. Nevertheless, the reprotonation of the Schiff base occurs fast, indicating that Lys96 facilitates proton transfer from the bulk. In this study we examined kinetics of light-induced transmembrane electrical potential difference, ΔΨ, generated in proteoliposomes reconstituted with ESR. We show that total magnitude of ΔΨ is comparable to that produced by bacteriorhodopsin but its kinetic components and their pH dependence are substantially different. The results are in agreement with the earlier finding that proton uptake precedes reprotonation of the Schiff base in ESR, suggesting that Lys96 is unprotonated in the initial state and gains a proton transiently in the photocycle. The electrogenic phases and the photocycle transitions related to proton transfer from the bulk to the Schiff base are pH dependent. At neutral pH, they occur with τ 0.5ms and 4.5ms. At alkaline pH, the fast component ceases and Schiff base reprotonation slows. At pH8.4, a spectrally silent electrogenic component with τ 0.25ms is detected, which can be attributed to proton transfer from the bulk to Lys96. At pH5.1, the amplitude of ΔΨ decreases 10 fold, reflecting a decreased yield and rate of proton transfer, apparently from protonation of the acceptor (Asp85-His57 pair) in the initial state. The features of the photoelectric potential generation correlate with the ESR structure and proposed mechanism of proton transfer. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Low temperature superconductor and aligned high temperature superconductor magnetic dipole system and method for producing high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh; Scanlan, Ronald; Ghosh, Arup K.; Weggel, Robert J.; Palmer, Robert; Anerella, Michael D.; Schmalzle, Jesse

    2017-10-17

    A dipole-magnet system and method for producing high-magnetic-fields, including an open-region located in a radially-central-region to allow particle-beam transport and other uses, low-temperature-superconducting-coils comprised of low-temperature-superconducting-wire located in radially-outward-regions to generate high magnetic-fields, high-temperature-superconducting-coils comprised of high-temperature-superconducting-tape located in radially-inward-regions to generate even higher magnetic-fields and to reduce erroneous fields, support-structures to support the coils against large Lorentz-forces, a liquid-helium-system to cool the coils, and electrical-contacts to allow electric-current into and out of the coils. The high-temperature-superconducting-tape may be comprised of bismuth-strontium-calcium-copper-oxide or rare-earth-metal, barium-copper-oxide (ReBCO) where the rare-earth-metal may be yttrium, samarium, neodymium, or gadolinium. Advantageously, alignment of the large-dimension of the rectangular-cross-section or curved-cross-section of the high-temperature-superconducting-tape with the high-magnetic-field minimizes unwanted erroneous magnetic fields. Alignment may be accomplished by proper positioning, tilting the high-temperature-superconducting-coils, forming the high-temperature-superconducting-coils into a curved-cross-section, placing nonconducting wedge-shaped-material between windings, placing nonconducting curved-and-wedge-shaped-material between windings, or by a combination of these techniques.

  2. A new support structure for high field magnets

    CERN Document Server

    Hafalia, R R; Caspi, S; Dietderich, D R; Gourlay, S A; Hannaford, R; Lietzke, A F; Liggins, N; McInturff, A D; Sabbi, G L; Scanlan, R M; O'Neill, J; Swanson, J H

    2002-01-01

    Pre-stress of superconducting magnets can be applied directly through the magnet yoke structure. We have replaced the collar functionality in our 14 Tesla R&D Nb//3Sn dipole magnets with an assembly procedure based on an aluminum shell and bladders. Bladders, placed between the coil pack and surrounding yoke inside the shell, are pressurized up to 10 ksi left bracket 70 MPa right bracket to create an interference gap. Keys placed into the interference gap replace the bladder functionality. Following the assembly, the bladders are deflated and removed. Strain gauges mounted directly on the shell are used to monitor the stress of the entire magnet structure, thereby providing a high degree of pre-stress control without the need for high tolerances. During assembly, a force of 8.2 multiplied by 10**5 lbs /ft left bracket 12 MN/m right bracket is generated by the bladders and the stress in the 1.57 double prime left bracket 40 mm right bracket aluminum shell reaches 20.3 ksi left bracket 140 MPa right bracket...

  3. High accuracy magnetic field mapping of the LEP spectrometer magnet

    CERN Document Server

    Roncarolo, F

    2000-01-01

    The Large Electron Positron accelerator (LEP) is a storage ring which has been operated since 1989 at the European Laboratory for Particle Physics (CERN), located in the Geneva area. It is intended to experimentally verify the Standard Model theory and in particular to detect with high accuracy the mass of the electro-weak force bosons. Electrons and positrons are accelerated inside the LEP ring in opposite directions and forced to collide at four locations, once they reach an energy high enough for the experimental purposes. During head-to-head collisions the leptons loose all their energy and a huge amount of energy is concentrated in a small region. In this condition the energy is quickly converted in other particles which tend to go away from the interaction point. The higher the energy of the leptons before the collisions, the higher the mass of the particles that can escape. At LEP four large experimental detectors are accommodated. All detectors are multi purpose detectors covering a solid angle of alm...

  4. High-field thermal transports properties of REBCO coated conductors

    CERN Document Server

    Bonura, M

    2015-01-01

    The use of REBCO coated conductors is envisaged for many applications, extending from power cables to high-field magnets. Whatever the case, thermal properties of REBCO tapes play a key role for the stability of superconducting devices. In this work, we present the first study on the longitudinal thermal conductivity (k) of REBCO coated conductors in magnetic fields up to 19 T applied both parallelly and perpendicularly to the thermal-current direction. Copper-stabilized tapes from six industrial manufacturers have been investigated. We show that zero-field k of coated conductors can be calculated with an accuracy of ‡ 15% from the residual resistivity ratio of the stabilizer and the Cu/non-Cu ratio. Measurements performed at high fields have allowed us to evaluate the consistency of the procedures generally used for estimating in-field k in the framework of the Wiedemann-Franz law from an electrical characterization of the materials. In-field data are intended to provide primary ingredients for the ...

  5. ESR study of thermal demagnetization processes in ferromagnetic nanoparticles with Curie temperatures between 40 and 60 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Oleg A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation)]. E-mail: kuznetsov_oa@yahoo.com; Sorokina, Olga N. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation); Leontiev, Vladimir G. [Institute of Metallurgy, Russian Academy of Sciences (RAS), Moscow 119991 (Russian Federation); Shlyakhtin, Oleg A. [Institute of Chemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation); Kovarski, Alexander L. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation); Kuznetsov, Anatoly A. [Institute of Biochemical Physics, Russian Academy of Sciences (RAS), Kosygin St. 4, Moscow 119991 (Russian Federation)

    2007-04-15

    Thermal demagnetization in the vicinity of the Curie temperature of silver and sodium manganite nanoparticles, as well as copper-nickel and palladium-nickel alloy nanoparticles were studied by both static magnetic measurements and by electron spin resonance (ESR). ESR data indicate that some magnetic ordering remains even above the Curie temperature, determined by static magnetometry. Mechanisms of thermal demagnetization in alloy nanoparticles appear to be different from that in manganites.

  6. ESR, U-series and paleomagnetic dating of Gigantopithecus fauna from Chuifeng Cave, Guangxi, southern China

    Science.gov (United States)

    Shao, Qingfeng; Wang, Wei; Deng, Chenglong; Voinchet, Pierre; Lin, Min; Zazzo, Antoine; Douville, Eric; Dolo, Jean-Michel; Falguères, Christophe; Bahain, Jean-Jacques

    2014-07-01

    Several Gigantopithecus faunas associated with taxonomically undetermined hominoid fossils and/or stone artifacts are known from southern China. These faunas are particularly important for the study of the evolution of humans and other mammals in Asia. However, the geochronology of the Gigantopithecus faunas remains uncertain. In order to solve this problem, a program of geochronological studies of Gigantopithecus faunas in Guangxi Province was recently initiated. Chuifeng Cave is the first studied site, which yielded 92 Gigantopithecus blacki teeth associated with numerous other mammalian fossils. We carried out combined ESR/U-series dating of fossil teeth and sediment paleomagnetic studies. Our ESR results suggest that the lower layers at this cave can be dated to 1.92 ± 0.14 Ma and the upper layers can be dated to older than 1.38 ± 0.17 Ma. Correlation of the recognized magnetozones to the geomagnetic polarity timescale was achieved by combining magnetostratigraphic, biostratigraphic and ESR data. The combined chronologies establish an Olduvai subchron (1.945-1.778 Ma) for the lowermost Chuifeng Cave sediments. We also analyzed the enamel δ13C values of the Gigantopithecus faunas. Our results show that southern China was dominated by C3 plants during the early Pleistocene and that the Gigantopithecus faunas lived in a woodland-forest ecosystem.

  7. [Using ESR technology observe the change of free radicals in cochlea after acute acoustic trauma].

    Science.gov (United States)

    Gao, Gang; Sun, Jianjun; Gong, Shusheng; Jiang, Ping

    2011-04-01

    To observe the changes of free radicals in the cochlea of guinea pigs after noise exposure directly using electron spin resonance (ESR) technology. Forty-two guinea pigs as experimental group were given (125 +/- 1) dB SPL noise exposure for 2 hours, and then investigated auditory function immediately, at 2, 6, 12, 24, 48 and 72 hour. After ABR examinations, 21 animals decollated and extracted cochlea immediately and then placed the cochleas to liquid nitrogen for deep freezing and measuring free radicals using ESR technology. Another 21 animals observed hair cells morphology by AgNO3 staining. Meantime, 6 animals without noise exposure were served as negative control group. A few free radicals were detected in the cochlea at control group and the relative value of free radicals were (21.68 +/- 1.27) dB SPL. After noise exposure, the relative value of free radicals increased obviously and achieved to the max of (147.01 +/- 4.95) dB SPL at 2 h and gradually decreased near the normal level. Free radicals in the cochlea increase evidently and have a concentration-time rule after acute acoustic trauma. The ESR method can be used to examine the content of free radicals in cochlea for its direct, objective and sensitive characters.

  8. Estrogen Receptor Alpha (ESR-1) Associations with Psychological Traits in Women with PMDD and Controls

    Science.gov (United States)

    Miller, Alexandra; Vo, Hoa; Huo, Liang; Roca, Catherine; Schmidt, Peter J.; Rubinow, David R.

    2010-01-01

    Premenstrual Dysphoric Disorder (PMDD) is a mood disorder affecting about 5% of women and is associated with substantial morbidity. Albeit inconsistently, PMDD is described as being characterized by heritable personality traits. Although PMDD is a heritable disorder, it is unclear whether any of the heritable susceptibility to PMDD resides in heritable personality traits. In groups of carefully characterized women with PMDD (n=68) and controls (n=56), we attempted to determine whether diagnosis-related traits could be confirmed, as well as to determine whether such traits were associated with SNPs in estrogen receptor alpha (ESR-1) that we previously demonstrated were associated with PMDD. We observed 7/25 traits to be significantly different in patients and controls and further showed that 11/12 significant associations observed between these 7 traits and 16 ESR-1 SNPs involved the intron 4 SNPs previously shown to be the locus of the association with PMDD. While several interactions between genotype and diagnosis were observed, the effect of genotype in most instances was in the same direction in patients and controls. These data demonstrate affective state-independent personality traits that distinguish patients with PMDD from controls and further support the relevance of ESR-1 polymorphic variants in the regulation of non-reproductive behaviors. PMID:20172536

  9. Influence of high frequency electric field on the dispersion of ion-acoustic waves in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Turky, A.; Cercek, M.; Tavzes, R.

    1981-01-01

    The modification of the ion-acoustic wave dispersion under the action of a high frequency electric field was studied experimentally, the wave propagating along and against the plasma stream. The frequency of the field amounted to approximately half the electron plasma frequency. It was found that the phase velocity of the ion wave and the plasma drift velocity decrease as the effective high frequency field power increases.

  10. In vivo high field magnetic resonance imaging and spectroscopy of adult zebrafish

    NARCIS (Netherlands)

    Kabli, Samira

    2009-01-01

    This thesis contains the results of imaging of adult zebrafish by using different MR approaches. We present the first high resolution mMR images of adult zebrafish. To achieve high spatial resolution we used a magnetic field of 9.4T, in combination with strong magnetic field gradients (1000 mT/m)

  11. Ultra-high field MRI: Advancing systems neuroscience towards mesoscopic human brain function

    NARCIS (Netherlands)

    Dumoulin, Serge O; Fracasso, A.; Van der Zwaag, W.; Siero, Jeroen C W; Petridou, Natalia

    2017-01-01

    Human MRI scanners at ultra-high magnetic field strengths of 7 T and higher are increasingly available to the neuroscience community. A key advantage brought by ultra-high field MRI is the possibility to increase the spatial resolution at which data is acquired, with little reduction in image

  12. Estimating the Reliability of Electronic Parts in High Radiation Fields

    Science.gov (United States)

    Everline, Chester; Clark, Karla; Man, Guy; Rasmussen, Robert; Johnston, Allan; Kohlhase, Charles; Paulos, Todd

    2008-01-01

    Radiation effects on materials and electronic parts constrain the lifetime of flight systems visiting Europa. Understanding mission lifetime limits is critical to the design and planning of such a mission. Therefore, the operational aspects of radiation dose are a mission success issue. To predict and manage mission lifetime in a high radiation environment, system engineers need capable tools to trade radiation design choices against system design and reliability, and science achievements. Conventional tools and approaches provided past missions with conservative designs without the ability to predict their lifetime beyond the baseline mission.This paper describes a more systematic approach to understanding spacecraft design margin, allowing better prediction of spacecraft lifetime. This is possible because of newly available electronic parts radiation effects statistics and an enhanced spacecraft system reliability methodology. This new approach can be used in conjunction with traditional approaches for mission design. This paper describes the fundamentals of the new methodology.

  13. Gendered Fields: Sports and Advanced Course Taking in High School.

    Science.gov (United States)

    Pearson, Jennifer; Crissey, Sarah R; Riegle-Crumb, Catherine

    2009-10-01

    This study explores the association between sports participation and course taking in high school, specifically comparing subjects with varied gendered legacies-science and foreign language. Analyses of a nationally representative longitudinal sample (N=5,447) of U.S. adolescents from the National Longitudinal Study of Adolescent Health and the linked Adolescent Health and Academic Achievement transcript study show that male and female athletes are more likely than non-athletes to take both advanced foreign language and Physics, largely because of their higher academic orientation. However, the association between sports participation and course taking was strongest for girls' Physics coursework, suggesting that sports may provide girls with a unique opportunity to develop the skills and confidence to persevere in the masculine domain of science.

  14. Wilderness medicine at high altitude: recent developments in the field

    Directory of Open Access Journals (Sweden)

    Shah NM

    2015-09-01

    Full Text Available Neeraj M Shah,1 Sidra Hussain,2 Mark Cooke,3 John P O’Hara,3 Adrian Mellor3,4 1Division of Asthma, Allergy and Lung Biology, King’s College London, UK; 2School of Medicine, University College London, London, UK; 3Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK; 4Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK Abstract: Travel to high altitude is increasingly popular. With this comes an increased incidence of high-altitude illness and therefore an increased need to improve our strategies to prevent and accurately diagnose these. In this review, we provide a summary of recent advances of relevance to practitioners who may be advising travelers to altitude. Although the Lake Louise Score is now widely used as a diagnostic tool for acute mountain sickness (AMS, increasing evidence questions the validity of doing so, and of considering AMS as a single condition. Biomarkers, such as brain natriuretic peptide, are likely correlating with pulmonary artery systolic pressure, thus potential markers of the development of altitude illness. Established drug treatments include acetazolamide, nifedipine, and dexamethasone. Drugs with a potential to reduce the risk of developing AMS include nitrate supplements, propagators of nitric oxide, and supplemental iron. The role of exercise in the development of altitude illness remains hotly debated, and it appears that the intensity of exercise is more important than the exercise itself. Finally, despite copious studies demonstrating the value of preacclimatization in reducing the risk of altitude illness and improving performance, an optimal protocol to preacclimatize an individual remains elusive. Keywords: hypoxia, acute mountain sickness, acclimatization, biomarkers, preacclimatization

  15. Full-field, high-spatial-resolution detection of local structural damage from low-resolution random strain field measurements

    Science.gov (United States)

    Yang, Yongchao; Sun, Peng; Nagarajaiah, Satish; Bachilo, Sergei M.; Weisman, R. Bruce

    2017-07-01

    Structural damage is typically a local phenomenon that initiates and propagates within a limited area. As such high spatial resolution measurement and monitoring is often needed for accurate damage detection. This requires either significantly increased costs from denser sensor deployment in the case of global simultaneous/parallel measurements, or increased measurement time and labor in the case of global sequential measurements. This study explores the feasibility of an alternative approach to this problem: a computational solution in which a limited set of randomly positioned, low-resolution global strain measurements are used to reconstruct the full-field, high-spatial-resolution, two-dimensional (2D) strain field and rapidly detect local damage. The proposed approach exploits the implicit low-rank and sparse data structure of the 2D strain field: it is highly correlated without many edges and hence has a low-rank structure, unless damage-manifesting itself as sparse local irregularity-is present and alters such a low-rank structure slightly. Therefore, reconstruction of the full-field, high-spatial-resolution strain field from a limited set of randomly positioned low-resolution global measurements is modeled as a low-rank matrix completion framework and damage detection as a sparse decomposition formulation, enabled by emerging convex optimization techniques. Numerical simulations on a plate structure are conducted for validation. The results are discussed and a practical iterative global/local procedure is recommended. This new computational approach should enable the efficient detection of local damage using limited sets of strain measurements.

  16. ESR spectroscopy on (Gd,La)O{sub 1-x}F{sub x}FeAs superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Alfonsov, A.; Muranyi, F.; Kataev, V.; Leps, N.; Klingeler, R.; Kondrat, A.; Hess, C.; Koehler, A.; Werner, J.; Behr, G.; Buechner, B. [IFW Dresden, Institute for Solid State Research, D-01171 Dresden (Germany)

    2009-07-01

    We present results on electron spin resonance (ESR) spectroscopy of polycrystalline samples of the (Gd,La)O{sub 1-x}F{sub x}FeAs superconductor with different levels of fluorine and gadolinium doping. The ESR signal of a small amount of Gd spins doped to the parent compound LaOFeAs is sensitive to the structural and in particular to the magnetic phase transition occurring in this material at temperatures {proportional_to}130-150 K. Fluorine doping suppresses both transitions and leads to superconductivity. Correspondingly, the Gd ESR response shows no signatures of the magnetic order in the FeAs planes of samples with a superconducting ground state. In the concentrated compound GdOFeAs the Gd ESR response is sensitive to the magnetism of the FeAs planes, too. Doping of this material with {proportional_to} 15 % of fluorine yields superconductivity with T{sub c}{approx}21 K. Surprisingly, Gd ESR gives clear indications of the enhancement of (quasi)-static magnetic correlations in the superconducting samples which set in below {proportional_to} 80 K and continue to develop even in the superconducting state. We compare ESR data with results of thermodynamic and transport measurements on these samples and discuss a possible role of magnetic rare-earths for the magnetism of the FeAs-planes in which the superconductivity evolves upon the fluorine doping.

  17. HIGH-GRADIENT, HIGH-TRANSFORMER-RATIO, DIELECTRIC WAKE FIELD ACCELERATOR

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L

    2012-04-12

    The Phase I work reported here responds to DoE'ss stated need "...to develop improved accelerator designs that can provide very high gradient (>200 MV/m for electrons...) acceleration of intense bunches of particles." Omega-P's approach to this goal is through use of a ramped train of annular electron bunches to drive a coaxial dielectric wakefield accelerator (CDWA) structure. This approach is a direct extension of the CDWA concept from acceleration in wake fields caused by a single drive bunch, to the more efficient acceleration that we predict can be realized from a tailored (or ramped) train of several drive bunches. This is possible because of a much higher transformer ratio for the latter. The CDWA structure itself has a number of unique features, including: a high accelerating gradient G, potentially with G > 1 GeV/m; continuous energy coupling from drive to test bunches without transfer structures; inherent transverse focusing forces for particles in the accelerated bunch; highly stable motion of high charge annular drive bunches; acceptable alignment tolerances for a multi-section system. What is new in the present approach is that the coaxial dielectric structure is now to be energized by-not one-but by a short train of ramped annular-shaped drive bunches moving in the outer coaxial channel of the structure. We have shown that this allows acceleration of an electron bunch traveling along the axis in the inner channel with a markedly higher transformer ratio T than for a single drive bunch. As described in this report, the structure will be a GHz-scale prototype with cm-scale transverse dimensions that is expected to confirm principles that can be applied to the design of a future THz-scale high gradient (> 500 MV/m) accelerator with mm-scale transverse dimensions. We show here a new means to significantly increase the transformer ratio T of the device, and thereby to significantly improve its suitability as a flexible and effective component in

  18. Zylon-reinforced high magnetic field coils for the K.U. Leuven pulsed field laboratory

    Science.gov (United States)

    Rosseel, K.; Herlach, F.; Boon, W.; Bruynseraede, Y.

    2001-01-01

    PBO Zylon ® fibers have been used for the internal reinforcement of pulsed magnets. Due to the very high packing density (80%) of these fibers, vacuum impregnation of Zylon reinforced coils is difficult. Impregnation test were performed using pressure-vacuum impregnation and wet winding. A prototype series of coils for 60-70 T with 1-2 ms pulse duration was designed and wound, using wet winding for both the internal Zylon and external carbon fiber reinforcement. Special precautions were taken to avoid insulation breakdown at the transitions between conductor layers. Furthermore, axial movement of the conductor wires was restrained by strong axial compression of the coil with a steel shell casing. These modifications were incorporated into an 80 T coil made of Zylon and soft Cu. The design, construction and performance of this coil are discussed.

  19. ESR/ERS white paper on lung cancer screening.

    NARCIS (Netherlands)

    Kauczor, H.U.; Bonomo, L.; Gaga, M.; Nackaerts, K.; Peled, N.; Prokop, M.; Remy-Jardin, M.; Stackelberg, O. von; Sculier, J.P.

    2015-01-01

    Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the

  20. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  1. EsrE-A yigP Locus-Encoded Transcript-Is a 3′ UTR sRNA Involved in the Respiratory Chain of E. coli

    Directory of Open Access Journals (Sweden)

    Hui Xia

    2017-08-01

    Full Text Available The yigP locus is widely conserved among γ-proteobacteria. Mutation of the yigP locus impacts aerobic growth of Gram-negative bacteria. However, the underlying mechanism of how the yigP locus influences aerobic growth remains largely unknown. Here, we demonstrated that the yigP locus in Escherichia coli encodes two transcripts; the mRNA of ubiquinone biosynthesis protein, UbiJ, and the 3′ untranslated region small regulatory RNA (sRNA, EsrE. EsrE is an independent transcript that is transcribed using an internal promoter of the yigP locus. Surprisingly, we found that both the EsrE sRNA and UbiJ protein were required for Q8 biosynthesis, and were sufficient to rescue the growth defect ascribed to deletion of the yigP locus. Moreover, our data showed that EsrE targeted multiple mRNAs involved in several cellular processes including murein biosynthesis and the tricarboxylic acid cycle. Among these targets, sdhD mRNA that encodes one subunit of succinate dehydrogenase (SDH, was significantly activated. Our findings provided an insight into the important function of EsrE in bacterial adaptation to various environments, as well as coordinating different aspects of bacterial physiology.

  2. Precise Determination of Zero-Field Splitting Parameters of Hemin by High-Field and High-Frequency Electron Paramagnetic Resonance

    Science.gov (United States)

    Okamoto, Tsubasa; Ohmichi, Eiji; Okubo, Susumu; Ohta, Hitoshi

    2018-01-01

    The zero-field splitting (ZFS) parameters of Fe(III) protoporphyrin IX chloride, or hemin, a model substance of hemoproteins, were determined precisely by high-field and high-frequency electron paramagnetic resonance (HFEPR). From multi-frequency measurements up to 700 GHz, multiple EPR absorptions were clearly resolved, and the rhombic component of ZFS was directly determined, for the first time, as |E| = 0.055 ± 0.005 cm-1, in addition to the axial component D = 6.90 ± 0.01 cm-1. This finding indicates the essential role of the rhombic symmetry of excited states in the ZFS parameters.

  3. Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

    Directory of Open Access Journals (Sweden)

    Ye Peng

    2016-01-01

    Full Text Available The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

  4. Kerr effect at high electric field in the isotropic phase of mesogenic materials.

    Science.gov (United States)

    Li, Bing-Xiang; Borshch, Volodymyr; Shiyanovskii, Sergij V; Liu, Shao-Bin; Lavrentovich, Oleg D

    2015-11-01

    The well-known Kerr effect in isotropic fluids consists in the appearance of uniaxial orientational order and birefringence that grows as the square of the applied electric field. We predict and observe that at a high electric field, the Kerr effect displays features caused by the nonlinear dependence of dielectric permittivity on the field-induced orientational order parameter. Namely, the field-induced birefringence grows faster than the square of the electric field and the dynamics of birefringence growth slows down as the field increases. As a function of temperature, the field-induced birefringence is inversely proportional to the departure from an asymptotic critical temperature, but this temperature is no longer a constant (corresponding to the lower limit of the supercooled isotropic phase) and increases proportionally to the square of the electric field.

  5. New perspectives in vacuum high voltage insulation. I. The transition to field emission

    CERN Document Server

    Diamond, W T

    1998-01-01

    Vacuum high-voltage insulation has been investigated for many years. Typically, electrical breakdown occurs between two broad-area electrodes at electric fields 100-1000 times lower than the breakdown field (about 5000 MV/m) between a well-prepared point cathode and a broad-area anode. Explanations of the large differences remain unsatisfactory, usually evoking field emission from small projections on the cathode that are subject to higher peak fields. The field emission then produces secondary effects that lead to breakdown. This article provides a significant resolution to this long standing problem. Field emission is not present at all fields, but typically starts after some process occurs at the cathode surface. Three effects have been identified that produce the transition to field emission: work function changes; mechanical changes produced by the strong electrical forces on the electrode surfaces; and gas desorption from the anode with sufficient density to support an avalanche discharge. Material adso...

  6. A Novel High Sensitivity Sensor for Remote Field Eddy Current Non-Destructive Testing Based on Orthogonal Magnetic Field

    Directory of Open Access Journals (Sweden)

    Xiaojie Xu

    2014-12-01

    Full Text Available Remote field eddy current is an effective non-destructive testing method for ferromagnetic tubular structures. In view of conventional sensors’ disadvantages such as low signal-to-noise ratio and poor sensitivity to axial cracks, a novel high sensitivity sensor based on orthogonal magnetic field excitation is proposed. Firstly, through a three-dimensional finite element simulation, the remote field effect under orthogonal magnetic field excitation is determined, and an appropriate configuration which can generate an orthogonal magnetic field for a tubular structure is developed. Secondly, optimized selection of key parameters such as frequency, exciting currents and shielding modes is analyzed in detail, and different types of pick-up coils, including a new self-differential mode pick-up coil, are designed and analyzed. Lastly, the proposed sensor is verified experimentally by various types of defects manufactured on a section of a ferromagnetic tube. Experimental results show that the proposed novel sensor can largely improve the sensitivity of defect detection, especially for axial crack whose depth is less than 40% wall thickness, which are very difficult to detect and identify by conventional sensors. Another noteworthy advantage of the proposed sensor is that it has almost equal sensitivity to various types of defects, when a self-differential mode pick-up coil is adopted.

  7. Genetic association between HER2 and ESR2 polymorphisms and ovarian cancer: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Tang L

    2018-03-01

    Full Text Available Liang Tang,1,2 Jianming Li,1,3 Meihua Bao,1,2 Ju Xiang,1,2 Yiwei Chen,1,2 Yan Wang1,2,4 1Department of Human Anatomy, Histology and Embryology, Institute of Neuroscience, Changsha Medical University, Changsha, People’s Republic of China; 2Department of Human Anatomy, School of Basic Medical Science, Changsha Medical University, Changsha, People’s Republic of China; 3Department of Neurology, Xiang-ya Hospital, Central South University, Changsha, People’s Republic of China; 4Department of Human Anatomy, Experiment Center for Function, Changsha Medical University, Changsha, People’s Republic of China Objective: The estrogen receptor (ER and the human epidermal growth factor receptor 2 (HER2 each play an important role in female cancers. This study aimed to investigate the genetic association between three common single nucleotide polymorphisms (SNPs and the risk of ovarian cancer. The SNPs investigated in this study were ESR2 rs1271572 and rs3020450 and HER2 rs1801200.Methods: In this study, databases were electronically searched in a meta-analysis. Databases used were PubMed, Embase, China National Knowledge Infrastructure (CNKI, Wanfang and Cochrane library. Case–control studies on the association between ESR2 and HER2 polymorphisms were selected according to inclusion and exclusion standard. Articles were evaluated for quality, and data were extracted.Results: A total of 13 articles with 5,461 cases and 7,603 controls were included in this meta-analysis. The recessive model of ESR2 rs1271572 was shown to be significantly associated with the risk of ovarian cancer (p = 0.008, odds ratio [OR] [95% confidence interval {CI}] = 1.13 [1.03, 1.24], and this significant association still existed in a subgroup analysis stratified by ethnicity (Asian: p = 0.04, OR [95% CI] = 1.92 [1.04, 3.56]; Caucasian: p = 0.02, OR [95% CI] = 1.12 [1.02, 1.23]. In addition, the distribution of the dominant model of ESR2 rs3020450 was significantly different in

  8. Measurements of nuclear masses and half-lives in the storage ring ESR

    Energy Technology Data Exchange (ETDEWEB)

    Klepper, O. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)

    1996-06-01

    Secondary beams of {sup 58}Ni, {sup 197}Au, and {sup 209}Bi fragments have been produced at energies of 200-370 A-MeV by projectile fragmentation, separated with the fragment separator FRS and injected into the storage-cooler ring ESR for mass and half-life measurements. Radioactive beams have also been generated by completely stripping all electrons from {sup 163}Dy and {sup 187}Re ions to investigate the resulting bound-state {beta} decay. For these studies the revolution frequencies and beam intensities of the stored and cooled unstable nuclei were measured via Schottky spectroscopy. In the {sup 58}Ni case the achieved relative momentum spread of 9.10{sup -7} (FWHM) allowed us to resolve the ground and isomeric states of cooled {sup 52}Mn and {sup 53}Fe. The circulating beams were fully ionized which rendered possible, for the first time, to measure pure {beta}{sup +} branches of ground states ({sup 52}Fe{sup g}, {sup 53}Fe{sup g}) and the sum of pure {beta}{sup +} and {gamma} branches of isomers ({sup 52}Mn{sup m}, {sup 53}Fe{sup m}). In the experiment with the heavier fragments the main goal was to study nuclei which are members of {alpha}-decay chains with unknown masses. We systematically mapped the ``mass surface`` in the holmium to polonium region from nuclei close to stability up to nuclei with unknown masses as far as their half-lives are >or{approx}0.5 min. Relative accuracies for the measured mass values in the order of 1.10{sup -6} and below can be achieved. Via {alpha}-decay energies from the literature the ``mass surface`` up to the proton drip-line can be accessed. Due to the high sensitivity of the Schottky diagnosis also small number of daughter nuclei of stored ions with half-lives up to years can be detected. In this way {sup 187}Re was identified as a second case of bound-state {beta}-decay. The status of the only partly completed analysis of these experiments is presented. (orig.)

  9. Very high-accuracy calibration of radiation pattern and gain of a near-field probe

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav

    2014-01-01

    In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission of the Europ......In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission...

  10. DOUBLE DEGENERATE MERGERS AS PROGENITORS OF HIGH-FIELD MAGNETIC WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Berro, Enrique; Loren-Aguilar, Pablo; Aznar-Siguan, Gabriela; Torres, Santiago; Camacho, Judit [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Althaus, Leandro G.; Corsico, Alejandro H. [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, (1900) La Plata (Argentina); Kuelebi, Baybars; Isern, Jordi, E-mail: garcia@fa.upc.edu [Institute for Space Studies of Catalonia, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

    2012-04-10

    High-field magnetic white dwarfs have been long suspected to be the result of stellar mergers. However, the nature of the coalescing stars and the precise mechanism that produces the magnetic field are still unknown. Here, we show that the hot, convective, differentially rotating corona present in the outer layers of the remnant of the merger of two degenerate cores can produce magnetic fields of the required strength that do not decay for long timescales. Using a state-of-the-art Monte Carlo simulator, we also show that the expected number of high-field magnetic white dwarfs produced in this way is consistent with that found in the solar neighborhood.

  11. Unipolar and Bipolar High-Magnetic-Field Sensors Based on Surface Acoustic Wave Resonators

    Science.gov (United States)

    Polewczyk, V.; Dumesnil, K.; Lacour, D.; Moutaouekkil, M.; Mjahed, H.; Tiercelin, N.; Petit Watelot, S.; Mishra, H.; Dusch, Y.; Hage-Ali, S.; Elmazria, O.; Montaigne, F.; Talbi, A.; Bou Matar, O.; Hehn, M.

    2017-08-01

    While surface acoustic wave (SAW) sensors have been used to measure temperature, pressure, strains, and low magnetic fields, the capability to measure bipolar fields and high fields is lacking. In this paper, we report magnetic surface acoustic wave sensors that consist of interdigital transducers made of a single magnetostrictive material, either Ni or TbFe2 , or based on exchange-biased (Co /IrMn ) multilayers. By controlling the ferromagnet magnetic properties, high-field sensors can be obtained with unipolar or bipolar responses. The issue of hysteretic response of the ferromagnetic material is especially addressed, and the control of the magnetic properties ensures the reversible behavior in the SAW response.

  12. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.

    Science.gov (United States)

    Niu, D; Zhu, F; Qiu, R; Niu, Q

    2016-01-01

    High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

  13. Dose equivalent measurements in a strongly pulsed high-energy radiation field

    CERN Document Server

    Mayer, S; Kyllonen, J E; Menzel, Hans Gregor; Otto, Thomas

    2004-01-01

    The stray radiation field outside the shielding of high-energy accelerators comprises neutrons, photons and charged particles with a wide range of energies. Often, accelerators operate by accelerating and ejecting short pulses of particles, creating an analogue, pulsed radiation field. The pulses can be as short as 10 mu s with high instantaneous fluence rates and dose rates. Measurements of average dose equivalent (rate) for radiation protection purposes in these fields present a challenge for instrumentation. The performance of three instruments (i.e. a recombination chamber, the Sievert Instrument and a HANDITEPC) measuring total dose equivalent is compared in a high-energy reference radiation field (CERF) and a strongly pulsed, high-energy radiation field at the CERN proton synchrotron (PS).

  14. A new approach for explanation of specimen rupture under high electric field.

    Science.gov (United States)

    Mikhailovskij, I M; Wanderka, N; Storizhko, V E; Ksenofontov, V A; Mazilova, T I

    2009-04-01

    Failure of needle-shaped specimens under the action of high electric fields is one of the most serious problems in many field-ionization devices and methods. It was shown that the length of what was removed during discharge part of specimens in most of the cases was several orders greater than that of an initial radius of the specimen apex. Experimental results obtained in this work indicate that electrical breakdown in field-ion microscopes is initiated by the impact of nanoparticles detached from a point anode in a high electric field. A new approach for explanation of an observed specimen failure in a high electric field was proposed, where the formation and expansion of the cathode plasma play the key role in the mechanical rupture and melting of field-ion tips. The expanding plasma behaves as a dynamic capacitor plate characterized by a high velocity and increasing field strength at the specimen tip. The field rise rate at a constant voltage in a dynamic plasma-to-tip capacitor is of the order of >10(20)V/m/s. The present experimental data along with the ecton model of the vacuum breakdown allow the results to be discussed as a mechanical sample failure under the action of the superhigh positive field pulse induced by the cathode plasma expansion.

  15. Magnetization and ESR studies of La{sub 0.67}(Ca{sub 1−x}Mg{sub x}){sub 0.33}MnO{sub 3} systems

    Energy Technology Data Exchange (ETDEWEB)

    Sendil Kumar, A., E-mail: sendilphy@gmail.com [School of Physics, University of Hyderabad, Hyderabad, Telangana, 500 046 (India); Ravinder Reddy, K [School of Engineering Sciences & Technology, University of Hyderabad, Hyderabad, Telangana, 500 046 (India); Bhatnagar, Anil K. [School of Physics, University of Hyderabad, Hyderabad, Telangana, 500 046 (India); School of Engineering Sciences & Technology, University of Hyderabad, Hyderabad, Telangana, 500 046 (India)

    2015-08-05

    Highlights: • Mg substitution reduces the ferromagnetic strength. • Inhomogeneous broadening is due to phase separation. • Griffiths phase existence is probed. - Abstract: Magnetization studies and line shape analysis on Electron Spin Resonance (ESR) spectra of La{sub 0.67}(Ca{sub 1−x}Mg{sub x}){sub 0.33}MnO{sub 3} are carried out. In paramagnetic phase well above T{sub c}, the ESR spectra are single Lorentzian but below and near T{sup ∗}{sub ΔHPP}, (T{sup ∗}{sub ΔHPP} is temperature at which line width is minimum) inhomogeneous broadening with asymmetry in the signal is observed due to phase separation. The resonance field below T{sup ∗}{sub ΔHPP} decreases with decreasing temperature. Above T{sub c} the intensity of the ESR spectra obeys the thermally activated model (Arrhenius behavior). Substitution of Mg weakens the ferromagnetic interaction and evolution of change in lineshape near T{sub c} is an evidence of Griffiths phase (coexistence of paramagnetic and ferromagnetic) in Mg doped LCMO system.

  16. High-spin chloro mononuclear MnIII complexes: a multifrequency high-field EPR study.

    Science.gov (United States)

    Mantel, Claire; Chen, Hongyu; Crabtree, Robert H; Brudvig, Gary W; Pécaut, Jacques; Collomb, Marie-Noëlle; Duboc, Carole

    2005-03-01

    The isolation, structural characterization, and electronic properties of two six-coordinated chloromanganese (III) complexes, [Mn(terpy)(Cl)3] (1) and [Mn(Phterpy)(Cl)3] (2), are reported (terpy = 2,2':6'2"-terpyridine, Phterpy = 4'-phenyl-2,2':6',2"-terpyridine). These complexes complement a series of mononuclear azide and fluoride Mn(lll) complexes synthesized with neutral N-tridentate ligands, [Mn(L)(X)3] (X = F- or N3 and L = terpy or bpea [N,N-bis(2-pyridylmethyl)-ethylamine)], previously described. Similar to these previous complexes, 1 and 2 exhibit a Jahn-Teller distortion of the octahedron, characteristic of a high-spin Mn(III) complex (S = 2). The analysis of the crystallographic data shows that, in both cases, the manganese ion lies in the center of a distorted octahedron characterized by an elongation along the tetragonal axis. Their electronic properties were investigated by multifrequency EPR (190-475 GHz) performed in the solid state at different temperatures (5-15 K). This study confirms our previous results and further shows that: i) the sign of D is correlated with the nature of the tetragonal distortion; ii) the magnitude of D is not sensitive to the nature of the anions in our series of rhombic complexes, contrary to the porphyrinic systems; iii) the [E/D] values (0.124 for 1 and 0.085 for 2) are smaller compared to those found for the [Mn(L)(X)3] complexes (in the range of 0.146 to 0.234); and iv) the E term increases when the ligand-field strength of the equatorial ligands decreases.

  17. Electron transport in bulk GaN under ultrashort high-electric field transient

    Science.gov (United States)

    Korotyeyev, V. V.; Kochelap, V. A.; Kim, K. W.

    2011-10-01

    We have investigated nonlinear electron transport in GaN induced by high-electric field transients by analyzing the temporal dependence of the electron drift velocity and temperature. For picosecond transients, our calculations have established that the electron dynamics retain almost all the features of the steady-state velocity-field characteristics including the portion with negative differential conductivity. It was also found that transient currents in GaN samples give rise to the THz re-emission effect—radiation of electromagnetic field, temporal and spectral properties of which directly relate to the velocity-field characteristics of the sample. The results clearly indicate that existing methods for the generation of high-electric field transients and subpicosecond signal measurements can be applied to the characterization of hot electron transport at ultrahigh fields while avoiding Joule self-heating, hot phonon accumulation and other undesirable effects.

  18. Recent developments in high-resolution global altimetric gravity field modeling

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Knudsen, Per; Berry, P. A .M.

    2010-01-01

    In recent years, dedicated effort has been made to improve high-resolution global marine gravity fields. One new global field is the Danish National Space Center (DNSC) 1-minute grid called DNSC08GRA, released in 2008. DNSC08GRA was derived from double-retracked satellite altimetry, mainly from...... the ERS-1 geodetic mission data, augmented with new retracked GEOSAT data which have significantly enhanced the range and hence the gravity field accuracy. DNSC08GRA is the first high-resolution global gravity field to cover the entire Arctic Ocean all the way to the North Pole. Comparisons with other...... older gravity fields show accuracy improvement of the order of 20-40% due to a combination of retracking, enhanced processing, and the use of the new EGM2008 geoid model. In coastal and polar regions, accuracy improved in many places by 40-50% (or more) compared with older global marine gravity fields....

  19. Tomographic reconstruction of circularly polarized high-harmonic fields: 3D attosecond metrology.

    Science.gov (United States)

    Chen, Cong; Tao, Zhensheng; Hernández-García, Carlos; Matyba, Piotr; Carr, Adra; Knut, Ronny; Kfir, Ofer; Zusin, Dimitry; Gentry, Christian; Grychtol, Patrik; Cohen, Oren; Plaja, Luis; Becker, Andreas; Jaron-Becker, Agnieszka; Kapteyn, Henry; Murnane, Margaret

    2016-02-01

    Bright, circularly polarized, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly polarized driving laser fields. Although the resulting circularly polarized harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly polarized bursts, varying rapidly in amplitude, frequency, and polarization. We extend attosecond metrology techniques to circularly polarized light by simultaneously irradiating a copper surface with circularly polarized high-harmonic and linearly polarized infrared laser fields. The resulting temporal modulation of the photoelectron spectra carries essential phase information about the EUV field. Utilizing the polarization selectivity of the solid surface and by rotating the circularly polarized EUV field in space, we fully retrieve the amplitude and phase of the circularly polarized harmonics, allowing us to reconstruct one of the most complex coherent light fields produced to date.

  20. Microscopic observation of highly mobile charge carriers in organic transistors of semicrystalline conducting polymers

    Science.gov (United States)

    Kawamura, Shinya; Wakamatsu, Ayato; Kuroda, Shin-ichi; Takenobu, Taishi; Tanaka, Hisaaki

    2018-02-01

    Charge carrier dynamics in organic field-effect transistors (OFETs) of semicrystalline conducting polymers poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT) and poly(3-hexylthiophene) (P3HT) have been investigated down to 4 K by field-induced electron spin resonance (FI-ESR) spectroscopy. The highly mobile nature of charge carriers within the ordered regions of the polymers has been clarified from the observation of the motional narrowing effect of the ESR spectra even below 30 K, where device operation cannot be observed presumably owing to the effect of domain boundaries. The activation energy of carrier motion observed by ESR has been determined as 17 meV for PBTTT and 13 meV for P3HT, which are an order of magnitude smaller than that of FET mobility (>110 meV) obtained for the same devices. These results demonstrate that the intrinsic carrier mobility within the ordered region is much higher than that expected from the macroscopic transport measurements in the semicrystalline polymers.

  1. ESR/ERS white paper on lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, Hans-Ulrich; Stackelberg, Oyunbileg von [University Hospital Heidelberg, Dept of Diagnostic and Interventional Radiology, Heidelberg (Germany); Member of the German Lung Research Center, Translational Lung Research Center, Heidelberg (Germany); Bonomo, Lorenzo [A. Gemelli University Hospital, Institute of Radiology, Rome (Italy); Gaga, Mina [Athens Chest Hospital, 7th Resp. Med. Dept and Asthma Center, Athens (Greece); Nackaerts, Kristiaan [KU Leuven-University of Leuven, University Hospitals Leuven, Department of Respiratory Diseases/Respiratory Oncology Unit, Leuven (Belgium); Peled, Nir [Tel Aviv University, Davidoff Cancer Center, Rabin Medical Center, Tel Aviv (Israel); Prokop, Mathias [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Remy-Jardin, Martine [Department of Thoracic Imaging, Hospital Calmette (EA 2694), CHRU et Universite de Lille, Lille (France); Sculier, Jean-Paul [Universite Libre de Bruxelles, Thoracic oncology, Institut Jules Bordet, Brussels (Belgium); Collaboration: on behalf of the European Society of Radiology (ESR) and the European Respiratory Society (ERS)

    2015-09-15

    Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low-dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the European Respiratory Society recommend lung cancer screening in comprehensive, quality-assured, longitudinal programmes within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. Minimum requirements include: standardised operating procedures for low-dose image acquisition, computer-assisted nodule evaluation, and positive screening results and their management; inclusion/exclusion criteria; expectation management; and smoking cessation programmes. Further refinements are recommended to increase quality, outcome and cost-effectiveness of lung cancer screening: inclusion of risk models, reduction of effective radiation dose, computer-assisted volumetric measurements and assessment of comorbidities (chronic obstructive pulmonary disease and vascular calcification). All these requirements should be adjusted to the regional infrastructure and healthcare system, in order to exactly define eligibility using a risk model, nodule management and a quality assurance plan. The establishment of a central registry, including a biobank and an image bank, and preferably on a European level, is strongly encouraged. (orig.)

  2. High-Intensity Nanosecond Pulsed Electric Field effects on Early Physiological Development in Arabidopsis thaliana

    OpenAIRE

    Wisuwat Songnuan; Phumin Kirawanich

    2011-01-01

    The influences of pulsed electric fields on early physiological development in Arabidopsis thaliana were studied. Inside a 4-mm electroporation cuvette, pre-germination seeds were subjected to high-intensity, nanosecond electrical pulses generated using laboratory-assembled pulsed electric field system. The field strength was varied from 5 to 20 kV.cm-1 and the pulse width and the pulse number were maintained at 10 ns and 100, respectively, corresponding to the specific t...

  3. High field magnetization process in Er sub 2 (Fe, Al) sub 14 B

    Energy Technology Data Exchange (ETDEWEB)

    Kohashi, T.; Kindo, K.; Date, M. (Dept. of Physics, Osaka Univ. (Japan)); Boer, F.R. de; Radwanski, R.J.; Zhong, X.P. (Natuurkundig Lab., Univ. Amsterdam (Netherlands)); Yamagishi, A. (Research Center for Extreme Materials, Osaka Univ. (Japan))

    1992-03-01

    A magnetization study in pulsed high magnetic fields up to 50 T has been performed on magnetically aligned powder samples of ferrimagnetic Er{sub 2}Fe{sub 14-x}Al{sub x}B (x = 0, 1, 2) compounds and field-induced transitions have been observed. Free-energy calculations with one Fe and four Er sublattices have been performed and the field-induced transitions can satisfactorily be explained. (orig.).

  4. Association between VDR and ESR1 gene polymorphisms with bone and obesity phenotypes in Chinese male nuclear families.

    Science.gov (United States)

    Gu, Jie-mei; Xiao, Wen-jin; He, Jin-wei; Zhang, Hao; Hu, Wei-wei; Hu, Yun-qiu; Li, Miao; Liu, Yu-juan; Fu, Wen-zhen; Yu, Jin-bo; Gao, Gao; Yue, Hua; Ke, Yao-hua; Zhang, Zhen-lin

    2009-12-01

    The goal of this study was to determine whether polymorphisms in the vitamin D receptor (VDR) and estrogen receptor alpha (ESR1) genes are associated with variations of peak bone mineral density (BMD) and obesity phenotypes in young Chinese men. A total of 1215 subjects from 400 Chinese nuclear families were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele-specific multiple PCR (ASM-PCR) analysis at the ApaI, FokI, and CDX2 sites in the VDR gene and the PvuII and XbaI sites in the ESR1 gene. BMD at the lumbar spine and hip, total fat mass, and total lean mass were measured using dual energy X-ray absorptiometry. The associations between VDR and ESR1 gene polymorphisms with peak BMD, body mass index (BMI), total fat mass, total lean mass, and percentage fat mass (PFM) were determined using quantitative transmission disequilibrium tests (QTDTs). Using QTDTs, no significant within-family associations were obtained between genotypes or haplotypes of the VDR and ESR1 genes and peak BMD. For the obesity phenotypes, the within-family associations were significant between CDX2 genotypes and BMI (P=0.046), fat mass (P=0.004), and PFM (P=0.020). Further, PvuII was significantly associated with the variation of fat mass and PFM (P=0.002 and P=0.039, respectively). A subsequent 1000 permutations were in agreement with these within-family association results. Our findings showed that VDR and ESR1 polymorphisms were associated with total fat mass in young Chinese men, but we failed to find a significant association between VDR and ESR1 genotypes and peak BMD. These findings suggested that the VDR and ESR1 genes are quantitative trait loci (QTL) underlying fat mass variation in young Chinese men.

  5. Studies on the reliability of high-field intra-operative MRI in brain glioma resection

    Directory of Open Access Journals (Sweden)

    Zhi-jun SONG

    2011-07-01

    Full Text Available Objective To evaluate the reliability of high-field intra-operative magnetic resonance imaging(iMRI in detecting the residual tumors during glioma resection.Method One hundred and thirty-one cases of brain glioma(69 males and 62 females,aged from 7 to 79 years with mean of 39.6 years hospitalized from Nov.2009 to Aug.2010 were involved in present study.All the patients were evaluated using magnetic resonance imaging(MRI before the operation.The tumors were resected under conventional navigation microscope,and the high-field iMRI was used for all the patients when the operators considered the tumor was satisfactorily resected,while the residual tumor was difficult to detect under the microscope,but resected after being revealed by high-field iMRI.Histopathological examination was performed.The patients without residual tumors recieved high-field MRI scan at day 4 or 5 after operation to evaluate the accuracy of high-field iMRI during operation.Results High quality intra-operative images were obtained by using high-field iMRI.Twenty-eight cases were excluded because their residual tumors were not resected due to their location too close to functional area.Combined with the results of intra-operative histopathological examination and post-operative MRI at the early recovery stage,the sensitivity of high-field iMRI in residual tumor diagnosis was 98.0%(49/50,the specificity was 94.3%(50/53,and the accuracy was 96.1%(99/103.Conclusion High-quality intra-operative imaging could be acquired by high-field iMRI,which maybe used as a safe and reliable method in detecting the residual tumors during glioma resection.

  6. Establishing resolution-improved NMR spectroscopy in high magnetic fields with unknown spatiotemporal variations

    Science.gov (United States)

    Zhang, Zhiyong; Smith, Pieter E. S.; Cai, Shuhui; Zheng, Zhenyao; Lin, Yulan; Chen, Zhong

    2015-12-01

    A half-century quest for higher magnetic fields has been an integral part of the progress undergone in the Nuclear Magnetic Resonance (NMR) study of materials' structure and dynamics. Because 2D NMR relies on systematic changes in coherences' phases as a function of an encoding time varied over a series of independent experiments, it generally cannot be applied in temporally unstable fields. This precludes most NMR methods from being used to characterize samples situated in hybrid or resistive magnets that are capable of achieving extremely high magnetic field strength. Recently, "ultrafast" NMR has been developed into an effective and widely applicable methodology enabling the acquisition of a multidimensional NMR spectrum in a single scan; it can therefore be used to partially mitigate the effects of temporally varying magnetic fields. Nevertheless, the strong interference of fluctuating fields with the spatial encoding of ultrafast NMR still severely restricts measurement sensitivity and resolution. Here, we introduce a strategy for obtaining high resolution NMR spectra that exploits the immunity of intermolecular zero-quantum coherences (iZQCs) to field instabilities and inhomogeneities. The spatial encoding of iZQCs is combined with a J-modulated detection scheme that removes the influence of arbitrary field inhomogeneities during acquisition. This new method can acquire high-resolution one-dimensional NMR spectra in large inhomogeneous and fluctuating fields, and it is tested with fields experimentally modeled to mimic those of resistive and resistive-superconducting hybrid magnets.

  7. High field magnetization and specific heat of ErNi{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Kayzel, F.E.; Franse, J.J.M. [Univ. van Amsterdam (Netherlands). Van der Waals-Zeeman Lab.; Radwanski, R.J. [Centre for Solid State Physics, Krakow (Poland)

    1994-03-01

    High field magnetization studies of single crystalline ErNi{sub 5} in fields up to 38T at 1.5K along the main crystallographic directions have been performed. Along the easy direction, the hexagonal axis, the spontaneous magnetization, M{sub s}, amounts to 8.62{mu}{sub B}/f.u. The high-field susceptibility is very small and equal to 41 {times} 10{sup {minus}4}{mu}{sub B}/Tf.u. There exists a distinct difference between the curves along the a- and b-axis. The a-axis curve monotonously increases with field up to 38T. The b-axis curve coincides with the a-axis curve up to 12T but starts to deviate from it above this field, resulting in a value for the magnetization at 38T which is almost the full moment value. The specific beat of a newly-grown single-crystalline sample has been measured in zero field and in applied fields along the c-axis (B = 0.3, 1, 2, 5T). The zero-field measurements coincide with previously reported results The specific heat shows a rapid decrease of the ferrimagnetic order with applied field. Already in 1T, the sharp lambda-type of peak at the magnetic transition is decreased by two third and becomes a broad bump that coincides with the la measurement above 30K. Higher fields further suppress the transition.

  8. Study on technology of high-frequency pulsed magnetic field strength measurement.

    Science.gov (United States)

    Chen, Yi-Mei; Liu, Zhi-Peng; Yin, Tao

    2012-01-01

    High-frequency transient weak magnetic field is always involved in researches about biomedical engineering field while common magnetic-field sensors cannot work properly at frequencies as high as MHz. To measure the value of MHz-level weak pulsed magnetic-field strength accurately, this paper designs a measurement and calibration method for pulsed magnetic-field. In this paper, a device made of Nonferromagnetic material was independently designed and applied to pulsed magnetic field measurement. It held an accurately relative position between the magnetic field generating coil and the detecting coil. By applying a sinusoidal pulse to the generator, collecting the induced electromotive force of the detector, the final magnetic field strength was worked out through algorithms written in Matlab according to Faraday's Law. Experiments were carried out for measurement and calibration. Experiments showed that, under good stability and consistency, accurate measurement of magnetic-field strength of a sinepulse magnetic-field can be achieved, with frequency at 0.5, 1, 1.5 MHz and strength level at micro-Tesla. Calibration results carried out a measuring relative error about 2.5%.

  9. GPU-accelerated FDTD modeling of radio-frequency field-tissue interactions in high-field MRI.

    Science.gov (United States)

    Chi, Jieru; Liu, Feng; Weber, Ewald; Li, Yu; Crozier, Stuart

    2011-06-01

    The analysis of high-field RF field-tissue interactions requires high-performance finite-difference time-domain (FDTD) computing. Conventional CPU-based FDTD calculations offer limited computing performance in a PC environment. This study presents a graphics processing unit (GPU)-based parallel-computing framework, producing substantially boosted computing efficiency (with a two-order speedup factor) at a PC-level cost. Specific details of implementing the FDTD method on a GPU architecture have been presented and the new computational strategy has been successfully applied to the design of a novel 8-element transceive RF coil system at 9.4 T. Facilitated by the powerful GPU-FDTD computing, the new RF coil array offers optimized fields (averaging 25% improvement in sensitivity, and 20% reduction in loop coupling compared with conventional array structures of the same size) for small animal imaging with a robust RF configuration. The GPU-enabled acceleration paves the way for FDTD to be applied for both detailed forward modeling and inverse design of MRI coils, which were previously impractical.

  10. A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

    Directory of Open Access Journals (Sweden)

    Yun-Wang Choi

    2015-01-01

    Full Text Available In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.

  11. Lumbar Modic Changes - A Comparison Between Findings at Low-and High-field MRI

    DEFF Research Database (Denmark)

    Bendix, Tom; Sorensen, Joan S; Henriksson, Gustaf A C

    2012-01-01

    -81), with or without sciatica, seen in a Danish outpatient LBP clinic were included. All patients had MRI scans on both a high-field and a low-field MRI scanner. Two radiologists evaluated all lumbar endplates independently using a standardized evaluation protocol. Kappa statistics were used to analyze the inter...

  12. Isolating Flow-field Discontinuities while Preserving Monotonicity and High-order Accuracy on Cartesian Meshes

    Science.gov (United States)

    2017-01-09

    19b. TELEPHONE NUMBER (Include area code) 01/09/2017 Briefing Charts 01 January 2017 - 31 January 2017 Isolating Flow -field Discontinuities while...Unclassified Unclassified Unclassified SAR 18 V. Sanakaran N/A Isolating Flow -field Discontinuities while Preserving Monotonicity and High-order

  13. Charge transport in poly(p-phenylene vinylene) at low temperature and high electric field

    NARCIS (Netherlands)

    Katsouras, I.; Najafi, A.; Asadi, K.; Kronemeijer, A. J.; Oostra, A. J.; Koster, L. J. A.; de Leeuw, D. M.; Blom, P. W. M.

    Charge transport in poly(2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV)-based hole-only diodes is investigated at high electric fields and low temperatures using a novel diode architecture. Charge carrier densities that are in the range of those in a field-effect transistor are

  14. Neutron scattering study of the incommensurate high-field phase of CuGeO3

    DEFF Research Database (Denmark)

    Rønnow, H.M.; Enderle, M.; McMorrow, D.F.

    2000-01-01

    CuGeO3 is a good realization of a spin-Peierls system. Using neutron scattering, we have investigated the transition from the dimerized spin-Peierls phase to an incommensurately modulated high-field phase. The incommensurate period has been measured for fields up to 14.5 T and is found...

  15. High-field 3He-F interaction at the surface of fluorocarbon spheres

    DEFF Research Database (Denmark)

    Schuhl, A.; Chapellier, M.; Rasmussen, Finn Berg

    1984-01-01

    High-field experiments on the relaxation betweenF in small Teflon spheres andHe on the surface are reported. WithHe as a monolayer, coupling times are found to be less than 5 sec, in magnetic fields up to 3 T and temperatures down to 50 mK, where electronic centers are completely polarized...

  16. A SIMPLE ANALYSIS OF THE PROPAGATING ACOUSTOELECTRIC HIGH-FIELD DOMAIN

    DEFF Research Database (Denmark)

    Mosekilde, Erik

    1968-01-01

    An analytical treatment of the uniformly propagating acoustoelectric high-field domain is presented in the limit of zero diffusion. Expressions for the electron density and the acoustic energy density as functions of the electric field are given. The domain velocity is determined. ©1968 The Ameri...... The American Institute of Physics...

  17. In-situ high field strength testing using a transportable reverberation chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes

    2008-01-01

    A reverberation chamber can create very high field strength with moderate input power. Existing chambers are making use of a paddle wheel to change the resonant modes in the chamber. In the case of a stepper motor, the field is stable for some time, and this type of reverberation chamber is called

  18. Application of Nb3Sn superconductors in high-field accelerator magnets

    NARCIS (Netherlands)

    den Ouden, A.; Wessel, Wilhelm A.J.; Krooshoop, Hendrikus J.G.; ten Kate, Herman H.J.

    1997-01-01

    Last year a record central field of 11 T at first excitation at 4.4 K has been achieved with the experimental LHC model dipole magnet MSUT by utilising a high Jc powder-in-tube Nb3Sn conductor. This is the first real breakthrough towards fields well above 10 T at 4 K. The clear influence of

  19. High-field Faraday rotation in II-VI-based semimagnetic semiconductors

    NARCIS (Netherlands)

    Savchuk, AI; Fediv, [No Value; Nikitin, PI; Perrone, A; Tatzenko, OM; Platonov, VV

    The effects of d-d exchange interaction have been studied by measuring high-field Faraday rotation in II-VI-based semimagnetic semiconductors. For Cd1-xMnxTe crystals with x = 0.43 and at room temperature a saturation in magnetic field dependence of the Faraday rotation has been observed. In the

  20. Development of an open source package for the processing of sun-sky photometric data in the European Skyrad Users network (ESR)

    Science.gov (United States)

    Estelles, V.; Smyth, T.; Campanelli, M.; Utrillas, M. P.

    2009-04-01

    ; therefore, 1) the instrument absence generates considerable data gaps, 2) it is also a chance for equipment damage during the transport, and 3) the proprietary group must cope with the economical cost of these international insured deliveries. Moreover, the protocol constrains the network capability to handle a large amount of instruments. In fact, AERONET is very reluctant at the moment to accept new sites in Europe. ESR has developed an improved version of the Langley plot technique (SKYIL) that allows the users to perform a continuous in situ calibration. Previous results show that the obtained uncertainties in the calibration factors (1.0 - 2.5%) are very similar to the uncertainty values for field instruments in AERONET (1.0 - 2.0%). A third difference that could make ESR more appealing to some European research groups is related to the algorithms itself. The core inversion code (Skyrad.pack), the calibration codes and all the automatization scripts are free open source codes that can be further customized by the users. Therefore, an advanced user could easily access and modify the algorithms for new improvements. As a conclusion, the ESR users network has been conceived as a flexible network and collaborative platform for European groups whose main research is focused on atmospheric aerosols characterization and model development. The package we have developed for the network is an open source product that is available for public use, both for Cimel CE318 and Prede POM instruments.

  1. Detection of 2-deoxy-D-ribose radicals generated by the reaction with the hydroxyl radical using a rapid flow-ESR method.

    Science.gov (United States)

    Ohashi, Yasunori; Yoshioka, Hisashi; Yoshioka, Hiroe

    2002-04-01

    ESR spectrum of the short-lived radicals derived from 2-deoxy-D-ribose by the reaction with the hydroxyl radical (HO*) was measured using a rapid flow method. A dielectric mixing resonator was used for the measurement, which made it possible to measure the highly sensitive ESR spectra of the radicals with a lifetime of the order of milliseconds. A complex spectrum was obtained and the spectral simulation was done to show that it was the superposition of the signals due to five radicals (I-V). Three of them were those formed by the dehydrogenation with the HO* at C-1 (I), C-3 (II), and C-4 (III) positions of the 2-deoxy-D-ribose molecule. The other two (IV and V) were carbonyl-conjugated radicals formed by the elimination of a water molecule from III and II. The results showed that dehydrogenation occurred randomly at the positions where hydroxyl groups are attached, but the most preferred position was C-3 and the radical position moved from C-3 to C-4 by the elimination of water molecule.

  2. Use of meta-analysis to combine candidate gene association studies: application to study the relationship between the ESR PvuII polymorphism and sow litter size

    Directory of Open Access Journals (Sweden)

    Alfonso Leopoldo

    2005-07-01

    Full Text Available Abstract This article investigates the application of meta-analysis on livestock candidate gene effects. The PvuII polymorphism of the ESR gene is used as an example. The association among ESR PvuII alleles with the number of piglets born alive and total born in the first (NBA1, TNB1 and later parities (NBA, TNB is reviewed by conducting a meta-analysis of 15 published studies including 9329 sows. Under a fixed effects model, litter size values were significantly lower in the "AA" genotype groups when compared with "AB" and "BB" homozygotes. Under the random effects model, the results were similar although differences between "AA" and "AB" genotype groups were not clearly significant for NBA and TNB. Nevertheless, the most noticeable result was the high and significant heterogeneity estimated among studies. This heterogeneity could be assigned to error sampling, genotype by environment interaction, linkage or epistasis, as referred to in the literature, but also to the hypothesis of population admixture/stratification. It is concluded that meta-analysis can be considered as a helpful analytical tool to synthesise and discuss livestock candidate gene effects. The main difficulty found was the insufficient information on the standard errors of the estimated genotype effects in several publications. Consequently, the convenience of publishing the standard errors or the concrete P-values instead of the test significance level should be recommended to guarantee the quality of candidate gene effect meta-analyses.

  3. Flexible, High Performance Microlens Array Technologies for Integral Field Spectrographs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For the purposes of advancing integral field spectrograph (IFS) microlens capabilities, a new class of high-quality optics-grade nanostructured organic-inorganic...

  4. Static high-gradient magnetic fields affect the functionality of monocytic cells

    Czech Academy of Sciences Publication Activity Database

    Syrovets, T.; Schmidt, Z.; Buechele, B.; Zablotskyy, Vitaliy A.; Dejneka, Alexandr; Dempsey, N.; Simmet, T.

    2014-01-01

    Roč. 28, č. 1 (2014), s. 1-2 ISSN 0892-6638 Institutional support: RVO:68378271 Keywords : static high-gradient * magnet ic fields * affect the functionality * monocytic cells Subject RIV: BM - Solid Matter Physics ; Magnet ism

  5. High Resolution Multispectral Flow Imaging of Cells with Extended Depth of Field Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Proposed is the development the extended depth of field (EDF) or confocal like imaging capabilities of a breakthrough multispectral high resolution imaging flow...

  6. Landau level splitting in Cd3As2 under high magnetic fields

    National Research Council Canada - National Science Library

    Cao, Junzhi; Liang, Sihang; Zhang, Cheng; Liu, Yanwen; Huang, Junwei; Jin, Zhao; Chen, Zhi-Gang; Wang, Zhijun; Wang, Qisi; Zhao, Jun; Li, Shiyan; Dai, Xi; Zou, Jin; Xia, Zhengcai; Li, Liang; Xiu, Faxian

    2015-01-01

    .... Here we report the first transport experiment on Landau level splitting in TDS Cd3As2 single crystals under high magnetic fields, suggesting the removal of spin degeneracy by breaking time reversal symmetry...

  7. Does high field MRI allow an earlier diagnosis of multiple sclerosis?

    NARCIS (Netherlands)

    Wattjes, M.P.; Harzheim, M.; Lutterbey, G.G.; Hojati, F.; Simon, B.; Schmidt, S.; Schild, H.H.; Barkhof, F.

    2008-01-01

    Background :High field magnetic resonance imaging (MRI) provides higher lesion load measurements in patients presenting with clinically isolated syndromes (CIS) suggestive of demyelination and has impact upon the classification of these syndromes and potentially, the diagnosis of multiple sclerosis

  8. Microstrip Resonator for High Field MRI with Capacitor-Segmented Strip and Ground Plane

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade

    2017-01-01

    ) segmenting stripe and ground plane of the resonator with series capacitors. The design equations for capacitors providing symmetric current distribution are derived. The performance of two types of segmented resonators are investigated experimentally. To authors’ knowledge, a microstrip resonator, where both......High field MRI coils are often based on transmission line resonators. Due to relatively short wavelength of RF fields, such coils produce uneven field patterns. Here we show, that it is possible to manipulate magnetic field patterns of microstrip resonators in both planes (sagittal and transverse......, strip and ground plane are capacitor-segmented, is shown here for the first time....

  9. ESR detection of free radicals produced in irradiated fresh fruits and dried foods

    Energy Technology Data Exchange (ETDEWEB)

    Bustos G, E. [CICATA, IPN, 07000 Mexico D.F. (Mexico); Gomes, V.; Garcia, F. [IQUNAM, 04500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2007-07-01

    Full text: Electron spin resonance (ESR) technique was used to measure the stability of free radicals produced by the irradiation treatment in mangoes and in four spices: black pepper, oregano, 'guajillo' chili and 'morron' chili. The ESR spectra for mangoes were scanned in three different parts from the seeds and were recorded in fresh and dried tissues. The ESR spectra in fresh tissue of no irradiated mangoes, were a sextet line signal produced by Mn{sup 2+} ion and a singlet centered at g = 2.00 produced by the endogenous radical. New resonances were observed in the irradiated samples at 1.5 mT and 3 mT respects to the center line for right and left side. These new resonance signals were-observed for eight days in mangoes treated at 1.00 kGy, and for three days at 0.15 kGy. The resonance due to the irradiation was observed in Iyophilized mangoes only one day after the treatment, in the vacuum dried samples, no new resonances were observed. The triplet signal, as well as the central single line appeared after irradiation in black pepper, morron chili and guajillo chili. These signals were also observed in the irradiated spices at any radiation dose higher than 1.0 kGy. The signals decrease promptly, in ten days after the 'irradiation. It was not possible to observe the triplet signal in oregano, even when the samples were analyzed immediately after irradiation treatment. The only signal observed in irradiated spice was the endogenous radical. This signal increased as the radiation dose increased and decreased during storage time at room temperature. Results showed that free radicals produced in irradiated fresh fruits or dried foods have a quick recombination. It was observed that in the spices the signal remains for several weeks meanwhile only eight days in mangoes. (Author)

  10. High-field magnetisation measurements on R sub 2 Fe sub 14 B single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Verhoef, R.; Franse, J.J.M.; Menovsky, A.A.; Radwanski, R.J. (Amsterdam Univ. (NL). Natuurkundig Lab.); Song-quan, J.; Fu-ming, Y. (Academia Sinica, Beijing (CN). Inst. of Physics); Li, H.S.; Gavigan, J.P. (Trinity Coll. Dublin (IE). Dept. of Pure and Applied Physics)

    1988-12-01

    High-field magnetisation measurements on single crystalline samples of Pr{sub 2}Fe{sub 14}B, Nd{sub 2}Fe{sub 14}B and Dy{sub 2}Fe{sub 14}B are presented and discussed within a two-sublattice model. Special attention is given to the high-field part of the curves (B{sub o} > 20 T).

  11. Theoretical analysis of ESR spectra of vanadyl 2-formul-3-hydroxybenzothiophene-2-hydroxyanilinate

    Energy Technology Data Exchange (ETDEWEB)

    Rakitin, Yu.V.; Kasumov, R.D.; Zelentsov, V.V.; Kalinnikov, V.T. (AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii; Moskovskij Inzhenerno-Fizicheskij Inst. (USSR))

    1981-01-01

    The dimer structure of vanadyl 2-formyl-3-hydroxybenzothiophene-2-hydroxyanilinate is confirmed on the basis of the analysis of ESR spectra. It is shown that the compound presents a mixture of two stereoisomers, in which yl oxygens are in cis- or trans-positions as to the coordination plane, the trans-form dominating. The data obtained are used to explain magnetic properties of vanadyl dimer complexes with three-dentate Schiff bases and to analyze the mechanisms of exchange interactions in the compounds.

  12. Microviscosity of water-containing heterogeneous systems. An ESR spin probe study

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, B.; Hanke, T.; Reuther, F.

    The microstructure of maltodextrin gels was studied by ESR spin probe technique. From investigations of the time dependence of the gelling process and from the Arrhenius plot of the rotational correlation time, important information about the phase behavior of the system is obtained. The microviscosity decreases with swelling time, whereas the macroviscosity increases. The conclusion is drawn that the maltodextrin gel is a two-phase system and can be characterized in the nomenclature of Papkov as a gel of the second type. (author).

  13. B0 mapping with multi-channel RF coils at high field.

    Science.gov (United States)

    Robinson, Simon; Jovicich, Jorge

    2011-10-01

    Mapping the static magnetic field via the phase evolution over gradient echo scans acquired at two or more echo times is an established method. A number of possibilities exist, however, for combining phase data from multi-channel coils, denoising and thresholding field maps for high field applications. Three methods for combining phase images when no body/volume coil is available are tested: (i) Hermitian product, (ii) phase-matching over channels, and (iii) a new approach based on calculating separate field maps for each channel. The separate channel method is shown to yield field maps with higher signal-to-noise ratio than the Hermitian product and phase-matching methods and fewer unwrapping errors at low signal-to-noise ratio. Separate channel combination also allows unreliable voxels to be identified via the standard deviation over channels, which is found to be the most effective means of denoising field maps. Tests were performed using multichannel coils with between 8 and 32 channels at 3 T, 4 T, and 7 T. For application in the correction of distortions in echo-planar images, a formulation is proposed for reducing the local gradient of field maps to eliminate signal pile-up or swapping artifacts. Field maps calculated using these techniques, implemented in a freely available MATLAB toolbox, provide the basis for an effective correction for echo-planar imaging distortions at high fields. Copyright © 2011 Wiley-Liss, Inc.

  14. In situ electrochemical ESR and voltammetric studies on the anodic oxidation of para-haloanilines in acetonitrile.

    Science.gov (United States)

    Streeter, Ian; Wain, Andrew J; Thompson, Mary; Compton, Richard G

    2005-06-30

    An in situ electrochemical electron spin resonance (ESR) study on the electro-oxidation of para-chloroaniline, para-bromoaniline, and para-iodoaniline dissolved in acetonitrile at gold electrodes is reported. ESR spectra obtained using a tubular flow cell reveal the presence of a paramagnetic dimer product derived from para-aminodiphenylamine, during oxidative electrolysis, suggesting the coupling of reactive electrogenerated radical cations with neutral parent haloaniline molecules. The ESR signal intensity behaves in a manner expected for a radical species reacting with second-order kinetics, suggesting the paramagnetic dimer is, itself, unstable. The theory describing the ESR signal intensity flow rate behavior for this reaction mechanism is developed for the tubular arrangement and used to extract mechanistic and kinetic data from the experimental results for the cases of para-chloroaniline and para-bromoaniline. Further mechanistic aspects, including proton and halide ion expulsion during dimerization, are explored voltammetrically and with the aid of digital simulations using Digisim. Comparison of the ESR signal and voltammetric measurements suggests that an additional mechanism operates which does not lead to paramagnetic products. Additionally, the in situ electrolysis of N,N-dimethyl-para-bromoaniline is reported to generate the stable radical cation of N,N,N',N'-tetramethylbenzidine, and a mechanism of electro-oxidation is, thus, proposed.

  15. Formation and texture of Bi-2223 phase during sintering in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.Y.; Nagata, A.; Watanabe, K.; Nojima, T.; Sugawara, K.; Hanada, S.; Kamada, S

    2003-10-15

    The formation and texture of Bi-2223 phase during sintering in high magnetic fields were investigated. Samples contained in silver crucibles were sintered at different temperatures from 835 to 860 deg. C for 120 h in a vertical tube furnace installed in a solenoid-type superconducting magnet. A vertical magnetic field, H{sub a} of 10 T can be applied parallel to the long axis of the furnace. It has been found that the mixed structures of the Bi-2223 and the Bi-2212 grains with their c-axis parallel to the magnetic field are formed in samples sintered at 850-855 deg. C in 10 T magnetic field. Below 845 deg. C sintering in 10 T, a high proportion of Bi-2223 phase is obtained, however no preferred orientation is observed. It is suggested that a liquid phase is important for the formation of the textured structure in magnetic fields.

  16. Effect of very high magnetic field on the optical properties of firefly light emitter oxyluciferin

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weihang; Nakamura, Daisuke [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Wang, Yu [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences (China); Mochizuki, Toshimitsu [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, 2-2-9 Machiike-dai, Koriyama, Fukushima 963-0215 (Japan); Akiyama, Hidefumi [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Takeyama, Shojiro, E-mail: takeyama@issp.u-tokyo.ac.jp [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2015-09-15

    Magnetic field effect on enzymatic reactions is under intensive study in the past decades. Recently, it was reported that firefly bioluminescence was suppressed and red-shifted significantly when exposed to external magnetic field. However in this work, by means of selective excitation, we confirmed that emission properties of firefly light emitter “oxyluciferin” are completely immune to external magnetic field of up to 53 T. These findings pose strong contrast to existing relevant results. Potential reasons for the discrepancies found and the underlying physics towards the understanding of firefly bioluminescence were discussed. - Highlights: • Effect of ultra-high magnetic field on the optical properties of firefly light emitter oxyluciferin was reported. • Emission properties of oxyluciferin were confirmed to be immune to external high magnetic fields up to 53 T. • .Potential reasons for the discrepancies between our results and previous reports and the underlying physics were discussed.

  17. High sensitive LPFG magnetic field sensor based on dual-peak resonance

    Science.gov (United States)

    Gu, Zhengtian; Ling, Qiang; Lan, Jinlong; Gao, Kan

    2017-11-01

    A high sensitivity magnetic field sensor based on magnetic-fluid-clad LPFG structure with dual peak resonance is presented and experimentally investigated. Based on coupled mode theory, the sensing principle of this sensor is originated from the sensibility of the dual peak based LPFG to the environment refractive index. In experiment, a dual peak interval change was available to 38 nm with a magnetic field strength varying from 0 to 12 mT when the temperature was 17.3 °C, and the dual peak interval displays a cubic polynomial dependence with the magnetic field strength at the low field regime. The sensitivity of this sensor to the magnetic field can be available to 4.08 nm/mT, and it is one order and two orders of magnitude higher than that of the sensors based on MSM and SMS fiber structure, respectively. The novel sensor has many advantages of simple technology, structure stability and high sensitivity.

  18. High field septum magnet using a superconducting shield for the Future Circular Collider

    CERN Document Server

    AUTHOR|(CDS)2069375

    2017-01-01

    A zero-field cooled superconducting shield is proposed to realize a high-field (3–4 T) septum magnet for the Future Circular Collider hadron-hadron (FCC-hh) ring. Three planned prototypes using different materials and technical solutions are presented, which will be used to evaluate the feasibility of this idea as a part of the FCC study. The numerical simulation methods are described to calculate the field patterns around such a shield. A specific excitation current configuration is presented that maintains a fairly homogeneous field outside of a rectangular shield in a wide range of field levels from 0 to 3 Tesla. It is shown that a massless septum configuration (with an opening in the shield) is also possible and gives satisfactory field quality with realistic superconducting material properties.

  19. Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions

    OpenAIRE

    Kapusta, Joseph I.; Chen, Guangyao; Fries, Rainer J.; Li, Yang

    2016-01-01

    Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for ene...

  20. Comparative High Field Magneto-transport Of Rare Earth Oxypnictides With Maximum Transition Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Balakirev, Fedor F [Los Alamos National Laboratory; Migliori, A [MPA-NHMFL; Riggs, S [NHMFL-FSU; Hunte, F [NHMFL-FSU; Gurevich, A [NHMFL-FSU; Larbalestier, D [NHMFL-FSU; Boebinger, G [NHMFL-FSU; Jaroszynski, J [NHMFL-FSU; Ren, Z [CHINA; Lu, W [CHINA; Yang, J [CHINA; Shen, X [CHINA; Dong, X [CHINA; Zhao, Z [CHINA; Jin, R [ORNL; Sefat, A [ORNL; Mcguire, M [ORNL; Sales, B [ORNL; Christen, D [ORNL; Mandrus, D [ORNL

    2008-01-01

    We compare magnetotransport of the three iron-arsenide-based compounds ReFeAsO (Re=La, Sm, Nd) in very high DC and pulsed magnetic fields up to 45 and 54 T, respectively. Each sample studied exhibits a superconducting transition temperature near the maximum reported to date for that particular compound. While high magnetic fields do not suppress the superconducting state appreciably, the resistivity, Hall coefficient, and critical magnetic fields, taken together, suggest that the phenomenology and superconducting parameters of the oxypnictide superconductors bridges the gap between MgB{sub 2} and YBCO.

  1. The Investigation of Field Plate Design in 500 V High Voltage NLDMOS

    Directory of Open Access Journals (Sweden)

    Donghua Liu

    2015-01-01

    Full Text Available This paper presents a 500 V high voltage NLDMOS with breakdown voltage (VBD improved by field plate technology. Effect of metal field plate (MFP and polysilicon field plate (PFP on breakdown voltage improvement of high voltage NLDMOS is studied. The coeffect of MFP and PFP on drain side has also been investigated. A 500 V NLDMOS is demonstrated with a 37 μm drift length and optimized MFP and PFP design. Finally the breakdown voltage 590 V and excellent on-resistance performance (Rsp = 7.88 ohm * mm2 are achieved.

  2. Determining of the electric field strength using high frequency broadband measurements

    OpenAIRE

    Vulević, Branislav D.

    2017-01-01

    Exposure of humans to electromagnetic fields of high frequency (above 100 kHz), i.e. radiofrequency radiation from the modern wireless systems, today inevitable is. The purpose of this paper is to highlight the importance of broadband measurements of the electric field of high frequency in order to fast and reliable assessment of human exposure. A practical method of ‘in situ’ measurement the electric field intensity which is related to the frequency range of 3 MHz to 18 GHz, is provided.

  3. High temperature study of flexible silicon-on-insulator fin field-effect transistors

    KAUST Repository

    Diab, Amer El Hajj

    2014-09-29

    We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry\\'s most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.

  4. A carbon nanotube field emission cathode with high current density and long-term stability

    Energy Technology Data Exchange (ETDEWEB)

    Calderon-Colon, Xiomara; Zhou, Otto [Curriculum in Applied Science and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States); Geng Huaizhi; Gao Bo [Xintek, Incorporated, 7020 Kit Creek Road, Research Triangle Park, NC (United States); An Lei; Cao Guohua [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 (United States)

    2009-08-12

    Carbon nanotube (CNT) field emitters are now being evaluated for a wide range of vacuum electronic applications. However, problems including short lifetime at high current density, instability under high voltage, poor emission uniformity, and pixel-to-pixel inconsistency are still major obstacles for device applications. We developed an electrophoretic process to fabricate composite CNT films with controlled nanotube orientation and surface density, and enhanced adhesion. The cathodes have significantly enhanced macroscopic field emission current density and long-term stability under high operating voltages. The application of this CNT electron source for high-resolution x-ray imaging is demonstrated.

  5. Prediction model of sinoatrial node field potential using high order partial least squares.

    Science.gov (United States)

    Feng, Yu; Cao, Hui; Zhang, Yanbin

    2015-01-01

    High order partial least squares (HOPLS) is a novel data processing method. It is highly suitable for building prediction model which has tensor input and output. The objective of this study is to build a prediction model of the relationship between sinoatrial node field potential and high glucose using HOPLS. The three sub-signals of the sinoatrial node field potential made up the model's input. The concentration and the actuation duration of high glucose made up the model's output. The results showed that on the premise of predicting two dimensional variables, HOPLS had the same predictive ability and a lower dispersion degree compared with partial least squares (PLS).

  6. Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

    DEFF Research Database (Denmark)

    Madsen, A. M.; Sharma, Anoop Kumar

    2008-01-01

    and 315 mg dust (net recovery of the lyophilized dust) was sampled during a period of 7 days, respectively. The sampling rates of the electrostatic field samplers were between 1.34 and 1.96 mg dust per hour, the value for the Gravikon was between 0.083 and 0.108 mg dust per hour and the values for the GSP...

  7. Transport Jc Measurements of HTS Conductors under High Magnetic Field at LNCMI

    Science.gov (United States)

    Chaud, Xavier; Debray, François; Mossang, Eric; Tixador, Pascal; Rey, Jean-Michel; Lecrevisse, Thibault; Bruzek, Christian-Eric

    The LNCMI, the national French high magnetic field facility, provides high fields generated mainly by resistive magnets. Because of the forecast increasing price of electricity, LNCMI has a strong incentive to participate to the development and characterizations of HTS conductors in view of their use for the generation of strong field. Latest YBCO coated conductors have improved properties showing a great potential with that respect, without excluding Bi2212 and MgB2 for particular cases. We present the existing set-up to measure short straight or VAMAS type coil samples at variable temperature and high field up to 30 T, and some measurements obtained on different HTS conductors, Bi2212 round wires and YBCO coated conductors. We also report on the first results obtained at 18 T with a pancake coil made of commercial YBCO coated conductor tapes on a newly developed solenoid test bench.

  8. ENPP1 and ESR1 genotypes influence temporomandibular disorders development and surgical treatment response in dentofacial deformities.

    Science.gov (United States)

    Nicot, Romain; Vieira, Alexandre R; Raoul, Gwénaël; Delmotte, Constance; Duhamel, Alain; Ferri, Joël; Sciote, James J

    2016-09-01

    Dentofacial deformities are dys-morpho-functional disorders involving the temporomandibular joints (TMJ). Many authors have reported a TMJ improvement in dysfunctional subjects with malocclusion after orthodontic or combined orthodontic and surgical treatment particularly for the relief of pain. In particular, few studies have highlighted the demographic and clinical predictors of response to surgical treatment. To date, no genetic factor has yet been identified as a predictor of response to surgical treatment. The aim of this cohort study is therefore to identify single-nucleotide polymorphisms associated with postoperative temporomandibular disorders (TMD) or with TMJ symptoms after orthognathic surgery. Here, we found the AA genotype of SNP rs1643821 (ESR1 gene) as a risk factor for dysfunctional worsening after orthognathic surgery. In addition, we have identified TT genotype of SNP rs858339 (ENPP1 gene) as a protective factor against TMD in a population of patients with dentofacial deformities. Conversely, the heterozygous genotype AT was identified as a risk factor of TMD with respect to the rest of our population. All these elements are particularly important to bring new screening strategies and tailor future treatment. This study allows us to identify sub-populations at high risk of developing postoperative temporomandibular disorders after orthognathic surgery procedures. Many other genes of interest could be potential factors influencing the dysfunctional response to orthognathic surgery, particularly genes of the Opera cohort. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. All rights reserved.

  9. Molecular genetic studies of bipolar disorder and puerperal psychosis at two polymorphisms in the estrogen receptor alpha gene (ESR 1).

    Science.gov (United States)

    Jones, I; Middle, F; McCandless, F; Coyle, N; Robertson, E; Brockington, I; Lendon, C; Craddock, N

    2000-12-04

    A number of lines of evidence point to the possible involvement of estrogen pathways in the pathophysiology of bipolar disorder in general and puerperal psychosis in particular. There is strong evidence from clinical, follow-up, and genetic studies to support the hypothesis that most cases of puerperal psychosis are manifestations of an affective disorder diathesis with a puerperal trigger and that genes influence susceptibility to both diathesis and trigger. The nature of the trigger is unknown but in view of the abrupt onset at a time of major physiological change it is widely believed that biological, probably hormonal, mechanisms are of paramount importance, with estrogen receiving the most attention to date. We have undertaken a case control association study of bipolar disorder and puerperal psychosis at two known polymorphisms within the estrogen receptor alpha gene (ESR 1) in a sample of 219 unrelated bipolar probands and 219 controls. We could exclude these polymorphisms from an important contribution to susceptibility to bipolar disorder with a high level of confidence. We found no support for the hypothesis that they contribute specific susceptibility to the puerperal trigger, but due to the small numbers of puerperal probands (n = 26) no firm conclusions can be drawn regarding their involvement in puerperal psychosis. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:850-853, 2000. Copyright 2000 Wiley-Liss, Inc.

  10. High magnetic field science and its application in the United States current status and future directions

    CERN Document Server

    National Research Council of the National Academies

    2013-01-01

    The Committee to Assess the Current Status and Future Direction of High Magnetic Field Science in the United States was convened by the National Research Council in response to a request by the National Science Foundation. This report answers three questions: (1) What is the current state of high-field magnet science, engineering, and technology in the United States, and are there any conspicuous needs to be addressed? (2) What are the current science drivers and which scientific opportunities and challenges can be anticipated over the next ten years? (3) What are the principal existing and planned high magnetic field facilities outside of the United States, what roles have U.S. high field magnet development efforts played in developing those facilities, and what potentials exist for further international collaboration in this area? A magnetic field is produced by an electrical current in a metal coil. This current exerts an expansive force on the coil, and a magnetic field is "high" if it challenges the str...

  11. 27 Al MAS NMR Studies of HBEA Zeolite at Low to High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Z.; Wan, Chuan; Vjunov, Aleksei; Wang, Meng; Zhao, Zhenchao; Hu, Mary Y.; Camaioni, Donald M.; Lercher, Johannes A.

    2017-06-01

    27Al single pulse (SP) MAS NMR spectra of HBEA zeolites with high Si/Al ratios of 71 and 75 were obtained at three magnetic field strengths of 7.05, 11.75 and 19.97 T. High field 27Al MAS NMR spectra acquired at 19.97 T show significantly improved spectral resolution, resulting in at least two well-resolved tetrahedral-Al NMR peaks. Based on the results obtained from 27Al MAS and MQMAS NMR acquired at 19.97 T, four different quadrupole peaks are used to deconvolute the 27Al SP MAS spectra acquired at vari-ous fields by using the same set of quadrupole coupling constants, asymmetric parameters and relative integrated peak intensities for the tetrahedral Al peaks. The line shapes of individual peaks change from typical quadrupole line shape at low field to essentially symmetrical line shapes at high field. We demonstrate that for fully hydrated HBEA zeolites the effect of second order quadrupole interaction can be ignored and quantitative spectral analysis can be performed by directly fitting the high field spectra using mixed Gaussian/Lorentzian line shapes. Also, the analytical steps described in our work allow direct assignment of spectral intensity to individual Al tetrahedral sites (T-sites) of zeolite HBEA. Finally, the proposed concept is suggested generally applicable to other zeo-lite framework types, thus, allowing a direct probing of Al distributions by NMR spectroscopic methods in zeolites with high confi-dence.

  12. High field magnetic behavior in Boron doped Fe{sub 2}VAl Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesh, Ch., E-mail: venkyphysicsiitm@gmail.com [Department of Physics, Indian Institute of Technology, Kharagpur (India); DCMP & MS, Tata Institute of Fundamental Research, Mumbai (India); Vasundhara, M., E-mail: vasu.mutta@gmail.com [Materials Science and Technology Division, National Institute for Interdisciplinary Science and Technology, CSIR, Trivandrum 695019 (India); Srinivas, V. [Department of Physics, Indian Institute of Technology, Chennai (India); Rao, V.V. [Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur (India)

    2016-11-15

    We have investigated the magnetic behavior of Fe{sub 2}VAl{sub 1−x}B{sub x} (x=0, 0.03, 0.06 and 0.1) alloys under high temperature and high magnetic field conditions separately. Although, the low temperature DC magnetization data for the alloys above x>0 show clear magnetic transitions, the zero field cooled (ZFC) and field cooled (FC) curves indicate the presence of spin cluster like features. Further, critical exponent (γ) deduced from the initial susceptibility above the T{sub c}, does not agree with standard models derived for 3 dimensional long range magnetic systems. The deviation in γ values are consistent with the short range magnetic nature of these alloys. We further extend the analysis of magnetic behavior by carrying the magnetization measurements at high temperatures and high magnetic fields distinctly. We mainly emphasize the following observations; (i) The magnetic hysteresis loops show sharp upturns at lower fields even at 900 K for all the alloys. (ii) High temperature inverse susceptibility do not overlap until T=900 K, indicating the persistent short range magnetic correlations even at high temperatures. (iii) The Arrott's plot of magnetization data shows spontaneous moment (M{sub S}) for the x=0 alloy at higher magnetic fields which is absent at lower fields (<50 kOe), while the Boron doped samples show feeble M{sub S} at lower fields. The origin of this short range correlation is due to presence of dilute magnetic heterogeneous phases which are not detected from the X-ray diffraction method. - Highlights: • Short range magnetic character has been confirmed by the critical exponents analysis. • Magnetoresistace is about −14% with non-saturating tendency even at 150 kOe for Fe{sub 2}VAl alloy. • Boron doped Fe{sub 2}VAl alloys show a weak magnetism even at T=900 K.

  13. Megagauss field generation for high-energy-density plasma science experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Rovang, Dean Curtis; Struve, Kenneth William; Porter, John Larry Jr.

    2008-10-01

    There is a need to generate magnetic fields both above and below 1 megagauss (100 T) with compact generators for laser-plasma experiments in the Beamlet and Petawatt test chambers for focused research on fundamental properties of high energy density magnetic plasmas. Some of the important topics that could be addressed with such a capability are magnetic field diffusion, particle confinement, plasma instabilities, spectroscopic diagnostic development, material properties, flux compression, and alternate confinement schemes, all of which could directly support experiments on Z. This report summarizes a two-month study to develop preliminary designs of magnetic field generators for three design regimes. These are, (1) a design for a relatively low-field (10 to 50 T), compact generator for modest volumes (1 to 10 cm3), (2) a high-field (50 to 200 T) design for smaller volumes (10 to 100 mm3), and (3) an extreme field (greater than 600 T) design that uses flux compression. These designs rely on existing Sandia pulsed-power expertise and equipment, and address issues of magnetic field scaling with capacitor bank design and field inductance, vacuum interface, and trade-offs between inductance and coil designs.

  14. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    Science.gov (United States)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  15. Combined passive and active shimming for in vivo MR spectroscopy at high magnetic fields

    Science.gov (United States)

    Juchem, Christoph; Muller-Bierl, Bernd; Schick, Fritz; Logothetis, Nikos K.; Pfeuffer, Josef

    2006-12-01

    The use of high magnetic fields increases the sensitivity and spectral dispersion in magnetic resonance spectroscopy (MRS) of brain metabolites. Practical limitations arise, however, from susceptibility-induced field distortions, which are increased at higher magnetic field strengths. Solutions to this problem include optimized shimming, provided that active, i.e., electronic, shimming can operate over a sufficient range. To meet our shim requirements, which were an order of magnitude greater than the active shim capacity of our 7 T MR system, we developed a combined passive and active shim approach. Simple geometries of ferromagnetic shim elements were derived and numerically optimized to generate a complete set of second-order spherical harmonic shim functions in a modular manner. The major goals of the shim design were maximization of shim field accuracy and ease of practical implementation. The theoretically optimized ferro-shim geometries were mounted on a cylindrical surface and placed inside the magnet bore, surrounding the subject's head and the RF coil. Passive shimming generated very strong shim fields and eliminated the worst of the field distortions, after which the field was further optimized by flexible and highly accurate active shimming. Here, the passive-shimming procedure was first evaluated theoretically, then applied in phantom studies and subsequently validated for in vivo1H MRS in the macaque visual cortex. No artifacts due to the passive shim setup were observed; adjustments were reproducible between sessions. The modularity and the reduction to two pieces per shim term in this study is an important simplification that makes the method applicable also for passive shimming within single sessions. The feasibility of very strong, flexible and high-quality shimming via a combined approach of passive and active shimming is of great practical relevance for MR imaging and spectroscopy at high field strengths where shim power is limited or where

  16. Quantitative measurement of nitroxyl radical in a rat head and a mouse by using an in vivo ESR imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Tomohiro; Kumakura, Mihoko [Yamagata Univ., Graduate School of Science and Engineering, Yonezawa, Yamagata (Japan); Yokoyama, Hidekatsu [Yamagata Public Corporation for the Development Industry, Inst. for Life Support Tehnology, Matsuei, Yamagata (Japan); Ogata, Tateaki [Yamagata Univ., Faculty of Engineering, Yonezawa, Yamagata (Japan)

    2002-04-01

    The concentration of a nitroxyl radical injected into living samples has been determined by using a standard marker of the known concentration in a radio frequency (about 720 MHz) ESR imaging. We have placed together a small animal (such as a rat or a mouse) and a marker of various concentration carbamoyl-PROXYL into the loop-gap resonator. The rat weighing about 300 g received an injection of carbamoyl-PROXYL saline solution (dose of radical; 4.7 mmol/kg-body weight) in the periotoneal cavity. The ESR imaging data were collected after five minutes and at about 10-min intervals until the ESR signals decreased to the background. The maximum radical concentration was calculated to be about 50 mM after 20 minutes of the radical injection. (author)

  17. Electroslag Remelting (ESR) Slags for Removal of Radioactive Oxide Contaminants from Stainless Steel, Annual Report (1998-1999)

    Energy Technology Data Exchange (ETDEWEB)

    PAL, UDAY B.

    1999-08-01

    Decontamination of radioactive contaminated stainless steel using the ESR process is investigated by conducting thermophysical and thermochemical laboratory studies on the slag. The ESR base slag investigated in this research project is 60wt%CaF{sub 2}-20wt%CaO-20wt%Al{sub 2}O{sub 3}. In this report, we present the data obtained to date on relevant slag properties, capacity to incorporate the radioactive contaminant (using CeO{sub 3}) as surrogate, simulant for PUO{sub 2} and UO{sub 2}, slag-metal partition coefficient, volatilization rate and volatile species, viscosity, electrical conductivity and surface tension as a function of temperature. The impact of these properties on the ESR decontamination process is presented.

  18. ESR study of photodegradation of N-alkylamide containing iron(III) chloride

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Y.; Yokoyama, Y.; Fujii, Y. (Yokohama National Univ. (Japan). Faculty of Engineering); Shirokaze, J.

    1982-07-01

    Photodegradation mechanism of N-alkylamides (N-methylformamide, N-methylacetamide, N-propylpropanamide, and N-propylhexanamide) containing FeCl/sub 3/ was studied mainly by means of ESR spectroscopy. Examination of IR and UV spectra revealed that amides coordinate to FeCl/sub 3/ through the oxygen atoms. A charge-transfer absorption band was observed (lambda sub(max) 312nm, epsilon = 4.3 x 10/sup 3/) in the case of N-propylpropanamide-FeCl/sub 3/. An ESR study determined structures of radicals generated by photo-irradiation of various kinds of amides containing FeCl/sub 3/. UV irradiation gave rise to a rupture of the amide linkage to produce an acyl radical. The acyl radical was decarbonylated to become an alkyl radical (or hydrogen atom in the case of N-methylformamide) by irradiation of visible light. When the alkyl radical was small (in such cases as N- methylformamide, N-methylacetamide, and N-propylpropanamide), an extraction of hydrogen atom from other molecules occurred during annealing, and two kinds of other radicals were produced : a radical bearing an unpaired electron on a carbon atom adjacent to a carbonyl group, and an iminyl radical. Detection of the iminyl radical confirmed that a generation of imine was accompanied with the formation of acyl radical at the initial process of UV irradiation.

  19. ESR isochron exercises: how accurately do modern dose rate measurements reflect paleodose rates?

    Science.gov (United States)

    Blackwell, B. A. B.; Skinner, A. R.; Blickstein, J. I. B.

    2001-12-01

    In electron spin resonance (ESR) dating tooth enamel, after selecting the appropriate U uptake model, the most significant uncertainty lies in the external dose rate, Dext( t), which can vary with time. Unlike standard ESR which measures the external dose rate in the modern context, Dext( t0), assuming that it reflects the actual external dose rate over the millennia, the isochron method calculates the time-averaged dose rate, D¯ext(t) , experienced by the tooth without such assumptions. In 45 teeth ranging from 30 ka to 4.5 Ma from 17 sites, D¯ext(t) determined by EU or LU isochrons only equalled Dext( t0) about 50% of the time. In several sites, geologic evidence indicates that secondary sedimentary processes have significantly altered sedimentary compositions and/or water concentrations, and hence, Dext( t), over time, accounting for 60-80% of D¯ext(t)-D ext(t 0) disagreements. Simulated isochrons suggest that at least seven teeth, whose isochrons had negative ages or D¯ext(t) , probably had lost U, while five, with accurate ages but very large D¯ext(t) , have likely experienced a second U uptake event.

  20. Identification of. gamma. -irradiated spices by electron spin resonance (ESR) spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Sadao; Kawamura, Yoko; Saito, Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan))

    1990-12-01

    The electron spin resonance (ESR) spectrometry spectra of white (WP), black (BP) and red (Capsicum annuum L. var. frutescerns L., RP) peppers each had a principal signal with a g-value of 2.0043, and the intensities of the principal signals were increased not only by {gamma}-irradiation but also by heating. Irradiated RP also showed a minor signal -30G from the principal one, and the intensity of the minor signal increased linearly with increasing dose from 10 to 50 kGy. Since the minor signal was observed in RP irradiated at 10 kGy and stored for one year, but did not appear either after heating or after exposure to this signal is unique to {gamma}-irradiated RP and should therefore be useful for the identification of {gamma}-irradiated spices of Capsicum genus, such as paprika and chili pepper. The computer simulation of the ESR spectra suggested that the minor signal should be assigned to methyl radical and the principal signal mainly to a combination of phenoxyl and peroxyl radicals. Such minor signals were found in {gamma}-irradiated allspice and cinnamon among 10 kinds of other spices. (author).

  1. In vivo copper-mediated free radical production: an ESR spin-trapping study

    Science.gov (United States)

    Kadiiska, Maria B.; Mason, Ronald P.

    2002-04-01

    Copper has been suggested to facilitate oxidative tissue injury through a free radical-mediated pathway analogous to the Fenton reaction. By applying the electron spin resonance (ESR) spin-trapping technique, evidence for hydroxyl radical formation in vivo was obtained in rats treated simultaneously with copper and ascorbic acid or paraquat. A secondary radical spin-trapping technique was used in which the hydroxyl radical formed the methyl radical upon reaction with dimethylsulfoxide. The methyl radical was then detected by ESR spectroscopy as its adduct with the spin trap phenyl- N- t-butyl- nitrone (PBN). In contrast, lipid derived radical was detected in vivo in copper-challenged, vitamin E and selenium-deficient rats. These findings support the proposal that dietary selenium and vitamin E can protect against lipid peroxidation and copper toxicity. Since copper excreted into the bile from treated animals is expected to be maintained in the Cu(I) state (by ascorbic acid or glutathione), a chelating agent that would redox-stablilize it in the Cu(I) state was used to prevent ex vivo redox chemistry. Bile samples were collected directly into solutions of bathocuproinedisulfonic acid, a Cu(I)-stabilizing agent, and 2,2'-dipyridyl, a Fe(II)-stabilizing agent. If these precautions were not taken, radical adducts generated ex vivo could be mistaken for radical adducts produced in vivo and excreted into the bile.

  2. [Effect of high-intensity alternating magnetic field 
on viscosity of sheep blood].

    Science.gov (United States)

    Tao, Pengxian; Wu, Xiangyang; Zhao, Lingzhi; Wang, Feng; Xia, Qi; Peng, Yan; Gao, Bingren

    2017-12-28

    To explore the changes of blood viscosity in high-intensity alternating magnetic field and the mechanisms.
 Methods: Five adult sheep were randomly selected and the blood samples were placed in high-intensity alternating magnetic field. Before and after exposure, the blood samples were taken and divided into 2 groups: a control group and a magnetic field group. The blood rheology and transmission electron microscopy (TEM) were performed.
 Results: Compared to the control group, the high shear viscosity of whole blood was decreased in the magnetic field group (P<0.05); the whole blood low shear viscosity and plasma viscosity were also decreased (both P<0.01). TEM showed the changes in red blood cell morphology and the double concave disc curvature. The radian of double concave disc and cell volume in the magnetic field group was larger than those in the control group.
 Conclusion: The high intensity alternating magnetic field may affect the distribution of surface charge and molecular current in blood cells, which in turn decrease the aggregation of cells and the blood viscosity.

  3. Low-field vortex dynamics in various high-Tc thin films

    Indian Academy of Sciences (India)

    Vortex dynamics; flux creep; high temperature superconductor; thin film; ac susceptibil- ity. PACS Nos 74.72.-h; 74.76.Bz; 74.60.Ge. 1. Introduction. Despite the predictions of fundamental new physics and intriguing vortex phenomena in high-Tc materials at very low fields [1–6], a vast majority of experimental vortex dynam-.

  4. High Performance Ambipolar Field-Effect Transistor of Random Network Carbon Nanotubes

    NARCIS (Netherlands)

    Bisri, Satria Zulkarnaen; Gao, Jia; Derenskyi, Vladimir; Gomulya, Widianta; Iezhokin, Igor; Gordiichuk, Pavlo; Herrmann, Andreas; Loi, Maria Antonietta

    2012-01-01

    Ambipolar field-effect transistors of random network carbon nanotubes are fabricated from an enriched dispersion utilizing a conjugated polymer as the selective purifying medium. The devices exhibit high mobility values for both holes and electrons (3 cm(2)/V.s) with a high on/off ratio (10(6)). The

  5. A new hybrid protection system for high-field superconducting magnets

    NARCIS (Netherlands)

    Ravaioli, Emanuele; Datskov, V.I.; Kirby, G.; ten Kate, Herman H.J.; Verweij, A.P.

    2014-01-01

    The new generation of high-field superconducting accelerator magnets poses a challenge concerning the protection of the magnet coil in the case of a quench. The very high stored energy per unit volume requires a fast and efficient quench heating system in order to avoid damage due to overheating. A

  6. High Field Linear Magnetoresistance Sensors with Perpendicular Anisotropy L10-FePt Reference Layer

    Directory of Open Access Journals (Sweden)

    X. Liu

    2016-01-01

    Full Text Available High field linear magnetoresistance is an important feature for magnetic sensors applied in magnetic levitating train and high field positioning measurements. Here, we investigate linear magnetoresistance in Pt/FePt/ZnO/Fe/Pt multilayer magnetic sensor, where FePt and Fe ferromagnetic layers exhibit out-of-plane and in-plane magnetic anisotropy, respectively. Perpendicular anisotropy L10-FePt reference layer with large coercivity and high squareness ratio was obtained by in situ substrate heating. Linear magnetoresistance is observed in this sensor in a large range between +5 kOe and −5 kOe with the current parallel to the film plane. This L10-FePt based sensor is significant for the expansion of linear range and the simplification of preparation for future high field magnetic sensors.

  7. Feasibility study of cellulose nanofiber alignment by high DC magnetic field

    Science.gov (United States)

    Kim, Hyun Chan; Kang, Jinmo; Park, Jung Ho; Akther, Asma; Kim, Jaehwan

    2017-04-01

    Cellulose nanofiber (CNF) has taken center stage as a future material with high specific strength, specific modulus and environmentally friendly behavior. However, natural CNFs are so randomly oriented that once CNFs are used in composites, their mechanical properties are not the same as expected from the CNFs. Thus, CNF alignment is important in fabricating composites and fibers. Interestingly, CNFs have negative diamagnetic anisotropy. In the presence of high magnetic field, the fiber axis of CNF can be aligned perpendicular to the applied field. This paper reports a preliminary study of CNF alignment by high dc magnetic field. The CNF emulsion is prepared by aqueous counter collision method and centrifugation. The CNF emulsion is placed in the high dc magnet and cured for a certain time. The alignment of CNF is investigated by scanning electron microscopy, mechanical tensile test.

  8. ESR1 Gene Polymorphisms and Prostate Cancer Risk: A HuGE Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Yu-Mei Wang

    Full Text Available Many published data on the association between single nucleotide polymorphisms (SNPs in the ESR1 gene and prostate cancer susceptibility are inconclusive. The aim of this Human Genome Epidemiology (HuGE review and meta-analysis is to derive a more precise estimation of this relationship.A literature search of PubMed, Embase, Web of Science and Chinese Biomedical (CBM databases was conducted from their inception through July 1st, 2012. Crude odds ratios (ORs with 95% confidence intervals (CIs were calculated to assess the strength of association.Twelve case-control studies were included with a total 2,165 prostate cancer cases and 3,361 healthy controls. When all the eligible studies were pooled into the meta-analysis, ESR1 PvuII (C>T and XbaI (A>G polymorphisms showed no association with the risk of prostate cancer. However, in the stratified analyses based on ethnicity and country, the results indicated that ESR1 PvuII (C>T polymorphism was significantly associated with increased risk of prostate cancer among Asian populations, especially among Indian population; while ESR1 XbaI (A>G polymorphism may significantly increase the risk of prostate cancer among American population. Furthermore, we also performed a pooled analysis for all eligible case-control studies to explore the role of codon 10 (T>C, codon 325 (C>G, codon 594 (G>A and +261G>C polymorphisms in prostate cancer risk. Nevertheless, no significant associations between these polymorphisms and the risk of prostate cancer were observed.Results from the current meta-analysis indicate that ESR1 PvuII (C>T polymorphism may be a risk factor for prostate cancer among Asian populations, especially among Indian population; while ESR1 XbaI (A>G polymorphism may increase the risk of prostate cancer among American population.

  9. Microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X Y [Faculty of Engineering and Resource Science, Akita University, Akita 010-8502 (Japan); Nagata, A [Faculty of Engineering and Resource Science, Akita University, Akita 010-8502 (Japan); Sugawara, K [Faculty of Engineering and Resource Science, Akita University, Akita 010-8502 (Japan); Watanabe, K [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Nojima, T [Center for Low Temperature Science, Tohoku University, Sendai 980-8577 (Japan)

    2006-11-15

    The microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in high magnetic fields were investigated. The results show that the partial-melting temperature has influence on the formation of Bi-2223 phase and the J{sub c}. The optimum partial-melting temperature is 855{sup 0}C. The magnetic field during sintering at 830{sup 0}C has no influence on the formation of Bi-2223 phase and the J{sub c}. However, the magnetic field during partial-melting process has obvious influence on the formation of Bi-2223 phase and the J{sub c}. The tape partially melted with 10 T magnetic field shows stronger c-axis alignment of Bi-2223 phase and higher J{sub c}value than that partially melted without magnetic field.

  10. Impact of Increased Football Field Width on Player High-Speed Collision Rate.

    Science.gov (United States)

    Joseph, Jacob R; Khalsa, Siri S; Smith, Brandon W; Park, Paul

    2017-07-01

    High-acceleration head impact is a known risk for mild traumatic brain injury (mTBI) based on studies using helmet accelerometry. In football, offensive and defensive players are at higher risk of mTBI due to increased speed of play. Other collision sport studies suggest that increased playing surface size may contribute to reductions in high-speed collisions. We hypothesized that wider football fields lead to a decreased rate of high-speed collisions. Computer football game simulation was developed using MATLAB. Four wide receivers were matched against 7 defensive players. Each offensive player was randomized to one of 5 typical routes on each play. The ball was thrown 3 seconds into play; ball flight time was 2 seconds. Defensive players were delayed 0.5 second before reacting to ball release. A high-speed collision was defined as the receiver converging with a defensive player within 0.5 second of catching the ball. The simulation counted high-speed collisions for 1 team/season (65 plays/game for 16 games/season = 1040 plays/season) averaged during 10 seasons, and was validated against existing data using standard field width (53.3 yards). Field width was increased in 1-yard intervals up to 58.3 yards. Using standard field width, 188 ± 4 high-speed collisions were seen per team per season (18% of plays). When field width increased by 3 yards, high-speed collision rate decreased to 135 ± 3 per team per season (28% decrease; P football field width can lead to substantial decline in high-speed collisions, with potential for reducing instances of mTBI in football players. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Natural geochemical analogues of the near field of high-level nuclear waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.A. [Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    United States practice has been to design high-level nuclear waste (HLW) geological repositories with waste densities sufficiently high that repository temperatures surrounding the waste will exceed 100{degrees}C and could reach 250{degrees}C. Basalt and devitrified vitroclastic tuff are among the host rocks considered for waste emplacement. Near-field repository thermal behavior and chemical alteration in such rocks is expected to be similar to that observed in many geothermal systems. Therefore, the predictive modeling required for performance assessment studies of the near field could be validated and calibrated using geothermal systems as natural analogues. Examples are given which demonstrate the need for refinement of the thermodynamic databases used in geochemical modeling of near-field natural analogues and the extent to which present models can predict conditions in geothermal fields.

  12. Hydrodynamic analysis of the high electric fields and double layers in expanding inhomogeneous plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goldsworthy, M.P.; Green, F.; Lalousis, P.; Stening, R.J.; Eliezer, S.; Hora, H.

    1986-12-01

    A genuine two-fluid model of plasmas with collisions permits the calculation of dynamic electric fields and double layers inside of plasmas including oscillations and damping. For the first time, a macroscopic model for coupling of electromagnetic and Langmuir waves was achieved with realistic damping. Starting points were laser-produced plasmas showing very high dynamic electric fields in nonlinear force-produced cavitons and inverted layers, in agreement with experiments. Applications for any inhomogeneous plasma as in laboratory or in astrophysical plasmas can then be followed up by a transparent hydrodynamic description. The authors find the rotation of plasmas in magnetic fields and a new second harmonic resonance. Explanation of inverted double layers, second harmonic emission from laser-produced plasmas, and laser acceleration of charged particles by the very high fields of the double layers is given.

  13. Landau level splitting in Cd3As2 under high magnetic fields.

    Science.gov (United States)

    Cao, Junzhi; Liang, Sihang; Zhang, Cheng; Liu, Yanwen; Huang, Junwei; Jin, Zhao; Chen, Zhi-Gang; Wang, Zhijun; Wang, Qisi; Zhao, Jun; Li, Shiyan; Dai, Xi; Zou, Jin; Xia, Zhengcai; Li, Liang; Xiu, Faxian

    2015-07-13

    Three-dimensional topological Dirac semimetals (TDSs) are a new kind of Dirac materials that exhibit linear energy dispersion in the bulk and can be viewed as three-dimensional graphene. It has been proposed that TDSs can be driven to other exotic phases like Weyl semimetals, topological insulators and topological superconductors by breaking certain symmetries. Here we report the first transport experiment on Landau level splitting in TDS Cd3As2 single crystals under high magnetic fields, suggesting the removal of spin degeneracy by breaking time reversal symmetry. The detected Berry phase develops an evident angular dependence and possesses a crossover from non-trivial to trivial state under high magnetic fields, a strong hint for a fierce competition between the orbit-coupled field strength and the field-generated mass term. Our results unveil the important role of symmetry breaking in TDSs and further demonstrate a feasible path to generate a Weyl semimetal phase by breaking time reversal symmetry.

  14. A permanent magnet device for producing variable high magnetic field in three dimensions

    CERN Document Server

    Hwang, C S; Chang, P C; Chen, H H; Chang, C H; Huang Ming Hsiung

    2000-01-01

    By combining four parallel rows of permanent magnet blocks, a magnet device that can produce variable high magnetic field in three dimensions has been designed. In this device, the magnetic field direction and strength can be varied by shifting the four rows along their longitudinal direction and by varying the magnet gap between the top and bottom rows. With a magnet gap of 10 mm, the magnetic field strength at the center of the device is about 1.4 T along the longitudinal and two transverse directions. This device can be utilized in X-ray magnetic circular dichroism and X-ray magnetic linear dichroism experiments as well as in other applications where a variable high magnetic field in three dimensions is needed.

  15. Magnetic and Magneto-Optical Properties in Paramagnetic NdF3 Under High Magnetic Field

    Science.gov (United States)

    Wang, Wei; Liu, Gong-Qiang

    2005-05-01

    In this paper, we first theoretically report the magnetic and magneto-optical properties in paramagnetic media under high external magnetic field. Considering the action of the external magnetic field He and indirect exchange interaction Hv, the characteristic of the magnetic saturation and the property of the Faraday rotation to be nonlinear with external magnetic field are presented in paramagnetic NdF3. In terms of our theory, the indirect exchange interaction plays an important role in the magnetization M and the Faraday rotation θ in NdF3 under high external magnetic field. The theory is in good agreement with experimental results. On the other hand, a reasonable explanation for the temperature dependence of the ratio of the Verdet constant to the magnetic susceptibility V/χ is obtained.

  16. A thermo-field bimetal deformable mirror for wavefront correction in high power lasers

    Science.gov (United States)

    Huang, L.; Xue, Q.; Yan, P.; Gong, M. L.; Li, T. H.; Feng, Z. X.; Ma, X. K.

    2014-01-01

    A novel thermo-field bimetal deformable mirror (TBDM) is proposed, which is mainly composed of a face plate, a base plate and some thermal elements, such as thermoelectric coolers (TECs). The TBDM utilizes the continuous thermal field to bend the face plate, via the TECs heating or cooling. A prototype is described, and the first results are presented. The simplicity and ultra-low cost make the TBDM attractive in correcting aberrations in high power lasers.

  17. High-field magnetic transitions in the R sub 2 T sub 17 compounds

    Energy Technology Data Exchange (ETDEWEB)

    Franse, J.J.M.; Sinnema, S. (Amsterdam Univ. (NL). Natuurkundig Lab.); Radwanski, R.J. (University of Mining and Metallurgy, Krakow (PL). Solid State Physics Dept.)

    1988-12-01

    In the past few years high-field magnetic transitions have been extensively studied for a number of single crystalline samples of the R{sub 2}T{sub 17} series (R = rare earths, T = Co or Fe). The transitions observed in Ho{sub 2}Co{sub 17} and Dy{sub 2}Co{sub 17} are exchange-driven transitions connected with a breaking of the ferromagnetic structure and only occur in applied fields above 20 T.

  18. Influence of atoms with high ionization potentials on a discharge in crossed E and H fields

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.A.; Timchenko, N.N.; Khripunov, B.I.; Shapkin, V.V.

    1980-11-01

    We consider processes connected with the separation of elements in a fully ionized plasma centrifuge with a plasma gun discharge in crossed E and H fields. We analyze the influence of atoms with high ionization potentials on the separation parameters, the value of the transverse ion current, and the separation coefficient. We not the role played by the radial electric field in the gas ionization processes and in the resulting growth of ion acoustic instabilities.

  19. The spontaneous generation of magnetic fields at high temperature in a supersymmetric theory

    OpenAIRE

    Demchik, V. I.; Skalozub, V. V.

    2002-01-01

    The spontaneous generation of magnetic and chromomagnetic fields at high temperature in the minimal supersymmetric standard model (MSSM) is investigated. The consistent effective potential including the one-loop and the daisy diagrams of all bosons and fermions is calculated and the magnetization of the vacuum is observed. The mixing of the generated fields due to the quark and s-quark loop diagrams and the role of superpartners are studied in detail. It is found that the contribution of thes...

  20. Nematic ordering in pyrochlore antiferromagnets: high-field phase of chromium spinel oxides

    OpenAIRE

    Takata, Emika; Momoi, Tsutomu; Oshikawa, Masaki

    2015-01-01

    Motivated by recent observation of a new high field phase near saturation in chromium spinels $A$Cr$_2$O$_4$ ($A=$ Zn, Cd, Hg), we study the $S = 3/2$ pyrochlore Heisenberg antiferromagnet with biquadratic interactions. Magnon instability analysis at the saturation field reveals that a very small biquadratic interaction can induce magnon pairing in pyrochlore antiferromagnets, which leads to the emergence of a ferro-quadrupolar phase, or equivalently a spin nematic phase, below the saturation...